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Sample records for dinitrogenase reductase-activating glycohydrolase

  1. ADP-ribosylation of dinitrogenase reductase in Rhodobacter capsulatus

    International Nuclear Information System (INIS)

    Jouanneau, Y.; Roby, C.; Meyer, C.M.; Vignais, P.M.

    1989-01-01

    In the photosynthetic bacterium Rhodobacter capsulatus, nitrogenase is regulated by a reversible covalent modification of Fe protein or dinitrogenase reductase (Rc2). The linkage of the modifying group to inactive Rc2 was found to be sensitive to alkali and to neutral hydroxylamine. Complete release of the modifying group was achieved by incubation of inactive Rc2 in 0.4 or 1 M hydroxylamine. After hydroxylamine treatment of the Rc2 preparation, the modifying group could be isolated and purified by affinity chromatography and ion-exchange HPLC. The modifying group comigrated with ADP-ribose on both ion-exchange HPLC and thin-layer chromatography. Analyses by 31 P NMR spectroscopy and mass spectrometry provided further evidence that the modifying group was ADP-ribose. The NMR spectrum of inactive Rc2 exhibited signals characteristic of ADP-ribose; integration of these signals allowed calculation of a molar ration ADP-ribose/Rc2 of 0.63. A hexapeptide carrying the ADP-ribose moiety was purified from a subtilisin digest of inactive Rc2. The structure of this peptide, determined by amino acid analysis and sequencing, is Gly-Arg(ADP-ribose)-Gly-Val-Ile-Thr. This structure allows identification of the binding site for ADP-ribose as Arg 101 of the polypeptide chain of Rc2. It is concluded that nitrogenase activity in R. capsulatus is regulated by reversible ADP-ribosylation of a specific arginyl residue of dinitrogenase reductase

  2. Oxygen and xenobiotic reductase activities of cytochrome P450.

    NARCIS (Netherlands)

    Goeptar, A.R.; Scheerens, H.; Vermeulen, N.P.E.

    1995-01-01

    The oxygen reductase and xenobiotic reductase activities of cytochrome P450 (P450) are reviewed. During the oxygen reductase activity of P450, molecular oxygen is reduced to superoxide anion radicals (O

  3. 5α-reductase activity in rat adipose tissue

    International Nuclear Information System (INIS)

    Zyirek, M.; Flood, C.; Longcope, C.

    1987-01-01

    We measured the 5 α-reductase activity in isolated cell preparations of rat adipose tissue using the formation of [ 3 H] dihydrotestosterone from [ 3 H] testosterone as an endpoint. Stromal cells were prepared from the epididymal fat pad, perinephric fat, and subcutaneous fat of male rats and from perinephric fat of female rats. Adipocytes were prepared from the epididymal fat pad and perinephric fat of male rats. Stromal cells from the epididymal fat pad and perinephric fat contained greater 5α-reductase activity than did the adipocytes from these depots. Stromal cells from the epididymal fat pad contained greater activity than those from perinephric and subcutaneous depots. Perinephric stromal cells from female rats were slightly more active than those from male rats. Estradiol (10 -8 M), when added to the medium, caused a 90% decrease in 5α-reductase activity. Aromatase activity was minimal, several orders of magnitude less than 5α-reductase activity in each tissue studied

  4. Dinitrogenase-Driven Photobiological Hydrogen Production Combats Oxidative Stress in Cyanothece sp. Strain ATCC 51142

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, Natalie C.; Bernstein, Hans C.; Melnicki, Matthew R.; Charania, Moiz A.; Hill, Eric A.; Anderson, Lindsey N.; Monroe, Matthew E.; Smith, Richard D.; Beliaev, Alexander S.; Wright, Aaron T.; Nojiri, H.

    2016-10-14

    ABSTRACT

    Photobiologically synthesized hydrogen (H2) gas is carbon neutral to produce and clean to combust, making it an ideal biofuel.Cyanothecesp. strain ATCC 51142 is a cyanobacterium capable of performing simultaneous oxygenic photosynthesis and H2production, a highly perplexing phenomenon because H2evolving enzymes are O2sensitive. We employed a system-levelin vivochemoproteomic profiling approach to explore the cellular dynamics of protein thiol redox and how thiol redox mediates the function of the dinitrogenase NifHDK, an enzyme complex capable of aerobic hydrogenase activity. We found that NifHDK responds to intracellular redox conditions and may act as an emergency electron valve to prevent harmful reactive oxygen species formation in concert with other cell strategies for maintaining redox homeostasis. These results provide new insight into cellular redox dynamics useful for advancing photolytic bioenergy technology and reveal a new understanding for the biological function of NifHDK.

    IMPORTANCEHere, we demonstrate that high levels of hydrogen synthesis can be induced as a protection mechanism against oxidative stress via the dinitrogenase enzyme complex inCyanothecesp. strain ATCC 51142. This is a previously unknown feature of cyanobacterial dinitrogenase, and we anticipate that it may represent a strategy to exploit cyanobacteria for efficient and scalable hydrogen production. We utilized a chemoproteomic approach to capture thein situdynamics of reductant partitioning within the cell, revealing proteins and reactive thiols that may be involved in redox sensing and signaling. Additionally, this method is widely applicable across biological systems to achieve a greater understanding of how cells

  5. Methemoglobin reductase activity in intact fish red blood cells

    DEFF Research Database (Denmark)

    Jensen, Frank B; Nielsen, Karsten

    2018-01-01

    RBCs in physiological saline at normal Pco2 and pH. After initial loading of oxygenated RBCs with nitrite (partly oxidizing Hb to metHb), the nitrite is removed by three washes of the RBCs in nitrite-free physiological saline to enable the detection of RBC metHb reductase activity in the absence......Hb reductase activity in fish offsets their higher Hb autoxidation and higher likelihood of encountering elevated nitrite. Deoxygenation significantly raised the rates of RBC metHb reduction, and more so in rainbow trout than in carp. The temperature sensitivity of metHb reduction in rainbow trout RBCs...

  6. Gamma-irradiation activates biochemical systems: induction of nitrate reductase activity in plant callus.

    OpenAIRE

    Pandey, K N; Sabharwal, P S

    1982-01-01

    Gamma-irradiation induced high levels of nitrate reductase activity (NADH:nitrate oxidoreductase, EC 1.6.6.1) in callus of Haworthia mirabilis Haworth. Subcultures of gamma-irradiated tissues showed autonomous growth on minimal medium. We were able to mimic the effects of gamma-irradiation by inducing nitrate reductase activity in unirradiated callus with exogenous auxin and kinetin. These results revealed that induction of nitrate reductase activity by gamma-irradiation is mediated through i...

  7. NAD+-Glycohydrolase Promotes Intracellular Survival of Group A Streptococcus.

    Directory of Open Access Journals (Sweden)

    Onkar Sharma

    2016-03-01

    Full Text Available A global increase in invasive infections due to group A Streptococcus (S. pyogenes or GAS has been observed since the 1980s, associated with emergence of a clonal group of strains of the M1T1 serotype. Among other virulence attributes, the M1T1 clone secretes NAD+-glycohydrolase (NADase. When GAS binds to epithelial cells in vitro, NADase is translocated into the cytosol in a process mediated by streptolysin O (SLO, and expression of these two toxins is associated with enhanced GAS intracellular survival. Because SLO is required for NADase translocation, it has been difficult to distinguish pathogenic effects of NADase from those of SLO. To resolve the effects of the two proteins, we made use of anthrax toxin as an alternative means to deliver NADase to host cells, independently of SLO. We developed a novel method for purification of enzymatically active NADase fused to an amino-terminal fragment of anthrax toxin lethal factor (LFn-NADase that exploits the avid, reversible binding of NADase to its endogenous inhibitor. LFn-NADase was translocated across a synthetic lipid bilayer in vitro in the presence of anthrax toxin protective antigen in a pH-dependent manner. Exposure of human oropharyngeal keratinocytes to LFn-NADase in the presence of protective antigen resulted in cytosolic delivery of NADase activity, inhibition of protein synthesis, and cell death, whereas a similar construct of an enzymatically inactive point mutant had no effect. Anthrax toxin-mediated delivery of NADase in an amount comparable to that observed during in vitro infection with live GAS rescued the defective intracellular survival of NADase-deficient GAS and increased the survival of SLO-deficient GAS. Confocal microscopy demonstrated that delivery of LFn-NADase prevented intracellular trafficking of NADase-deficient GAS to lysosomes. We conclude that NADase mediates cytotoxicity and promotes intracellular survival of GAS in host cells.

  8. Increased 5α-reductase activity in idiopathic hirsutism

    International Nuclear Information System (INIS)

    Serafini, P.; Lobo, R.A.

    1985-01-01

    In vitro, genital skin 5α-reductase activity (5α-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5α-RA. In vitro 5α-RA was assessed by incubations of skin with 14 C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5α-androstane 3α-17β-estradiol (3α-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3α-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3α-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5α-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5α-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5α-RA

  9. Increased 5. cap alpha. -reductase activity in idiopathic hirsutism

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, P.; Lobo, R.A.

    1985-01-01

    In vitro, genital skin 5..cap alpha..-reductase activity (5..cap alpha..-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5..cap alpha..-RA. In vitro 5..cap alpha..-RA was assessed by incubations of skin with /sup 14/C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5..cap alpha..-androstane 3..cap alpha..-17..beta..-estradiol (3..cap alpha..-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3..cap alpha..-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3..cap alpha..-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5..cap alpha..-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5..cap alpha..-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5..cap alpha..-RA.

  10. Acid Glycohydrolases in Rat Spermatocytes, Spermatids and Spermatozoa: Enzyme Activities, Biosynthesis and Immunolocalization

    Directory of Open Access Journals (Sweden)

    Abou-Haila Aida

    2001-01-01

    Full Text Available Mammalian sperm acrosome contains several glycohydrolases thought to aid in the dispersion and digestion of vestments surrounding the egg. In this study, we have used multiple approaches to examine the origin of acrosome-associated glycohdyrdolases. Mixed spermatogenic cells, prepared from rat testis, were separated by unit gravity sedimentation. The purified germ cells (spermatocytes [SP], round spermatids [RS], and elongated/condensed spermatids [E/CS] contained several glycohydrolase activities. Metabolic labeling in the cell culture, immunoprecipitation, and autoradiographic approaches revealed that &bgr;-D-galactosidase was synthesized in SP and RS in 88/90 kDa forms which undergo processing in a cell-specific manner. Immunohistochemical approaches demonstrated that the enzyme was localized in Golgi membranes/vesicles, and lysosome-like structures in SP and RS, and forming/formed acrosome of E/CS.

  11. Azospirillum Inoculation Alters Nitrate Reductase Activity and Nitrogen Uptake in Wheat Plant Under Water Deficit Conditions

    OpenAIRE

    N. Aliasgharzad, N. Aliasgharzad; Heydaryan, Zahra; Sarikhani, M.R

    2014-01-01

    Water deficit stress usually diminishes nitrogen uptake by plants. There are evidences that some nitrogen fixing bacteria can alleviate this stress by supplying nitrogen and improving its metabolism in plants. Four Azospirillum strains, A. lipoferum AC45-II, A. brasilense AC46-I, A. irakense AC49-VII and A. irakense AC51-VI were tested for nitrate reductase activity (NRA). In a pot culture experiment using a sandy loam soil, wheat plants (Triticum aestivum L. cv. Sardari) were inoculated with...

  12. Nitrate reductase activity of Staphylococcus carnosus affecting the color formation in cured raw ham.

    Science.gov (United States)

    Bosse Née Danz, Ramona; Gibis, Monika; Schmidt, Herbert; Weiss, Jochen

    2016-07-01

    The influence of the nitrate reductase activity of two Staphylococcus carnosus strains used as starter cultures on the formation of nitrate, nitrite and color pigments in cured raw ham was investigated. In this context, microbiological, chemical and multivariate image analyses were carried out on cured raw hams, which were injected with different brines containing either nitrite or nitrate, with or without the S. carnosus starter cultures. During processing and storage, the viable counts of staphylococci remained constant at 6.5logcfu/g in the hams inoculated with starter cultures, while the background microbiota of the hams processed without the starter cultures developed after 14days. Those cured hams inoculated with S. carnosus LTH 7036 (high nitrate reductase activity) showed the highest decrease in nitrate and high nitrite concentrations in the end product, but were still in the range of the legal European level. The hams cured with nitrate and without starter culture or with the other strain, S. carnosus LTH 3838 (low nitrate reductase activity) showed higher residual nitrate levels and a lower nitrite content in the end product. The multivariate image analysis identified spatial and temporal differences in the meat pigment profiles of the differently cured hams. The cured hams inoculated with S. carnosus LTH 3838 showed an uncured core due to a delay in pigment formation. Therefore, the selection of starter cultures based on their nitrate reductase activity is a key point in the formation of curing compounds and color pigments in cured raw ham manufacture. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Nitrate reductase activity and its relationship with applied nitrogen in soybean

    International Nuclear Information System (INIS)

    Ge Wenting; Jin Xijun; Ma Chunmei; Dong Shoukun; Gong Zhenping; Zhang Lei

    2011-01-01

    Field experiments were conducted to study the nitrate reductase activity and its relationship to nitrogen by using frame tests (pot without bottom), sand culture and 15 N-urea at transplanting in soybean variety Suinong 14. Results showed that the activity of nitrate reductase in leaf changed as a signal peak curve with the soybean growth, lower in vegetative growth phase, higher in reproductive growth period and reached the peak in blooming period, then decreased gradually. Nitrogen application showed obvious effect on the nitrate reductase activity. The activities of nitrate reductase in leaves followed the order of N 135 > N 90 > N 45 > N 0 in vegetative growth stage, no clear regularity was found during the whole reproductive growth period. The activities of nitrate reductase in leaves were accorded with the order of upper leaves > mid leaves > lower leaves, and it was very significant differences (P 15 N labeling method during beginning seed stage and full seed stage shown that 15 N abundance in various organs at different node position also followed the same order, suggesting that high level of nitrate reductase activity at upper leaves of soybean promoted the assimilation of NO 3 - . (authors)

  14. Nitrite-dependent vasodilation is facilitated by hypoxia and is independent of known NO-generating nitrite reductase activities

    DEFF Research Database (Denmark)

    Fago, Angela; Dalsgaard, Thomas; Fago, Angela

    2007-01-01

    is largely intrinsic to the vessel and that under hypoxia physiological nitrite concentrations are sufficient to induce NO-mediated vasodilation independently of the nitrite reductase activities investigated here. Possible reaction mechanisms for nitrite vasoactivity, including formation of S...

  15. Colour formation in fermented sausages by meat-associated staphylococci with different nitrite- and nitrate-reductase activities

    DEFF Research Database (Denmark)

    Gøtterup, Jacob; Olsen, Karsten; Knøchel, Susanne

    2008-01-01

    nitrate depended on the specific Staphylococcus strain. Strains with high nitrate-reductase activity showed a significantly faster rate of pigment formation, but other factors were of influence as well. Product stability for the sliced, packaged sausage was evaluated as surface colour and oxidation......Three Staphylococcus strains, S. carnosus, S. simulans and S. saprophyticus, selected due to their varying nitrite and/or nitrate-reductase activities, were used to initiate colour formation during sausage fermentation. During fermentation of sausages with either nitrite or nitrate added, colour...... with hexanal content, and may be used as predictive tools. Overall, nitrite- and nitrate-reductase activities of Staphylococcus strains in nitrite-cured sausages were of limited importance regarding colour development, while in nitrate-cured sausages strains with higher nitrate reductase activity were crucial...

  16. Crystallographic and biochemical analysis of the mouse poly(ADP-ribose glycohydrolase.

    Directory of Open Access Journals (Sweden)

    Zhizhi Wang

    Full Text Available Protein poly(ADP-ribosylation (PARylation regulates a number of important cellular processes. Poly(ADP-ribose glycohydrolase (PARG is the primary enzyme responsible for hydrolyzing the poly(ADP-ribose (PAR polymer in vivo. Here we report crystal structures of the mouse PARG (mPARG catalytic domain, its complexes with ADP-ribose (ADPr and a PARG inhibitor ADP-HPD, as well as four PARG catalytic residues mutants. With these structures and biochemical analysis of 20 mPARG mutants, we provide a structural basis for understanding how the PAR polymer is recognized and hydrolyzed by mPARG. The structures and activity complementation experiment also suggest how the N-terminal flexible peptide preceding the PARG catalytic domain may regulate the enzymatic activity of PARG. This study contributes to our understanding of PARG catalytic and regulatory mechanisms as well as the rational design of PARG inhibitors.

  17. Effect of cystamine on rat tissue GSH level and glutathione reductase activity

    International Nuclear Information System (INIS)

    Kovarova, H.; Pulpanova, J.

    1979-01-01

    Reduced glutathione (GSH) level and glutathione reductase activity were determined by means of the spectrophotometric method in various rat tissues after i.p. administration of cystamine (50 mg/kg and 20 mg/kg). GSH amount dropped in the spleen and kidney at 10 and 20 min; following this interval, an increase of GSH level was observed in the liver at 20-30 min, in the spleen and kidney at 60 min after the treatment with a radioprotective cystamine dose (50 mg/kg). The changes in GSH level induced by a non-radioprotective cystamine dose (20 mg/kg) had an opposite tendency. The activity of glutathione reductase was decreased in all tissues studied. As to the mechanism of the radioprotective action, both the inactivation of glutathione reductase activity and the changes in GSH level seem to be the factors contributing to the radioprotective effect of cystamine by strengthening the cellular radioresistance. (orig.) 891 MG/orig. 892 RKD [de

  18. Response to arsenate treatment in Schizosaccharomyces pombe and the role of its arsenate reductase activity.

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    Alejandro Salgado

    Full Text Available Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V to As (III. Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast.

  19. Regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and cholesterol biosynthesis by oxylanosterols

    Energy Technology Data Exchange (ETDEWEB)

    Panini, S.R.; Sexton, R.C.; Gupta, A.K.; Parish, E.J.; Chitrakorn, S.; Rudney, H.

    1986-11-01

    Treatment of rat intestinal epithelial cell cultures with the oxidosqualene cyclase inhibitor, 3 beta-(2-(diethylamino)-ethoxy)androst-5-en-17-one (U18666A), resulted in an accumulation of squalene 2,3:22,23-dioxide (SDO). When U18666A was withdrawn and the cells were treated with the sterol 14 alpha-demethylase inhibitor, ketoconazole, SDO was metabolized to a product identified as 24(S),25-epoxylanosterol. To test the biological effects and cellular metabolism of this compound, we prepared 24(RS),25-epoxylanosterol by chemical synthesis. The epimeric mixture of 24,25-epoxylanosterols could be resolved by high performance liquid chromatography on a wide-pore, non-endcapped, reverse phase column. Both epimers were effective suppressors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity of IEC-6 cells. The suppressive action of the natural epimer, 24(S),25-epoxylanosterol, but not that of 24(R),25-epoxylanosterol could be completely prevented by ketoconazole. IEC-6 cells could efficiently metabolize biosynthetic 24(S),25-epoxy(/sup 3/H)anosterol mainly to the known reductase-suppressor 24(S),25-epoxycholesterol. This metabolism was substantially reduced by ketoconazole. These data support the conclusion that 24(S),25-epoxylanosterol per se is not a suppressor of HMG-CoA reductase activity but is a precursor to a regulatory oxysterol(s). It has recently been reported that 25-hydroxycholesterol can occur naturally in cultured cells in amounts sufficient to effect regulation of HMG-CoA reductase. In order to investigate the biological effects of possible precursors of 25-hydroxycholesterol, we chemically synthesized 25-hydroxylanosterol and 25-hydroxylanostene-3-one. Both oxylanosterol derivatives suppressed cellular sterol synthesis at the level of HMG-CoA reductase. (Abstract Truncated)

  20. Regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and cholesterol biosynthesis by oxylanosterols

    International Nuclear Information System (INIS)

    Panini, S.R.; Sexton, R.C.; Gupta, A.K.; Parish, E.J.; Chitrakorn, S.; Rudney, H.

    1986-01-01

    Treatment of rat intestinal epithelial cell cultures with the oxidosqualene cyclase inhibitor, 3 beta-[2-(diethylamino)-ethoxy]androst-5-en-17-one (U18666A), resulted in an accumulation of squalene 2,3:22,23-dioxide (SDO). When U18666A was withdrawn and the cells were treated with the sterol 14 alpha-demethylase inhibitor, ketoconazole, SDO was metabolized to a product identified as 24(S),25-epoxylanosterol. To test the biological effects and cellular metabolism of this compound, we prepared 24(RS),25-epoxylanosterol by chemical synthesis. The epimeric mixture of 24,25-epoxylanosterols could be resolved by high performance liquid chromatography on a wide-pore, non-endcapped, reverse phase column. Both epimers were effective suppressors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity of IEC-6 cells. The suppressive action of the natural epimer, 24(S),25-epoxylanosterol, but not that of 24(R),25-epoxylanosterol could be completely prevented by ketoconazole. IEC-6 cells could efficiently metabolize biosynthetic 24(S),25-epoxy[ 3 H]anosterol mainly to the known reductase-suppressor 24(S),25-epoxycholesterol. This metabolism was substantially reduced by ketoconazole. These data support the conclusion that 24(S),25-epoxylanosterol per se is not a suppressor of HMG-CoA reductase activity but is a precursor to a regulatory oxysterol(s). It has recently been reported that 25-hydroxycholesterol can occur naturally in cultured cells in amounts sufficient to effect regulation of HMG-CoA reductase. In order to investigate the biological effects of possible precursors of 25-hydroxycholesterol, we chemically synthesized 25-hydroxylanosterol and 25-hydroxylanostene-3-one. Both oxylanosterol derivatives suppressed cellular sterol synthesis at the level of HMG-CoA reductase. (Abstract Truncated)

  1. Effect of pharmaceutical potential endocrine disruptor compounds on protein disulfide isomerase reductase activity using di-eosin-oxidized-glutathione.

    Directory of Open Access Journals (Sweden)

    Danièle Klett

    Full Text Available BACKGROUND: Protein Disulfide Isomerase (PDI in the endoplasmic reticulum of all cells catalyzes the rearrangement of disulfide bridges during folding of membrane and secreted proteins. As PDI is also known to bind various molecules including hormones such as estradiol and thyroxin, we considered the hypothesis that adverse effects of endocrine-disrupter compounds (EDC could be mediated through their interaction with PDI leading to defects in membrane or secreted proteins. METHODOLOGY/PRINCIPAL FINDINGS: Taking advantage of the recent description of the fluorescence self quenched substrate di-eosin-oxidized-glutathione (DiE-GSSG, we determined kinetically the effects of various potential pharmaceutical EDCs on the in-vitro reductase activity of bovine liver PDI by measuring the fluorescence of the reaction product (E-GSH. Our data show that estrogens (ethynylestradiol and bisphenol-A as well as indomethacin exert an inhibition whereas medroxyprogesteroneacetate and nortestosterone exert a potentiation of bovine PDI reductase activity. CONCLUSIONS: The present data indicate that the tested EDCs could not only affect endocrine target cells through nuclear receptors as previously shown, but could also affect these and all other cells by positively or negatively affecting PDI activity. The substrate DiE-GSSG has been demonstrated to be a convenient substrate to measure PDI reductase activity in the presence of various potential EDCs. It will certainly be usefull for the screening of potential effect of all kinds of chemicals on PDI reductase activity.

  2. Colour formation in fermented sausages by meat-associated staphylococci with different nitrite- and nitrate-reductase activities.

    Science.gov (United States)

    Gøtterup, Jacob; Olsen, Karsten; Knøchel, Susanne; Tjener, Karsten; Stahnke, Louise H; Møller, Jens K S

    2008-04-01

    Three Staphylococcus strains, S. carnosus, S. simulans and S. saprophyticus, selected due to their varying nitrite and/or nitrate-reductase activities, were used to initiate colour formation during sausage fermentation. During fermentation of sausages with either nitrite or nitrate added, colour was followed by L(∗)a(∗)b measurements and the content of nitrosylmyoglobin (MbFe(II)NO) quantified by electron spin resonance (ESR). MbFe(II)NO was rapidly formed in sausages with added nitrite independent of the presence of nitrite reducing bacteria, whereas the rate of MbFe(II)NO formation in sausages with added nitrate depended on the specific Staphylococcus strain. Strains with high nitrate-reductase activity showed a significantly faster rate of pigment formation, but other factors were of influence as well. Product stability for the sliced, packaged sausage was evaluated as surface colour and oxidation by autofluorescence and hexanal content, respectively. No significant direct effect of the Staphylococcus addition was observed, however, there was a clear correspondence between high initial amount of MbFe(II)NO in the different sausages and the colour stability during storage. Autofluorescence data correlated well with hexanal content, and may be used as predictive tools. Overall, nitrite- and nitrate-reductase activities of Staphylococcus strains in nitrite-cured sausages were of limited importance regarding colour development, while in nitrate-cured sausages strains with higher nitrate reductase activity were crucial for ensuring optimal colour formation during initial fermentation stages.

  3. TFEB activation promotes the recruitment of lysosomal glycohydrolases β-hexosaminidase and β-galactosidase to the plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Magini, Alessandro [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Department of Medical and Biological Sciences (DSMB), University of Udine, Udine (Italy); Polchi, Alice; Urbanelli, Lorena [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Cesselli, Daniela; Beltrami, Antonio [Department of Medical and Biological Sciences (DSMB), University of Udine, Udine (Italy); Tancini, Brunella [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy); Emiliani, Carla, E-mail: carla.emiliani@unipg.it [Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia (Italy)

    2013-10-18

    Highlights: •TFEB activation promotes the increase of Hex and Gal activities. •The increase of Hex and Gal activities is related to transcriptional regulation. •TFEB promotes the recruitment of mature Hex and Gal on cell surface. -- Abstract: Lysosomes are membrane-enclosed organelles containing acid hydrolases. They mediate a variety of physiological processes, such as cellular clearance, lipid homeostasis, energy metabolism and pathogen defence. Lysosomes can secrete their content through a process called lysosome exocytosis in which lysosomes fuse with the plasma membrane realising their content into the extracellular milieu. Lysosomal exocytosis is not only responsible for the secretion of lysosomal enzymes, but it also has a crucial role in the plasma membrane repair. Recently, it has been demonstrated that lysosome response to the physiologic signals is regulated by the transcription factor EB (TFEB). In particular, lysosomal secretion is transcriptionally regulated by TFEB which induces both the docking and fusion of lysosomes with the plasma membrane. In this work we demonstrated that TFEB nuclear translocation is accompanied by an increase of mature glycohydrolases β-hexosaminidase and β-galactosidase on cell surface. This evidence contributes to elucidate an unknown TFEB biological function leading the lysosomal glycohydrolases on plasma membrane.

  4. TFEB activation promotes the recruitment of lysosomal glycohydrolases β-hexosaminidase and β-galactosidase to the plasma membrane

    International Nuclear Information System (INIS)

    Magini, Alessandro; Polchi, Alice; Urbanelli, Lorena; Cesselli, Daniela; Beltrami, Antonio; Tancini, Brunella; Emiliani, Carla

    2013-01-01

    Highlights: •TFEB activation promotes the increase of Hex and Gal activities. •The increase of Hex and Gal activities is related to transcriptional regulation. •TFEB promotes the recruitment of mature Hex and Gal on cell surface. -- Abstract: Lysosomes are membrane-enclosed organelles containing acid hydrolases. They mediate a variety of physiological processes, such as cellular clearance, lipid homeostasis, energy metabolism and pathogen defence. Lysosomes can secrete their content through a process called lysosome exocytosis in which lysosomes fuse with the plasma membrane realising their content into the extracellular milieu. Lysosomal exocytosis is not only responsible for the secretion of lysosomal enzymes, but it also has a crucial role in the plasma membrane repair. Recently, it has been demonstrated that lysosome response to the physiologic signals is regulated by the transcription factor EB (TFEB). In particular, lysosomal secretion is transcriptionally regulated by TFEB which induces both the docking and fusion of lysosomes with the plasma membrane. In this work we demonstrated that TFEB nuclear translocation is accompanied by an increase of mature glycohydrolases β-hexosaminidase and β-galactosidase on cell surface. This evidence contributes to elucidate an unknown TFEB biological function leading the lysosomal glycohydrolases on plasma membrane

  5. The nitrate reductase activity of some root and stem parasites and their hosts

    International Nuclear Information System (INIS)

    Hunter, J.J.

    1984-12-01

    This investigation surveyed the nitrate reductase activity (NRA) of some South African root and stem parasites, as well as their hosts. Fourteen species - five stem and nine root parasites, representative of seven families - and eleven different hosts from eight families, were studied. Two methods were applied in the determination of the NRA of parasite and host, namely the in vivo and in vitro methods. Because of the limited literature on the NRA of parasitic flowering plants both the in vivo and in vitro methods were developed for the host species and subsequently applied to that specific species of parasite as well. Parasites and hosts were also investigated in their natural habitat. The NRA of the roots could, however, only be increased providing phorsynthetic products as a source of NADH, were available. By using [U- 14 C]-Sucrose it was confirmed that the parasite could have fulfilled this need. Generally, the investigation showed that the parasites that were studied, have not altogether lost their ability to reduce nitrate. However, it would appear that the host is used as a source of reduced nitrogen, rather than nitrate, under natural conditions

  6. Nitrite reductase activity and inhibition of H₂S biogenesis by human cystathionine ß-synthase.

    Directory of Open Access Journals (Sweden)

    Carmen Gherasim

    Full Text Available Nitrite was recognized as a potent vasodilator >130 years and has more recently emerged as an endogenous signaling molecule and modulator of gene expression. Understanding the molecular mechanisms that regulate nitrite metabolism is essential for its use as a potential diagnostic marker as well as therapeutic agent for cardiovascular diseases. In this study, we have identified human cystathionine ß-synthase (CBS as a new player in nitrite reduction with implications for the nitrite-dependent control of H₂S production. This novel activity of CBS exploits the catalytic property of its unusual heme cofactor to reduce nitrite and generate NO. Evidence for the possible physiological relevance of this reaction is provided by the formation of ferrous-nitrosyl (Fe(II-NO CBS in the presence of NADPH, the human diflavin methionine synthase reductase (MSR and nitrite. Formation of Fe(II-NO CBS via its nitrite reductase activity inhibits CBS, providing an avenue for regulating biogenesis of H₂S and cysteine, the limiting reagent for synthesis of glutathione, a major antioxidant. Our results also suggest a possible role for CBS in intracellular NO biogenesis particularly under hypoxic conditions. The participation of a regulatory heme cofactor in CBS in nitrite reduction is unexpected and expands the repertoire of proteins that can liberate NO from the intracellular nitrite pool. Our results reveal a potential molecular mechanism for cross-talk between nitrite, NO and H₂S biology.

  7. Latent nitrate reductase activity is associated with the plasma membrane of corn roots

    Science.gov (United States)

    Ward, M. R.; Grimes, H. D.; Huffaker, R. C.

    1989-01-01

    Latent nitrate reductase activity (NRA) was detected in corn (Zea mays L., Golden Jubilee) root microsome fractions. Microsome-associated NRA was stimulated up to 20-fold by Triton X-100 (octylphenoxy polyethoxyethanol) whereas soluble NRA was only increased up to 1.2-fold. Microsome-associated NRA represented up to 19% of the total root NRA. Analysis of microsomal fractions by aqueous two-phase partitioning showed that the membrane-associated NRA was localized in the second upper phase (U2). Analysis with marker enzymes indicated that the U2 fraction was plasma membrane (PM). The PM-associated NRA was not removed by washing vesicles with up to 1.0 M NACl but was solubilized from the PM with 0.05% Triton X-100. In contrast, vanadate-sensitive ATPase activity was not solubilized from the PM by treatment with 0.1% Triton X-100. The results show that a protein capable of reducing nitrate is embedded in the hydrophobic region of the PM of corn roots.

  8. 14CO2-fixation and nitrate reductase activity in vivo in relation to hybrid vigour in maize

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Shanthakumari, P.; Sinha, S.K.

    1977-01-01

    Dry matter accumulation in maize shoots, leaf area, 14 CO 2 -fixation and nitrate reductase activity in vivo were measured in the field grown heterotic hybrid CM 400x CM 300 and its inbred parents CM 300 and CM 400 from seedling to maturity. Rates of dry matter accumulation and leaf area development were higher in the hybrid during the initial vegetative phase than in the inbreds. The hybrid had more absolute level of 14 CO 2 -fixation and nitrate reductase activity, although the rates of these processes on unit weight basis were not higher than those of inbreds. It is concluded that the rapid development of leaf area in hybrids during the early stages of vegetative growth is probably important for hybrid vigour. (author)

  9. Inhibition of aldose reductase activity by Cannabis sativa chemotypes extracts with high content of cannabidiol or cannabigerol.

    Science.gov (United States)

    Smeriglio, Antonella; Giofrè, Salvatore V; Galati, Enza M; Monforte, Maria T; Cicero, Nicola; D'Angelo, Valeria; Grassi, Gianpaolo; Circosta, Clara

    2018-02-07

    Aldose reductase (ALR2) is a key enzyme involved in diabetic complications and the search for new aldose reductase inhibitors (ARIs) is currently very important. The synthetic ARIs are often associated with deleterious side effects and medicinal and edible plants, containing compounds with aldose reductase inhibitory activity, could be useful for prevention and therapy of diabetic complications. Non-psychotropic phytocannabinoids exert multiple pharmacological effects with therapeutic potential in many diseases such as inflammation, cancer, diabetes. Here, we have investigated the inhibitory effects of extracts and their fractions from two Cannabis sativa L. chemotypes with high content of cannabidiol (CBD)/cannabidiolic acid (CBDA) and cannabigerol (CBG)/cannabigerolic acid (CBGA), respectively, on human recombinant and pig kidney aldose reductase activity in vitro. A molecular docking study was performed to evaluate the interaction of these cannabinoids with the active site of ALR2 compared to known ARIs. The extracts showed significant dose-dependent aldose reductase inhibitory activity (>70%) and higher than fractions. The inhibitory activity of the fractions was greater for acidic cannabinoid-rich fractions. Comparative molecular docking results have shown a higher stability of the ALR2-cannabinoid acids complex than the other inhibitors. The extracts of Cannabis with high content of non-psychotropic cannabinoids CBD/CBDA or CBG/CBGA significantly inhibit aldose reductase activity. These results may have some relevance for the possible use of C. sativa chemotypes based preparations as aldose reductase inhibitors. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Silencing of poly(ADP-ribose) glycohydrolase sensitizes lung cancer cells to radiation through the abrogation of DNA damage checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Nakadate, Yusuke [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Kodera, Yasuo; Kitamura, Yuka [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Tachibana, Taro [Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Tamura, Tomohide [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Koizumi, Fumiaki, E-mail: fkoizumi@ncc.go.jp [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2013-11-29

    Highlights: •Radiosensitization by PARG silencing was observed in multiple lung cancer cells. •PAR accumulation was enhanced by PARG silencing after DNA damage. •Radiation-induced G2/M arrest and checkpoint activation were impaired by PARG siRNA. -- Abstract: Poly(ADP-ribose) glycohydrolase (PARG) is a major enzyme that plays a role in the degradation of poly(ADP-ribose) (PAR). PARG deficiency reportedly sensitizes cells to the effects of radiation. In lung cancer, however, it has not been fully elucidated. Here, we investigated whether PARG siRNA contributes to an increased radiosensitivity using 8 lung cancer cell lines. Among them, the silencing of PARG induced a radiosensitizing effect in 5 cell lines. Radiation-induced G2/M arrest was largely suppressed by PARG siRNA in PC-14 and A427 cells, which exhibited significantly enhanced radiosensitivity in response to PARG knockdown. On the other hand, a similar effect was not observed in H520 cells, which did not exhibit a radiosensitizing effect. Consistent with a cell cycle analysis, radiation-induced checkpoint signals were not well activated in the PC-14 and A427 cells when treated with PARG siRNA. These results suggest that the increased sensitivity to radiation induced by PARG knockdown occurs through the abrogation of radiation-induced G2/M arrest and checkpoint activation in lung cancer cells. Our findings indicate that PARG could be a potential target for lung cancer treatments when used in combination with radiotherapy.

  11. Interspecific variation and plasticity in hemoglobin nitrite reductase activity and its correlation with oxygen affinity in vertebrates

    DEFF Research Database (Denmark)

    Jensen, Frank B.; Kolind, Rasmus A. H.; Jensen, Natashia S.

    2017-01-01

    -dependent manner. The initial second order rate constant of the deoxyHb-mediated nitrite reduction showed a strong curvilinear correlation with oxygen affinity among all ectothermic vertebrates, and the relationship also applied to plastic variations of Hb properties via organic phosphates. The relationship...... determines oxygen affinity. In the present study we investigated nitrite reductase activity and O2 affinity in Hbs from ten different vertebrate species under identical conditions to disclose interspecific variations and allow an extended test for a correlation between the rate constant for nitrite reduction...... and O2 affinity. We also tested plastic changes in Hb properties via addition of T-structure-stabilizing organic phosphates (ATP and GTP). The decay in deoxyHb during its reaction with nitrite was exponential-like in ectotherms (Atlantic hagfish, carp, crucian carp, brown trout, rainbow trout, cane toad...

  12. The roles of tissue nitrate reductase activity and myoglobin in securing nitric oxide availability in deeply hypoxic crucian carp

    DEFF Research Database (Denmark)

    Hansen, Marie Niemann; Lundberg, Jon O; Filice, Mariacristina

    2016-01-01

    . We also tested whether liver, muscle and heart tissue possess nitrate reductase activity that supplies nitrite to the tissues during severe hypoxia. Crucian carp exposed to deep hypoxia (1nitrite in red musculature to more than double the value in normoxic fish......In mammals, treatment with low doses of nitrite has a cytoprotective effect in ischemia/reperfusion events, as a result of nitric oxide formation and S-nitrosation of proteins. Interestingly, anoxia-tolerant lower vertebrates possess an intrinsic ability to increase intracellular nitrite...... concentration during anoxia in tissues with high myoglobin and mitochondria content, such as the heart. Here, we tested the hypothesis that red and white skeletal muscles develop different nitrite levels in crucian carp exposed to deep hypoxia and assessed whether this correlates with myoglobin concentration...

  13. Nitrogen nutrition of Canna indica: Effects of ammonium versus nitrate on growth, biomass allocation, photosynthesis, nitrate reductase activity and N uptake rates

    DEFF Research Database (Denmark)

    Konnerup, Dennis; Brix, Hans

    2010-01-01

    The effects of inorganic nitrogen (N) source (NH4+, NO3- or both) on growth, biomass allocation, photosynthesis, N uptake rate, nitrate reductase activity and mineral composition of Canna indica were studied in hydroponic culture. The relative growth rates (0.05-0.06 g g-1 d-1), biomass allocation...

  14. Characterization of a cultured human T-cell line with genetically altered ribonucleotide reductase activity. Model for immunodeficiency.

    Science.gov (United States)

    Waddell, D; Ullman, B

    1983-04-10

    From human CCRF-CEM T-cells growing in continuous culture, we have selected, isolated, and characterized a clonal cell line, APHID-D2, with altered ribonucleotide reductase activity. In comparative growth rate experiments, the APHID-D2 cell line is less sensitive than the parental cell line to growth inhibition by deoxyadenosine in the presence of 10 microM erythro-9-(2-hydroxy-3-nonyl)adenine, an inhibitor of adenosine deaminase. The APHID-D2 cell line has elevated levels of all four dNTPs. The resistance of the APHID-D2 cell line to growth inhibition by deoxyadenosine and the abnormal dNTP levels can be explained by the fact that the APHID-D2 ribonucleotide reductase, unlike the parental ribonucleotide reductase, is not normally sensitive to inhibition by dATP. These results suggest that the allosteric site of ribonucleotide reductase which binds both dATP and ATP is altered in the APHID-D2 line. The isolation of a mutant clone of human T-cells which contains a ribonucleotide reductase that has lost its normal sensitivity to dATP and which is resistant to deoxyadenosine-mediated growth inhibition suggests that a primary pathogenic target of accumulated dATP in lymphocytes from patients with adenosine deaminase deficiency may be the cellular ribonucleotide reductase.

  15. Extreme nitrite tolerance in the clown knifefish Chitala ornata is linked to up-regulation of methaemoglobin reductase activity

    DEFF Research Database (Denmark)

    Le Thi Hong Gam; Jensen, Frank Bo; Damsgaard, Christian

    2017-01-01

    and fell towards control values during the last half of the exposure period. Plasma nitrate, in contrast, rose continuously, reflecting detoxification of nitrite to nitrate. MetHb generated from the reaction between nitrite and erythrocyte Hb reached 38% at day 2, but then decreased to 17% by the end......The clown knifefish is a facultative air breather, which is widely farmed in freshwater ponds in Vietnam. Here we report a very high nitrite tolerance (96h LC50 of 7.82mM) in this species and examine the effects of 1mM (LC5) and 2.5mM (LC10) ambient nitrite on haemoglobin (Hb) derivatives......, electrolyte levels, acid-base status, and total body water content during 7days of exposure. Furthermore, we tested the hypothesis that erythrocyte methaemoglobin (metHb) reductase activity is upregulated by nitrite exposure. Plasma nitrite levels increased for 2-3days but stayed below environmental levels...

  16. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L.) and association with seed iron accumulation QTL.

    Science.gov (United States)

    Blair, Matthew W; Knewtson, Sharon Jb; Astudillo, Carolina; Li, Chee-Ming; Fernandez, Andrea C; Grusak, Michael A

    2010-10-05

    Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L.) take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 x G19833), to identify quantitative trait loci (QTL) for this trait, and to assess possible associations with seed iron levels. The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III)-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient) were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe) on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe) on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO) homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity under iron limited conditions may be useful in

  17. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L. and association with seed iron accumulation QTL

    Directory of Open Access Journals (Sweden)

    Fernandez Andrea C

    2010-10-01

    Full Text Available Abstract Background Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L. take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 × G19833, to identify quantitative trait loci (QTL for this trait, and to assess possible associations with seed iron levels. Results The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Conclusions Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity

  18. The Effect of Nitrate Levels and Harvest Times on Fe, Zn, Cu, and K, Concentrations and Nitrate Reductase Activity in Lettuce and Spinach

    OpenAIRE

    Z. Gheshlaghi; R. Khorassani; G.H. Haghnia; M. Kafi

    2015-01-01

    Leafy vegetables are considered as the main sources of nitrate in the human diet. In order to investigate the effect of nitrate levels and harvest times on nitrate accumulation, nitrate reductase activity, concentrations of Fe, Zn, Cu and K in Lettuce and Spinach and their relation to nitrate accumulation in these leafy vegetables, two harvest times (29 and 46 days after transplanting), two vegetable species of lettuce and spinach and two concentrations of nitrate (10 and 20 mM) were used in ...

  19. The Effect of Nitrate Levels and Harvest Times on Fe, Zn, Cu, and K, Concentrations and Nitrate Reductase Activity in Lettuce and Spinach

    Directory of Open Access Journals (Sweden)

    Z. Gheshlaghi

    2015-09-01

    Full Text Available Leafy vegetables are considered as the main sources of nitrate in the human diet. In order to investigate the effect of nitrate levels and harvest times on nitrate accumulation, nitrate reductase activity, concentrations of Fe, Zn, Cu and K in Lettuce and Spinach and their relation to nitrate accumulation in these leafy vegetables, two harvest times (29 and 46 days after transplanting, two vegetable species of lettuce and spinach and two concentrations of nitrate (10 and 20 mM were used in a hydroponics greenhouse experiment with a completely randomized design and 3 replications. Modified Hoagland and Arnon nutrient solutions were used for the experiment. The results indicated that by increasing nitrate concentration of solution, nitrate accumulation in roots and shoots of lettuce and spinach increased significantly (P ≤ 0.05, and the same trend was observed for the nitrate reductase activity in the shoots of the two species. Increasing the nitrate concentrations of solution, reduced the shoot dry weight and the concentration of Fe and Cu in both species, where as it increased the K and Zn concentrations in the shoots of the two species in each both harvest times, the nitrate accumulation increased, but the nitrate reductase activity decreased in the shoots of the two species over the course of the growth. The Concentration of Fe, Cu and K decreased in the shoots of lettuce and the spinach with the time, despite the increase in Zn concentration in the shoots. The results also indicated that increasing nitrate concentrations of solution to the levels greater than the plant capacity for reduction and net uptake of nitrate, leads to the nitrate accumulation in the plants. Nitrate accumulation in plant tissue led to decreases in fresh shoot yield and Fe and Cu concentrations and nitrate reductase activities in both lettuce and spinach.

  20. Correlation of changes in rate of sterol synthesis with changes in HMG CoA reductase activity in cultured lens epithelial cells

    International Nuclear Information System (INIS)

    Cenedella, R.J.; Hitchener, W.R.

    1986-01-01

    In the present study, the authors correlated changes in HMG CoA reductase activity with changes in relative rates of sterol synthesis measured from either 3 H 2 O or 1- 14 C-acetate for bovine lens epithelial cells cultured in the presence or absence of lipoproteins. Enzyme activity and rates of incorporation of 3 H 2 O or 1- 14 C-acetate into digitonin precipitable sterols were measured in cells on the 4th day of subculture in DMEM containing 9% whole calf serum (WM) or 9% lipoprotein deficient serum (LDM). In three experiments, HMG CoA reductase activity (U/10 6 cells) averaged 2.2 +/- 0.1 times greater for cells grown in LDM than WM. Sterol synthesis averaged 3.0 +/- 0.4 times greater when measured with 3 H 2 O and 4.0 +/- 1.1 times greater when measured with 14 C-acetate. Thus, 3 H 2 O and 14 C-acetate appear to be comparable substrates for estimating changes in relative rates of sterol synthesis by cultured cells. The larger increases in rates of sterol synthesis than in reductase activity in response to decreased cholesterol could reflect stimulation at additional metabolic steps in the cholesterol pathway beyond mevalonic acid

  1. Enzymology of biological nitrogen fixation. Final report, May 1, 1987--April 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    Biological nitrogen fixation is of central importance in the earth`s nitrogen economy. Fixation of nitrogen is accomplished by a variety of microorganisms, all of them procaryotic. Some operate independently and some function symbiotically or associatively with photosynthesizing plants. Biological nitrogen fixation is accomplished via the reaction: N{sub 2} + 8H{sup +} + 8e{sup {minus}} {yields} 2NH{sub 3} + H{sub 2}. This reaction requires a minimum of 16 ATP under ideal laboratory conditions, so it is obvious that the energy demand of the reaction is very high. When certain nitrogen-fixing organisms are supplied fixed nitrogen (e.g., ammonium) the organisms use the fixed nitrogen and turn off their nitrogenase system, thus conserving energy. When the fixed nitrogen is exhausted, the organism reactivates its nitrogenase. The system is turned off by dinitrogenase reductase ADP-ribosyl transferase (DRAT) and turned back on by dinitrogenase reductase-activating glycohydrolase (DRAG). The authors have investigated the details of how DRAT and DRAG are formed, how they function, and the genetics of their formation and operation.

  2. High-resolution crystal structure of Streptococcus pyogenes β-NAD{sup +} glycohydrolase in complex with its endogenous inhibitor IFS reveals a highly water-rich interface

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ji Young; An, Doo Ri; Yoon, Hye-Jin [Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Hyoun Sook [Seoul National University, Seoul 151-747 (Korea, Republic of); Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Sang Jae [Seoul National University, Seoul 151-742 (Korea, Republic of); Im, Ha Na; Jang, Jun Young [Seoul National University, Seoul 151-747 (Korea, Republic of); Suh, Se Won, E-mail: sewonsuh@snu.ac.kr [Seoul National University, Seoul 151-747 (Korea, Republic of); Seoul National University, Seoul 151-747 (Korea, Republic of)

    2013-11-01

    The crystal structure of the complex between the C-terminal domain of Streptococcus pyogenes β-NAD{sup +} glycohydrolase and an endogenous inhibitor for SPN was determined at 1.70 Å. It reveals that the interface between the two proteins is highly rich in water molecules. One of the virulence factors produced by Streptococcus pyogenes is β-NAD{sup +} glycohydrolase (SPN). S. pyogenes injects SPN into the cytosol of an infected host cell using the cytolysin-mediated translocation pathway. As SPN is toxic to bacterial cells themselves, S. pyogenes possesses the ifs gene that encodes an endogenous inhibitor for SPN (IFS). IFS is localized intracellularly and forms a complex with SPN. This intracellular complex must be dissociated during export through the cell envelope. To provide a structural basis for understanding the interactions between SPN and IFS, the complex was overexpressed between the mature SPN (residues 38–451) and the full-length IFS (residues 1–161), but it could not be crystallized. Therefore, limited proteolysis was used to isolate a crystallizable SPN{sub ct}–IFS complex, which consists of the SPN C-terminal domain (SPN{sub ct}; residues 193–451) and the full-length IFS. Its crystal structure has been determined by single anomalous diffraction and the model refined at 1.70 Å resolution. Interestingly, our high-resolution structure of the complex reveals that the interface between SPN{sub ct} and IFS is highly rich in water molecules and many of the interactions are water-mediated. The wet interface may facilitate the dissociation of the complex for translocation across the cell envelope.

  3. High-resolution crystal structure of Streptococcus pyogenes β-NAD+ glycohydrolase in complex with its endogenous inhibitor IFS reveals a highly water-rich interface

    International Nuclear Information System (INIS)

    Yoon, Ji Young; An, Doo Ri; Yoon, Hye-Jin; Kim, Hyoun Sook; Lee, Sang Jae; Im, Ha Na; Jang, Jun Young; Suh, Se Won

    2013-01-01

    The crystal structure of the complex between the C-terminal domain of Streptococcus pyogenes β-NAD + glycohydrolase and an endogenous inhibitor for SPN was determined at 1.70 Å. It reveals that the interface between the two proteins is highly rich in water molecules. One of the virulence factors produced by Streptococcus pyogenes is β-NAD + glycohydrolase (SPN). S. pyogenes injects SPN into the cytosol of an infected host cell using the cytolysin-mediated translocation pathway. As SPN is toxic to bacterial cells themselves, S. pyogenes possesses the ifs gene that encodes an endogenous inhibitor for SPN (IFS). IFS is localized intracellularly and forms a complex with SPN. This intracellular complex must be dissociated during export through the cell envelope. To provide a structural basis for understanding the interactions between SPN and IFS, the complex was overexpressed between the mature SPN (residues 38–451) and the full-length IFS (residues 1–161), but it could not be crystallized. Therefore, limited proteolysis was used to isolate a crystallizable SPN ct –IFS complex, which consists of the SPN C-terminal domain (SPN ct ; residues 193–451) and the full-length IFS. Its crystal structure has been determined by single anomalous diffraction and the model refined at 1.70 Å resolution. Interestingly, our high-resolution structure of the complex reveals that the interface between SPN ct and IFS is highly rich in water molecules and many of the interactions are water-mediated. The wet interface may facilitate the dissociation of the complex for translocation across the cell envelope

  4. Nitrate decreases xanthine oxidoreductase-mediated nitrite reductase activity and attenuates vascular and blood pressure responses to nitrite.

    Science.gov (United States)

    Damacena-Angelis, Célio; Oliveira-Paula, Gustavo H; Pinheiro, Lucas C; Crevelin, Eduardo J; Portella, Rafael L; Moraes, Luiz Alberto B; Tanus-Santos, Jose E

    2017-08-01

    Nitrite and nitrate restore deficient endogenous nitric oxide (NO) production as they are converted back to NO, and therefore complement the classic enzymatic NO synthesis. Circulating nitrate and nitrite must cross membrane barriers to produce their effects and increased nitrate concentrations may attenuate the nitrite influx into cells, decreasing NO generation from nitrite. Moreover, xanthine oxidoreductase (XOR) mediates NO formation from nitrite and nitrate. However, no study has examined whether nitrate attenuates XOR-mediated NO generation from nitrite. We hypothesized that nitrate attenuates the vascular and blood pressure responses to nitrite either by interfering with nitrite influx into vascular tissue, or by competing with nitrite for XOR, thus inhibiting XOR-mediated NO generation. We used two independent vascular function assays in rats (aortic ring preparations and isolated mesenteric arterial bed perfusion) to examine the effects of sodium nitrate on the concentration-dependent responses to sodium nitrite. Both assays showed that nitrate attenuated the vascular responses to nitrite. Conversely, the aortic responses to the NO donor DETANONOate were not affected by sodium nitrate. Further confirming these results, we found that nitrate attenuated the acute blood pressure lowering effects of increasing doses of nitrite infused intravenously in freely moving rats. The possibility that nitrate could compete with nitrite and decrease nitrite influx into cells was tested by measuring the accumulation of nitrogen-15-labeled nitrite ( 15 N-nitrite) by aortic rings using ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS). Nitrate exerted no effect on aortic accumulation of 15 N-nitrite. Next, we used chemiluminescence-based NO detection to examine whether nitrate attenuates XOR-mediated nitrite reductase activity. Nitrate significantly shifted the Michaelis Menten saturation curve to the right, with a 3-fold increase in the

  5. The Effects of Dose Rhizoctonia Binucleat (BNR and Phosphorus to Nitrate Reductase Activity (NRA and Chlorophyll of Vanilla Seedling (Vanilla planifolia Andrews

    Directory of Open Access Journals (Sweden)

    Haryuni Haryuni

    2016-09-01

    Full Text Available Vanilla (Vanilla planifolia Andrews is one of the important exported commodities in Indonesia. Indonesia is one of top five major vanilla exporters in the world, that produce the high quality of Indonesian vanilla with high vanillin content (2.75%. The aims of this research were to determine the effects of dose binukleat Rhizoctonia (BNR and phosphorus as well as the interaction of the nitrate reductase activity (NRA and chlorophyll of the vanilla seedling (Vanilla planifolia Andrew. Method in this research used completely randomized factorial design, by involving two factors (dose of BNR inoculation and Phosphor. The first factor is without inoculation and inoculation BNR (M0, M1, M2, M3 wich consists of (0,5, 10, 15 g/polybag, the second factor is the dose of phosphorus fertilizer (P0, P1, P2, P3 which consists of (0, 3, 6, 9 g/polibag. The results showed that the inoculation dose of BNR and doses of phosphorus not significant and lower levels of NRA and chlorophyll while the interaction dose of BNR and phosphorus significantly and increase levels of NRA and chlorophyll of vanilla seedling. Nitrate Reductase Activity and chlorophyll has important role in metabolism process as a plant growth indicator.How to CiteHaryuni, H., & Dewi, T. S. K. (2016. The Effects of Dose Rhizoctonia Binucleat (BNR and Phosphorus to Nitrate Reductase Activity (NRA and Chlorophyll of Vanilla Seedling (Vanilla planifolia Andrews. Biosaintifika: Journal of Biology & Biology Education, 8(2, 141-147.

  6. Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

    Science.gov (United States)

    Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

    2008-09-19

    It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

  7. Ibrutinib synergizes with poly(ADP-ribose) glycohydrolase inhibitors to induce cell death in AML cells via a BTK-independent mechanism.

    Science.gov (United States)

    Rotin, Lianne E; Gronda, Marcela; MacLean, Neil; Hurren, Rose; Wang, XiaoMing; Lin, Feng-Hsu; Wrana, Jeff; Datti, Alessandro; Barber, Dwayne L; Minden, Mark D; Slassi, Malik; Schimmer, Aaron D

    2016-01-19

    Targeting Bruton's tyrosine kinase (BTK) with the small molecule BTK inhibitor ibrutinib has significantly improved patient outcomes in several B-cell malignancies, with minimal toxicity. Given the reported expression and constitutive activation of BTK in acute myeloid leukemia (AML) cells, there has been recent interest in investigating the anti-AML activity of ibrutinib. We noted that ibrutinib had limited single-agent toxicity in a panel of AML cell lines and primary AML samples, and therefore sought to identify ibrutinib-sensitizing drugs. Using a high-throughput combination chemical screen, we identified that the poly(ADP-ribose) glycohydrolase (PARG) inhibitor ethacridine lactate synergized with ibrutinib in TEX and OCI-AML2 leukemia cell lines. The combination of ibrutinib and ethacridine induced a synergistic increase in reactive oxygen species that was functionally important to explain the observed cell death. Interestingly, synergistic cytotoxicity of ibrutinib and ethacridine was independent of the inhibitory effect of ibrutinib against BTK, as knockdown of BTK did not sensitize TEX and OCI-AML2 cells to ethacridine treatment. Thus, our findings indicate that ibrutinib may have a BTK-independent role in AML and that PARG inhibitors may have utility as part of a combination therapy for this disease.

  8. Poly(ADP-ribose) Glycohydrolase and Poly(ADP-ribose)-interacting Protein Hrp38 Regulate Pattern Formation during Drosophila Eye Development

    Science.gov (United States)

    Ji, Yingbiao; Jarnik, Michael; Tulin, Alexei V.

    2013-01-01

    Drosophila Hrp38, a homolog of human hnRNP A1, has been shown to regulate splicing, but its function can be modified by poly(ADP-ribosyl)ation. Notwithstanding such findings, our understanding of the roles of poly(ADP-ribosyl)ated Hrp38 on development is limited. Here, we have demonstrated that Hrp38 is essential for fly eye development based on a rough-eye phenotype with disorganized ommatidia observed in adult escapers of the hrp38 mutant. We also observed that Poly(ADP-ribose) Glycohydrolase (Parg) loss-of-function, which caused increased Hrp38 poly(ADP-ribosyl)ation, also resulted in the rough-eye phenotype with disrupted ommatidial lattice and reduced number of photoreceptor cells. In addition, ectopic expression of DE-cadherin, which is required for retinal morphogenesis, fully rescued the rough-eye phenotype of the hrp38 mutant. Similarly, Parg mutant eye clones had decreased expression level of DE-cadherin with orientation defects, which is reminiscent of DE-cadherin mutant eye phenotype. Therefore, our results suggest that Hrp38 poly(ADP-ribosyl)ation controls eye pattern formation via regulation of DE-cadherin expression, a finding which has implications for understanding the pathogenic mechanisms of Hrp38-related Fragile X syndrome and PARP1-related retinal degeneration diseases. PMID:23711619

  9. Camphene, a plant-derived monoterpene, reduces plasma cholesterol and triglycerides in hyperlipidemic rats independently of HMG-CoA reductase activity.

    Directory of Open Access Journals (Sweden)

    Ioanna Vallianou

    Full Text Available Central to the pathology of coronary heart disease is the accumulation of lipids, cholesterol and triglycerides, within the intima of arterial blood vessels. The search for drugs to treat dislipidemia, remains a major pharmaceutical focus. In this study, we evaluated the hypolipidemic properties of the essential oil from Chios mastic gum (MGO.The hypolipidemic effect of MGO was investigated in naïve as well as in rats susceptible to detergent-induced hyperlipidemia. Serum cholesterol and triglycerides were determined using commercial kits. HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A reductase activity was measured in HepG2 cell extracts using a radioactive assay; cellular cholesterol and cholesterol esters were assessed using gas chromatography. MGO administration into naïve rats resulted in a dose-dependent reduction in the constitutive synthesis of serum cholesterol and triglycerides. In hyperlipidemic rats, MGO treatment had also a strong hypolipidemic effect. By testing various components of MGO, we show for the first time that the hypolipidemic action is associated with camphene. Administration of camphene at a dose of 30 µg/gr of body weight in hyperlipidemic rats resulted in a 54.5% reduction of total cholesterol (p<0.001, 54% of Low Density Lipoprotein (LDL-cholesterol (p<0.001 and 34.5% of triglycerides (p<0.001. Treatment of HepG2 cells with camphene led to a decrease in cellular cholesterol content to the same extend as mevinolin, a known HMG-CoA reductase inhibitor. The hypolipidemic action of camphene is independent of HMG-CoA reductase activity, suggesting that its hypocholesterolemic and hypotriglyceridemic effects are associated with a mechanism of action different than that of statins.Given the critical role that the control of hyperlipidemia plays in cardiovascular disease, the results of our study provide insights into the use of camphene as an alternative lipid lowering agent and merits further evaluation.

  10. Resolution of two native monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina and the sequence of two napA genes

    International Nuclear Information System (INIS)

    Simpson, Philippa J.L.; McKinzie, Audra A.; Codd, Rachel

    2010-01-01

    Research highlights: → Two monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina. → Sequence of napA from napEDABC-type operon and napA from NapDAGHB-type operon. → Isolation of NAP as NapA or NapAB correlated with NapA P47E amino acid substitution. -- Abstract: The reduction of nitrate to nitrite in the bacterial periplasm occurs in the 90 kDa NapA subunit of the periplasmic nitrate reductase (NAP) system. Most Shewanella genomes contain two nap operons: napEDABC and napDAGHB, which is an unusual feature of this genus. Two native, monomeric, 90 kDa nitrate reductase active proteins were resolved by hydrophobic interaction chromatography from aerobic cultures of Shewanella gelidimarina replete with reduced nitrogen compounds. The 90 kDa protein obtained in higher yield was characterized as NapA by electronic absorption and electron paramagnetic resonance spectroscopies and was identified by LC/MS/MS and MALDI-TOF/TOF MS as NapA from the napEDABC-type operon. The other 90 kDa protein, which was unstable and produced in low yields, was posited as NapA from the napDAGHB-type operon. Two napA genes have been sequenced from the napEDABC-type and napDAGHB-type operons of S. gelidimarina. Native NAP from S. putrefaciens was resolved as one NapA monomer and one NapAB heterodimer. Two amino acid substitutions in NapA correlated with the isolation of NAP as a NapA monomer or a NapAB heterodimer. The resolution of native, redox-active NapA isoforms in Shewanella provides new insight into the respiratory versatility of this genus, which has implications in bioremediation and the assembly of microbial fuel cells.

  11. Mercury (II) removal by resistant bacterial isolates and mercuric (II) reductase activity in a new strain of Pseudomonas sp. B50A.

    Science.gov (United States)

    Giovanella, Patricia; Cabral, Lucélia; Bento, Fátima Menezes; Gianello, Clesio; Camargo, Flávio Anastácio Oliveira

    2016-01-25

    This study aimed to isolate mercury resistant bacteria, determine the minimum inhibitory concentration for Hg, estimate mercury removal by selected isolates, explore the mer genes, and detect and characterize the activity of the enzyme mercuric (II) reductase produced by a new strain of Pseudomonas sp. B50A. The Hg removal capacity of the isolates was determined by incubating the isolates in Luria Bertani broth and the remaining mercury quantified by atomic absorption spectrophotometry. A PCR reaction was carried out to detect the merA gene and the mercury (II) reductase activity was determined in a spectrophotometer at 340 nm. Eight Gram-negative bacterial isolates were resistant to high mercury concentrations and capable of removing mercury, and of these, five were positive for the gene merA. The isolate Pseudomonas sp. B50A removed 86% of the mercury present in the culture medium and was chosen for further analysis of its enzyme activity. Mercuric (II) reductase activity was detected in the crude extract of this strain. This enzyme showed optimal activity at pH 8 and at temperatures between 37 °C and 45 °C. The ions NH4(+), Ba(2+), Sn(2+), Ni(2+) and Cd(2+) neither inhibited nor stimulated the enzyme activity but it decreased in the presence of the ions Ca(2+), Cu(+) and K(+). The isolate and the enzyme detected were effective in reducing Hg(II) to Hg(0), showing the potential to develop bioremediation technologies and processes to clean-up the environment and waste contaminated with mercury. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Camphene, a Plant-Derived Monoterpene, Reduces Plasma Cholesterol and Triglycerides in Hyperlipidemic Rats Independently of HMG-CoA Reductase Activity

    Science.gov (United States)

    Vallianou, Ioanna; Peroulis, Nikolaos; Pantazis, Panayotis; Hadzopoulou-Cladaras, Margarita

    2011-01-01

    Background Central to the pathology of coronary heart disease is the accumulation of lipids, cholesterol and triglycerides, within the intima of arterial blood vessels. The search for drugs to treat dislipidemia, remains a major pharmaceutical focus. In this study, we evaluated the hypolipidemic properties of the essential oil from Chios mastic gum (MGO). Methodology/Principal Findings The hypolipidemic effect of MGO was investigated in naïve as well as in rats susceptible to detergent-induced hyperlipidemia. Serum cholesterol and triglycerides were determined using commercial kits. HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase activity was measured in HepG2 cell extracts using a radioactive assay; cellular cholesterol and cholesterol esters were assessed using gas chromatography. MGO administration into naïve rats resulted in a dose-dependent reduction in the constitutive synthesis of serum cholesterol and triglycerides. In hyperlipidemic rats, MGO treatment had also a strong hypolipidemic effect. By testing various components of MGO, we show for the first time that the hypolipidemic action is associated with camphene. Administration of camphene at a dose of 30 µg/gr of body weight in hyperlipidemic rats resulted in a 54.5% reduction of total cholesterol (p<0.001), 54% of Low Density Lipoprotein (LDL)-cholesterol (p<0.001) and 34.5% of triglycerides (p<0.001). Treatment of HepG2 cells with camphene led to a decrease in cellular cholesterol content to the same extend as mevinolin, a known HMG-CoA reductase inhibitor. The hypolipidemic action of camphene is independent of HMG-CoA reductase activity, suggesting that its hypocholesterolemic and hypotriglyceridemic effects are associated with a mechanism of action different than that of statins. Conclusions Given the critical role that the control of hyperlipidemia plays in cardiovascular disease, the results of our study provide insights into the use of camphene as an alternative lipid lowering agent

  13. DIETARY-CHOLESTEROL INDUCED DOWN-REGULATION OF INTESTINAL 3-HYDROXY-3-METHYLGLUTARYL COENZYME-A REDUCTASE-ACTIVITY IS DIMINISHED IN RABBITS WITH HYPERRESPONSE OF SERUM-CHOLESTEROL TO DIETARY-CHOLESTEROL

    NARCIS (Netherlands)

    MEIJER, GW; SMIT, MJ; VANDERPALEN, JGP; KUIPERS, F; VONK, RJ; VANZUTPHEN, BFM; BEYNEN, AC

    Key enzymes of cholesterol metabolism were studied in two inbred strains of rabbits with hyper- or hyporesponse of serum cholesterol to dietary cholesterol. Baseline 3-hydroxy-3-methylglutaryl (HMG)CoA reductase activity in liver was similar in hypo- and hyperresponders, but that in intestine was

  14. Altered poly(ADP-ribose) metabolism impairs cellular responses to genotoxic stress in a hypomorphic mutant of poly(ADP-ribose) glycohydrolase

    International Nuclear Information System (INIS)

    Gao Hong; Coyle, Donna L.; Meyer-Ficca, Mirella L.; Meyer, Ralph G.; Jacobson, Elaine L.; Wang, Zhao-Qi; Jacobson, Myron K.

    2007-01-01

    Genotoxic stress activates nuclear poly(ADP-ribose) (PAR) metabolism leading to PAR synthesis catalyzed by DNA damage activated poly(ADP-ribose) polymerases (PARPs) and rapid PAR turnover by action of nuclear poly(ADP-ribose) glycohydrolase (PARG). The involvement of PARP-1 and PARP-2 in responses to DNA damage has been well studied but the involvement of nuclear PARG is less well understood. To gain insights into the function of nuclear PARG in DNA damage responses, we have quantitatively studied PAR metabolism in cells derived from a hypomorphic mutant mouse model in which exons 2 and 3 of the PARG gene have been deleted (PARG-Δ2,3 cells), resulting in a nuclear PARG containing a catalytic domain but lacking the N-terminal region (A domain) of the protein. Following DNA damage induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), we found that the activity of both PARG and PARPs in intact cells is increased in PARG-Δ2,3 cells. The increased PARG activity leads to decreased PARP-1 automodification with resulting increased PARP activity. The degree of PARG activation is greater than PARP, resulting in decreased PAR accumulation. Following MNNG treatment, PARG-Δ2,3 cells show reduced formation of XRCC1 foci, delayed H2AX phosphorylation, decreased DNA break intermediates during repair, and increased cell death. Our results show that a precise coordination of PARPs and PARG activities is important for normal cellular responses to DNA damage and that this coordination is defective in the absence of the PARG A domain

  15. Discovery of novel poly(ADP-ribose) glycohydrolase inhibitors by a quantitative assay system using dot-blot with anti-poly(ADP-ribose)

    International Nuclear Information System (INIS)

    Okita, Naoyuki; Ashizawa, Daisuke; Ohta, Ryo; Abe, Hideaki; Tanuma, Sei-ichi

    2010-01-01

    Poly(ADP-ribosyl)ation, which is mainly regulated by poly(ADP-ribose) polymerase (PARP) and poly(ADP-ribose) glycohydrolase (PARG), is a unique protein modification involved in cellular responses such as DNA repair and replication. PARG hydrolyzes glycosidic linkages of poly(ADP-ribose) synthesized by PARP and liberates ADP-ribose residues. Recent studies have suggested that inhibitors of PARG are able to be potent anti-cancer drug. In order to discover the potent and specific Inhibitors of PARG, a quantitative and high-throughput screening assay system is required. However, previous PARG assay systems are not appropriate for high-throughput screening because PARG activity is measured by radioactivities of ADP-ribose residues released from radioisotope (RI)-labeled poly(ADP-ribose). In this study, we developed a non-RI and quantitative assay system for PARG activity based on dot-blot assay using anti-poly(ADP-ribose) and nitrocellulose membrane. By our method, the maximum velocity (V max ) and the michaelis constant (k m ) of PARG reaction were 4.46 μM and 128.33 μmol/min/mg, respectively. Furthermore, the IC50 of adenosine diphosphate (hydroxymethyl) pyrrolidinediol (ADP-HPD), known as a non-competitive PARG inhibitor, was 0.66 μM. These kinetics values were similar to those obtained by traditional PARG assays. By using our assay system, we discovered two novel PARG inhibitors that have xanthene scaffold. Thus, our quantitative and convenient method is useful for a high-throughput screening of PARG specific inhibitors.

  16. Isoniazid acetylating phenotype in patients with paracoccidioidomycosis and its relationship with serum sulfadoxin levels, glucose-6-phosphate dehydrogenase and glutathione reductase activities

    Directory of Open Access Journals (Sweden)

    Benedito Barraviera

    1991-06-01

    Full Text Available The authors evaluated the isoniazid acetylating phenotype and measured hematocrit, hemoglobin, glucose-6-phosphate dehydrogenase and glutathione reductase activities plus serum sulfadoxin levels in 39 patients with paracoccidioidomycosis (33 males and 6 females aged 17 to 58 years. Twenty one (53.84% of the patients presented a slow acetylatingphenotype and 18(46.16% a fast acetylating phenotype. Glucose-6-phosphate- dehydrogenase (G6PD acti vity was decreased in 5(23.80% slow acetylators and in 4(22.22% fast acetylators. Glutathione reductase activity was decreased in 14 (66.66% slow acetylators and in 12 (66.66% fast acetylators. Serum levels of free and total sulfadoxin Were higher in slow acetylator (p Os autores avaliaram o fenótipo acetilador da isoniazida, hematócrito, hemoglobina, atividade da glicose-6- fosfato desidrogenase, glutationa redutase e os níveis séricos de sulfadoxina de 39 doentes com paracoccidíoidomicose, senão 33 do sexo masculino e 6 do feminino, com idades compreendidas entre 17 e 58 anos. Vinte e um (53,84% doentes apresentaram fenótipo acetilador lento e 18 (46,16% rápido. A atividade da glicose-6-fosfato desidrogenase (G6PD esteve diminuída em 5 (23,80% acetiladores lentos e 4 (22,22% rápidos. A atividade da glutationa redutase esteve diminuída em 14 (66,66% acetiladores lentos e 12 (66,66% rápidos. Os níveis séricos de sulfadoxina livre e total foram maiores nos acetiladores lentos (p < 0,02. A análise dos resultados permite concluir que os níveis séricos de sulfadoxina relaciona-se com o fenótipo acetilador. Além disso, os níveis estiveram sempre acima de 50 µg/ml, níveis estes considerados terapêuticos. Por outro lado, a deficiência de glutationa redutase pode estar relacionada com a má absorção intestinal de nutrientes, entre eles riboflavina, vitamina precursora de FAD.

  17. Protective effect of Pterocarpus marsupium bark extracts against cataract through the inhibition of aldose reductase activity in streptozotocin-induced diabetic male albino rats.

    Science.gov (United States)

    Xu, YanLi; Zhao, Yongxia; Sui, YaNan; Lei, XiaoJun

    2018-04-01

    The present study was aimed to investigate the protective effect of Pterocarpus marsupium bark extracts against cataract in streptozotocin-induced diabetic male albino rats. Aldose reductase is a key enzyme in the intracellular polyol pathway, which plays a major role in the development of diabetic cataract. Rats were divided into five groups as normal control, diabetic control, and diabetic control treated with different concentrations of Pterocarpus marsupium bark extracts. Presence of major constituents in Pterocarpus marsupium bark extract was performed by qualitative analysis. Body weight changes, blood glucose, blood insulin, and reduced glutathione (GSH) and aldose reductase mRNA and protein expression were determined. Rat body weight gain was noted following treatment with bark extracts. The blood glucose was reduced up to 36% following treatment with bark extracts. The blood insulin and tissue GSH contents were substantially increased more than 100% in diabetic rats following treatment with extracts. Aldose reductase activity was reduced up to 79.3% in diabetic rats following treatment with extracts. V max , K m , and K i of aldose reductase were reduced in the lens tissue homogenate compared to the diabetic control. Aldose reductase mRNA and protein expression were reduced more than 50% following treatment with extracts. Treatment with Pterocarpus marsupium bark was able to normalize these levels. Taking all these data together, it is concluded that the use of Pterocarpus marsupium bark extracts could be the potential therapeutic approach for the reduction of aldose reductase against diabetic cataract.

  18. YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

    Science.gov (United States)

    Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

    2015-05-01

    Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Nitrate reductase activity (NRA in the invasive alien Fallopia japonica: seasonal variation, differences among habitats types, and comparison with native species

    Directory of Open Access Journals (Sweden)

    Damian Chmura

    2016-09-01

    Full Text Available Nitrate reductase activity (NRA was studied in the invasive alien plant F. japonica (Japanese knotweed during the vegetation season and among natural, semi-natural, and human-made habitats and compared with NRA in selected native species. NRA was measured directly in the field from the beginning of May until the beginning of October. NRA was much higher than in the plant’s native range, i.e., East Asia, and showed a high degree of variation over time with the highest values being reached at the stage of fast vegetative growth and at the beginning of fruiting. NRA was highest on dumping sites probably due to the high nitrogen input into soils and near traffic and the emission of NOx by vehicles. A comparison of the enzyme activity in four selected native plant species indicated that NRA in F. japonica was the highest with the exception of Urtica dioica, which exhibited a similar activity of the enzyme. A detailed comparison with this species showed that differences between these species on particular dates were influenced by differences in the phenology of both plants. The initial results that were obtained suggest that nitrogen pollution in an environment can contribute to habitat invasibility and a high level of NRA, which in addition to the many plant traits that are commonly accepted as characteristic of invasiveness features, may be an important factor that enhances invasion success.

  20. Nitrogen nutrition of Salvinia natans: Effects of inorganic nitrogen form on growth, morphology, nitrate reductase activity and uptake kinetics of ammonium and nitrate

    DEFF Research Database (Denmark)

    Jampeetong, Arunothai; Brix, Hans

    2009-01-01

    In this study we assessed the growth, morphological responses, and N uptake kinetics of Salvinia natans when supplied with nitrogen as NO3-, NH4+, or both at equimolar concentrations (500 μM). Plants supplied with only NO3- had lower growth rates (0.17 ± 0.01 g g-1 d-1), shorter roots, smaller...... leaves with less chlorophyll than plants supplied with NH4+ alone or in combination with NO3- (RGR = 0.28 ± 0.01 g g-1 d-1). Ammonium was the preferred form of N taken up. The maximal rate of NH4+ uptake (Vmax) was 6-14 times higher than the maximal uptake rate of NO3- and the minimum concentration...... for uptake (Cmin) was lower for NH4+ than for NO3-. Plants supplied with NO3- had elevated nitrate reductase activity (NRA) particularly in the roots showing that NO3- was primarily reduced in the roots, but NRA levels were generally low (NH4...

  1. Fine-tuning of Smad protein function by poly(ADP-ribose polymerases and poly(ADP-ribose glycohydrolase during transforming growth factor β signaling.

    Directory of Open Access Journals (Sweden)

    Markus Dahl

    Full Text Available Initiation, amplitude, duration and termination of transforming growth factor β (TGFβ signaling via Smad proteins is regulated by post-translational modifications, including phosphorylation, ubiquitination and acetylation. We previously reported that ADP-ribosylation of Smads by poly(ADP-ribose polymerase 1 (PARP-1 negatively influences Smad-mediated transcription. PARP-1 is known to functionally interact with PARP-2 in the nucleus and the enzyme poly(ADP-ribose glycohydrolase (PARG can remove poly(ADP-ribose chains from target proteins. Here we aimed at analyzing possible cooperation between PARP-1, PARP-2 and PARG in regulation of TGFβ signaling.A robust cell model of TGFβ signaling, i.e. human HaCaT keratinocytes, was used. Endogenous Smad3 ADP-ribosylation and protein complexes between Smads and PARPs were studied using proximity ligation assays and co-immunoprecipitation assays, which were complemented by in vitro ADP-ribosylation assays using recombinant proteins. Real-time RT-PCR analysis of mRNA levels and promoter-reporter assays provided quantitative analysis of gene expression in response to TGFβ stimulation and after genetic perturbations of PARP-1/-2 and PARG based on RNA interference.TGFβ signaling rapidly induces nuclear ADP-ribosylation of Smad3 that coincides with a relative enhancement of nuclear complexes of Smads with PARP-1 and PARP-2. Inversely, PARG interacts with Smads and can de-ADP-ribosylate Smad3 in vitro. PARP-1 and PARP-2 also form complexes with each other, and Smads interact and activate auto-ADP-ribosylation of both PARP-1 and PARP-2. PARP-2, similar to PARP-1, negatively regulates specific TGFβ target genes (fibronectin, Smad7 and Smad transcriptional responses, and PARG positively regulates these genes. Accordingly, inhibition of TGFβ-mediated transcription caused by silencing endogenous PARG expression could be relieved after simultaneous depletion of PARP-1.Nuclear Smad function is negatively

  2. Inhibition of NADH-ubiquinone reductase activity by N,N'-dicyclohexylcarbodiimide and correlation of this inhibition with the occurrence of energy-coupling site 1 in various organisms

    International Nuclear Information System (INIS)

    Yagi, T.

    1987-01-01

    The NADH-ubiquinone reductase activity of the respiratory chains of several organisms was inhibited by the carboxyl-modifying reagent N,N'-dicyclohexylcarbodiimide (DCCD). This inhibition correlated with the presence of an energy-transducing site in this segment of the respiratory chain. Where the NADH-quinone reductase segment involved an energy-coupling site (e.g., in bovine heart and rat liver mitochondria, and in Paracoccus denitrificans, Escherichia coli, and Thermus thermophilus HB-8 membranes), DCCD acted as an inhibitor of ubiquinone reduction by NADH. By contrast, where energy-coupling site 1 was absent (e.g., in Saccharomyces cerevisiae mitochondria and BacilLus subtilis membranes), there was no inhibition of NADH-ubiquinone reductase activity by DCCD. In the bovine and P. denitrificans systems, DCCD inhibition was pseudo first order with respect to incubation time, and reaction order with respect to inhibitor concentration was close to unity, indicating that inhibition resulted from the binding of one inhibitor molecule per active unit of NADH-ubiquinone reductase. In the bovine NADH-ubiquinone reductase complex (complex I), [ 14 C]DCCD was preferentially incorporated into two subunits of molecular weight 49,000 and 29,000. The time course of labeling of the 29,000 molecular weight subunit with [ 14 C]DCCD paralleled the time course of inhibition of NADH-ubiquinone reductase activity

  3. Glucose-6-phosphate dehydrogenase and glutathione reductase activity in methemoglobin reduction by methylene blue and cyst amine: study on glucose-6-phosphate dehydrogenase-deficient individuals, on normal subjects and on riboflavin-treated subjects

    Directory of Open Access Journals (Sweden)

    Benedito Barraviera

    1988-10-01

    Full Text Available The authors have standardized methods for evaluation of the activity of the glucose-6-phosphate dehydrogenase and of glutathione reductase. The general principle of the first method was based on methemoglobin formation by sodium nitrite followed by stimulation of the glucose-6-phosphate dehydrogenase with methylene blue. Forty six adults (23 males and 23 females were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. The results showed that methemoglobin reduction by methylene blue was 154.40 and 139.90 mg/min (p<0.05 for males and females, respectively, in whole blood, and 221.10 and 207.85 mg/min (n.s., respectively, in washed red cells. These data showed that using washed red cells and 0.7g% sodium nitrite concentration produced no differences between sexes and also shortened reading time for the residual amount of methemoglobin to 90 minutes. Glutathione reductase activity was evaluated on the basis of the fact that cystamine (a thiol agent binds to the SH groups of hemoglobin, forming complexes. These complexes are reversed by the action of glutathione reductase, with methemoglobin reduction occurring simultaneously with this reaction. Thirty two adults (16 males and 16 females were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. Methemoglobin reduction by cystamine was 81.27 and 91.13 mg/min (p<0.01 for males and females, respectively. These data showed that using washed red cells and 0.1 M cystamine concentration permits a reading of the residual amount of methemoglobin at 180 minutes of incubation. Glutathione reductase activity was evaluated by methemoglobin reduction by cystamine in 14 females before and after treatment with 10 mg riboflavin per day for 8 days. The results were 73.69 and 94.26 jug/min (p<0.01 before and after treatment, showing that riboflavin treatment increase glutathione reductase activity even in normal individuals. Three Black G6PD-deficient individuals (2 males and 1

  4. ACCUMULATION OF NITROGEN COMPOUNDS AND NITRATE REDUCTASE ACTIVITY IN LETTUCE CULTIVATED IN DIFFERENT CROP SYSTEMS ACÚMULO DE COMPOSTOS NITROGENADOS E ATIVIDADE DA REDUTASE DO NITRATO EM ALFACE PRODUZIDA EM DIFERENTES SISTEMAS DE CULTIVO

    Directory of Open Access Journals (Sweden)

    Fernanda Nunes Ibrahim

    2008-09-01

    Full Text Available

    Nitrate content determination is important for food quality evaluation, therefore when ingested nitrate is reduced the nitrite, which can generate harmful compounds to the human organism. Ahead of this, the present work had as objective to study the transport and accumulation of nitrogen compounds and the nitrate reductase activity in lettuce cultivar 'Vera' produced in Registro (SP in different cropping systems. Were collected samples of the xylem sap, aerial part and root for quantification of nitrogen compounds and of the reductase activity in vivo. The nitrate concentration in the xylem sap, the nitrate and amino acids contents, as well as the nitrate reductase activity, demonstrated more intense transport, accumulation and assimilation in plants cultivated in in hydroponic solution, followed of the conventional system and finally, of the organic. The stem of the plant in the three systems of culture presented high capacity of accumulation and assimilation the nitrogen compounds. The nitrate reductase activity in leaves was superior of the root. The content nitrate, independent of the culture system, varied of 24.32 the 800.06 mg kg-1 of FW in the different parts of the plant. However, it did not exceed the maximum

  5. The effect of aluminium-stress and exogenous spermidine on chlorophyll degradation, glutathione reductase activity and the photosystem II D1 protein gene (psbA) transcript level in lichen Xanthoria parietina.

    Science.gov (United States)

    Sen, Gulseren; Eryilmaz, Isil Ezgi; Ozakca, Dilek

    2014-02-01

    In this study, the effects of short-term aluminium toxicity and the application of spermidine on the lichen Xanthoria parietina were investigated at the physiological and transcriptional levels. Our results suggest that aluminium stress leads to physiological processes in a dose-dependent manner through differences in lipid peroxidation rate, chlorophyll content and glutathione reductase (EC 1.6.4.2) activity in aluminium and spermidine treated samples. The expression of the photosystem II D1 protein (psbA) gene was quantified using semi-quantitative RT-PCR. Increased glutathione reductase activity and psbA mRNA transcript levels were observed in the X. parietina thalli that were treated with spermidine before aluminium-stress. The results showed that the application of spermidine could mitigate aluminium-induced lipid peroxidation and chlorophyll degradation on lichen X. parietina thalli through an increase in psbA transcript levels and activity of glutathione reductase (GR) enzymes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Inhibitory Effect on In Vitro LDL Oxidation and HMG Co-A Reductase Activity of the Liquid-Liquid Partitioned Fractions of Hericium erinaceus (Bull. Persoon (Lion’s Mane Mushroom

    Directory of Open Access Journals (Sweden)

    Mohammad Azizur Rahman

    2014-01-01

    Full Text Available Oxidation of low-density lipoprotein (LDL has been strongly suggested as the key factor in the pathogenesis of atherosclerosis. Mushrooms have been implicated in having preventive effects against chronic diseases due especially to their antioxidant properties. In this study, in vitro inhibitory effect of Hericium erinaceus on LDL oxidation and the activity of the cholesterol biosynthetic key enzyme, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG Co-A reductase, was evaluated using five liquid-liquid solvent fractions consisting of methanol : dichloromethane (M : DCM, hexane (HEX, dichloromethane (DCM, ethyl acetate (EA, and aqueous residue (AQ. The hexane fraction showed the highest inhibition of oxidation of human LDL as reflected by the increased lag time (100 mins for the formation of conjugated diene (CD at 1 µg/mL and decreased production (68.28%, IC50 0.73 mg/mL of thiobarbituric acid reactive substances (TBARS at 1 mg/mL. It also mostly inhibited (59.91% the activity of the HMG Co-A reductase at 10 mg/mL. The GC-MS profiling of the hexane fraction identified the presence of myconutrients: inter alia, ergosterol and linoleic acid. Thus, hexane fraction of Hericium erinaceus was found to be the most potent in vitro inhibitor of both LDL oxidation and HMG Co-A reductase activity having therapeutic potential for the prevention of oxidative stress-mediated vascular diseases.

  7. Inhibitory effect on in vitro LDL oxidation and HMG Co-A reductase activity of the liquid-liquid partitioned fractions of Hericium erinaceus (Bull.) Persoon (lion's mane mushroom).

    Science.gov (United States)

    Rahman, Mohammad Azizur; Abdullah, Noorlidah; Aminudin, Norhaniza

    2014-01-01

    Oxidation of low-density lipoprotein (LDL) has been strongly suggested as the key factor in the pathogenesis of atherosclerosis. Mushrooms have been implicated in having preventive effects against chronic diseases due especially to their antioxidant properties. In this study, in vitro inhibitory effect of Hericium erinaceus on LDL oxidation and the activity of the cholesterol biosynthetic key enzyme, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG Co-A) reductase, was evaluated using five liquid-liquid solvent fractions consisting of methanol : dichloromethane (M : DCM), hexane (HEX), dichloromethane (DCM), ethyl acetate (EA), and aqueous residue (AQ). The hexane fraction showed the highest inhibition of oxidation of human LDL as reflected by the increased lag time (100 mins) for the formation of conjugated diene (CD) at 1 µg/mL and decreased production (68.28%, IC50 0.73 mg/mL) of thiobarbituric acid reactive substances (TBARS) at 1 mg/mL. It also mostly inhibited (59.91%) the activity of the HMG Co-A reductase at 10 mg/mL. The GC-MS profiling of the hexane fraction identified the presence of myconutrients: inter alia, ergosterol and linoleic acid. Thus, hexane fraction of Hericium erinaceus was found to be the most potent in vitro inhibitor of both LDL oxidation and HMG Co-A reductase activity having therapeutic potential for the prevention of oxidative stress-mediated vascular diseases.

  8. Biomass accumulation, photochemical efficiency of photosystem II, nutrient contents and nitrate reductase activity in young rosewood plants (Aniba rosaeodora Ducke submitted to different NO3-:NH4+ ratios Acúmulo de biomassa, eficiência fotoquímica do fotossistema II, conteúdo de nutrientes e atividade da redutase do nitrato em plantas jovens de pau-rosa (Aniba rosaeodora Ducke submetidas a diferentes relações NO3-:NH4+

    Directory of Open Access Journals (Sweden)

    Denize Caranhas de Sousa Barreto

    2007-01-01

    Full Text Available The rosewood (Aniba rosaeodora Ducke is a native tree species of Amazon rainforest growing naturally in acidic forest soils with reduced redox potential. However, this species can also been found growing in forest gaps containing oxide soils. Variations in the forms of mineral nitrogen (NO3- or NH4+ may be predicted in these different edaphic conditions. Considering that possibility, an experiment was carried out to analyze the effects of different NO3-:NH4+ ratios on the growth performance, mineral composition, chloroplastid pigment contents, photochemical efficiency photosystem II (PSII, and nitrate redutase activity (RN, E.C.1.6.6.1 on A. rosaeodora seedlings. Nine-month-old seedlings were grown in pots with a washed sand capacity of 7.5 kg and submitted to different NO3-:NH4+ ratios (T1 = 0:100%, T2 = 25:75%, T3 = 50:50%, T4 = 75:25%, and T5 = 100:0%. The lowest relative growth rate was observed when the NO3-:NH4+ ratio was equal to 0:100%. In general, high concentrations of NO3- rather than NH4+ favored a greater nutrient accumulation in different parts of the plant. For the chloroplastid pigment, the highest Chl a, Chl b, Chl tot, Chl a/b and Chl tot/Cx+c contents were found in the treatment with 75:25% of NO3-:NH4+, and for Chl b and Cx+c it was observed no difference. In addition, there was a higher photochemical efficiency of PSII (Fv/Fm when high NO3- concentrations were used. A linear and positive response for the nitrate reductase activity was recorded when the nitrate content increased on the culture substrate. Our results suggest that A. rosaeodora seedlings have a better growth performance when the NO3- concentrations in the culture substrate were higher than the NH4+ concentrations.O pau-rosa (Aniba rosaeodora Ducke habita, naturalmente, solos florestais ácidos com potencial redox reduzido. No entanto, estas espécies têm sido encontradas também em clareiras que, teoricamente, apresentam solos mais oxidados. Nestas diferentes

  9. A role for 5alpha-reductase activity in the development of male homosexuality?

    Science.gov (United States)

    Alias, A G

    2004-12-01

    Higher body hair with lower mesmorphism ratings were observed in Caucasian homosexual men compared with the general male population, reflecting elevated 5alpha-reductase (5alphaR) activity, and higher dihydrotestosterone-to-testosterone (DHT-to-T) ratio, in sharp contrast to 46,XY 5alphaR 2 deficiency subjects, who are often born with ambiguous, or female genitalia, but tend to grow up to be muscular, heterosexual men with very little body hair, or beard. One study also showed them scoring around dull normal IQs. A greater prevalence of liberal body hair growth in men with higher IQs and/or educational levels was also observed in several samples. The exceptions to this statistical trend are too unsettling, however. Nevertheless, the results of a number of published studies, including one showing higher DHT-to-T ratio in homosexual men, done with different objectives over a span of 80 years, together strongly support these findings. Furthermore, in an animal model, "cognitive-enhancing effects" of "5alpha-reduced androgen [metabolites]" were recently demonstrated.

  10. A genetic screen reveals a periplasmic copper chaperone required for nitrite reductase activity in pathogenic Neisseria.

    Science.gov (United States)

    Jen, Freda E-C; Djoko, Karrera Y; Bent, Stephen J; Day, Christopher J; McEwan, Alastair G; Jennings, Michael P

    2015-09-01

    Under conditions of low oxygen availability, Neisseria meningitidis and Neisseria gonorrhoeae are able to respire via a partial denitrification pathway in which nitrite is converted to nitrous oxide. In this process, nitrite reductase (AniA), a copper (Cu)-containing protein converts nitrite to NO, and this product is converted to nitrous oxide by nitric oxide reductase (NorB). NorB also confers protection against toxic NO, and so we devised a conditional lethal screen, using a norB mutant, to identify mutants that were resistant to nitrite-dependent killing. After random-deletion mutagenesis of N. meningitidis, this genetic screen identified a gene encoding a Cu chaperone that is essential for AniA function, AccA. Purified AccA binds one Cu (I) ion and also possesses a second binding site for Cu (II). This novel periplasmic Cu chaperone (AccA) appears to be essential for provision of Cu ions to AniA of pathogenic Neisseria to generate an active nitrite reductase. Apart from the Neisseria genus, AccA is distributed across a wide range of environmental Proteobacteria species. © FASEB.

  11. Glutathione-dependent extracellular ferric reductase activities in dimorphic zoopathogenic fungi

    Science.gov (United States)

    Zarnowski, Robert; Woods, Jon P.

    2009-01-01

    In this study, extracellular glutathione-dependent ferric reductase (GSH-FeR) activities in different dimorphic zoopathogenic fungal species were characterized. Supernatants from Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis and Sporothrix schenckii strains grown in their yeast form were able to reduce iron enzymically with glutathione as a cofactor. Some variations in the level of reduction were noted amongst the strains. This activity was stable in acidic, neutral and slightly alkaline environments and was inhibited when trivalent aluminium and gallium ions were present. Using zymography, single bands of GSH-FeRs with apparent molecular masses varying from 430 to 460 kDa were identified in all strains. The same molecular mass range was determined by size exclusion chromatography. These data demonstrate that dimorphic zoopathogenic fungi produce and secrete a family of similar GSH-FeRs that may be involved in the acquisition and utilization of iron. Siderophore production by these and other fungi has sometimes been considered to provide a full explanation of iron acquisition in these organisms. Our work reveals an additional common mechanism that may be biologically and pathogenically important. Furthermore, while some characteristics of these enzymes such as extracellular location, cofactor utilization and large size are not individually unique, when considered together and shared across a range of fungi, they represent an important novel physiological feature. PMID:16000713

  12. Development and nitrate reductase activity of sugarcane inoculated with five diazotrophic strains.

    Science.gov (United States)

    Dos Santos, Silvana Gomes; da Silva Ribeiro, Flaviane; da Fonseca, Camila Sousa; Pereira, Willian; Santos, Leandro Azevedo; Reis, Veronica Massena

    2017-08-01

    Diazotrophs are able to stimulate plant growth. This study aimed at evaluating the effect of inoculation of five diazotrophic strains on growth promotion and nitrate reductase (NR, EC 1.7.1.1) activity in sugarcane. An experiment was carried out from three stages of cultivation: sprouting, tubes, and in hydroponics. On the first two stages, seven treatments were adopted: uninoculated control; mixed inoculation with five strains; and individual inoculation with Gluconacetobacter diazotrophicus (Gd), Herbaspirillum rubrisubalbicans (Hr), Herbaspirillum seropedicae (Hs), Nitrospirillum amazonense (Na), and Paraburkholderia tropica (Pt). The four treatments showing the best performance were transferred to the hydroponic system for analysis of NR activity. Hs, Pt, and the mixture of all strains led to the highest seedling biomass in tubes, followed by Hr. In hydroponics, the mixture and the strain Hr had the highest growth-promoting effect. NR activity was influenced by inoculation only under low N supply conditions, with positive effect of Hr, Pt, and the mixture.

  13. In situ assay of nitrate reductase activity using portable water bath

    Science.gov (United States)

    Adam Rajsz; Bronisław Wojtuń; Andrzej Bytnerowicz

    2017-01-01

    In environmental research (i.e., plant ecophysiology, environmental microbiology, and environmental chemistry), some assays require incubation of samples at controlled temperature and darkness. Until now, due to a lack of equipment providing such possibility in situ, researchers had to move collected samples to the laboratory for incubation. Obviously, a delayed...

  14. Mercury resistance and mercuric reductase activities and expression among chemotrophic thermophilic Aquificae.

    Science.gov (United States)

    Freedman, Zachary; Zhu, Chengsheng; Barkay, Tamar

    2012-09-01

    Mercury (Hg) resistance (mer) by the reduction of mercuric to elemental Hg is broadly distributed among the Bacteria and Archaea and plays an important role in Hg detoxification and biogeochemical cycling. MerA is the protein subunit of the homodimeric mercuric reductase (MR) enzyme, the central function of the mer system. MerA sequences in the phylum Aquificae form the deepest-branching lineage in Bayesian phylogenetic reconstructions of all known MerA homologs. We therefore hypothesized that the merA homologs in two thermophilic Aquificae, Hydrogenobaculum sp. strain Y04AAS1 (AAS1) and Hydrogenivirga sp. strain 128-5-R1-1 (R1-1), specified Hg resistance. Results supported this hypothesis, because strains AAS1 and R1-1 (i) were resistant to >10 μM Hg(II), (ii) transformed Hg(II) to Hg(0) during cellular growth, and (iii) possessed Hg-dependent NAD(P)H oxidation activities in crude cell extracts that were optimal at temperatures corresponding with the strains' optimal growth temperatures, 55°C for AAS1 and 70°C for R1-1. While these characteristics all conformed with the mer system paradigm, expression of the Aquificae mer operons was not induced by exposure to Hg(II) as indicated by unity ratios of merA transcripts, normalized to gyrA transcripts for hydrogen-grown AAS1 cultures, and by similar MR specific activities in thiosulfate-grown cultures with and without Hg(II). The Hg(II)-independent expression of mer in the deepest-branching lineage of MerA from bacteria whose natural habitats are Hg-rich geothermal environments suggests that regulated expression of mer was a later innovation likely in environments where microorganisms were intermittently exposed to toxic concentrations of Hg.

  15. NITRITE REDUCTASE ACTIVITY OF NON-SYMBIOTIC HEMOGLOBINS FROM ARABIDOPSIS THALIANA†

    Science.gov (United States)

    Tiso, Mauro; Tejero, Jesús; Kenney, Claire; Frizzell, Sheila; Gladwin, Mark T.

    2013-01-01

    Plant non-symbiotic hemoglobins possess hexa-coordinate heme geometry similar to the heme protein neuroglobin. We recently discovered that deoxygenated neuroglobin converts nitrite to nitric oxide (NO), an important signaling molecule involved in many processes in plants. We sought to determine whether Arabidopsis thaliana non-symbiotic hemoglobins class 1 and 2 (AHb1 and AHb2) might function as nitrite reductases. We found that the reaction of nitrite with deoxygenated AHb1 and AHb2 generates NO gas and iron-nitrosyl-hemoglobin species. The bimolecular rate constants for nitrite reduction to NO are 19.8 ± 3.2 and 4.9 ± 0.2 M−1s−1, at pH = 7.4 and 25°C, respectively. We determined the pH dependence of these bimolecular rate constants and found a linear correlation with the concentration of protons, indicating the requirement for one proton in the reaction. Release of free NO gas during reaction in anoxic and hypoxic (2% oxygen) conditions was confirmed by chemiluminescence detection. These results demonstrate that deoxygenated AHb1 and AHb2 reduce nitrite to form NO via a mechanism analogous to that observed for hemoglobin, myoglobin and neuroglobin. Our findings suggest that during severe hypoxia and in the anaerobic plant roots, especially in water submerged species, non-symbiotic hemoglobins provide a viable pathway for NO generation via nitrite reduction. PMID:22620259

  16. Superoxide radical formation, superoxide dismutase and glutathione reductase activity in the brain of irradiated rats

    International Nuclear Information System (INIS)

    Stanimirovic, D.; Ivanovic, L.; Simovic, M.; Cernak, I.; Savic, J.

    1989-01-01

    In the forebrain cortex, basal ganglia and hippocampus of irradiated rats (whole body, X-ray, 9 Gy), nitroblue-tetrazolium (NBT) reduction was measured as a probe of superoxide radical formation 1 hr, 6 hrs, 24 hrs and 72 hrs after irradiation. Increased superoxide radical formation was found in parallel with increase of superoxide dismutase (SOD) activity and marked decrease of glutathione reductase (GR) activity which is the most pronounced in basal ganglia. The results indicate that in the postradiation period disproportion among free radical production and capacity of brain antioxidative system occurs. This disbalance is more expressed in the brain regions known as selective vulnerable (basal ganglia, hippocampus). (author). 10 refs.; 2 tabs

  17. Possible inhibition of hydroxy methyl glutaryl CoA reductase activity ...

    African Journals Online (AJOL)

    ). 3. Bioactive Natural Products Research Group. 4. Production of bio-products for industrial applications Research group, .... enized using glass homogenizer. The homogenate was centrifuged for 10 min at 12,000 g to remove mito- chondria.

  18. Consequence of absence of nitrate reductase activity on photosynthesis in Nicotiana plumbaginifolia plants

    International Nuclear Information System (INIS)

    Saux, C.; Lemoine, Y.; Marion-Poll, A.; Valadier, M.H.; Deng, M.; Morot-Gaudry, J.F.

    1987-01-01

    Chlorate-resistant Nicotiana plumbaginifolia (cv Viviani) mutants were found to be deficient in the nitrate reductase apoprotein (NR - nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild-type Nicotiana tabacum plants. The grafts of mutant plants were chlorotic compared to the grafts of wild type. Mutant leaves did not accumulate nitrogen but contained less malate and more glutamine than wild leaves. They exhibited a slight increase of the proportion of the light-harvesting chlorophyll a/b protein complexes and a lowering of the efficiency of energy transfer between these complexes and the active centers. After a 3 second 14 CO 2 pulse, the total 14 C incorporation of the mutant leaves was approximately 20 5 of that of the control. The 14 C was essentially recovered in ribulose bisphosphate in these plants. It was consistent with a decline of ribulose bisphosphate carboxylase activity observed in the mutant. After a 3 second 14 CO 2 pulse followed by a 60 second chase with normal CO 2 , 14 C was mainly accumulated in starch which was labeled more in the mutant than in the wild type. These results confirm the observation that in the nitrate reductase deficient leaves, chloroplasts were loaded with large starch inclusions preceding disorganization of the photosynthetic apparatus

  19. Consequence of absence of nitrate reductase activity on photosynthesis in Nicotiana plumbaginifolia plants

    Energy Technology Data Exchange (ETDEWEB)

    Saux, C.; Lemoine, Y.; Marion-Poll, A.; Valadier, M.H.; Deng, M.; Morot-Gaudry, J.F.

    1987-05-01

    Chlorate-resistant Nicotiana plumbaginifolia (cv Viviani) mutants were found to be deficient in the nitrate reductase apoprotein (NR/sup -/ nia). Because they could not grow with nitrate as sole nitrogen source, they were cultivated as graftings on wild-type Nicotiana tabacum plants. The grafts of mutant plants were chlorotic compared to the grafts of wild type. Mutant leaves did not accumulate nitrogen but contained less malate and more glutamine than wild leaves. They exhibited a slight increase of the proportion of the light-harvesting chlorophyll a/b protein complexes and a lowering of the efficiency of energy transfer between these complexes and the active centers. After a 3 second /sup 14/CO/sub 2/ pulse, the total /sup 14/C incorporation of the mutant leaves was approximately 20/sup 5/ of that of the control. The /sup 14/C was essentially recovered in ribulose bisphosphate in these plants. It was consistent with a decline of ribulose bisphosphate carboxylase activity observed in the mutant. After a 3 second /sup 14/CO/sub 2/ pulse followed by a 60 second chase with normal CO/sub 2/, /sup 14/C was mainly accumulated in starch which was labeled more in the mutant than in the wild type. These results confirm the observation that in the nitrate reductase deficient leaves, chloroplasts were loaded with large starch inclusions preceding disorganization of the photosynthetic apparatus.

  20. Exogenous Methyl Jasmonate Treatment Increases Glucosinolate Biosynthesis and Quinone Reductase Activity in Kale Leaf Tissue

    Science.gov (United States)

    Ku, Kang-Mo; Jeffery, Elizabeth H.; Juvik, John A.

    2014-01-01

    Methyl jasmonate (MeJA) spray treatments were applied to the kale varieties ‘Dwarf Blue Curled Vates’ and ‘Red Winter’ in replicated field plantings in 2010 and 2011 to investigate alteration of glucosinolate (GS) composition in harvested leaf tissue. Aqueous solutions of 250 µM MeJA were sprayed to saturation on aerial plant tissues four days prior to harvest at commercial maturity. The MeJA treatment significantly increased gluconasturtiin (56%), glucobrassicin (98%), and neoglucobrassicin (150%) concentrations in the apical leaf tissue of these genotypes over two seasons. Induction of quinone reductase (QR) activity, a biomarker for anti-carcinogenesis, was significantly increased by the extracts from the leaf tissue of these two cultivars. Extracts of apical leaf tissues had greater MeJA mediated increases in phenolics, glucosinolate concentrations, GS hydrolysis products, and QR activity than extracts from basal leaf tissue samples. The concentration of the hydrolysis product of glucoraphanin, sulforphane was significantly increased in apical leaf tissue of the cultivar ‘Red Winter’ in both 2010 and 2011. There was interaction between exogenous MeJA treatment and environmental conditions to induce endogenous JA. Correlation analysis revealed that indole-3-carbanol (I3C) generated from the hydrolysis of glucobrassicin significantly correlated with QR activity (r = 0.800, Pkale leaf tissues of both cultivars in 2011. Correlation analysis of these results indicated that sulforaphane, NI3C, neoascorbigen, I3C, and diindolylmethane were all significantly correlated with QR activity. Thus, increased QR activity may be due to combined increases in phenolics (quercetin and kaempferol) and GS hydrolysis product concentrations rather than by individual products alone. PMID:25084454

  1. Inhibitory effect of rhetsinine isolated from Evodia rutaecarpa on aldose reductase activity.

    Science.gov (United States)

    Kato, A; Yasuko, H; Goto, H; Hollinshead, J; Nash, R J; Adachi, I

    2009-03-01

    Aldose reductase inhibitors have considerable potential for the treatment of diabetic complications, without increased risk of hypoglycemia. Search for components inhibiting aldose reductase led to the discovery of active compounds contained in Evodia rutaecarpa Bentham (Rutaceae), which is the one of the component of Kampo-herbal medicine. The hot water extract from the E. rutaecarpa was subjected to distribution or gel filtration chromatography to give an active compound, N2-(2-methylaminobenzoyl)tetrahydro-1H-pyrido[3,4-b]indol-1-one (rhetsinine). It inhibited aldose reductase with IC(50) values of 24.1 microM. Furthermore, rhetsinine inhibited sorbitol accumulation by 79.3% at 100 microM. These results suggested that the E. rutaecarpa derived component, rhetsinine, would be potentially useful in the treatment of diabetic complications.

  2. Identification of fungal ene-reductase activity by means of a functional screening.

    Science.gov (United States)

    Romagnolo, Alice; Spina, Federica; Brenna, Elisabetta; Crotti, Michele; Parmeggiani, Fabio; Varese, Giovanna Cristina

    2015-06-01

    Bioeconomy stresses the need of green processes promoting the development of new methods for biocatalyzed alkene reductions. A functional screening of 28 fungi belonging to Ascomycota, Basidiomycota, and Zygomycota isolated from different habitats was performed to analyze their capability to reduce C=C double bonds towards three substrates (cyclohexenone, α-methylnitrostyrene, and α-methylcinnamaldehyde) with different electron-withdrawing groups, i.e., ketone, nitro, and aldehyde, respectively. Almost all the fungi showed this reducing activity. Noteworthy Gliomastix masseei, Mucor circinelloides, and Mucor plumbeus resulted versatile and effective, being able to reduce all the model substrates quickly and with high yields. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  3. Requirement of histidine 217 for ubiquinone reductase activity (Qi site) in the cytochrome bc1 complex.

    Science.gov (United States)

    Gray, K A; Dutton, P L; Daldal, F

    1994-01-25

    Folding models suggest that the highly conserved histidine 217 of the cytochrome b subunit from the cytochrome bc1 complex is close to the quinone reductase (Qi) site. This histidine (bH217) in the cytochrome b polypeptide of the photosynthetic bacterium Rhodobacter capsulatus has been replaced with three other residues, aspartate (D), arginine (R), and leucine (L). bH217D and bH217R are able to grow photoheterotrophically and contain active cytochrome bc1 complexes (60% of wild-type activity), whereas the bH217L mutant is photosynthetically incompetent and contains a cytochrome bc1 complex that has only 10% of the wild-type activity. Single-turnover flash-activated electron transfer experiments show that cytochrome bH is reduced via the Qo site with near native rates in the mutant strains but that electron transfer between cytochrome bH and quinone bound at the Qi site is greatly slowed. These results are consistent with redox midpoint potential (Em) measurements of the cytochrome b subunit hemes and the Qi site quinone. The Em values of cyt bL and bH are approximately the same in the mutants and wild type, although the mutant strains have a larger relative concentration of what may be the high-potential form of cytochrome bH, called cytochrome b150. However, the redox properties of the semiquinone at the Qi site are altered significantly. The Qi site semiquinone stability constant of bH217R is 10 times higher than in the wild type, while in the other two strains (bH217D and bH217L) the stability constant is much lower than in the wild type. Thus H217 appears to have major effects on the redox properties of the quinone bound at the Qi site. These data are incorporated into a suggestion that H217 forms part of the binding pocket of the Qi site in a manner reminiscent of the interaction between quinone bound at the Qb site and H190 of the L subunit of the bacterial photosynthetic reaction center.

  4. Syringic Acid Extracted from Herba dendrobii Prevents Diabetic Cataract Pathogenesis by Inhibiting Aldose Reductase Activity

    Directory of Open Access Journals (Sweden)

    Xiaoyong Wei

    2012-01-01

    Full Text Available Objective. Effects of Syringic acid (SA extracted from dendrobii on diabetic cataract (DC pathogenesis were explored. Methods. Both in vitro and in vivo DC lens models were established using D-gal, and proliferation of HLEC exposed to SA was determined by MMT assay. After 60-day treatment with SA, rat lens transparency was observed by anatomical microscopy using a slit lamp. SA protein targets were extracted and isolated using 2-DE and MALDI TOF/TOF. AR gene expression was investigated using qRT-PCR. Interaction sites and binding characteristics were determined by molecule-docking techniques and dynamic models. Results. Targeting AR, SA provided protection from D-gal-induced damage by consistently maintaining lens transparency and delaying lens turbidity development. Inhibition of AR gene expression by SA was confirmed by qRT-PCR. IC50 of SA for inhibition of AR activity was 213.17 μg/mL. AR-SA binding sites were Trp111, His110, Tyr48, Trp20, Trp79, Leu300, and Phe122. The main binding modes involved hydrophobic interactions and hydrogen bonding. The stoichiometric ratio of non-covalent bonding between SA and AR was 1.0 to 13.3. Conclusion. SA acts to prevent DC in rat lenses by inhibiting AR activity and gene expression, which has potential to be developed into a novel drug for therapeutic management of DC.

  5. An Interbacterial NAD(P)+ Glycohydrolase Toxin Requires Elongation Factor Tu for Delivery to Target Cells

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, John C.; Quentin, Dennis; Sawai, Shin; LeRoux, Michele; Harding, Brittany N.; Ledvina, Hannah E.; Tran, Bao Q.; Robinson, Howard; Goo, Young Ah; Goodlett, David R.; Raunser, Stefan; Mougous, Joseph D.

    2015-10-08

    Type VI secretion (T6S) influences the composition of microbial communities by catalyzing the delivery of toxins between adjacent bacterial cells. Here, we demonstrate that a T6S integral membrane toxin from Pseudomonas aeruginosa, Tse6, acts on target cells by degrading the universally essential dinucleotides NAD+ and NADP+. Structural analyses of Tse6 show that it resembles mono-ADP-ribosyltransferase proteins, such as diphtheria toxin, with the exception of a unique loop that both excludes proteinaceous ADP-ribose acceptors and contributes to hydrolysis. We find that entry of Tse6 into target cells requires its binding to an essential housekeeping protein, translation elongation factor Tu (EF-Tu). These proteins participate in a larger assembly that additionally directs toxin export and provides chaperone activity. Visualization of this complex by electron microscopy defines the architecture of a toxin-loaded T6S apparatus and provides mechanistic insight into intercellular membrane protein delivery between bacteria.

  6. HiPIP oxido-reductase activity in membranes from aerobically grown cells of the facultative phototroph Rhodoferax fermentans

    DEFF Research Database (Denmark)

    Hochkoeppler, Alejandro; Kofod, Pauli; Zannoni, Davide

    1995-01-01

    The role of the periplasmically located, water-soluble, HiPIP (high-potential iron-sulfur protein) in the respiratory chain of the facultative phototroph Rhodoferax fermentans has been examined. The oxidized HiPIP is reduced by succinate-dependent respiration via the bc 1 complex, this reaction...... being inhibited by myxothiazol and/or stigmatellin. The reduced HiPIP can be oxidized by the membrane-bound cytochrome oxidase, this reaction being inhibited by 0.1 mM cyanide. We conclude that aerobically grown Rf. fermentans contains a redox chain in which HiPIP mediates electron transfer between...... the bc 1 complex and the cb-type cytochrome oxidase....

  7. Methylenetetrahydrofolate Reductase Activity Is Involved in the Plasma Membrane Redox System Required for Pigment Biosynthesis in Filamentous Fungi

    DEFF Research Database (Denmark)

    Frandsen, Rasmus John Normand; Albertsen, K.S.; Stougaard, P.

    2010-01-01

    be rescued by exogenous methionine. The F. graminearum strain with a mutation of MET12 (Fg Delta MET12) displayed a delay in the production of the mycelium pigment aurofusarin and instead accumulated norrubrofusarin and rubrofusarin. High methionine concentrations or prolonged incubation eventually led...... to production of aurofusarin in the MET12 mutant. This suggested that the chemotype was caused by a lack of SAM units for the methylation of nor-rubrofusarin to yield rubrofusarin, thereby imposing a rate-limiting step in aurofusarin biosynthesis. The Fg Delta MET13 mutant, however, remained aurofusarin...... are the first to show that MET13, in addition to its function in methionine biosynthesis, is required for the generation of the extracellular reduction potential necessary for pigment production in filamentous fungi....

  8. Correlation of quinone reductase activity and allyl isothiocyanate formation among different genotypes and grades of horseradish roots.

    Science.gov (United States)

    Ku, Kang-Mo; Jeffery, Elizabeth H; Juvik, John A; Kushad, Mosbah M

    2015-03-25

    Horseradish (Armoracia rusticana) is a perennial crop and its ground root tissue is used in condiments because of the pungency of the glucosinolate (GS)-hydrolysis products allyl isothiocyanate (AITC) and phenethyl isothiocyanate (PEITC) derived from sinigrin and gluconasturtiin, respectively. Horseradish roots are sold in three grades: U.S. Fancy, U.S. No. 1, and U.S. No. 2 according to the USDA standards. These grading standards are primarily based on root diameter and length. There is little information on whether root grades vary in their phytochemical content or potential health promoting properties. This study measured GS, GS-hydrolysis products, potential anticancer activity (as quinone reductase inducing activity), total phenolic content, and antioxidant activities from different grades of horseradish accessions. U.S. Fancy showed significantly higher sinigrin and AITC concentrations than U.S. No. 1 ,whereas U.S. No. 1 showed significantly higher concentrations of 1-cyano 2,3-epithiopropane, the epithionitrile hydrolysis product of sinigrin, and significantly higher total phenolic concentrations than U.S. Fancy.

  9. Positive correlation between decreased cellular uptake, NADPH-glutathione reductase activity and adriamycin resistance in Ehrlich ascites tumor lines.

    Science.gov (United States)

    Scheulen, M E; Hoensch, H; Kappus, H; Seeber, S; Schmidt, C G

    1987-01-01

    From a wild type strain of Ehrlich ascites tumor (EATWT) sublines resistant to daunorubicin (EATDNM), etoposide (EATETO), and cisplatinum (EATCIS) have been developed in vivo. Increase in survival and cure rate caused by adriamycin (doxorubicin) have been determined in female NMRI mice which were inoculated i.p. with EAT cells. Adriamycin concentrations causing 50% inhibition of 3H-thymidine (ICT) and 3H-uridine incorporation (ICU) and intracellular adriamycin steady-state concentrations (SSC) were measured in vitro. Adriamycin resistance increased and SSC decreased in the following sequence: EATWT - EATCIS - EATDNM - EATETO. When ICT and ICU were corrected for intracellular adriamycin concentrations in consideration of the different SSC (ICTc, ICUc), ICTc and ICUc still varied up to the 3.2 fold in EATCIS, EATDNM and EATETO in comparison to EATWT. Thus, in addition to different SSC other factors must be responsible for adriamycin resistance. Therefore, enzymes which may play a role in the cytotoxicity related to adriamycin metabolism (NADPH-cytochrome P-450 reductase, NADPH-glutathione reductase, NADP-glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) were measured. In contrast to the other parameters determined, NADPH-glutathione reductase was significantly (p less than 0.01) increased up to the 3.2 fold parallel to adriamycin resistance as determined by increase in life span, cure rate, ICTc, and ICUc, respectively. It is concluded that high activities of NADPH-glutathione reductase may contribute to an increase in adriamycin resistance of malignant tumors.

  10. The effect of water stress on nitrate reductase activity and nitrogen and phosphorus contents in cuminum cyminum l

    Energy Technology Data Exchange (ETDEWEB)

    Sepehr, M F [Islamic Azad University, Saveh (Iran, Islamic Republic of). Dept. of Biology; Amini, F [Tehran Shomal Branch Islamic Azad University, Tehran (Iran, Islamic Republic of). Dept. of Biology

    2012-06-15

    Cumin (Cuminum cyminum L.) is a plant with great medicinal importance cultivated in many regions such as Iran, India, Indonesia, Afghanistan, Pakistan, Lebanon, Syria and Turkey. In this research, nitrogen and phosphorus concentrations and nitrate reductase enzyme activity were studied in cumin under flooding stress. Cumin plants were cultivated in pots containing garden soil (in 1 cm depth, 15 -20 degree C, 14 h light and 10 h darkness). Germination took place after 2 weeks. Flooding stress was applied 6 weeks after germination on a number of pots according to their field capacity (FC) (2, 3, and 4 fold) for 1 week; a number of pots were also considered as controls with field capacity. Plants were then harvested and chemical analysis of the factors under study was done using roots and shoots of the plants exposed to flooding conditions and the control plants. The experiment had a completely randomized design in which four levels of water in the soil (2FC, 3FC, 4FC) were compared. Analysis of variance was carried out using SPSS software and means were compared by Duncan's test at [ greater or equal to = 0.05 significance level. The results showed that in comparison with control plants, nitrogen and phosphorus concentrations were significantly lower in both shoots and roots of flooded plants. This decrease was more pronounced in treated plants exposed to 4 X field capacity conditions. Nitrogen concentration in roots and shoots of treated plants showed a significant decrease in comparison with control plants and this was more noticeable in treated plants exposed to 4 X field capacity conditions. Moreover, concentration of nitrite produced from nitrate reduction catalyzed by nitrate reductase enzyme in roots and shoots of treated plants had a significant increase in comparison with control plants. Treated plants exposed to 4 X field capacity conditions showed the most increase. Also the study showed that cumin seeds could survive in flooding environment for 14 days. Thus, flooding stress in cumin seeds decreased nitrogen and phosphorus concentrations in roots and shoots. This stress increased the activity of nitrate reductase enzyme in both roots and shoots. (author)

  11. The effect of water stress on nitrate reductase activity and nitrogen and phosphorus contents in cuminum cyminum l

    International Nuclear Information System (INIS)

    Sepehr, M.F.; Amini, F.

    2012-01-01

    Cumin (Cuminum cyminum L.) is a plant with great medicinal importance cultivated in many regions such as Iran, India, Indonesia, Afghanistan, Pakistan, Lebanon, Syria and Turkey. In this research, nitrogen and phosphorus concentrations and nitrate reductase enzyme activity were studied in cumin under flooding stress. Cumin plants were cultivated in pots containing garden soil (in 1 cm depth, 15 -20 degree C, 14 h light and 10 h darkness). Germination took place after 2 weeks. Flooding stress was applied 6 weeks after germination on a number of pots according to their field capacity (FC) (2, 3, and 4 fold) for 1 week; a number of pots were also considered as controls with field capacity. Plants were then harvested and chemical analysis of the factors under study was done using roots and shoots of the plants exposed to flooding conditions and the control plants. The experiment had a completely randomized design in which four levels of water in the soil (2FC, 3FC, 4FC) were compared. Analysis of variance was carried out using SPSS software and means were compared by Duncan's test at [ greater or equal to = 0.05 significance level. The results showed that in comparison with control plants, nitrogen and phosphorus concentrations were significantly lower in both shoots and roots of flooded plants. This decrease was more pronounced in treated plants exposed to 4 X field capacity conditions. Nitrogen concentration in roots and shoots of treated plants showed a significant decrease in comparison with control plants and this was more noticeable in treated plants exposed to 4 X field capacity conditions. Moreover, concentration of nitrite produced from nitrate reduction catalyzed by nitrate reductase enzyme in roots and shoots of treated plants had a significant increase in comparison with control plants. Treated plants exposed to 4 X field capacity conditions showed the most increase. Also the study showed that cumin seeds could survive in flooding environment for 14 days. Thus, flooding stress in cumin seeds decreased nitrogen and phosphorus concentrations in roots and shoots. This stress increased the activity of nitrate reductase enzyme in both roots and shoots. (author)

  12. Post-translational control of nitrate reductase activity responding to light and photosynthesis evolved already in the early vascular plants.

    Science.gov (United States)

    Nemie-Feyissa, Dugassa; Królicka, Adriana; Førland, Nina; Hansen, Margarita; Heidari, Behzad; Lillo, Cathrine

    2013-05-01

    Regulation of nitrate reductase (NR) by reversible phosphorylation at a conserved motif is well established in higher plants, and enables regulation of NR in response to rapid fluctuations in light intensity. This regulation is not conserved in algae NR, and we wished to test the evolutionary origin of the regulatory mechanism by physiological examination of ancient land plants. Especially a member of the lycophytes is of interest since their NR is candidate for regulation by reversible phosphorylation based on sequence analysis. We compared Selaginella kraussiana, a member of the lycophytes and earliest vascular plants, with the angiosperm Arabidopsis thaliana, and also tested the moss Physcomitrella patens. Interestingly, optimization of assay conditions revealed that S. kraussiana NR used NADH as an electron donor like A. thaliana, whereas P. patens NR activity depended on NADPH. Examination of light/darkness effects showed that S. kraussiana NR was rapidly regulated similar to A. thaliana NR when a differential (Mg(2+) contra EDTA) assay was used to reveal activity state of NR. This implies that already existing NR enzyme was post-translationally activated by light in both species. Light had a positive effect also on de novo synthesis of NR in S. kraussiana, which could be shown after the plants had been exposed to a prolonged dark period (7 days). Daily variations in NR activity were mainly caused by post-translational modifications. As for angiosperms, the post-translational light activation of NR in S. kraussiana was inhibited by 3-(3,4-dichlorophenyl)-1*1-dimethylurea (DCMU), an inhibitor of photosynthesis and stomata opening. Evolutionary, a post-translational control mechanism for NR have occurred before or in parallel with development of vascular tissue in land plants, and appears to be part of a complex mechanisms for coordination of CO2 and nitrogen metabolism in these plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  13. Effect of cephalandra indica against advanced glycation end products, sorbitol accumulation and aldose reductase activity in homoeopathic formulation

    Directory of Open Access Journals (Sweden)

    Lalit Kishore

    2018-01-01

    Full Text Available Background: Extreme generation of free radicals leads to oxidative stress which has been apprehensive in several disease processes such as diabetic complications and vascular and neurodegenerative diseases. Objective: The present study was designed to evaluate the potential of homoeopathic preparations of Cephalandra indica L. against oxidative stress. Materials and Methods: Potencies of Cephalandra indica (mother tincture, 6C and 30C were procured from Dr. Willmar Schwabe India Pvt. Ltd. The antioxidant activity of Cephalandra indica was evaluated by employing various in vitro antioxidant methods. Results: The total phenol content was found to be 1905, 849 and 495 mg/g gallic acid equivalents in mother tincture, 6C and 30C of Cephalandra indica and total antioxidant capacity was found to be 2710, 759 and 510 μM/g ascorbic acid equivalents, respectively. Mother tincture, 6C and 30C of Cephalandra indica was found to have strong reducing power, 2,2-diphenyl-1-picrylhydrazyl radical, hydrogen peroxide, nitric oxide and superoxide radical scavenging activity. Percentage inhibition of AGEs formation by mother tincture, 6C and 30C of Cephalandra indica (10–50 μl was found to be 30.34%–91.77%, 29.98%–65.71% and 33.05%–57.75%, respectively. Mother tincture, 6C and 30C of Cephalandra indica showed inhibitory effect against sorbitol accumulation with IC50value of 26.12 μl, 203.10 μl and 897.3 μl, respectively, whereas, in aldose reductase inhibition assay, the IC50value was 32.54 μl, 175.02 μl and 834.34 μl, respectively. Conclusion: The results revealed that homoeopathic preparations of Cephalandra indica exhibit protective effect against oxidative stress.

  14. Do Fanconi anemia genes control cell response to cross-linking agents by modulating cytochrome P-450 reductase activity?

    NARCIS (Netherlands)

    Kruyt, FAE; Youssoufian, H

    2000-01-01

    The Fanconi anemia (FA) genes play an important role in maintaining chromosomal stability and the defense of mammalian cells against cross-linking agents, such as cisplatin and mitomycin C (MMC). Cells derived from FA patients display a characteristic hypersensitivity toward cross-linking agents.

  15. Overexpression of Nitrate Reductase in Tobacco Delays Drought-Induced Decreases in Nitrate Reductase Activity and mRNA1

    Science.gov (United States)

    Ferrario-Méry, Sylvie; Valadier, Marie-Hélène; Foyer, Christine H.

    1998-01-01

    Transformed (cauliflower mosaic virus 35S promoter [35S]) tobacco (Nicotiana plumbaginifolia L.) plants constitutively expressing nitrate reductase (NR) and untransformed controls were subjected to drought for 5 d. Drought-induced changes in biomass accumulation and photosynthesis were comparable in both lines of plants. After 4 d of water deprivation, a large increase in the ratio of shoot dry weight to fresh weight was observed, together with a decrease in the rate of photosynthetic CO2 assimilation. Foliar sucrose increased in both lines during water stress, but hexoses increased only in leaves from untransformed controls. Foliar NO3− decreased rapidly in both lines and was halved within 2 d of the onset of water deprivation. Total foliar amino acids decreased in leaves of both lines following water deprivation. After 4 d of water deprivation no NR activity could be detected in leaves of untransformed plants, whereas about 50% of the original activity remained in the leaves of the 35S-NR transformants. NR mRNA was much more stable than NR activity. NR mRNA abundance increased in the leaves of the 35S-NR plants and remained constant in controls for the first 3 d of drought. On the 4th d, however, NR mRNA suddenly decreased in both lines. Rehydration at d 3 caused rapid recovery (within 24 h) of 35S-NR transcripts, but no recovery was observed in the controls. The phosphorylation state of the protein was unchanged by long-term drought. There was a strong correlation between maximal extractable NR activity and ambient photosynthesis in both lines. We conclude that drought first causes increased NR protein turnover and then accelerates NR mRNA turnover. Constitutive NR expression temporarily delayed drought-induced losses in NR activity. 35S-NR expression may therefore allow more rapid recovery of N assimilation following short-term water deficit. PMID:9576799

  16. Variation of glucosinolates and quinone reductase activity among different varieties of Chinese kale and improvement of glucoraphanin by metabolic engineering.

    Science.gov (United States)

    Qian, Hongmei; Sun, Bo; Miao, Huiying; Cai, Congxi; Xu, Chaojiong; Wang, Qiaomei

    2015-02-01

    The variation of glucosinolates and quinone reductase (QR) activity in fourteen varieties of Chinese kale (Brassica oleracea var. alboglabra Bailey) was investigated in the present study. Results showed that gluconapin (GNA), instead of glucoraphanin (GRA), was the most predominant glucosinolate in all varieties, and QR activity was remarkably positively correlated with the glucoraphanin level. AOP2, a tandem 2-oxoglutarate-dependent dioxygenase, catalyzes the conversion of glucoraphanin to gluconapin in glucosinolate biosynthesis. Here, antisense AOP2 was transformed into Gailan-04, the variety with the highest gluconapin content and ratio of GNA/GRA. The glucoraphanin content and corresponding QR activity were notably increased in transgenic plants, while no significant difference at the level of other main nutritional compounds (total phenolics, vitamin C, carotenoids and chlorophyll) was observed between the transgenic lines and the wide-type plants. Taken together, metabolic engineering is a good practice for improvement of glucoraphanin in Chinese kale. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Kinetic assays for determining in vitro APS reductase activity in plants without the use of radioactive substances.

    Science.gov (United States)

    Brychkova, Galina; Yarmolinsky, Dmitry; Sagi, Moshe

    2012-09-01

    Adenosine 5'-phosphosulfate (APS) reductase (APR; EC 1.8.4.9) catalyzes the two-electron reduction of APS to sulfite and AMP, a key step in the sulfate assimilation pathway in higher plants. In spite of the importance of this enzyme, methods currently available for detection of APR activity rely on radioactive labeling and can only be performed in a very few specially equipped laboratories. Here we present two novel kinetic assays for detecting in vitro APR activity that do not require radioactive labeling. In the first assay, APS is used as substrate and reduced glutathione (GSH) as electron donor, while in the second assay APS is replaced by an APS-regenerating system in which ATP sulfurylase catalyzes APS in the reaction medium, which employs sulfate and ATP as substrates. Both kinetic assays rely on fuchsin colorimetric detection of sulfite, the final product of APR activity. Incubation of the desalted protein extract, prior to assay initiation, with tungstate that inhibits the oxidation of sulfite by sulfite oxidase activity, resulted in enhancement of the actual APR activity. The reliability of the two methods was confirmed by assaying leaf extract from Arabidopsis wild-type and APR mutants with impaired or overexpressed APR2 protein, the former lacking APR activity and the latter exhibiting much higher activity than the wild type. The assays were further tested on tomato leaves, which revealed a higher APR activity than Arabidopsis. The proposed APR assays are highly specific, technically simple and readily performed in any laboratory.

  18. [Effects of nitrogen application rate on nitrate reductase activity, nitric oxide content and gas exchange in winter wheat leaves].

    Science.gov (United States)

    Shangguan, Zhou-Ping

    2007-07-01

    In this paper, the effects of different nitrogen application rates on the nitrate reductase (NR) activity, nitric oxide (NO) content and gas exchange parameters in winter wheat (Triticum aestivum L.) leaves from tillering stage to heading stage and on grain yield were studied. The results showed that the photosynthetic rate (P(n)), transpiration rate (T(r)) and instantaneous water use efficiency (IWUE) of leaves as well as the grain yield were increased with increasing nitrogen application rate first but decreased then, with the values of all these parameters reached the highest in treatment N180. The NR activity increased with increasing nitrogen application rate, and there was a significant linear correlation between NR activity and NO content at tillering and jointing stages (R2 > or = 0.68, n = 15). NO content had a quadratic positive correlation with stomatal conductance (G(s)) (R2 > or = 0.43, n = 15). The lower NO content produced by lower NR activity under lower nitrogen application rate promoted the stoma opened, while the higher NO content produced by higher NR activity under higher nitrogen application rate induced the stoma closed. Although the leaf NO content had a quadratic positive correlation with stomatal conductance (R2 > or = 0.36, n = 15), no remarkable correlation was observed between NR activity and NO content at heading stage, suggesting that nitrogen fertilization could not affect leaf NO content through promoting NR activity, and further more, regulate the stomatal action. Under appropriate nitrogen application the leaf NR activity and NO content were lower, G(s), T(r) and IWUE were higher, and thus, the crop had a better drought-resistant ability, higher P(n), and higher grain yield.

  19. QTL mapping for quinone reductase activity in broccoli with Hepa1c1c7 cell lines

    Science.gov (United States)

    Floret tissue from 125 F2:3 broccoli families derived from the cross 'VI-158 x Brocolette Neri E. Cespuglio (BNC)' was harvested in 2009. Tissue was freeze-dried and stored in the dark at -80 until use. Distilled water was added to floret tissue (50 mg/mL) and auto-hydrolyzed for 24 hours in room te...

  20. Nitrogenase and nitrate reductase activities in young Alnus glutinosa, relationship and effect of light-dark treatments

    International Nuclear Information System (INIS)

    Benamar, S.; Thiery, G.; Pizelle, G.

    1995-01-01

    Relations between in vivo nitrogenase (N-2-ase; EC 1.18.6.1) and nitrate reductase (NR; EC 1.6.6.1) activities were studied in young nodulated Alnus glutinosa (L. ) Gaertn. Positive correlations linked N-2-ase activity, constitutive (non-inducible by nitrate) leaf NR activity and plant growth. Light/dark treatments applied to the whole shoot or, separately, to the upper and lower part of shoot led to the finding that(a) the constitutive leaf NR activity depended on direct illumination of the leaf and did not appear subordinate to the N-2-ase activity; (b) the N-2-ase activity was much more efficiently supported by the illumination of the upper (young) leaves than by that of the lower (mature) leaves; (c) the maintenance of nitrate-inducible root NR activity required leaf illumination. The variations of both N-2-ase and root NR activities in response to light/dark treatments emphasize the importance of the photosynthesis for the reduction of dinitrogen and nitrate in nodulated roots of Alnus glutinosa

  1. Thioredoxin Reductase Activity may be More Important than GSH Level in Protecting Human Lens Epithelial Cells Against UVA Light

    Science.gov (United States)

    Padgaonkar, Vanita A.; Leverenz, Victor R.; Bhat, Aparna V.; Pelliccia, Sara E.; Giblin, Frank J.

    2014-01-01

    This study compares the abilities of the glutathione (GSH) and thioredoxin (Trx) antioxidant systems in defending cultured human lens epithelial cells (LECs) against UVA light. Levels of GSH were depleted with either L-buthionine-(S,R)-sulfoximine (BSO) or 1-chloro-2,4-dinitrobenzene (CDNB). CDNB treatment also inhibited the activity of thioredoxin reductase (TrxR). Two levels of O2, 3% and 20%, were employed during a 1 hr exposure of the cells to 25 J/cm2 of UVA radiation (338-400nm wavelength, peak at 365nm). Inhibition of TrxR activity by CDNB, combined with exposure to UVA light, produced a substantial loss of LECs and cell damage, with the effects being considerably more severe at 20% O2 compared to 3%. In contrast, depletion of GSH by BSO, combined with exposure to UVA light, produced only a slight cell loss, with no apparent morphological effects. Catalase was highly sensitive to UVA-induced inactivation, but was not essential for protection. Although UVA light presented a challenge for the lens epithelium, it was well-tolerated under normal conditions. The results demonstrate an important role for TrxR activity in defending the lens epithelium against UVA light, possibly related to the ability of the Trx system to assist DNA synthesis following UVA-induced cell damage. PMID:25495870

  2. Ebselen: A substrate for human thioredoxin reductase strongly stimulating its hydroperoxide reductase activity and a superfast thioredoxin oxidant

    OpenAIRE

    Zhao, Rong; Masayasu, Hiroyuki; Holmgren, Arne

    2002-01-01

    Ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], a seleno-organic compound with glutathione peroxidase-like activity is used in clinical trials against stroke. Human and bovine TrxR catalyzed the reduction of ebselen to ebselen selenol by NADPH with an apparent KM-value of 2.5 μM and a kcat of 588 min−1. The addition of thioredoxin (Trx) stimulated the TrxR-catalyzed reduction of ebselen several-fold. This result was caused by a very fast oxidation of reduced Trx by ebselen with a rate cons...

  3. Reduced glutathione concentration and glutathione reductase activity in various rat tissues after the administration of some radioprotective agents

    International Nuclear Information System (INIS)

    Pulpanova, J.; Kovarova, H.; Ledvina, M.

    1982-01-01

    The concentrations of reduced glutathione (GSH) and activity of glutathione reductase were investigated in rat liver, kidney and spleen after intraperitoneal administration of cystamine (50 mg/kg), mexamine (10 mg/kg), or a mixture of cystamine with mexamine (20 + 10 mg/kg). The GSH concentration increased after the administration of cystamine in the liver (maximum between the 20th and 30th min), in the kidney and spleen (maximum after 60 min). The cystamine + mexamine mixture also caused a significant increase of the GSH concentration in all the organs investigated; however, the values increased at earlier intervals as after the cystamine administration. No substantial effect was shown in the case of the mexamine administration, only 30 min after the administration the values were higher. The activity of glutathione reductase was significantly lower over the entire period examined. This was found in the liver and kidney as after the administration of cystamine, as after the radioprotective mixture. There was also a less pronounced inhibition of the enzyme activity in the spleen. Mexamine as a single radioprotector had practically no influence on the activity. (author)

  4. Clone-Specific Response in Leaf Nitrate Reductase Activity among Unrelated Hybrid Poplars in relation to Soil Nitrate Availability

    Directory of Open Access Journals (Sweden)

    Julien Fortier

    2012-01-01

    Full Text Available In this field study, we used in vivo NRA activity in hybrid poplar leaves as an indicator of NO3- assimilation for five unrelated hybrid poplar clones. We also examined if leaf NRA of these clones is influenced to the same extent by different levels of soil NO3- availability in two riparian agroforestry systems located in pastures. Leaf NRA differences of more than one order of magnitude were observed between the clones, clearly showing their different abilities to reduce NO3- in leaves. Clone DxN-3570, a P. deltoides x P. nigra hybrid (Aigeiros intrasectional hybrid, always had the highest leaf NRA during the field assays. This clone was also the only one to increase its leaf NRA with increasing NO3- soil availability, which resulted in a significant Site x Clone interaction and a positive relationship between soil NO3- concentration and NRA. All of the four other clones studied had one or both parental species from the Tacamahaca section. They had relatively low leaf NRA and they did not increase their leaf NRA when grown on the NO3- rich site. These results provide evidence that NO3- assimilation in leaves varies widely among hybrid poplars of different parentages, suggesting potential preferences for N forms.

  5. GenBank blastx search result: AK103983 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK103983 001-017-F09 U49859.1 Anabaena variabilis Mo-nitrogenase operon NifB2, NifS2, NifU2, dinitrogen...ase reductase (nifH2), dinitrogenase alpha subunit (nifD2), dinitrogenase beta subunit (

  6. GenBank blastx search result: AK058791 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058791 001-002-F06 U49859.1 Anabaena variabilis Mo-nitrogenase operon NifB2, NifS2, NifU2, dinitrogen...ase reductase (nifH2), dinitrogenase alpha subunit (nifD2), dinitrogenase beta subunit (

  7. GenBank blastx search result: AK060074 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060074 006-306-B05 U49859.1 Anabaena variabilis Mo-nitrogenase operon NifB2, NifS2, NifU2, dinitrogen...ase reductase (nifH2), dinitrogenase alpha subunit (nifD2), dinitrogenase beta subunit (

  8. GenBank blastx search result: AK059171 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059171 001-023-F01 U49859.1 Anabaena variabilis Mo-nitrogenase operon NifB2, NifS2, NifU2, dinitrogen...ase reductase (nifH2), dinitrogenase alpha subunit (nifD2), dinitrogenase beta subunit (

  9. GenBank blastx search result: AK062234 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK062234 001-047-D11 U49859.1 Anabaena variabilis Mo-nitrogenase operon NifB2, NifS2, NifU2, dinitrogen...ase reductase (nifH2), dinitrogenase alpha subunit (nifD2), dinitrogenase beta subunit (

  10. Molecular effects of bioactive fraction of Curcuma mangga (DLBS4847) as a downregulator of 5α-reductase activity pathways in prostatic epithelial cells

    International Nuclear Information System (INIS)

    Karsono, Agung Heru; Tandrasasmita, Olivia Mayasari; Tjandrawinata, Raymond R

    2014-01-01

    DLBS4847 is a standardized bioactive fraction of Curcuma mangga. In this study, we used prostate cancer (PC)-3 as the cell line to study the effects of DLBS4847 on prostatic cell viability, as well as related molecular changes associated with the decreased cell number. The observation revealed that DLBS4847 inhibited the growth of PC3 cells through downregulation of the 5α-reductase (5AR) pathway. At the transcription level, 5AR1 and androgen-receptor gene expressions were downregulated in a dose-dependent manner. Furthermore, 5AR-1 and dihydrotestosterone expression were also downregulated at the protein level. A microarray study was also performed to see the effects of DLBS4847 on differential gene expressions in prostate cancer 3 cells. Among others, DLBS4847 downregulated genes related to prostate growth and hypertrophy. Our results suggested that DLBS4847 could potentially become an alternative treatment for prostate disorders, such as benign prostatic hyperplasia. In this regard, DLBS4847 exerts its growth inhibition partially through downregulation of the 5AR pathway

  11. Drought-Induced Effects on Nitrate Reductase Activity and mRNA and on the Coordination of Nitrogen and Carbon Metabolism in Maize Leaves1

    Science.gov (United States)

    Foyer, Christine H.; Valadier, Marie-Hélène; Migge, Andrea; Becker, Thomas W.

    1998-01-01

    Maize (Zea mays L.) plants were grown to the nine-leaf stage. Despite a saturating N supply, the youngest mature leaves (seventh position on the stem) contained little NO3− reserve. Droughted plants (deprived of nutrient solution) showed changes in foliar enzyme activities, mRNA accumulation, photosynthesis, and carbohydrate and amino acid contents. Total leaf water potential and CO2 assimilation rates, measured 3 h into the photoperiod, decreased 3 d after the onset of drought. Starch, glucose, fructose, and amino acids, but not sucrose (Suc), accumulated in the leaves of droughted plants. Maximal extractable phosphoenolpyruvate carboxylase activities increased slightly during water deficit, whereas the sensitivity of this enzyme to the inhibitor malate decreased. Maximal extractable Suc phosphate synthase activities decreased as a result of water stress, and there was an increase in the sensitivity to the inhibitor orthophosphate. A correlation between maximal extractable foliar nitrate reductase (NR) activity and the rate of CO2 assimilation was observed. The NR activation state and maximal extractable NR activity declined rapidly in response to drought. Photosynthesis and NR activity recovered rapidly when nutrient solution was restored at this point. The decrease in maximal extractable NR activity was accompanied by a decrease in NR transcripts, whereas Suc phosphate synthase and phosphoenolpyruvate carboxylase mRNAs were much less affected. The coordination of N and C metabolism is retained during drought conditions via modulation of the activities of Suc phosphate synthase and NR commensurate with the prevailing rate of photosynthesis. PMID:9576798

  12. Influence of beet sugar, calcium lactate, and Staphylococcus xylosus (with nitrate reductase activity) on the chemical, microbiological, and sensorial properties of Persian uncured frankfurters.

    Science.gov (United States)

    Tahmouzi, Saeed; Razavi, Seyed Hadi; Safari, Mohammad; Emam-Djomeh, Zahra

    2012-10-01

    This study investigated the effects of beet sugar (BS), calcium lactate (CL), and Staphylococcus xylosus (SX) on the general characteristics of uncured frankfurters. Minimum residual nitrite was observed in samples with a high level of BS and S. xylosus (8log(10) l0 viable cfu/g) after 2 mo. There was an increase in total aerobic counts in frankfurters after 4 wk. Samples containing higher BS and CL had no Clostridium perfringens at storage time. Histamine content was similar for all treatments except SX. No differences were observed in textural properties among the treatments. Water activity was decreased significantly in treatment CL1+BS2. The results indicated that samples treated with BS or CL had (P meat products in many countries. Health problems (such as cancer) associated with the overconsumption of cured meat have led to searches for new, alternative methods of preservation. Hurdle technology (combinations of beet sugar, calcium lactate, and Staphylococcus xylosus in different concentrations) can be developed for frankfurter processing. Results of this research will be useful for meat manufacturers; however, any new process may affect the strategies chosen for marketing these products. © 2012 Institute of Food Technologists®

  13. Post-fire erosion control mulches alter belowground processes and nitrate reductase activity of a perennial forb, heartleaf arnica (Arnica cordifolia)

    Science.gov (United States)

    Erin M. Berryman; Penelope Morgan; Peter R. Robichaud; Deborah Page-Dumroese

    2014-01-01

    Four years post-wildfire, we measured soil and plant properties on hillslopes treated with two different mulches (agricultural wheat straw and wood strands) and a control (unmulched, but burned). Soil total N was about 40% higher and microbial respiration of a standard wood substrate was nearly twice as high in the mulched plots compared to the unmulched plots. Greater...

  14. The effect of ionic and non-ionic surfactants on the growth, nitrate reductase and nitrite reductase activities of Spirodela polyrrhiza (L. Schleiden

    Directory of Open Access Journals (Sweden)

    Józef Buczek

    2014-01-01

    Full Text Available Inclusion into the medium of 5 mg•dm-3 of non-ionic (ENF or ionic (DBST surfactant caused 50-60% inhibition of nitrite reductase MR activity in S. polyrrhiza. At the same time, increased accumulation of NO2- in the plant tissues and lowering of the total and soluble protein contents were found. DBST also lowered the nitrate reductase (NR activity and the dry mass of the plants.

  15. Improvement of erythrose reductase activity, deletion of by-products and statistical media optimization for enhanced erythritol production from Yarrowia lipolytica mutant 49.

    Science.gov (United States)

    Ghezelbash, Gholam Reza; Nahvi, Iraj; Emamzadeh, Rahman

    2014-08-01

    The purpose of the present investigation was to produce erythritol by Yarrowia lipolytica mutant without any by-products. Mutants of Y. lipolytica were generated by ultra-violet for enhancing erythrose reductase (ER) activity and erythritol production. The mutants showing the highest ER activity were screened by triphenyl tetrazolium chloride agar plate assay. Productivity of samples was analyzed by thin-layer chromatography and high-performance liquid chromatography equipped with the refractive index detector. One of the mutants named as mutant 49 gave maximum erythritol production without any other by-products (particularly glycerol). Erythritol production and specific ER activity in mutant 49 increased to 1.65 and 1.47 times, respectively, in comparison with wild-type strain. The ER gene of wild and mutant strains was sequenced and analyzed. A general comparison of wild and mutant gene sequences showed the replacement of Asp(270) with Glu(270) in ER protein. In order to enhance erythritol production, we used a three component-three level-one response Box-Behnken of response surface methodology model. The optimum medium composition for erythritol production was found to be (g/l) glucose 279.49, ammonium sulfate 9.28, and pH 5.41 with 39.76 erythritol production.

  16. Molecular effects of bioactive fraction of Curcuma mangga (DLBS4847 as a downregulator of 5α-reductase activity pathways in prostatic epithelial cells

    Directory of Open Access Journals (Sweden)

    Karsono AH

    2014-06-01

    Full Text Available Agung Heru Karsono, Olivia Mayasari Tandrasasmita, Raymond R TjandrawinataSection of Molecular Pharmacology, Research Innovation and Invention, Dexa Laboratories of Biomolecular Sciences, Dexa Medica, Cikarang, IndonesiaAbstract: DLBS4847 is a standardized bioactive fraction of Curcuma mangga. In this study, we used prostate cancer (PC-3 as the cell line to study the effects of DLBS4847 on prostatic cell viability, as well as related molecular changes associated with the decreased cell number. The observation revealed that DLBS4847 inhibited the growth of PC3 cells through downregulation of the 5α-reductase (5AR pathway. At the transcription level, 5AR1 and androgen-receptor gene expressions were downregulated in a dose-dependent manner. Furthermore, 5AR-1 and dihydrotestosterone expression were also downregulated at the protein level. A microarray study was also performed to see the effects of DLBS4847 on differential gene expressions in prostate cancer 3 cells. Among others, DLBS4847 downregulated genes related to prostate growth and hypertrophy. Our results suggested that DLBS4847 could potentially become an alternative treatment for prostate disorders, such as benign prostatic hyperplasia. In this regard, DLBS4847 exerts its growth inhibition partially through downregulation of the 5AR pathway.Keywords: DLBS4847, Curcuma mangga, 5α-reductase inhibitor, benign prostatic hyperplasia (BPH, prostate cancer

  17. The SUD1 gene encodes a putative E3 ubiquitin ligase and is a positive regulator of 3-hydroxy-3-methylglutaryl coenzyme a reductase activity in Arabidopsis.

    Science.gov (United States)

    Doblas, Verónica G; Amorim-Silva, Vítor; Posé, David; Rosado, Abel; Esteban, Alicia; Arró, Montserrat; Azevedo, Herlander; Bombarely, Aureliano; Borsani, Omar; Valpuesta, Victoriano; Ferrer, Albert; Tavares, Rui M; Botella, Miguel A

    2013-02-01

    The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) enzyme catalyzes the major rate-limiting step of the mevalonic acid (MVA) pathway from which sterols and other isoprenoids are synthesized. In contrast with our extensive knowledge of the regulation of HMGR in yeast and animals, little is known about this process in plants. To identify regulatory components of the MVA pathway in plants, we performed a genetic screen for second-site suppressor mutations of the Arabidopsis thaliana highly drought-sensitive drought hypersensitive2 (dry2) mutant that shows decreased squalene epoxidase activity. We show that mutations in SUPPRESSOR OF DRY2 DEFECTS1 (SUD1) gene recover most developmental defects in dry2 through changes in HMGR activity. SUD1 encodes a putative E3 ubiquitin ligase that shows sequence and structural similarity to yeast Degradation of α factor (Doα10) and human TEB4, components of the endoplasmic reticulum-associated degradation C (ERAD-C) pathway. While in yeast and animals, the alternative ERAD-L/ERAD-M pathway regulates HMGR activity by controlling protein stability, SUD1 regulates HMGR activity without apparent changes in protein content. These results highlight similarities, as well as important mechanistic differences, among the components involved in HMGR regulation in plants, yeast, and animals.

  18. Effects of elevated CO2 on the photosynthesis and nitrate reductase activity of Pyropia haitanensis (Bangiales, Rhodophyta) grown at different nutrient levels

    Science.gov (United States)

    Liu, Chunxiang; Zou, Dinghui

    2015-03-01

    Pyropia haitanensis, a commercially important species, was cultured at two CO2 concentrations (390×10-6 and 700×10-6 (parts per million)) and at low and high nutrient levels, to explore the effect of elevated CO2 on the species under nutrient enrichment. Results show that in CO2-enriched thalli, relative growth rate (RGR) was enhanced under nutrient enrichment. Elevated CO2 decreased phycobiliprotein (PB) contents, but increased the contents of soluble carbohydrates. Nutrient enrichment increased the contents of chlorophyll a (Chl a) and PB, while soluble carbohydrate content decreased. CO2 enrichment enhanced the relative maximum electronic transport rate and light saturation point. In nutrient-enriched thalli the activity of nitrate reductase (NRA) increased under elevated CO2. An instantaneous pH change in seawater (from 8.1 to 9.6) resulted in reduction of NRA, and the thalli grown under both elevated CO2 and nutrient enrichment exhibited less pronounced reduction than in algae grown at the ambient CO2. The thermal optima of NRA under elevated CO2 and/or nutrient enrichment shifted to a lower temperature (10-15°C) compared to that in ambient conditions (20°C). We propose that accelerated photosynthesis could result in growth increment. N assimilation remained high in acidified seawater and reflected increased temperature sensitivity in response to elevated CO2 and eutrophication.

  19. Ionic liquid mediated stereoselective synthesis of alanine linked hybrid quinazoline-4(3H)-one derivatives perturbing the malarial reductase activity in folate pathway.

    Science.gov (United States)

    Patel, Tarosh S; Bhatt, Jaimin D; Vanparia, Satish F; Patel, Urmila H; Dixit, Ritu B; Chudasama, Chaitanya J; Patel, Bhavesh D; Dixit, Bharat C

    2017-12-15

    Grimmel's method was optimized as well as modified leading to the cyclization and incorporation of alanine linked sulphonamide in 4-quinazolin-(3H)-ones. Further, the generation of heterocyclic motif at position-3 of 4-quinazolinones was explored by synthesis of imines, which unfortunately led to an isomeric mixture of stereoisomers. The hurdle of diastereomers encountered on the path was eminently rectified by development of new rapid and reproducible methodology involving the use of imidazolium based ionic liquid as solvents as well as catalyst for cyclization as well as synthesis of imines in situ at position-3 leading to procurement of single E-isomer as the target hybrid heterocyclic molecules. The purity and presence of single isomer was also confirmed by HPLC and spectroscopic techniques. Further, the synthesized sulphonamide linked 4-quinazolin-(3H)-ones hybrids were screened for their antimalarial potency rendering potent entities (4b, 4c, 4 l, 4 t and 4u). The active hybrids were progressively screened for enzyme inhibitory efficacy against presumed receptor Pf-DHFR and h-DHFR computationally as well as in vitro, proving their potency as dihydrofolate reductase inhibitors. The ADME properties of these active molecules were also predicted to enhance the knowhow of the oral bioavailability, indicating good bioavailability of the active entities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate.

    Science.gov (United States)

    Corradi, Lara S; Góes, Rejane M; Carvalho, Hernandes F; Taboga, Sebastião R

    2004-06-01

    Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5 alpha-reductase (5 alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5 alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5 alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.

  1. Senescence-induced ectopic expression of A. tumefaciens ipt gene in wheat delays leaf senescence, increases cytokinin content, nitrate influx and nitrate reductase activity but does not affect grain yield

    Czech Academy of Sciences Publication Activity Database

    Sýkorová, Blanka; Kurešová, G.; Daskalova, S.; Trčková, M.; Hoyerová, Klára; Raimanová, I.; Motyka, Václav; Trávníčková, Alena; Elliott, M. C.; Kamínek, Miroslav

    2008-01-01

    Roč. 59, č. 2 (2008), s. 377-387 ISSN 0022-0957 R&D Projects: GA ČR GA522/02/0530; GA MŠk 1M06030; GA AV ČR(CZ) IAA600380507 Keywords : Cytokinins * grain yield * ipt gene Subject RIV: EF - Botanics Impact factor: 4.001, year: 2008

  2. Two enzymes catalyze vitamin K 2,3-epoxide reductase activity in mouse: VKORC1 is highly expressed in exocrine tissues while VKORC1L1 is highly expressed in brain.

    Science.gov (United States)

    Caspers, Michael; Czogalla, Katrin J; Liphardt, Kerstin; Müller, Jens; Westhofen, Philipp; Watzka, Matthias; Oldenburg, Johannes

    2015-05-01

    VKORC1 and VKORC1L1 are enzymes that both catalyze the reduction of vitamin K2,3-epoxide via vitamin K quinone to vitamin K hydroquinone. VKORC1 is the key enzyme of the classical vitamin K cycle by which vitamin K-dependent (VKD) proteins are γ-carboxylated by the hepatic γ-glutamyl carboxylase (GGCX). In contrast, the VKORC1 paralog enzyme, VKORC1L1, is chiefly responsible for antioxidative function by reduction of vitamin K to prevent damage by intracellular reactive oxygen species. To investigate tissue-specific vitamin K 2,3-epoxide reductase (VKOR) function of both enzymes, we quantified mRNA levels for VKORC1, VKORC1L1, GGCX, and NQO1 and measured VKOR enzymatic activities in 29 different mouse tissues. VKORC1 and GGCX are highly expressed in liver, lung and exocrine tissues including mammary gland, salivary gland and prostate suggesting important extrahepatic roles for the vitamin K cycle. Interestingly, VKORC1L1 showed highest transcription levels in brain. Due to the absence of detectable NQO1 transcription in liver, we assume this enzyme has no bypass function with respect to activation of VKD coagulation proteins. Our data strongly suggest diverse functions for the vitamin K cycle in extrahepatic biological pathways. Copyright © 2015. Published by Elsevier Ltd.

  3. Hypothalamic digoxin, hemispheric chemical dominance, and oncogenesis: evidence from multiple myeloma.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Paramesware Achutha

    2003-12-01

    This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with

  4. Sequence Classification: 515518 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|39935702|ref|NP_947978.1| possible nitrogen...ase molybdenum-iron protein alpha chain (nitrogenase component I) (dinitrogenase) || http://www.ncbi.nlm.nih.gov/protein/39935702 ...

  5. Sequence Classification: 515248 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|39935432|ref|NP_947708.1| possible nitrogen...ase molybdenum-iron protein alpha chain (nitrogenase component I) (dinitrogenase) || http://www.ncbi.nlm.nih.gov/protein/39935432 ...

  6. Sequence Classification: 514328 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|39934511|ref|NP_946787.1| putative nitrogen...ase molybdenum-iron protein alpha chain (nitrogenase component I) (dinitrogenase) || http://www.ncbi.nlm.nih.gov/protein/39934511 ...

  7. Sequence Classification: 515233 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|39935417|ref|NP_947693.1| possible nitrogen...ase molybdenum-iron protein alpha chain (nitrogenase component I) (dinitrogenase) || http://www.ncbi.nlm.nih.gov/protein/39935417 ...

  8. Diversity of nitrogen-fixing bacteria in cyanobacterial mats

    NARCIS (Netherlands)

    Severin, I.; Acinas, S.G.; Stal, L.J.

    2010-01-01

    The structure of the microbial community and the diversity of the functional gene for dinitrogenase reductase and its transcripts were investigated by analyzing >1400 16S rRNA gene and nifH sequences from two microbial mats situated in the intertidal zone of the Dutch barrier island Schiermonnikoog.

  9. Genetic diversity of nifH gene sequences in Paenibacillus azotofixans strains and soil samples analyzed by denaturing gradiënt gel electrophoresis of PCR-amplified gene fragments

    NARCIS (Netherlands)

    Rosado, A.S.; Duarte, G.F.; Seldin, L.; Elsas, van J.D.

    1998-01-01

    The diversity of dinitrogenase reductase gene (nifH) fragments in Paenibacillus azotofixans strains was investigated by using molecular methods. The partial nifH gene sequences of eight P. azotofixans strains, as well as one strain each of the close relatives Paenibacillus durum, Paenibacillus

  10. Investigations of the radiosensitivity of enzymes of the NAD metabolism localized in the cell nucleus in the spleen of white mice

    International Nuclear Information System (INIS)

    Beisel, P.

    1975-01-01

    The radiosensitivity of enzymes of the NAD metabolism localized in the cell nuclei and of NAD glycohydrolase in the total homogenate of the spleen of white mice was investigated. At the same time the DNA and protein contents were determined. After whole-body irradiation with 510 R, the activity of NAD pyrophosphorylase and NAD glycohydrolase located in the cell nuclei is markedly lower as early as 3 hours after irradiation; this decrease is noticeable until the 10th day after irradiation. With regard to the dose dependence of the radiosensitivity at 6 and 24 hours after irradiation, it was found that NAD pyrophosphorylase and the NAD glycohydrolase localized in the cell nuclei were very radiosensitive even at doses [de

  11. Inhibition of substrate synthesis as a strategy for glycolipid lysosomal storage disease therapy

    NARCIS (Netherlands)

    Platt, F. M.; Jeyakumar, M.; Andersson, U.; Priestman, D. A.; Dwek, R. A.; Butters, T. D.; Cox, T. M.; Lachmann, R. H.; Hollak, C.; Aerts, J. M.; van Weely, S.; Hrebícek, M.; Moyses, C.; Gow, I.; Elstein, D.; Zimran, A.

    2001-01-01

    The glycosphingolipid (GSL) lysosomal storage diseases are caused by mutations in the genes encoding the glycohydrolases that catabolize GSLs within lysosomes. In these diseases the substrate for the defective enzyme accumulates in the lysosome and the stored GSL leads to cellular dysfunction and

  12. The effect of used engine oil on carbohydrate, mineral content and ...

    African Journals Online (AJOL)

    MICHAEL

    reductase activity in plants that were exposed to engine oil. Therefore ... change oil from motor vehicles and power generating machines. ... The availability of essential mineral element is ... representing each treatment and this was replicated.

  13. Ammonium inhibition of nitrogenase activity in Herbaspirillum seropedicae

    Energy Technology Data Exchange (ETDEWEB)

    Fu, H.; Burris, R.H. (Univ. of Wisconsin, Madison (USA))

    1989-06-01

    The effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated N{sub 2}-fixing bacterium Herbaspirillum seropedicae was investigated in comparison with Azospirillum spp. and Rhodospirillum rubrum. H. seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kPa for dinitrogen fixation but higher when it is supplied with fixed nitrogen. No nitrogenase activity was detected when the dissolved O{sub 2} level corresponded to 4.0 kPa. Ammonium, a product of the nitrogenase reaction, reversible inhibited nitrogenase activity when added to derepressed cell cultures. However, the inhibition of nitrogenase activity was only partial even with concentrations of ammonium chloride as high as 20 mM. Amides such as glutamine and asparagine partially inhibited nitrogenase activity, but glutamate did not. Nitrogenase in crude extracts prepared from ammonium-inhibited cells showed activity as high as in extracts from N{sub 2}-fixing cells. The pattern of the dinitrogenase and the dinitrogenase reductase revealed by the immunoblotting technique did not change upon ammonium chloride treatment of cells in vivo. No homologous sequences were detected with the draT-draG probe from Azospirillum lipoferum. There is no clear evidence that ADP-ribosylation of the dinitrogenase reductase is involved in the ammonium inhibition of H. seropedicae. The uncoupler carbonyl cyanide m-chlorophenylhydrazone decreased the intracellular ATP concentration and inhibited the nitrogenase activity of whole cells. The ATP pool was significantly disturbed when cultures were treated with ammonium in vivo.

  14. Differential expression of disulfide reductase enzymes in a free-living platyhelminth (Dugesia dorotocephala.

    Directory of Open Access Journals (Sweden)

    Alberto Guevara-Flores

    Full Text Available A search of the disulfide reductase activities expressed in the adult stage of the free-living platyhelminth Dugesia dorotocephala was carried out. Using GSSG or DTNB as substrates, it was possible to obtain a purified fraction containing both GSSG and DTNB reductase activities. Through the purification procedure, both disulfide reductase activities were obtained in the same chromatographic peak. By mass spectrometry analysis of peptide fragments obtained after tryptic digestion of the purified fraction, the presence of glutathione reductase (GR, thioredoxin-glutathione reductase (TGR, and a putative thioredoxin reductase (TrxR was detected. Using the gold compound auranofin to selectively inhibit the GSSG reductase activity of TGR, it was found that barely 5% of the total GR activity in the D. dorotocephala extract can be assigned to GR. Such strategy did allow us to determine the kinetic parameters for both GR and TGR. Although It was not possible to discriminate DTNB reductase activity due to TrxR from that of TGR, a chromatofocusing experiment with a D. dorotocephala extract resulted in the obtention of a minor protein fraction enriched in TrxR, strongly suggesting its presence as a functional protein. Thus, unlike its parasitic counterparts, in the free-living platyhelminth lineage the three disulfide reductases are present as functional proteins, albeit TGR is still the major disulfide reductase involved in the reduction of both Trx and GSSG. This fact suggests the development of TGR in parasitic flatworms was not linked to a parasitic mode of life.

  15. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species

    Science.gov (United States)

    Pourshahid, Seyedmohammad; Mehryar, Pouyan; Pakshir, Keyvan; Rahimi, Mohammad Javad; Arabi Monfared, Ali

    2016-01-01

    Currently, researchers turn to natural processes such as using biological microorganisms in order to develop reliable and ecofriendly methods for the synthesis of metallic nanoparticles. In this study, we have investigated extracellular biosynthesis of silver nanoparticles using four Aspergillus species including A. fumigatus, A. clavatus, A. niger, and A. flavus. We have also analyzed nitrate reductase activity in the studied species in order to determine the probable role of this enzyme in the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM). There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity. PMID:27652264

  16. Cloning of genes and enzymatic characterizations of novel dioscorin isoforms from Dioscorea japonica.

    Science.gov (United States)

    Xue, You-Lin; Miyakawa, Takuya; Sawano, Yoriko; Tanokura, Masaru

    2012-02-01

    Dioscorin, the major tuber storage protein of yam, has been shown to possess carbonic anhydrase, trypsin inhibitor, dehydroascorbate reductase, and monodehydroascorbate reductase activities. In the present study, dioscorin from Dioscorea japonica was confirmed as a glycoprotein using the enhanced concanavalin A-peroxidase staining method, and the protein was shown to have both N- and O-glycans. Following the gene cloning, four full-length isoforms of dioscorin were expressed in Escherichia coli and purified by affinity purification and anion-exchange chromatography for structural and biochemical experiments. It was clearly observed that the recombinant dioscorins had carbonic anhydrase, trypsin inhibitor, dehydroascorbate reductase, and monodehydroascorbate reductase activities. However, the dehydroascorbate reductase and monodehydroascorbate reductase activities were markedly decreased in recombinant dioscorins compared with native dioscorin. The decreased activities were closely related to the loss of the glycosylation from the protein. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Improving the hydrogen production capacity of Rhodobacter capsulatus by genetically modifying redox balancing pathways

    Energy Technology Data Exchange (ETDEWEB)

    Oeztuerk, Yavuz [TUEBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze Kocaeli (Turkey); Goekce, Abdulmecit [Istanbul Technical Univ. (Turkey). Dept. of Molecular Biology and Genetics; Guergan, Muazzez; Yuecel, Meral [Middle East Technical Univ., Ankara (Turkey). Dept. of Biology

    2010-07-01

    In Rhodobacter capsulatus, balancing the oxidation-reduction potential (redox-balance) is maintained via a number of inter-dependent regulatory mechanisms that enable these organisms to accommodate divergent growth modes. In order to maintain redox homeostasis, this bacterium possesses regulatory mechanisms functioning as electron sinks affecting the oxidation-reduction state of the ubiquinone pool. Under the photoheterotrophic growth conditions with reduced carbon sources, the excess reducing equivalents are primarily consumed via the reduction of CO{sub 2} through the Calvin-Benson-Bassham (CBB) pathway or by the reduction of protons into hydrogen with the use of dinitrogenase enzyme system. In this study, our aim was to develop strategies to funnel the excess reducing equivalents to nitrogenase-dependent hydrogen production by blocking the carbon-fixation pathway. To realize this purpose, CO{sub 2} fixation was blocked by inactivating the Phosphoribulokinase (PRK) of CBB pathway in wild type (MT1131), uptake-hydrogenase (YO3) and cyt cbb{sub 3} oxidase deficient (YO4) strains. The hydrogen production capacity of newly generated strains deficient in the Calvin-Benson-Bassham pathway were analyzed and compared with wild type strains. The results indicated that, the hydrogen production efficiency and capacity of R. capsulatus was further improved by directing the excess reducing equivalents to dinitrogenase-dependent hydrogen production. (orig.)

  18. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals

    DEFF Research Database (Denmark)

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E

    2017-01-01

    examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals...... in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken...

  19. Mitochondrial and Nuclear Cross Talk in Cell Death: Parthanatos

    OpenAIRE

    Andrabi, Shaida A.; Dawson, Ted M.; Dawson, Valina L.

    2008-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) PARP-1 is an abundant nuclear protein first described to facilitate DNA base excision repair. Recent work has expanded the physiologic functions of PARP-1 and it is clear that the full range of biologic actions of this important protein are not yet fully understood. Regulation of the product of PARP-1, poly(ADP-ribose) (PAR), is a dynamic process with poly(ADP-ribose) glycohydrolase (PARG) playing a major role in the degradation of the polymer. Under pat...

  20. Crystal structure of the C3bot–RalA complex reveals a novel type of action of a bacterial exoenzyme

    OpenAIRE

    Pautsch, Alexander; Vogelsgesang, Martin; Tränkle, Jens; Herrmann, Christian; Aktories, Klaus

    2005-01-01

    C3 exoenzymes from bacterial pathogens ADP-ribosylate and inactivate low-molecular-mass GTPases of the Rho subfamily. Ral, a Ras subfamily GTPase, binds the C3 exoenzymes from Clostridium botulinum and C. limosum with high affinity without being a substrate for ADP ribosylation. In the complex, the ADP-ribosyltransferase activity of C3 is blocked, while binding of NAD and NAD-glycohydrolase activity remain. Here we report the crystal structure of C3 from C. botulinum in a complex with GDP-bou...

  1. Lifelong endurance training attenuates age-related genotoxic stress in human skeletal muscle

    OpenAIRE

    Cobley, James N; Sakellariou, George K; Murray, Scott; Waldron, Sarah; Gregson, Warren; Burniston, Jatin G; Morton, James P; Iwanejko, Lesley A; Close, Graeme L

    2013-01-01

    Background The aim of the present study was to determine the influence of age and habitual activity level, at rest and following a single bout of high-intensity exercise, on the levels of three proteins poly(ADP-ribose) polymerase-1 (PARP-1), cleaved-PARP-1 and poly(ADP-ribose) glycohydrolase (PARG), involved in the DNA repair and cell death responses to stress and genotoxic insults. Muscle biopsies were obtained from the vastus lateralis of young trained (22 ± 3 years, n = 6), young untraine...

  2. Host cells and methods for production of isobutanol

    Science.gov (United States)

    Anthony, Larry Cameron; He, Hongxian; Huang, Lixuan Lisa; Okeefe, Daniel P.; Kruckeberg, Arthur Leo; Li, Yougen; Maggio-Hall, Lori; McElvain, Jessica; Nelson, Mark J.; Patnaik, Ranjan; Rothman, Steven Cary

    2017-10-17

    Provided herein are recombinant yeast host cells and methods for their use for production of isobutanol. Yeast host cells provided comprise an isobutanol biosynthetic pathway and at least one of reduced or eliminated aldehyde dehydrogenase activity, reduced or eliminated acetolactate reductase activity; or a heterologous polynucleotide encoding a polypeptide having ketol-acid reductoisomerase activity.

  3. SUPEROXIDE-DEPENDENT IRON UPTAKE: A NEW ROLE FOR ANION EXCHANGE PROTEIN 2

    Science.gov (United States)

    Lung cells import iron across the plasma membrane as ferrous (Fe2+) ion by incompletely understood mechanisms. We tested the hypothesis that human bronchial epithelial (HBE) cells import non-transferrin-bound iron (NTBI) using superoxide-dependent ferri-reductase activity involvi...

  4. Tetrathionate reductase of Salmonella thyphimurium: a molybdenum containing enzyme

    International Nuclear Information System (INIS)

    Hinojosa-Leon, M.; Dubourdieu, M.; Sanchez-Crispin, J.A.; Chippaux, M.

    1986-01-01

    Use of radioactive molybdenum demonstrates that the tetrathionate reductase of Salmonella typhimurium is a molydenum containing enzyme. It is proposed that this enzyme shares with other molybdo-proteins, such as nitrate reductase, a common molybdenum containing cofactor the defect of which leads to the loss of the tetrathionate reductase and nitrate reductase activities

  5. Phytochemical composition and antioxidant capacity of whole wheat products

    Science.gov (United States)

    Whole wheat contains an array of phytochemicals. We quantified alkylresorcinols (AR), phenolic acids, phytosterols, and tocols in six whole wheat products and characterized their antioxidant capacity and ability to induce quinone reductase activity (QR). Total AR content ranged from 136.8 to 233.9 m...

  6. ORF Alignment: NC_000913 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Escherichia coli] ref|NP_417047.1| ... dihydropteridine reductase, ferrisiderophore reductase ... ... ... activity [Escherichia coli K12] gb|AAC75605.1| ... dihydropteridine reductase, ferrisiderophore r... ... dihydropteridine reductase 2; ferrisiderophore reductase ... [Escherichia coli K12] pir||S15992 fl

  7. Sequence Classification: 290085 [

    Lifescience Database Archive (English)

    Full Text Available ropteridine reductase, ferrisiderophore reductase activity || http://www.ncbi.nlm.nih.gov/protein/16130477 ... ...Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|16130477|ref|NP_417047.1| dihyd

  8. Sequence Classification: 558868 [

    Lifescience Database Archive (English)

    Full Text Available ropteridine reductase, ferrisiderophore reductase activity || http://www.ncbi.nlm.nih.gov/protein/74313075 ... ...Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|74313075|ref|YP_311494.1| dihyd

  9. Sequence Classification: 295249 [

    Lifescience Database Archive (English)

    Full Text Available ropteridine reductase, ferrisiderophore reductase activity || http://www.ncbi.nlm.nih.gov/protein/15803077 ... ...Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15803077|ref|NP_289108.1| dihyd

  10. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    Ecological Indicators,1, 261 – 270. [11] Wekbeker G. & Cory G., 1988. Robo nucleotide reductase activity and growth of glutathione depleted mouse leukemia 1210 cells in vitro. Cancer letters, 40, 257 – 264. [12] Bradford M., 1976. A rapid and sensitive method for the quantification of microgram quantities of protein utilizing ...

  11. Download this PDF file

    African Journals Online (AJOL)

    AJTCAM

    HRESIMS – high resolution electron impact ionization mass spectrometer; IIE ID – Institute of ... In African folk medicine, water decoction made from the dry seeds of Hunteria umbellata is employed ... Plant identification and deposit ..... min, the supernatant was collected and kept in ice to determine aldose reductase activity.

  12. Chromium stress in Brassica juncea L. cv. 'Pusa Jai Kissan' under ...

    African Journals Online (AJOL)

    Valued Customer

    2012-11-08

    Nov 8, 2012 ... growth, chlorophyll, total soluble protein, free amino acids and nitrate reductase activity. Cr was found .... −2. , 14 h of light,. 10 h of dark and a relative humidity of 60%. .... function of genes that govern the synthesis of enzymes,.

  13. Labeled Azospirillum brasilense wild type and excretion-ammonium strains in association with barley roots.

    Science.gov (United States)

    Santos, Adrian Richard Schenberger; Etto, Rafael Mazer; Furmam, Rafaela Wiegand; Freitas, Denis Leandro de; Santos, Karina Freire d'Eça Nogueira; Souza, Emanuel Maltempi de; Pedrosa, Fábio de Oliveira; Ayub, Ricardo Antônio; Steffens, Maria Berenice Reynaud; Galvão, Carolina Weigert

    2017-09-01

    Soil bacteria colonization in plants is a complex process, which involves interaction between many bacterial characters and plant responses. In this work, we labeled Azospirillum brasilense FP2 (wild type) and HM053 (excretion-ammonium) strains by insertion of the reporter gene gusA-kanamycin into the dinitrogenase reductase coding gene, nifH, and evaluated bacteria colonization in barley (Hordeum vulgare). In addition, we determined inoculation effect based on growth promotion parameters. We report an uncommon endophytic behavior of A. brasilense Sp7 derivative inside the root hair cells of barley and highlight the promising use of A. brasilense HM053 as plant growth-promoting bacterium. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Project in determination of crystal structure of nitrogen fixation proteins from azospirilum brasiliense and herbaspirilum seropedicae by synchrotron x-ray diffraction

    International Nuclear Information System (INIS)

    Barbosa, Valma M.; Leggs, Luciana A.; Delboni, Luis F.; Chubatsu, LedaS.; Souza, Emanuel M.; Machado, Hidevaldo B.; Yates, Geoffrey M.; Pedrosa, Fabio O.

    1996-01-01

    Full text. Biological nitrogen fixation is essential for maintaining the nitrogen cycle on earth and of high importance for Brazilian agriculture. The nitrogenase enzyme system, which provides the biochemical machinery for nitrogen fixation, consists of two component metalloproteins, the molybdenumiron (Mo Fe) protein and the iron (Fe) protein. Nitrogen fixation is a very energy-intensive process, requiring around 16 moles of ATP for each mol of N 2 fixed (reduced). As a consequence, synthesis and activity of nitrogenase is tighty regulated at two levels: general and specific. The general level regulation is mediated by the ntr (nitrogen regulation) system. Two gene products are involved: the ntrB gene product (NtrB) is responsible for the activation of the ntrC gene product (NtrC) by phosphorylating a conserved Asp54, which activates the expression of the nifA gene. The nif specific control system is mediated by the NifA protein, which binds to a DNA specific sequence (UAS, Upstream Activator Sequence) and activates nif promoter transcriptions by RNA polymerase- α54 , following ATP hydrolysis. The aim of this project is to solve the crystal structure of dinitrogenase reductase (iron protein) and dinitrogenase (molybdenum-iron protein) from Azospirilim brasiliense and the regulatory proteins NifA from Herbaspirillum seropedicae and NtrC Azospirillum brasiliense. The three dimensional structure of the proteins involved in this project will allow a better understanding of the mechanism of biological nitrogen fixation. To this end, the data collection will probably be done at the LNLS facilities which will be available in the near future. (author)

  15. Project in determination of crystal structure of nitrogen fixation proteins from azospirilum brasiliense and herbaspirilum seropedicae by synchrotron x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Valma M.; Leggs, Luciana A.; Delboni, Luis F.; Chubatsu, LedaS.; Souza, Emanuel M.; Machado, Hidevaldo B.; Yates, Geoffrey M.; Pedrosa, Fabio O. [Parana Univ., Curitiba, PR (Brazil). Dept. de Bioquimica

    1996-12-31

    Full text. Biological nitrogen fixation is essential for maintaining the nitrogen cycle on earth and of high importance for Brazilian agriculture. The nitrogenase enzyme system, which provides the biochemical machinery for nitrogen fixation, consists of two component metalloproteins, the molybdenumiron (Mo Fe) protein and the iron (Fe) protein. Nitrogen fixation is a very energy-intensive process, requiring around 16 moles of ATP for each mol of N{sub 2} fixed (reduced). As a consequence, synthesis and activity of nitrogenase is tighty regulated at two levels: general and specific. The general level regulation is mediated by the ntr (nitrogen regulation) system. Two gene products are involved: the ntrB gene product (NtrB) is responsible for the activation of the ntrC gene product (NtrC) by phosphorylating a conserved Asp54, which activates the expression of the nifA gene. The nif specific control system is mediated by the NifA protein, which binds to a DNA specific sequence (UAS, Upstream Activator Sequence) and activates nif promoter transcriptions by RNA polymerase-{sup {alpha}54}, following ATP hydrolysis. The aim of this project is to solve the crystal structure of dinitrogenase reductase (iron protein) and dinitrogenase (molybdenum-iron protein) from Azospirilim brasiliense and the regulatory proteins NifA from Herbaspirillum seropedicae and NtrC Azospirillum brasiliense. The three dimensional structure of the proteins involved in this project will allow a better understanding of the mechanism of biological nitrogen fixation. To this end, the data collection will probably be done at the LNLS facilities which will be available in the near future. (author)

  16. Destruction of enzymatic activities of corn and soybean leaves exposed to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Leffler, H R; Cherry, J H

    1974-01-01

    Experiments were conducted to determine the effects of a single ozone exposure on selected enzymatic activities and chlorophyll contents of corn and soybean seedlings. Both nitrite reductase activity and chlorophyll content of the seedlings were found to be quite sensitive to ozonation and were seen to decrease as much as 50% after exposure to 80 parts per hundred million (pphm) ozone. After exposure to lower levels of ozone, less-pronounced decreases were observed. Nitrate reductase activity was reduced only after exposure to seedling leaf tissues to high concentrations of ozone. These results are discussed in relation to the concept of a two-phase response to oxidant exposure. The first phase is at the chloroplast level and is quite sensitive to the low as well as the high concentrations of ozone; the second is at the cellular level and is relatively resistant to all but the highest ozone concentrations. 27 references, 2 tables.

  17. Influence of rete testis fluid deprivation on the kinetic parameters of goat epididymal 5 alpha-reductase.

    Science.gov (United States)

    Kelce, W R; Lubis, A M; Braun, W F; Youngquist, R S; Ganjam, V K

    1990-01-01

    A surgical technique to cannulate the rete testis of the goat was utilized to examine the effects of rete testis fluid (RTF) deprivation on the enzymatic activity of epididymal 5 alpha-reductase. Kinetic techniques were used to determine whether the regional enzymatic effect of RTF deprivation is to decrease the apparent number of 5 alpha-reductase active sites or the catalytic activity of each active site within the epididymal epithelium. Paired comparisons of (Vmax)app and (Km)app values between control and RTF-deprived epididymides indicated that RTF deprivation affected the value of (Vmax)app with no apparent change in the values of (Km)app in caput, corpus, and cauda epididymal regions. We conclude that RTF deprivation in the goat epididymis for 7 days results in a decreased number of apparent 5 alpha-reductase active sites within the epididymal epithelium.

  18. Nitrate reductase and nitrous oxide production by Fusarium oxysporum 11dn1 under aerobic and anaerobic conditions.

    Science.gov (United States)

    Kurakov, A V; Nosikov, A N; Skrynnikova, E V; L'vov, N P

    2000-08-01

    The fungus Fusarium oxysporum 11dn1 was found to be able to grow and produce nitrous oxide on nitrate-containing medium in anaerobic conditions. The rate of nitrous oxide formation was three to six orders of magnitude lower than the rates of molecular nitrogen production by common denitrifying bacteria. Acetylene and ammonia did not affect the release of nitrous oxide release. It was shown that under anaerobic conditions fast increase of nitrate reductase activity occurred, caused by the synthesis of enzyme de novo and protein dephosphorylation. Reverse transfer of the mycelium to aerobic conditions led to a decline in nitrate reductase activity and stopped nitrous oxide production. The presence of two nitrate reductases was shown, which differed in molecular mass, location, temperature optima, and activity in nitrate- and ammonium-containing media. Two enzymes represent assimilatory and dissimilatory nitrate reductases, which are active in aerobic and anaerobic conditions, respectively.

  19. Cholesterol metabolism: use of D2O for determination of synthesis rate in cell culture

    International Nuclear Information System (INIS)

    Esterman, A.L.; Cohen, B.I.; Javitt, N.B.

    1985-01-01

    Cholesterol synthesis in cell culture in the presence of D 2 O yields a spectrum of enriched molecules having a relative abundance that indicates random substitution of deuterium for hydrogen. Quantitation of the absolute rate of cholesterol synthesis is obtained by isotope ratio mass spectrometry. Mevinolin and 26-hydroxycholesterol both decrease cholesterol synthesis rate but have a discordant effect on HMG-CoA reductase activity

  20. Dietary Supplementation with the Microalga Galdieria sulphuraria (Rhodophyta) Reduces Prolonged Exercise-Induced Oxidative Stress in Rat Tissues

    OpenAIRE

    Carfagna, Simona; Napolitano, Gaetana; Barone, Daniela; Pinto, Gabriele; Pollio, Antonino; Venditti, Paola

    2015-01-01

    We studied the effects of ten-day 1% Galdieria sulphuraria dietary supplementation on oxidative damage and metabolic changes elicited by acute exercise (6-hour swimming) determining oxygen consumption, lipid hydroperoxides, protein bound carbonyls in rat tissue (liver, heart, and muscle) homogenates and mitochondria, tissue glutathione peroxidase and glutathione reductase activities, glutathione content, and rates of H2O2 mitochondrial release. Exercise increased oxidative damage in tissues a...

  1. Mitochondrial toxicity of phthalate esters.

    OpenAIRE

    Melnick, R L; Schiller, C M

    1982-01-01

    The effects of mono- and dibutyl phthalate and mono- and di(2-ethylhexyl) phthalate on energy-dependent K+ uptake, respiration rates, and succinate cytochrome c reductase activities of isolated rat liver mitochondria were evaluated. The energy-coupling processes, active K+ transport and oxidative phosphorylation, were affected most by di-n-butyl phthalate and mono(2-ethylhexyl) phthalate. Mono-n-butyl phthalate had a moderate effect on energy coupling and di(2-ethylhexyl) phthalate had no app...

  2. YqhD. A broad-substrate range aldehyde reductase with various applications in production of biorenewable fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Jarboe, Laura R. [Iowa State Univ., Ames, IA (United States). Dept. of Chemical and Biological Engineering

    2011-01-15

    The Escherichia coli NADPH-dependent aldehyde reductase YqhD has contributed to a variety of metabolic engineering projects for production of biorenewable fuels and chemicals. As a scavenger of toxic aldehydes produced by lipid peroxidation, YqhD has reductase activity for a broad range of short-chain aldehydes, including butyraldehyde, glyceraldehyde, malondialdehyde, isobutyraldehyde, methylglyoxal, propanealdehyde, acrolein, furfural, glyoxal, 3-hydroxypropionaldehyde, glycolaldehyde, acetaldehyde, and acetol. This reductase activity has proven useful for the production of biorenewable fuels and chemicals, such as isobutanol and 1,3- and 1,2-propanediol; additional capability exists for production of 1-butanol, 1-propanol, and allyl alcohol. A drawback of this reductase activity is the diversion of valuable NADPH away from biosynthesis. This YqhD-mediated NADPH depletion provides sufficient burden to contribute to growth inhibition by furfural and 5-hydroxymethyl furfural, inhibitory contaminants of biomass hydrolysate. The structure of YqhD has been characterized, with identification of a Zn atom in the active site. Directed engineering efforts have improved utilization of 3-hydroxypropionaldehyde and NADPH. Most recently, two independent projects have demonstrated regulation of yqhD by YqhC, where YqhC appears to function as an aldehyde sensor. (orig.)

  3. Anatomic and physiological modifications in seedlings of Coffea arabica cultivar Siriema under drought conditions

    Directory of Open Access Journals (Sweden)

    Emanuelle Ferreira Melo

    2014-02-01

    Full Text Available Due to the weather changes prognostic for the coming years, the understanding of water deficit and physiological responses of plants to drought becomes an important requirement in order to develop technologies such as mechanisms to assist plants to cope with longer drought periods, which will be essential to maintenance of Brazilian and worldwide production. This study aimed to evaluate ecophysiological and anatomical aspects as well as the nitrate reductase activity in Siriema coffee seedlings subjected to four treatments: Daily irrigated, non-irrigated, re-irrigated 24 hours and re-irrigated 48 hours after different stress periods. Non-irrigation promoted a reduction in leaf water potential being accented from the ninth day of evaluation onwards. Re-irrigation promoted a partial recovery of the plant water potential. Non-irrigated plants showed an increase in stomatal resistance and reduction of transpiration and nitrate reductase activity. In the roots, there was a decrease in nitrate reductase activity under water stress. Leaf anatomical modifications were significant only for the adaxial surface epidermis and palisade parenchyma thickness, this latter characteristic being higher in control plants. Stomatal density and polar and equatorial diameter ratios showed the highest values in plants under water stress. In the roots, differences only in the cortex thickness being bigger in the non-irrigated treatment could be observed. Therefore, Siriema coffee plants under water stress show physiological, biochemical and anatomical modifications that contribute to the tolerance of this genotype to these conditions.

  4. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Osman, A.M.; Besten, P.J. den; Noort, P.C.M. van

    2003-10-08

    NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that {center_dot}O{sub 2}{sup -} is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinone, thus circumventing the formation of semiquinone.

  5. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity

    International Nuclear Information System (INIS)

    Osman, A.M.; Besten, P.J. den; Noort, P.C.M. van

    2003-01-01

    NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that ·O 2 - is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinone, thus circumventing the formation of semiquinone

  6. Nitrite-Mediated Hypoxic Vasodilation Predicted from Mathematical Modeling and Quantified from in Vivo Studies in Rat Mesentery

    Directory of Open Access Journals (Sweden)

    Donald G. Buerk

    2017-12-01

    Full Text Available Nitric oxide (NO generated from nitrite through nitrite reductase activity in red blood cells has been proposed to play a major role in hypoxic vasodilation. However, we have previously predicted from mathematical modeling that much more NO can be derived from tissue nitrite reductase activity than from red blood cell nitrite reductase activity. Evidence in the literature suggests that tissue nitrite reductase activity is associated with xanthine oxidoreductase (XOR and/or aldehyde oxidoreductase (AOR. We investigated the role of XOR and AOR in nitrite-mediated vasodilation from computer simulations and from in vivo exteriorized rat mesentery experiments. Vasodilation responses to nitrite in the superfusion medium bathing the mesentery equilibrated with 5% O2 (normoxia or zero O2 (hypoxia at either normal or acidic pH were quantified. Experiments were also conducted following intraperitoneal (IP injection of nitrite before and after inhibiting XOR with allopurinol or inhibiting AOR with raloxifene. Computer simulations for NO and O2 transport using reaction parameters reported in the literature were also conducted to predict nitrite-dependent NO production from XOR and AOR activity as a function of nitrite concentration, PO2 and pH. Experimentally, the largest arteriolar responses were found with nitrite >10 mM in the superfusate, but no statistically significant differences were found with hypoxic and acidic conditions in the superfusate. Nitrite-mediated vasodilation with IP nitrite injections was reduced or abolished after inhibiting XOR with allopurinol (p < 0.001. Responses to IP nitrite before and after inhibiting AOR with raloxifene were not as consistent. Our mathematical model predicts that under certain conditions, XOR and AOR nitrite reductase activity in tissue can significantly elevate smooth muscle cell NO and can serve as a compensatory pathway when endothelial NO production is limited by hypoxic conditions. Our theoretical and

  7. Molecular and phenotypic characterization of transgenic soybean expressing the Arabidopsis ferric chelate reductase gene, FRO2.

    Science.gov (United States)

    Vasconcelos, Marta; Eckert, Helene; Arahana, Venancio; Graef, George; Grusak, Michael A; Clemente, Tom

    2006-10-01

    Soybean (Glycine max Merr.) production is reduced under iron-limiting calcareous soils throughout the upper Midwest regions of the US. Like other dicotyledonous plants, soybean responds to iron-limiting environments by induction of an active proton pump, a ferric iron reductase and an iron transporter. Here we demonstrate that heterologous expression of the Arabidopsis thaliana ferric chelate reductase gene, FRO2, in transgenic soybean significantly enhances Fe(+3) reduction in roots and leaves. Root ferric reductase activity was up to tenfold higher in transgenic plants and was not subjected to post-transcriptional regulation. In leaves, reductase activity was threefold higher in the transgenic plants when compared to control. The enhanced ferric reductase activity led to reduced chlorosis, increased chlorophyll concentration and a lessening in biomass loss in the transgenic events between Fe treatments as compared to control plants grown under hydroponics that mimicked Fe-sufficient and Fe-deficient soil environments. However, the data indicate that constitutive FRO2 expression under non-iron stress conditions may lead to a decrease in plant productivity as reflected by reduced biomass accumulation in the transgenic events under non-iron stress conditions. When grown at Fe(III)-EDDHA levels greater than 10 microM, iron concentration in the shoots of transgenic plants was significantly higher than control. The same observation was found in the roots in plants grown at iron levels higher than 32 microM Fe(III)-EDDHA. These results suggest that heterologous expression of an iron chelate reductase in soybean can provide a route to alleviate iron deficiency chlorosis.

  8. The crystal structure of the bifunctional deaminase/reductase RibD of the riboflavin biosynthetic pathway in Escherichia coli: implications for the reductive mechanism.

    Science.gov (United States)

    Stenmark, Pål; Moche, Martin; Gurmu, Daniel; Nordlund, Pär

    2007-10-12

    We have determined the crystal structure of the bi-functional deaminase/reductase enzyme from Escherichia coli (EcRibD) that catalyzes two consecutive reactions during riboflavin biosynthesis. The polypeptide chain of EcRibD is folded into two domains where the 3D structure of the N-terminal domain (1-145) is similar to cytosine deaminase and the C-terminal domain (146-367) is similar to dihydrofolate reductase. We showed that EcRibD is dimeric and compared our structure to tetrameric RibG, an ortholog from Bacillus subtilis (BsRibG). We have also determined the structure of EcRibD in two binary complexes with the oxidized cofactor (NADP(+)) and with the substrate analogue ribose-5-phosphate (RP5) and superposed these two in order to mimic the ternary complex. Based on this superposition we propose that the invariant Asp200 initiates the reductive reaction by abstracting a proton from the bound substrate and that the pro-R proton from C4 of the cofactor is transferred to C1 of the substrate. A highly flexible loop is found in the reductase active site (159-173) that appears to control cofactor and substrate binding to the reductase active site and was therefore compared to the corresponding Met20 loop of E. coli dihydrofolate reductase (EcDHFR). Lys152, identified by comparing substrate analogue (RP5) coordination in the reductase active site of EcRibD with the homologous reductase from Methanocaldococcus jannaschii (MjaRED), is invariant among bacterial RibD enzymes and could contribute to the various pathways taken during riboflavin biosynthesis in bacteria and yeast.

  9. BIOLOGICAL ROLE OF ALDO-KETO REDUCTASES IN RETINOIC ACID BIOSYNTHESIS AND SIGNALING

    Directory of Open Access Journals (Sweden)

    F. Xavier eRuiz

    2012-04-01

    Full Text Available Several aldo-keto reductase (AKR enzymes from subfamilies 1B and 1C show retinaldehyde reductase activity, having low Km and kcat values. Only AKR1B10 and 1B12, with all-trans-retinaldehyde, and AKR1C3, with 9-cis-retinaldehyde, display high catalytic efficiency. Major structural determinants for retinaldehyde isomer specificity are located in the external loops (A and C for AKR1B10, and B for AKR1C3, as assessed by site-directed mutagenesis and molecular dynamics. Cellular models have shown that AKR1B and 1C enzymes are well suited to work in vivo as retinaldehyde reductases and to regulate retinoic acid (RA biosynthesis at hormone pre-receptor level. An additional physiological role for the retinaldehyde reductase activity of these enzymes, consistent with their tissue localization, is their participation in β-carotene absorption. Retinaldehyde metabolism may be subjected to subcellular compartmentalization, based on enzyme localization. While retinaldehyde oxidation to RA takes place in the cytosol, reduction to retinol could take place in the cytosol by AKRs or in the membranes of endoplasmic reticulum by microsomal retinaldehyde reductases. Upregulation of some AKR1 enzymes in different cancer types may be linked to their induction by oxidative stress and to their participation in different signaling pathways related to cell proliferation. AKR1B10 and AKR1C3, through their retinaldehyde reductase activity, trigger a decrease in the RA biosynthesis flow, resulting in RA deprivation and consequently lower differentiation, with an increased cancer risk in target tissues. Rational design of selective AKR inhibitors could lead to development of novel drugs for cancer treatment as well as reduction of chemotherapeutic drug resistance.

  10. Evaluation of constitutive iron reductase (AtFRO2 expression on mineral accumulation and distribution in soybean (Glycine max. L

    Directory of Open Access Journals (Sweden)

    Marta Wilton Vasconcelos

    2014-04-01

    Full Text Available Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene's expression on root, leaf, pod wall, and seed mineral concentrations. High Fe supply, in combination with the constitutive expression of AtFRO2, resulted in significantly higher concentrations of different minerals in roots (K, P, Zn, Ca, Ni, Mg and Mo, pod walls (Fe, K, P, Cu and Ni, leaves (Fe, P, Cu, Ca, Ni and Mg and seeds (Fe, Zn, Cu and Ni. Leaf and pod wall iron concentrations increased as much as 500% in transgenic plants, while seed iron concentrations only increased by 10%, suggesting that factors other than leaf and pod wall reductase activity were limiting the translocation of iron to seeds. Protoplasts isolated from transgenic leaves had three-fold higher reductase activity than controls. Expression levels of the iron storage protein, ferritin, were higher in the transgenic leaves than in wild-type, suggesting that the excess iron may be stored as ferritin in the leaves and therefore unavailable for phloem loading and delivery to the seeds. Also, citrate and malate levels in the roots and leaves of transgenic plants were significantly higher than in wild-type, suggesting that organic acid production could be related to the increased accumulation of minerals in roots, leaves and pod walls, but not in the seeds. All together, these results suggest a more ubiquitous role for the iron reductase in whole-plant mineral accumulation and

  11. Biochemical and Molecular Phylogenetic Study of Agriculturally Useful Association of a Nitrogen-Fixing Cyanobacterium and Nodule Sinorhizobium with Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    E. V. Karaushu

    2015-01-01

    Full Text Available Seed inoculation with bacterial consortium was found to increase legume yield, providing a higher growth than the standard nitrogen treatment methods. Alfalfa plants were inoculated by mono- and binary compositions of nitrogen-fixing microorganisms. Their physiological and biochemical properties were estimated. Inoculation by microbial consortium of Sinorhizobium meliloti T17 together with a new cyanobacterial isolate Nostoc PTV was more efficient than the single-rhizobium strain inoculation. This treatment provides an intensification of the processes of biological nitrogen fixation by rhizobia bacteria in the root nodules and an intensification of plant photosynthesis. Inoculation by bacterial consortium stimulates growth of plant mass and rhizogenesis and leads to increased productivity of alfalfa and to improving the amino acid composition of plant leaves. The full nucleotide sequence of the rRNA gene cluster and partial sequence of the dinitrogenase reductase (nifH gene of Nostoc PTV were deposited to GenBank (JQ259185.1, JQ259186.1. Comparison of these gene sequences of Nostoc PTV with all sequences present at the GenBank shows that this cyanobacterial strain does not have 100% identity with any organisms investigated previously. Phylogenetic analysis showed that this cyanobacterium clustered with high credibility values with Nostoc muscorum.

  12. ATP-dependent and NAD-dependent modification of glutamine synthetase from Rhodospirillum rubrum in vitro

    International Nuclear Information System (INIS)

    Woehle, D.L.; Lueddecke, B.A.; Ludden, P.W.

    1990-01-01

    Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification. Incubation of R. rubrum cell supernatant with [α- 32 P]NAD results in the labeling of glutamine synthetase and two other unidentified proteins. Dinitrogenase reductase ADP-ribosyltransferase does not appear to be responsible for the modification of glutamine synthetase or the unidentified proteins. The [α- 32 P]ATP- and [α- 32 P] NAD-dependent modifications of R. rubrum glutamine synthetase appear to be exclusive and the two forms of modified glutamine synthetase are separable on two-dimensional gels. Loss of enzymatic activity by glutamine synthetase did not correlate with [α- 32 P]NAD labeling. This is in contrast to inactivation by nonphysiological ADP-ribosylation of other glutamine synthetases by an NAD:arginine ADP-ribosyltransferase from turkey erythrocytes. A 32 P-labeled protein spot comigrates with the NAD-treated glutamine synthetase spot when glutamine synthetase purified from H 3 32 PO 4 -grown cells is analyzed on two-dimensional gels. The adenylylation site of R. rubrum glutamine synthetase has been determined to be Leu-(Asp)-Tyr-Leu-Pro-Pro-Glu-Glu-Leu-Met; the tyrosine residue is the site of modification

  13. Expressed proteins of Herbaspirillum seropedicae in maize (DKB240) roots-bacteria interaction revealed using proteomics.

    Science.gov (United States)

    Ferrari, Cibele Santos; Amaral, Fernanda Plucani; Bueno, Jessica Cavalheiro Ferreira; Scariot, Mirella Christine; Valentim-Neto, Pedro Alexandre; Arisi, Ana Carolina Maisonnave

    2014-11-01

    Several molecular tools have been used to clarify the basis of plant-bacteria interaction; however, the mechanism behind the association is still unclear. In this study, we used a proteomic approach to investigate the root proteome of Zea mays (cv. DKB240) inoculated with Herbaspirillum seropedicae strain SmR1 grown in vitro and harvested 7 days after inoculation. Eighteen differentially accumulated proteins were observed in root samples, ten of which were identified by MALDI-TOF mass spectrometry peptide mass fingerprint. Among the identified proteins, we observed three proteins present exclusively in inoculated root samples and six upregulated proteins and one downregulated protein relative to control. Differentially expressed maize proteins were identified as hypothetical protein ZEAMMB73_483204, hypothetical protein ZEAMMB73_269466, and tubulin beta-7 chain. The following were identified as H. seropedicae proteins: peroxiredoxin protein, EF-Tu elongation factor protein, cation transport ATPase, NADPH:quinone oxidoreductase, dinitrogenase reductase, and type III secretion ATP synthase. Our results presented the first evidence of type III secretion ATP synthase expression during H. seropedicae-maize root interaction.

  14. Comparative proteomics analysis of the rice roots colonized by Herbaspirillum seropedicae strain SmR1 reveals induction of the methionine recycling in the plant host.

    Science.gov (United States)

    Alberton, Dayane; Müller-Santos, Marcelo; Brusamarello-Santos, Liziane Cristina Campos; Valdameri, Glaucio; Cordeiro, Fabio Aparecido; Yates, Marshall Geoffrey; de Oliveira Pedrosa, Fabio; de Souza, Emanuel Maltempi

    2013-11-01

    Although the use of plant growth-promoting bacteria in agriculture is a reality, the molecular basis of plant-bacterial interaction is still poorly understood. We used a proteomic approach to study the mechanisms of interaction of Herbaspirillum seropedicae SmR1 with rice. Root proteins of rice seedlings inoculated or noninoculated with H. seropedicae were separated by 2-D electrophoresis. Differentially expressed proteins were identified by MALDI-TOF/TOF and MASCOT program. Among the identified proteins of H. seropedicae, the dinitrogenase reductase NifH and glutamine synthetase GlnA, which participate in nitrogen fixation and ammonium assimilation, respectively, were the most abundant. The rice proteins up-regulated included the S-adenosylmethionine synthetase, methylthioribose kinase, and acireductone dioxygenase 1, all of which are involved in the methionine recycling. S-Adenosylmethionine synthetase catalyzes the synthesis of S-adenosylmethionine, an intermediate used in transmethylation reactions and in ethylene, polyamine, and phytosiderophore biosynthesis. RT-qPCR analysis also confirmed that the methionine recycling and phytosiderophore biosynthesis genes were up-regulated, while ACC oxidase mRNA level was down-regulated in rice roots colonized by bacteria. In agreement with these results, ethylene production was reduced approximately three-fold in rice roots colonized by H. seropedicae. The results suggest that H. seropedicae stimulates methionine recycling and phytosiderophore synthesis and diminishes ethylene synthesis in rice roots.

  15. Enzymology of biological nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Burris, R.H.

    1992-01-01

    Two genes involved in the regulation of nitrogenase activity, draT and draG, were cloned and found to be contiguous on the Azospirillum brasilense chromosome. The nifH gene, encoding dinitrogenase reductase, is near to draT with an intervening gap of 1.9 kb. The organization of these genes in Azospirillum lipoferum and Rhodosprillum rubrum is similar, but nifH and draT are separated by only 400 bp in the organisms. A. brasilense draTG is very similar to draTG in R. rubrum with 91.8% similarity and 85.3% identity at the amino acid level. Apparently A. brasilense uses the normal ATG initiation codon for draT, and draG. The genes for A. brasilense were able to restore function to appropriate mutants of R. rubrum. The heterologous expression of A. brasilense draTG in R. rubrum was not fully normal, as it responded more slowly to darkness and more quickly to ammonia than wild type cells. Our mutational analysis of the draTG region of A. brasilense confirms the function of these genes in the regulation of nitrogenase activity, but it also revealed minor but demonstrable differences in the control systems of R. rubrum and A. brasilense.

  16. Enzymology of biological nitrogen fixation. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Burris, R.H.

    1992-05-01

    Two genes involved in the regulation of nitrogenase activity, draT and draG, were cloned and found to be contiguous on the Azospirillum brasilense chromosome. The nifH gene, encoding dinitrogenase reductase, is near to draT with an intervening gap of 1.9 kb. The organization of these genes in Azospirillum lipoferum and Rhodosprillum rubrum is similar, but nifH and draT are separated by only 400 bp in the organisms. A. brasilense draTG is very similar to draTG in R. rubrum with 91.8% similarity and 85.3% identity at the amino acid level. Apparently A. brasilense uses the normal ATG initiation codon for draT, and draG. The genes for A. brasilense were able to restore function to appropriate mutants of R. rubrum. The heterologous expression of A. brasilense draTG in R. rubrum was not fully normal, as it responded more slowly to darkness and more quickly to ammonia than wild type cells. Our mutational analysis of the draTG region of A. brasilense confirms the function of these genes in the regulation of nitrogenase activity, but it also revealed minor but demonstrable differences in the control systems of R. rubrum and A. brasilense.

  17. Network analysis reveals ecological links between N-fixing bacteria and wood-decaying fungi.

    Science.gov (United States)

    Hoppe, Björn; Kahl, Tiemo; Karasch, Peter; Wubet, Tesfaye; Bauhus, Jürgen; Buscot, François; Krüger, Dirk

    2014-01-01

    Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase) genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH, almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa.

  18. Network analysis reveals ecological links between N-fixing bacteria and wood-decaying fungi.

    Directory of Open Access Journals (Sweden)

    Björn Hoppe

    Full Text Available Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH, almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa.

  19. Characterization of hydroxyurea (HYU) S49 T lymphoma cells

    International Nuclear Information System (INIS)

    Albert, D.A.; Gudas, L.J.

    1986-01-01

    This paper tests the hypotheses that in vivo ribonucleotide reductase activity and consequent deoxyribonucleoside triphosphate production is rate-limited by the availability of M2 activity. The authors selected and characterized cell lines with variable resistance to hydroxyurea and comparing them with wild type S49 T-lymphoma cells. Ribonucleotide reductase assay was measured and in the process C 14-CDP was added in the final volume of assay mixture. It is shown that hydroxourea reversibly binds to the tyrosine radical of the M2 subunit of ribonucleotide reductase that is required for catalytic activity

  20. Pharmacologically relevant receptor binding characteristics and 5alpha-reductase inhibitory activity of free Fatty acids contained in saw palmetto extract.

    Science.gov (United States)

    Abe, Masayuki; Ito, Yoshihiko; Oyunzul, Luvsandorj; Oki-Fujino, Tomomi; Yamada, Shizuo

    2009-04-01

    Saw palmetto extract (SPE), used widely for the treatment of benign prostatic hyperplasia (BPH) has been shown to bind alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine (1,4-DHP) calcium channel antagonist receptors. Major constituents of SPE are lauric acid, oleic acid, myristic acid, palmitic acid and linoleic acid. The aim of this study was to investigate binding affinities of these fatty acids for pharmacologically relevant (alpha(1)-adrenergic, muscarinic and 1,4-DHP) receptors. The fatty acids inhibited specific [(3)H]prazosin binding in rat brain in a concentration-dependent manner with IC(50) values of 23.8 to 136 microg/ml, and specific (+)-[(3)H]PN 200-110 binding with IC(50) values of 24.5 to 79.5 microg/ml. Also, lauric acid, oleic acid, myristic acid and linoleic acid inhibited specific [(3)H]N-methylscopolamine ([(3)H]NMS) binding in rat brain with IC(50) values of 56.4 to 169 microg/ml. Palmitic acid had no effect on specific [(3)H]NMS binding. The affinity of oleic acid, myristic acid and linoleic acid for each receptor was greater than the affinity of SPE. Scatchard analysis revealed that oleic acid and lauric acid caused a significant decrease in the maximal number of binding sites (B(max)) for [(3)H]prazosin, [(3)H]NMS and (+)-[(3)H]PN 200-110. The results suggest that lauric acid and oleic acid bind noncompetitively to alpha(1)-adrenergic, muscarinic and 1,4-DHP calcium channel antagonist receptors. We developed a novel and convenient method of determining 5alpha-reductase activity using LC/MS. With this method, SPE was shown to inhibit 5alpha-reductase activity in rat liver with an IC(50) of 101 microg/ml. Similarly, all the fatty acids except palmitic acid inhibited 5alpha-reductase activity, with IC(50) values of 42.1 to 67.6 microg/ml. In conclusion, lauric acid, oleic acid, myristic acid, and linoleic acid, major constituents of SPE, exerted binding activities of alpha(1)-adrenergic, muscarinic and 1,4-DHP receptors and inhibited 5

  1. In vivo photoinactivation of Escherichia coli ribonucleoside reductase by near-ultraviolet light

    International Nuclear Information System (INIS)

    Peters, J.

    1977-01-01

    Some experimental work is described showing that near-U.V. irradiation of E.coli cells selectively destroys RDP-reductase (ribonucleoside diphosphate reductase) activity in vivo are providing evidence relating the loss of RDP-reductase to loss of cellular visibility and the inactivity of irrdiated cells to support the replication of DNA phages. The data are consistent with the interpretation that the principal cause in the killing of exponentially growing E.coli cells by near-U.V., and the loss of ability of irradiated host cells to support the replication of DNA phages, is the photoinactivation of the RDP-reductase complex. (U.K.)

  2. Phytotoxic Effects of Cinnamic Acid on Cabbage (Brassica oleracea var. capitata

    Directory of Open Access Journals (Sweden)

    Singh, N. B.

    2013-04-01

    Full Text Available The present study deals with the effects of exogenous application of cinnamic acid (CA on growth and metabolism in growing seedlings of Brassica oleracea var. capitata (cabbage in hydroponic culture. CA was added at 0.5, 1.0 and 1.5 mM concentrations. CA has shown inhibitory effects on shoot and root length, fresh and dry weight of seedlings. CA significantly decreased the photosynthetic pigments, nitrate reductase activity and protein content. Graded concentrations of CA increased lipid peroxidation and sugar content. The increasing concentrations of CA significantly increased the antioxidative enzyme activities viz. superoxide dismutase, catalase, peroxidase against the oxidative stress caused by CA.

  3. Laboratoire de Chimie Bactérienne C.N.R.S., Marsielle, France.

    Science.gov (United States)

    Chippaux, M; Giudici, D; Abou-Jaoudé, A; Casse, F; Pascal, M C

    1978-04-06

    Mutants of E. coli, completely devoid of nitrite reductase activity with glucose or formate as donor were studied. Biochemical analysis indicates that they are simultaneously affected in nitrate reductase, nitrite reductase, fumarate reductase and hydrogenase activities as well as in cytochrome C552 biosynthesis. The use of an antiserum specific for nitrate reductase shows that the nitrate reductase protein is probably missing. A single mutation is responsible for this phenotype: the gene affected, nir R, is located close to tyr R i.e. at 29 min on the chromosomal map.

  4. [Effect of UV-radiation on the level of ascorbic acid, SH-groups, and activity of glutathione reductase in the eye lens].

    Science.gov (United States)

    Byshneva, L N; Senchuk, V V

    2002-01-01

    The effect of UV radiation in vitro on the level of ascorbate, SH-groups and glutathione reductase activity in the soluble fraction of bovine eye lens was studied. UV-Irradiation increased NADPH-oxidoreductase activity, the level of ascorbate oxidation and decreased the content of SH-groups and activity of glutathione reductase. Significant activation of the NADPH-oxidoreductase activity in the presence of ascorbate and Cu2+ was observed after UV-irradiation. It is suggested that ascorbate may play an important role in the UV-induced lens pathology.

  5. Effect of sulphurous gas and γ-radiation upon nitricreductase activity in the lichen Lobaria pulmonaria (L.) Hoffm

    International Nuclear Information System (INIS)

    Shapiro, I.A.; Nifontova, M.G.

    1991-01-01

    A study was made on damaging effect of sulphurous gas and γ-radiation on nitric-reductase activity in the lichen lobaria pulmonaria, sensitive to contamination. The lowest gas concentration (2.0 mg/l) increased the enzyme activity by 32.5%; concentration growth up to 20.3 and 40.6 mg/l caused the enzyme inhibition. Gamma-irradiation dose of 50000 Gy reduced practically twice the activity of nitric reductase, if dry thalli were irradiated. Irradiation of wet lichen by 500 Gy dose activated the enzyme, by 5000 Gy dose - decreased it's activity; nitrate reduction was almost terminated under irradiation by 40000 Gy dose

  6. Optimal copper supply is required for normal plant iron deficiency responses.

    Science.gov (United States)

    Waters, Brian M; Armbrust, Laura C

    2013-01-01

    Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. Understanding crosstalk between Fe and Cu nutrition could lead to strategies for improved growth on soils with low or excess metals, with implications for agriculture and phytoremediation. Here, we show that Cu and Fe nutrition interact to increase or decrease Fe and/or Cu accumulation in leaves and Fe uptake processes. Leaf Cu concentration increased under low Fe supply, while high Cu lowered leaf Fe concentration. Ferric reductase activity, an indicator of Fe demand, was inhibited at insufficient or high Cu supply. Surprisingly, plants grown without Fe were more susceptible to Cu toxicity.

  7. In vivo photoinactivation of Escherichia coli ribonucleoside reductase by near-ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Peters, J [California Univ., Irvine (USA)

    1977-06-09

    Some experimental work is described showing that near-uv irradiation of E.coli cells selectively destroys RDP-reductase (ribonucleoside diphosphate reductase) activity in vivo are providing evidence relating the loss of RDP-reductase to loss of cellular visibility and the inactivity of irrdiated cells to support the replication of DNA phages. The data are consistent with the interpretation that the principal cause in the killing of exponentially growing E.coli cells by near-uv, and the loss of ability of irradiated host cells to support the replication of DNA phages, is the photoinactivation of the RDP-reductase complex.

  8. Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4

    International Nuclear Information System (INIS)

    Short, Duncan M.; Lyon, Robert; Watson, David G.; Barski, Oleg A.; McGarvie, Gail; Ellis, Elizabeth M.

    2006-01-01

    The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a V max of 2141 ± 500 nmol/min/mg and a K m of 11 ± 4 μM. This enzyme was inhibited by pyrazole with a K I of 3.1 ± 0.57 μM. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a V max of 115 nmol/min/mg and a K m of 15 ± 2 μM and was not inhibited by pyrazole

  9. Lactobacillus fermentum CRL1446 Ameliorates Oxidative and Metabolic Parameters by Increasing Intestinal Feruloyl Esterase Activity and Modulating Microbiota in Caloric-Restricted Mice

    Directory of Open Access Journals (Sweden)

    Matias Russo

    2016-07-01

    Full Text Available The purpose of this study was to determine whether the administration of the feruloyl esterase (FE-producing strain Lactobacillus fermentum CRL1446 enhances metabolic and oxidative parameters in caloric-restricted (CR mice. Balb/c male mice were divided into ad libitum fed Group (ALF Group, CR diet Group (CR Group and CR diet plus L. fermentum Group (CR-Lf Group. CR diet was administered during 45 days and CRL1446 strain was given in the dose of 108 cells/mL/day/mouse. FE activity was determined in intestinal mucosa and content at Day 1, 20 and 45. Triglyceride, total cholesterol, glucose, thiobarbituric acid reactive substances (TBARS levels and glutathione reductase activity were determined in plasma. Gut microbiota was evaluated by high-throughput sequencing of 16S rRNA gene amplicons. At Day 45, total intestinal FE activity in CR-Lf Group was higher (p = 0.020 than in CR and ALF groups and an improvement in both metabolic (reductions in triglyceride (p = 0.0025, total cholesterol (p = 0.005 and glucose (p < 0.0001 levels and oxidative (decrease of TBARS levels and increase of plasmatic glutathione reductase activity (p = 0.006 parameters was observed, compared to ALF Group. CR diet increased abundance of Bacteroidetes and CRL1446 administration increased abundance of Bifidobacterium and Lactobacillus genus. L. fermentun CRL1446 exerted a bifidogenic effect under CR conditions.

  10. Treatment performance and microorganism community structure of integrated vertical-flow constructed wetland plots for domestic wastewater.

    Science.gov (United States)

    Wu, Su-qing; Chang, Jun-jun; Dai, Yanran; Wu, Zhen-bin; Liang, Wei

    2013-06-01

    In order to investigate the treatment performance and microorganism mechanism of IVCW for domestic wastewater in central of China, two parallel pilot-scale IVCW systems were built to evaluate purification efficiencies, microbial community structure and enzyme activities. The results showed that mean removal efficiencies were 81.03 % for COD, 51.66 % for total nitrogen (TN), 42.50 % for NH4 (+)-N, and 68.01 % for TP. Significant positive correlations between nitrate reductase activities and TN and NH4 (+)-N removal efficiencies, along with a significant correlation between substrate enzyme activity and operation time, were observed. Redundancy analysis demonstrated gram-negative bacteria were mainly responsible for urease and phosphatase activities, and also played a major role in dehydrogenase and nitrate reductase activities. Meanwhile, anaerobic bacteria, gram-negative bacteria, and saturated FA groups, gram-positive bacteria exhibited good correlations with the removal of COD (p=0.388), N (p=0.236), and TP (p=0.074), respectively. The IVCW system can be used to treat domestic wastewater effectively.

  11. Physiology and enzymology involved in denitrification by Shewanella putrefaciens

    Science.gov (United States)

    Krause, B.; Nealson, K. H.

    1997-01-01

    Nitrate reduction to N2O was investigated in batch cultures of Shewanella putrefaciens MR-1, MR-4, and MR-7. All three strains reduced nitrate to nitrite to N2O, and this reduction was coupled to growth, whereas ammonium accumulation was very low (0 to 1 micromol liter-1). All S. putrefaciens isolates were also capable of reducing nitrate aerobically; under anaerobic conditions, nitrite levels were three- to sixfold higher than those found under oxic conditions. Nitrate reductase activities (31 to 60 micromol of nitrite min-1 mg of protein-1) detected in intact cells of S. putrefaciens were equal to or higher than those seen in Escherichia coli LE 392. Km values for nitrate reduction ranged from 12 mM for MR-1 to 1.3 mM for MR-4 with benzyl viologen as an artifical electron donor. Nitrate and nitrite reductase activities in cell-free preparations were demonstrated in native gels by using reduced benzyl viologen. Detergent treatment of crude and membrane extracts suggested that the nitrate reductases of MR-1 and MR-4 are membrane bound. When the nitrate reductase in MR-1 was partially purified, three subunits (90, 70, and 55 kDa) were detected in denaturing gels. The nitrite reductase of MR-1 is also membrane bound and appeared as a 60-kDa band in sodium dodecyl sulfate-polyacrylamide gels after partial purification.

  12. Exposure of the blue mussel, Mytilus edulis, to gold nanoparticles and the pro-oxidant menadione.

    Science.gov (United States)

    Tedesco, Sara; Doyle, Hugh; Blasco, Julian; Redmond, Gareth; Sheehan, David

    2010-03-01

    Relatively little is known about how gold nanoparticles (GNP) might interact in vivo with marine organisms. Mytilus edulis was exposed (24h) to approximately 15 nm GNP, menadione and both compounds simultaneously (GNP/menadione). GNP was detected by inductively coupled plasma-optical emission spectroscopy mainly in digestive gland of samples exposed to GNP though not GNP/menadione, perhaps due to impaired feeding. Thioredoxin reductase activity and malondialdehyde levels were determined in all tissues. Thioredoxin reductase inhibition was detected only in digestive gland exposed to menadione whilst malondialdehyde levels did not vary in response to treatment in all tissues. GNP caused a decrease in the reduced/oxidized glutathione ratio in digestive gland, but no difference was found in other tissues or for other treatments. One dimensional electrophoresis of proteins containing thiol groups was performed in all tissues and revealed a reduction in protein thiols for all treatments in digestive gland. Two dimensional electrophoresis of digestive gland extracts, from GNP and control groups, showed decreased levels of thiol proteins in response to GNP which we attribute to oxidation. Our results suggest that GNP causes a modest level of oxidative stress sufficient to oxidize thiols in glutathione and proteins but without causing lipid peroxidation or induction of thioredoxin reductase activity.

  13. Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L. and Persea americana Mill.

    Directory of Open Access Journals (Sweden)

    Guy Sedar Singor Njateng

    2018-01-01

    Full Text Available Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana (traditionally used in Cameroon against diabetes on α -glucosidase, β -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α -glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03 to (31.77 ± 1.17 μg/mL. Among the tested extracts, P. americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23. But, none of the extracts showed interesting inhibitory effect against β -glucosidase as their percentage inhibitions were less than 16%. From gas chromatography-mass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P. americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.

  14. Early effects of dietary orotic acid upon liver lipid synthesis and bile cholesterol secretion in rats

    International Nuclear Information System (INIS)

    Tokmakjian, S.D.; Haines, D.S.

    1985-01-01

    Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. The authors found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1- 14 C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl ester was observed. These changes may result from the known decreases in liver levels of adenine nucleotides or, as reported here, from decreased liver CoASH levels in orotic acid-fed rats. The increase in hepatic cholesterol synthesis occurred during the second day of orotic acid feeding. It was detected by increased incorporation of [1,2- 14 C]acetate into cholesterol by liver slices and by a 7-fold increase in HMG-CoA reductase activity. At the same time the biliary output of cholesterol was increased 2-fold and studies using 3 H 2 O revealed that the output of newly synthesized cholesterol in bile was increased 5-fold. The content of cholesteryl ester in hepatic microsomes decreased during orotic acid feeding but free cholesterol was unchanged. The findings are interpreted to suggest that the increased bile cholesterol secretion caused by orotic acid is a result of impaired hepatic cholesterol esterification and that the increase in HMG-CoA reductase activity is a result of diminished negative feedback due to the depleted content of cholesteryl ester in the hepatic microsomes

  15. Antihyperlipidemic effect of Scoparia dulcis (sweet broomweed) in streptozotocin diabetic rats.

    Science.gov (United States)

    Pari, Leelavinothan; Latha, Muniappan

    2006-01-01

    We have investigated Scoparia dulcis, an indigenous plant used in Ayurvedic medicine in India, for its possible antihyperlipidemic effect in rats with streptozotocin-induced experimental diabetes. Oral administration of an aqueous extract of S. dulcis plant (200 mg/kg of body weight) to streptozotocin diabetic rats for 6 weeks resulted in a significant reduction in blood glucose, serum and tissue cholesterol, triglycerides, free fatty acids, phospholipids, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity, and very low-density lipoprotein and low-density lipoprotein cholesterol levels. The decreased serum high-density lipoprotein cholesterol, anti-atherogenic index, and HMG-CoA reductase activity in diabetic rats were also reversed towards normalization after the treatment. Similarly, the administration of S. dulcis plant extract (SPEt) to normal animals resulted in a hypolipidemic effect. The effect was compared with glibenclamide (600 microg/kg of body weight). The results showed that SPEt had antihyperlipidemic action in normal and experimental diabetic rats in addition to its antidiabetic effect.

  16. Identification of Multiple Soluble Fe(III Reductases in Gram-Positive Thermophilic Bacterium Thermoanaerobacter indiensis BSB-33

    Directory of Open Access Journals (Sweden)

    Subrata Pal

    2014-01-01

    Full Text Available Thermoanaerobacter indiensis BSB-33 has been earlier shown to reduce Fe(III and Cr(VI anaerobically at 60°C optimally. Further, the Gram-positive thermophilic bacterium contains Cr(VI reduction activity in both the membrane and cytoplasm. The soluble fraction prepared from T. indiensis cells grown at 60°C was found to contain the majority of Fe(III reduction activity of the microorganism and produced four distinct bands in nondenaturing Fe(III reductase activity gel. Proteins from each of these bands were partially purified by chromatography and identified by mass spectrometry (MS with the help of T. indiensis proteome sequences. Two paralogous dihydrolipoamide dehydrogenases (LPDs, thioredoxin reductase (Trx, NADP(H-nitrite reductase (Ntr, and thioredoxin disulfide reductase (Tdr were determined to be responsible for Fe(III reductase activity. Amino acid sequence and three-dimensional (3D structural similarity analyses of the T. indiensis Fe(III reductases were carried out with Cr(VI reducing proteins from other bacteria. The two LPDs and Tdr showed very significant sequence and structural identity, respectively, with Cr(VI reducing dihydrolipoamide dehydrogenase from Thermus scotoductus and thioredoxin disulfide reductase from Desulfovibrio desulfuricans. It appears that in addition to their iron reducing activity T. indiensis LPDs and Tdr are possibly involved in Cr(VI reduction as well.

  17. Functional properties of myoglobins from five whale species with different diving capacities.

    Science.gov (United States)

    Helbo, Signe; Fago, Angela

    2012-10-01

    Whales show an exceptionally wide range of diving capabilities and many express high amounts of the O(2) carrier protein myoglobin (Mb) in their muscle tissues, which increases their aerobic diving capacity. Although previous studies have mainly focused on the muscle Mb concentration and O(2) carrying capacity as markers of diving behavior in whales, it still remains unexplored whether whale Mbs differ in their O(2) affinities and nitrite reductase and peroxidase enzymatic activities, all functions that could contribute to differences in diving capacities. In this study, we have measured the functional properties of purified Mbs from five toothed whales and two baleen whales and have examined their correlation with average dive duration. Results showed that some variation in functional properties exists among whale Mbs, with toothed whale Mbs having higher O(2) affinities and nitrite reductase activities (similar to those of horse Mb) compared with baleen whale Mbs. However, these differences did not correlate with average dive duration. Instead, a significant correlation was found between whale Mb concentration and average duration and depth of dives, and between O(2) affinity and nitrite reductase activity when including horse Mb. Despite the fact that the functional properties showed little species-specific differences in vitro, they may still contribute to enhancing diving capacity as a result of the increased muscle Mb concentration found in extreme divers. In conclusion, Mb concentration rather than specific functional reactivities may support whale diving performance.

  18. Effect of testosterone replacement on the alteration of steroid metabolism in the hypothalamic-preoptic area of male hamsters treated with melatonin.

    Science.gov (United States)

    Petterborg, L J; West, D A; Rudeen, P K; Ganjam, V K

    1991-11-01

    Adult male hamsters were maintained under 14 hours of light per day and randomly assigned to groups that received daily afternoon melatonin (25 micrograms) or vehicle injections. Animals from both groups were killed following 4, 8, and 12 weeks of treatment. By 12 weeks, the melatonin-treated hamsters had significant reductions in the weights of the testes and seminal vesicles, serum testosterone levels, and activities did not differ between groups. In a second experiment, hamsters were hypothalamic-preoptic area (HPOA) aromatase activities. Hypothalamic-preoptic area 5 alpha-reductase activities did not differ between groups. In a second experiment, hamsters were again treated with melatonin or vehicle for 12 weeks prior to being killed. After 10 weeks of treatment, groups of melatonin-treated animals received subcutaneous silastic capsules (5, 10, or 20 mm) filled with testosterone. Animals in two other groups were given blank implants or no implants at all. Two weeks later, at autopsy, reproductive organ weights, serum testosterone levels, and HPOA aromatase activities were significantly suppressed by melatonin administration. 5 alpha-Reductase activity in the HPOA was not affected. Hamsters that had been given the 10- and 20-mm testosterone implants exhibited normal seminal vesicle weights and HPOA aromatase activities. These results suggest that melatonin-induced reduction of HPOA aromatase activity is mediated by decreased circulating levels of testosterone.

  19. Astragalus polysaccharides lowers plasma cholesterol through mechanisms distinct from statins.

    Directory of Open Access Journals (Sweden)

    Yunjiu Cheng

    Full Text Available To determine the efficacy and underlying mechanism of Astragalus polysaccharides (APS on plasma lipids in hypercholesterolemia hamsters. The effect of APS (0.25 g/kg/d on plasma and liver lipids, fecal bile acids and neutral sterol, cholesterol absorption and synthesis, HMG-CoA reductase activity, and gene and protein expressions in the liver and small intestine was investigated in twenty-four hypercholesterolemia hamsters. Treatment periods lasted for three months. APS significantly lowered plasma total cholesterol by 45.8%, triglycerides by 30%, and low-density lipoprotein-cholesterol by 47.4%, comparable to simvastatin. Further examinations revealed that APS reduced total cholesterol and triglycerides in the liver, increased fecal bile acid and neutral sterol excretion, inhibited cholesterol absorption, and by contrast, increased hepatic cholesterol synthesis and HMG-CoA reductase activity. Plasma total cholesterol or low-density lipoprotein-cholesterol levels were significantly correlated with cholesterol absorption rates. APS up-regulated cholesterol-7α-hydroxylase and LDL-receptor gene expressions. These new findings identify APS as a potential natural cholesterol lowering agent, working through mechanisms distinct from statins.

  20. Ferric reductase genes involved in high-affinity iron uptake are differentially regulated in yeast and hyphae of Candida albicans.

    Science.gov (United States)

    Jeeves, Rose E; Mason, Robert P; Woodacre, Alexandra; Cashmore, Annette M

    2011-09-01

    The pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron-restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form, which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked. It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also makes a significant contribution to cell surface ferric and cupric reductase activity. It is also shown, for the first time, that transcription of FRE10 and FRE7 is lower in hyphae compared to yeast and that this leads to a corresponding decrease in cell surface ferric, but not cupric, reductase activity. This demonstrates that the regulation of two virulence determinants, the reductive iron uptake system and the morphological form of C. albicans, are linked. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Constitutive non-inducible expression of the Arabidopsis thaliana Nia 2 gene in two nitrate reductase mutants of Nicotiana plumbaginifolia.

    Science.gov (United States)

    Kaye, C; Crawford, N M; Malmberg, R L

    1997-04-01

    We have isolated a haploid cell line of N. plumbaginifolia, hNP 588, that is constitutive and not inducible for nitrate reductase. Nitrate reductase mutants were isolated from hNP 588 protoplasts upon UV irradiation. Two of these nitrate reductase-deficient cell lines, nia 3 and nia 25, neither of which contained any detectable nitrate reductase activity, were selected for complementation studies. A cloned Arabidopsis thaliana nitrate reductase gene Nia 2 was introduced into each of the two mutants resulting in 56 independent kanamycin-resistant cell lines. Thirty of the 56 kanamycin-resistant cell lines were able to grow on nitrate as the sole nitrogen source. Eight of these were further analyzed for nitrate reductase enzyme activity and nitrate reductase mRNA production. All eight lines had detectable nitrate reductase activity ranging from 7% to 150% of wild-type hNP 588 callus. The enzyme activity levels were not influenced by the nitrogen source in the medium. The eight lines examined expressed a constitutive, non-inducible 3.2 kb mRNA species that was not present in untransformed controls.

  2. Biological activity of Penaeus monodon GILT in shrimp pathogen protection

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    Aekkaraj Nualla-ong

    2017-04-01

    Full Text Available Gamma-interferon-inducible lysosomal thiol reductase (GILT contains a CXXC active site motif that possesses thiol reductase activity by catalyzing the disulfide bond reduction of exogenous antigens. Mutating the active site of human GILT to change the cysteine residues to serine residues eliminates this property. Our previous study reported that Penaeus monodon GILT (PmGILT contained a CXXS active site motif. Therefore, we assessed the enzymatic activity of PmGILT and demonstrated that it displayed identical thiol reductase activity at an acidic pH. In addition, the biological activity of PmGILT against shrimp pathogens, including white spot syndrome virus (WSSV and Gram-negative bacteria, was investigated. The neutralization of WSSV with PmGILT indicated the inhibition of WSSV invasion into shrimp hemocyte cells. Moreover, the relative percentage survival of shrimp injected with PmGILT-treated virus solution was 75%. Finally, the antimicrobial activity of PmGILT was confirmed by the growth inhibition of Vibrio harveyi. These results establish the role of PmGILT in the inhibition of the virulence of two major shrimp pathogens.

  3. Pectin isolated from prickly pear (Opuntia SSP) modifies LDL metabolism in cholesterol-fed guinea pigs

    International Nuclear Information System (INIS)

    Fernandez, M.L.; McNamara, D.J.

    1990-01-01

    The effects of dietary pectin on plasma and hepatic cholesterol (CH) levels, plasma lipoprotein profiles, hepatic 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase activity, and low density lipoprotein (LDL) binding to hepatic membranes were investigated by feeding 1% pectin to guinea pigs on a high CH diet. Animals were fed either chow + 0.25% CH (HC diet) or the CH diet + 1% prickly pear pectin (HC-P diet) for 25 days. Plasma CH levels were decreased 26% by the HC-P with 33% decreases in LDL and KDL. LDL peak density shifted from 1.040 to 1.055 g/ml with pectin. Hepatic total, free and esterified CH levels were reduced 60, 40 and 85% respectively by the HC-P diet. In contrast, HMG-CoA reductase activity was unaffected. 125 I-LDL binding to hepatic membranes was increased by intake of the HC-P diet compared to the HC diet. The affinity of the apo B/E receptor for LDL was not affected by dietary pectin while the receptor number was increased 1.5-fold in animals on the HC-P diet. These data suggest that the parameters of HC metabolism affected by dietary pectin are consistent with an increased demand on the hepatic CH pools which possibly results from increased fecal excretion of bile acids

  4. Aluminum induced enzymatic disorder as an important eco biomarker in seedlings of lens culinaris medic

    International Nuclear Information System (INIS)

    Azmat, R.; Qamar, N.; Naz, U.

    2015-01-01

    This article discusses the Al (Aluminum) induced disorder on the activities of nitrate and nitrite reductase (NR), protease (PA) and proline contents of seedlings of Lens culinaris as some important eco-biomarkers. The seedlings were cultured hydroponically in the nutrient solution with or without AlCl/sub 3/, 6H/sub 2/O (pH = 4.0) for 15 days. The relative toxicity of Al3+ was found to be directly related with Al concentration in the nutrient medium. The reduction in the seedlings growth may be attributed with the poor root growth which in turns related with an inhibition in the cell division. Al treatments for 15 days increased the nitrate reductase activities in the seedlings while protease activity was decreased. Increase in the proline contents may cause a substantial shield to the enzymes against the detrimental effects of the tense components Al. The essential electrolyte like sodium (Na) and potassium (K) contents were found to be decreased, accredited to the rupturing of cell membrane. These results suggest that inhibition of the root growth by Al, closely related to the metabolic changes including an increase in nitrate reductase activity and decline in proteases activity in of the seedlings. (author)

  5. Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Molle, Virginie; Gulten, Gulcin; Vilchèze, Catherine; Veyron-Churlet, Romain; Zanella-Cléon, Isabelle; Sacchettini, James C.; Jacobs, Jr, William R.; Kremer, Laurent (CNRS-UMR); (Einstein); (TAM)

    2011-08-24

    The remarkable survival ability of Mycobacterium tuberculosis in infected hosts is related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate expression of these lipids in response to environmental changes are unknown. Here we demonstrate that the enoyl-ACP reductase activity of InhA, an essential enzyme of the mycolic acid biosynthetic pathway and the primary target of the anti-tubercular drug isoniazid, is controlled via phosphorylation. Thr-266 is the unique kinase phosphoacceptor, both in vitro and in vivo. The physiological relevance of Thr-266 phosphorylation was demonstrated using inhA phosphoablative (T266A) or phosphomimetic (T266D/E) mutants. Enoyl reductase activity was severely impaired in the mimetic mutants in vitro, as a consequence of a reduced binding affinity to NADH. Importantly, introduction of inhA{_}T266D/E failed to complement growth and mycolic acid defects of an inhA-thermosensitive Mycobacterium smegmatis strain, in a similar manner to what is observed following isoniazid treatment. This study suggests that phosphorylation of InhA may represent an unusual mechanism that allows M. tuberculosis to regulate its mycolic acid content, thus offering a new approach to future anti-tuberculosis drug development.

  6. Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis.

    Science.gov (United States)

    Molle, Virginie; Gulten, Gulcin; Vilchèze, Catherine; Veyron-Churlet, Romain; Zanella-Cléon, Isabelle; Sacchettini, James C; Jacobs, William R; Kremer, Laurent

    2010-12-01

    The remarkable survival ability of Mycobacterium tuberculosis in infected hosts is related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate expression of these lipids in response to environmental changes are unknown. Here we demonstrate that the enoyl-ACP reductase activity of InhA, an essential enzyme of the mycolic acid biosynthetic pathway and the primary target of the anti-tubercular drug isoniazid, is controlled via phosphorylation. Thr-266 is the unique kinase phosphoacceptor, both in vitro and in vivo. The physiological relevance of Thr-266 phosphorylation was demonstrated using inhA phosphoablative (T266A) or phosphomimetic (T266D/E) mutants. Enoyl reductase activity was severely impaired in the mimetic mutants in vitro, as a consequence of a reduced binding affinity to NADH. Importantly, introduction of inhA_T266D/E failed to complement growth and mycolic acid defects of an inhA-thermosensitive Mycobacterium smegmatis strain, in a similar manner to what is observed following isoniazid treatment. This study suggests that phosphorylation of InhA may represent an unusual mechanism that allows M. tuberculosis to regulate its mycolic acid content, thus offering a new approach to future anti-tuberculosis drug development. © 2010 Blackwell Publishing Ltd.

  7. Enhanced bioreduction synthesis of ethyl (R)-4-chloro-3-hydroybutanoate by alkalic salt pretreatment.

    Science.gov (United States)

    Chong, Ganggang; Di, Junhua; Ma, Cuiluan; Wang, Dajing; Wang, Chu; Wang, Lingling; Zhang, Pengqi; Zhu, Jun; He, Yucai

    2018-08-01

    In this study, biomass-hydrolysate was used for enhancing the bioreduction of ethyl 4-chloro-3-oxobutanoate (COBE). Firstly, dilute alkalic salt pretreatment was attempted to pretreat bamboo shoot shell (BSS). It was found that enzymatic in situ hydrolysis of 20-50 g/L BSS pretreated with dilute alkalic salts (0.4% Na 2 CO 3 , 0.032% Na 2 S) at 7.5% sulfidity by autoclaving at 110 °C for 40 min gave sugar yields at 59.9%-73.5%. Moreover, linear relationships were corrected on solid recovery-total delignification-sugar yield. In BSS-hydrolysates, xylose and glucose could promote the reductase activity of recombinant E. coli CCZU-A13. Compared with glucose, hydrolysate could increase the reductase activity by 1.35-folds. Furthermore, the cyclohexane-hydrolysate (10:90, v/v) biphasic media containing ethylene diamine tetraacetic acid (EDTA, 40 mM) and l-glutamine (150 mM) was built for the effective biosynthesis of ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (94.6% yield) from 500 mM COBE. In conclusion, this strategy has high potential for the effective biosynthesis of (R)-CHBE (>99% e.e.). Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Nitrate reductase and photosynthetic activities of wheat and their relationship with plant productivity under soil water deficit conditions (abstract)

    International Nuclear Information System (INIS)

    Ashraf, M.Y.; Sarwar, G.; Hussain, F.

    2005-01-01

    Experiments were conducted in lysimeters with wheat during two consecutive years. The first year experiment comprised of eight wheat genotypes with four water stress treatments, i.e. normal irrigation, pre-anthesis drought, post-anthesis drought and terminal drought, with four replications. The results showed that yield and yield parameters reduced with the severity of drought in all wheat lines. However, wheat lines Chakwal-86, DS-4 and Barani-83 had comparatively higher yield and yield components than others. The maximum reduction in all parameters was under terminal drought. The difference between pre- and post-anthesis drought was nonsignificant, particularly for grain yield. The second experiment was conducted with four wheat lines: two were tolerant (Chakwal-86 and DS-4) and two susceptible (Pavon and DS-17) under similar environments with same treatments to study the photosynthetic efficiency, nitrogen metabolism and their relationship with plant productivity (yield). The results showed that leaf area, transpiration, dry matter accumulation and nitrate reductase activity were reduced while diffusive resistance and total amino acids increased in all the wheat lines under water deficit conditions. The relationship between yield and leaf area, transpiration, dry matter accumulation and nitrate reductase activity was positive. The overall results showed that wheat lines Chakwal-86 and DS-4 showed better performance than others. (author)

  9. Complementary roles for lipid and protein allergens in triggering innate and adaptive immune systems.

    Science.gov (United States)

    Russano, A M; Agea, E; Casciari, C; de Benedictis, F M; Spinozzi, F

    2008-11-01

    Recent advances in allergy research mostly focussed on two major headings: improving protein allergen purification, which is aimed towards a better characterization of IgE- and T-cell reactive epitopes, and the potential new role for unconventional innate and regulatory T cells in controlling airway inflammation. These advancements could appear to be in conflict each other, as innate T cells have a poorly-defined antigen specificity that is often directed toward nonprotein substances, such as lipids. To reconcile these contrasting findings, the model of cypress pollinosis as paradigmatic for studying allergic diseases in adults is suggested. The biochemical characterization of major native protein allergens from undenatured pollen grain demonstrated that the most relevant substance with IgE-binding activity is a glycohydrolase enzyme, which easily denaturizes in stored grains. Moreover, lipids from the pollen membrane are implicated in early pollen grain capture and recognition by CD1(+) dendritic cells (DC) and CD1-restricted T lymphocytes. These T cells display Th0/Th2 functional activity and are also able to produce regulatory cytokines, such as IL-10 and TGF-beta. CD1(+) immature DCs expand in the respiratory mucosa of allergic subjects and are able to process both proteins and lipids. A final scenario may suggest that expansion and functional activation of CD1(+) DCs is a key step for mounting a Th0/Th2-deviated immune response, and that such innate response does not confer long-lasting protective immunity.

  10. VERO cells harbor a poly-ADP-ribose belt partnering their epithelial adhesion belt

    Directory of Open Access Journals (Sweden)

    Laura Lafon-Hughes

    2014-10-01

    Full Text Available Poly-ADP-ribose (PAR is a polymer of up to 400 ADP-ribose units synthesized by poly-ADP-ribose-polymerases (PARPs and degraded by poly-ADP-ribose-glycohydrolase (PARG. Nuclear PAR modulates chromatin compaction, affecting nuclear functions (gene expression, DNA repair. Diverse defined PARP cytoplasmic allocation patterns contrast with the yet still imprecise PAR distribution and still unclear functions. Based on previous evidence from other models, we hypothesized that PAR could be present in epithelial cells where cadherin-based adherens junctions are linked with the actin cytoskeleton (constituting the adhesion belt. In the present work, we have examined through immunofluorescence and confocal microscopy, the subcellular localization of PAR in an epithelial monkey kidney cell line (VERO. PAR was distinguished colocalizing with actin and vinculin in the epithelial belt, a location that has not been previously reported. Actin filaments disruption with cytochalasin D was paralleled by PAR belt disruption. Conversely, PARP inhibitors 3-aminobenzamide, PJ34 or XAV 939, affected PAR belt synthesis, actin distribution, cell shape and adhesion. Extracellular calcium chelation displayed similar effects. Our results demonstrate the existence of PAR in a novel subcellular localization. An initial interpretation of all the available evidence points towards TNKS-1 as the most probable PAR belt architect, although TNKS-2 involvement cannot be discarded. Forthcoming research will test this hypothesis as well as explore the existence of the PAR belt in other epithelial cells and deepen into its functional implications.

  11. Animal models of GM2 gangliosidosis: utility and limitations

    Directory of Open Access Journals (Sweden)

    Lawson CA

    2016-07-01

    Full Text Available Cheryl A Lawson,1,2 Douglas R Martin2,3 1Department of Pathobiology, 2Scott-Ritchey Research Center, 3Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL, USA Abstract: GM2 gangliosidosis, a subset of lysosomal storage disorders, is caused by a deficiency of the glycohydrolase, β-N-acetylhexosaminidase, and includes the closely related Tay–Sachs and Sandhoff diseases. The enzyme deficiency prevents the normal, stepwise degradation of ganglioside, which accumulates unchecked within the cellular lysosome, particularly in neurons. As a result, individuals with GM2 gangliosidosis experience progressive neurological diseases including motor deficits, progressive weakness and hypotonia, decreased responsiveness, vision deterioration, and seizures. Mice and cats are well-established animal models for Sandhoff disease, whereas Jacob sheep are the only known laboratory animal model of Tay–Sachs disease to exhibit clinical symptoms. Since the human diseases are relatively rare, animal models are indispensable tools for further study of pathogenesis and for development of potential treatments. Though no effective treatments for gangliosidoses currently exist, animal models have been used to test promising experimental therapies. Herein, the utility and limitations of gangliosidosis animal models and how they have contributed to the development of potential new treatments are described. Keywords: GM2 gangliosidosis, Tay–Sachs disease, Sandhoff disease, lysosomal storage disorder, sphingolipidosis, brain disease

  12. Animal models of GM2 gangliosidosis: utility and limitations

    Science.gov (United States)

    Lawson, Cheryl A; Martin, Douglas R

    2016-01-01

    GM2 gangliosidosis, a subset of lysosomal storage disorders, is caused by a deficiency of the glycohydrolase, β-N-acetylhexosaminidase, and includes the closely related Tay–Sachs and Sandhoff diseases. The enzyme deficiency prevents the normal, stepwise degradation of ganglioside, which accumulates unchecked within the cellular lysosome, particularly in neurons. As a result, individuals with GM2 gangliosidosis experience progressive neurological diseases including motor deficits, progressive weakness and hypotonia, decreased responsiveness, vision deterioration, and seizures. Mice and cats are well-established animal models for Sandhoff disease, whereas Jacob sheep are the only known laboratory animal model of Tay–Sachs disease to exhibit clinical symptoms. Since the human diseases are relatively rare, animal models are indispensable tools for further study of pathogenesis and for development of potential treatments. Though no effective treatments for gangliosidoses currently exist, animal models have been used to test promising experimental therapies. Herein, the utility and limitations of gangliosidosis animal models and how they have contributed to the development of potential new treatments are described. PMID:27499644

  13. The enhanced radiation response of an in vitro tumour model by cyanide released from hydrolysed amygdalin

    International Nuclear Information System (INIS)

    Biaglow, J.E.; Durand, R.E.

    1978-01-01

    Any inhibition of oxygen consumption by respiring cells should result in indirect radiosensitization of the more centrally located hypoxic cells of a tumour. Amygdalin (D-mandelonitrile-β-D-glucosido-6-β-D-glucoside) when hydrolysed by the enzyme β-D-glucoside glycohydrolase (β-glucosidase) releases the respiratory inhibitor cyanide. A study has been made of the conditions for enhancing the gamma radiation response of multi-cell spheroids of V79 cells by cyanide or by cyanide released by enzymatic hydrolysis of amygdalin. Amygdalin hydrolysis was monitored by the increase in absorbancy at 250nm (production of benzaldehyde). Oxygen utilization was recorded by an oxygen electrode. The respiratory effects produced by the additon of amygdalin to cell suspensions containing β-glucosidase were immediate and essentially the same as those obtained by adding the equivalent amounts of KCN to the cell suspensions. The radio-resistant 'tail' of the survival curve of multi-cell spheroids was reduced in the presence of cyanide (added directly or secondarily released). The radiation response of the spheroids in the presence of cyanide was slightly greater than that for reoxygenation alone. (U.K.)

  14. The Dichotomy of the Poly(ADP-Ribose Polymerase-Like Thermozyme from Sulfolobus solfataricus

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    Maria Rosaria Faraone Mennella

    2018-01-01

    Full Text Available The first evidence of an ADP-ribosylating activity in Archaea was obtained in Sulfolobus solfataricus(strain MT-4 where a poly(ADP-ribose polymerase (PARP-like thermoprotein, defined with the acronymous PARPSso, was found. Similarly to the eukaryotic counterparts PARPSso cleaves beta-nicotinamide adenine dinucleotide to synthesize oligomers of ADP-ribose; cross-reacts with polyclonal anti-PARP-1 catalytic site antibodies; binds DNA. The main differences rely on the molecular mass (46.5 kDa and the thermophily of PARPSso which works at 80 °C. Despite the biochemical properties that allow correlating it to PARP enzymes, the N-terminal and partial amino acid sequences available suggest that PARPSso belongs to a different group of enzymes, the DING proteins, an item discussed in detail in this review.This finding makes PARPSso the first example of a DING protein in Archaea and extends the existence of DING proteins into all the biological kingdoms. PARPSsohas a cell peripheral localization, along with the edge of the cell membrane. The ADP-ribosylation reaction is reverted by a poly(ADP-ribose glycohydrolase-like activity, able to use the eukaryotic poly(ADP-ribose as a substrate too. Here we overview the research of (ADP-ribosylation in Sulfolobus solfataricus in the past thirty years and discuss the features of PARPSso common with the canonical poly(ADP-ribose polymerases, and the structure fitting with that of DING proteins.

  15. Radiation-induced mitotic catastrophe in PARG-deficient cells

    Energy Technology Data Exchange (ETDEWEB)

    Ame, J.Ch.; Fouquerel, E.; Dantzer, F.; De Murcia, G.; Schreiber, V. [IREBS-FRE3211 du CNRS, Universite de Strasbourg, ESBS, Bd Sebastien Brant, BP 10413, 67412 Illkirch Cedex (France); Gauthier, L.R.; Boussin, F.D. [Laboratoire de Radiopathologie/INSERM U967, CEA-DSV-IRCM, 92265 Fontenay aux Roses, Cedex 6 (France); Biard, D. [CEA-DSV-IRCM/INSERM U935, Institut A. Lwoff-CNRS, BP 8, 94801 Villejuif cedex (France)

    2009-07-01

    Poly(ADP-ribosyl)ation is a post-translational modification of proteins involved in the regulation of chromatin structure, DNA metabolism, cell division and cell death. Through the hydrolysis of poly(ADP-ribose) (PAR), Poly(ADP-ribose) glyco-hydrolase (PARG) has a crucial role in the control of life-and-death balance following DNA insult. Comprehension of PARG function has been hindered by the existence of many PARG isoforms encoded by a single gene and displaying various subcellular localizations. To gain insight into the function of PARG in response to irradiation, we constitutively and stably knocked down expression of PARG isoforms in HeLa cells. PARG depletion leading to PAR accumulation was not deleterious to undamaged cells and was in fact rather beneficial, because it protected cells from spontaneous single-strand breaks and telomeric abnormalities. By contrast, PARG-deficient cells showed increased radiosensitivity, caused by defects in the repair of single- and double-strand breaks and in mitotic spindle checkpoint, leading to alteration of progression of mitosis. Irradiated PARG-deficient cells displayed centrosome amplification leading to mitotic supernumerary spindle poles, and accumulated aberrant mitotic figures, which induced either polyploidy or cell death by mitotic catastrophe. Our results suggest that PARG could be a novel potential therapeutic target for radiotherapy. (authors)

  16. NADP+ enhances cholera and pertussis toxin-catalyzed ADP-ribosylation of membrane proteins

    International Nuclear Information System (INIS)

    Kawai, Y.; Whitsel, C.; Arinze, I.J.

    1986-01-01

    Cholera or pertussis toxin-catalyzed [ 32 P]ADP-ribosylation is frequently used to estimate the concentration of the stimulatory (Ns) or inhibitory (Ni) guanine nucleotide regulatory proteins which modulate the activity of adenylate cyclase. With this assay, however, the degradation of the substrate, NAD + , by endogenous enzymes such as NAD + -glycohydrolase (NADase) present in the test membranes can influence the results. In this study the authors show that both cholera and pertussis toxin-catalyzed [ 32 P]ADP-ribosylation of liver membrane proteins is markedly enhanced by NADP + . The effect is concentration dependent; with 20 μM [ 32 P]NAD + as substrate maximal enhancement is obtained at 0.5-1.0 mM NADP + . The enhancement of [ 32 P]ADP-ribosylation by NADP + was much greater than that by other known effectors such as Mg 2+ , phosphate or isoniazid. The effect of NADP + on ADP-ribosylation may occur by inhibition of the degradation of NAD + probably by acting as an alternate substrate for NADase. Among inhibitors tested (NADP + , isoniazid, imidazole, nicotinamide, L-Arg-methyl-ester and HgCl 2 ) to suppress NADase activity, NADP + was the most effective and, 10 mM, inhibited activity of the enzyme by about 90%. In membranes which contain substantial activities of NADase the inclusion of NADP + in the assay is necessary to obtain maximal ADP-ribosylation

  17. Metaproteomic identification of diazotrophic methanotrophs and their localization in root tissues of field-grown rice plants.

    Science.gov (United States)

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi; Minamisawa, Kiwamu

    2014-08-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Nitrogen fixation in denitrified marine waters.

    Directory of Open Access Journals (Sweden)

    Camila Fernandez

    Full Text Available Nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. Currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria, whereas nitrogen losses occur in oxygen-depleted intermediate waters and sediments (mostly via denitrifying and anammox bacteria. Here we report on rates of nitrogen fixation obtained during two oceanographic cruises in 2005 and 2007 in the eastern tropical South Pacific (ETSP, a region characterized by the presence of coastal upwelling and a major permanent oxygen minimum zone (OMZ. Our results show significant rates of nitrogen fixation in the water column; however, integrated rates from the surface down to 120 m varied by ∼30 fold between cruises (7.5±4.6 versus 190±82.3 µmol m(-2 d(-1. Moreover, rates were measured down to 400 m depth in 2007, indicating that the contribution to the integrated rates of the subsurface oxygen-deficient layer was ∼5 times higher (574±294 µmol m(-2 d(-1 than the oxic euphotic layer (48±68 µmol m(-2 d(-1. Concurrent molecular measurements detected the dinitrogenase reductase gene nifH in surface and subsurface waters. Phylogenetic analysis of the nifH sequences showed the presence of a diverse diazotrophic community at the time of the highest measured nitrogen fixation rates. Our results thus demonstrate the occurrence of nitrogen fixation in nutrient-rich coastal upwelling systems and, importantly, within the underlying OMZ. They also suggest that nitrogen fixation is a widespread process that can sporadically provide a supplementary source of fixed nitrogen in these regions.

  19. Corals Form Characteristic Associations with Symbiotic Nitrogen-Fixing Bacteria

    Science.gov (United States)

    Lema, Kimberley A.; Willis, Bette L.

    2012-01-01

    The complex symbiotic relationship between corals and their dinoflagellate partner Symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). In this study, we investigated the diversity of diazotrophic bacterial communities associated with three common coral species (Acropora millepora, Acropora muricata, and Pocillopora damicormis) from three midshelf locations of the Great Barrier Reef (GBR) by profiling the conserved subunit of the nifH gene, which encodes the dinitrogenase iron protein. Comparisons of diazotrophic community diversity among coral tissue and mucus microenvironments and the surrounding seawater revealed that corals harbor diverse nifH phylotypes that differ between tissue and mucus microhabitats. Coral mucus nifH sequences displayed high heterogeneity, and many bacterial groups overlapped with those found in seawater. Moreover, coral mucus diazotrophs were specific neither to coral species nor to reef location, reflecting the ephemeral nature of coral mucus. In contrast, the dominant diazotrophic bacteria in tissue samples differed among coral species, with differences remaining consistent at all three reefs, indicating that coral-diazotroph associations are species specific. Notably, dominant diazotrophs for all coral species were closely related to the bacterial group rhizobia, which represented 71% of the total sequences retrieved from tissue samples. The species specificity of coral-diazotroph associations further supports the coral holobiont model that bacterial groups associated with corals are conserved. Our results suggest that, as in terrestrial plants, rhizobia have developed a mutualistic relationship with corals and may contribute fixed nitrogen to Symbiodinium. PMID:22344646

  20. Nitrogen Fixation in Denitrified Marine Waters

    Science.gov (United States)

    Fernandez, Camila; Farías, Laura; Ulloa, Osvaldo

    2011-01-01

    Nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. Currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria), whereas nitrogen losses occur in oxygen-depleted intermediate waters and sediments (mostly via denitrifying and anammox bacteria). Here we report on rates of nitrogen fixation obtained during two oceanographic cruises in 2005 and 2007 in the eastern tropical South Pacific (ETSP), a region characterized by the presence of coastal upwelling and a major permanent oxygen minimum zone (OMZ). Our results show significant rates of nitrogen fixation in the water column; however, integrated rates from the surface down to 120 m varied by ∼30 fold between cruises (7.5±4.6 versus 190±82.3 µmol m−2 d−1). Moreover, rates were measured down to 400 m depth in 2007, indicating that the contribution to the integrated rates of the subsurface oxygen-deficient layer was ∼5 times higher (574±294 µmol m−2 d−1) than the oxic euphotic layer (48±68 µmol m−2 d−1). Concurrent molecular measurements detected the dinitrogenase reductase gene nifH in surface and subsurface waters. Phylogenetic analysis of the nifH sequences showed the presence of a diverse diazotrophic community at the time of the highest measured nitrogen fixation rates. Our results thus demonstrate the occurrence of nitrogen fixation in nutrient-rich coastal upwelling systems and, importantly, within the underlying OMZ. They also suggest that nitrogen fixation is a widespread process that can sporadically provide a supplementary source of fixed nitrogen in these regions. PMID:21687726

  1. The uptake and accumulation of phosphorous and nitrates and the activity of nitrate reductase in cucumber seedlings treated with PbCl2 or CdCl2

    Directory of Open Access Journals (Sweden)

    Marek Burzyński

    2014-01-01

    Full Text Available Treatment of 4-day-old cucumber (Cucumis sativus L. seedlings with PbCl2 or CdCl2 caused a significant increase in the accumulation of heavy metals by the plants, especially in the roots. The accumulated Pb initially enhanced the uptake of phosphorous after the plants had been transferred to a nutrient medium (6, 24 hrs, but after only 48 Ins the uptake had dropped to below control level. The plants treated with Cd exhibited a constant decreased phosphorous uptake level. The accumulated lead and cadmium also inhibited nitrate uptake and the activity of nitrate reductase. It is suggested that the reason for the decreased nitrate reductase activity lay rather in the lower nitrate uptake than in a direct effect of the heavy metals on the enzyme.

  2. Failure of isolated rat tibial periosteal cells to 5 alpha reduce testosterone to 5 alpha-dihydrotestosterone

    International Nuclear Information System (INIS)

    Turner, R.T.; Bleiberg, B.; Colvard, D.S.; Keeting, P.E.; Evans, G.; Spelsberg, T.C.

    1990-01-01

    Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-alpha 2(I) chain of type 1 precollagen. The isolated periosteal cells were incubated with 1 nM [3H]testosterone [( 3 H]T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. [ 3 H]5 alpha-dihydrotestosterone [( 3 H]DHT) was not detected in extracts of periosteal cell incubations. In contrast, [ 3 H]DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5 alpha-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT

  3. VISUALIZATION OF BIOCHEMICAL ACTIVITY OF MICROORGANISMS GENUS AEROCOCCUS SPECIES AEROCOCCUS VIRIDANS

    Directory of Open Access Journals (Sweden)

    Stepansky DO

    2016-03-01

    Full Text Available Introduction. Aerococci are catalase-negative Gram-positive microorganisms, widespread in the environment, in the cold-blooded microbiocenoses [1, 2] and warm-blooded organisms [3]. Currently, there are seven species of the Aerococcus genus [4]. Type A. viridans got its name as a result of greening blood agar around the growing colonies. It was found that one of the products of A. viridans growth is hydrogen peroxide, has an antagonistic effect on various kinds of bacteria "in vitro" and "in vivo" [5]. It was subsequently found that hydrogen peroxide and superoxide radical are produced as a result of NAD-independent lactatoxidase [6,7] and piruvatoxidase functioning[8]. The oxidative ability of A. viridans is a distinctive feature and allows to visualize these properties using a specific indicator medium [9]. We have developed an indicator that enables to visualize oxidation and reduction properties of aerococci. Material & methods. Auto-symbiotic cultures of A. viridans was used for studying of oxidase - reductase activity, inoculated from human body, an industrial strain of A. viridans 167, used for the preparation of "A-bacterin", culture of Aureobasidium pullulans B5, isolated from the soil and having glucose oxidase activity [10]. Designed indicating medium were also tested in the inoculation of aerococci crops, having lactatoxidase activity of biomaterials from birds and mammals. As a basis for the indicating media (IM IM1 media was selected with following composition (g per 1 liter of water Iodide / potassium 26.0 Soluble starch 10.0 Nutrient agar 30.0 For visualization of oxidase-reductase activity of aerococci acellular components IM4 was developed based on IM3, in which distilled water after double purification was used instead of tap water and highly purified agar-agar was used instead of standard nutrient agar. Results & discussion. IM1 is used to test the oxidative properties of aerococci crops. IM manifests the appearance of a dark

  4. Aqueous extract from Vitis vinifera tendrils is able to enrich keratinocyte antioxidant defences.

    Science.gov (United States)

    Fraternale, Daniele; De Bellis, Roberta; Calcabrini, Cinzia; Potenza, Lucia; Cucchiarini, Luigi; Mancini, Umberto; Dachà, Marina; Ricci, Donata

    2011-09-01

    An aqueous extract of V. vinifera L. tendrils was evaluated for its ability to enrich the antioxidant capacity of cultured cells. The long-time antioxidant capability of the extract was measured by in vitro chemical methods, and its influence on reduced glutathione levels and plasma membrane oxido reductase activity was determined in cultured human keratinocytes (NCTC 2544). Keratinocytes are cells normally exposed to oxidative stress, and for this reason adequately equipped with antioxidant defences. However, it has long been suggested that exogenous antioxidants may play an important role in minimizing the adverse effects of oxidative stress on skin.We demonstrated that V. vinifera tendril aqueous extract was able to increase, in a time- and dose-dependent manner, the reduced glutathione concentration and activity of trans plasma membrane oxido reductase as an indirect evaluation of the intracellular redox status of the cells demonstrating a relevant antioxidant activity of this phytocomplex.

  5. Physiology of inactivation of microbial cells by near-ultraviolet light: mode of action and application for the enrichment of mutants of Escherichia coli and saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Peters, J.

    1976-01-01

    The mode of action of near-ultraviolet (NUV) light was studied in Escherichia coli. NUV light (maximum emission at 365 nm) caused the photodestruction of ribonucleoside diphosphate (RDP) reductase activity in vivo. Evidence was presented for a model suggesting that the loss of RDP-reductase resulted in a metabolic state analogous to that produced during starvation for thymine. Some important properties of cells irradiated by NUV light, cell death, loss of the ability to support the replication of DNA phages and a delay in the onset of cell division in sublethally irradiated cells, were accounted for in terms of photoinactivation of RDP-reductase. Conditions were described under which NUV light was an effective counterselective agent for the enrichment of mutants of Escherichia coli and Saccharomyces cerevisiae

  6. Hypolipidemic effect of hemicellulose component of coconut fiber.

    Science.gov (United States)

    Sindhurani, J A; Rajamohan, T

    1998-08-01

    The neutral detergent fiber (NDF) isolated from coconut kernel was digested with cellulase and hemicellulase and the residual fiber rich in hemicellulose (without cellulose) and cellulose (with out hemicellulose) were fed to rats and compared with a fiber free group. The results indicate that hemicellulose rich fiber showed decreased concentration of total cholesterol, LDL + VLDL cholesterol and increased HDL cholesterol, while cellulose rich fiber showed no significant alteration. There was increased HMG CoA reductase activity and increased incorporation of labeled acetate into free cholesterol. Rats fed hemicellulose rich coconut fiber produced lower concentration of triglycerides and phospholipids and lower release of lipoproteins into circulation. There was increased concentration of hepatic bile acids and increased excretion of faecal sterols and bile acids. These results indicate that the hemicellulose component of coconut fiber was responsible for the observed hypolipidemic effect.

  7. Circulating nitric oxide metabolites and cardiovascular changes in the turtle Trachemys scripta during normoxia, anoxia and reoxygenation

    DEFF Research Database (Denmark)

    Jacobsen, Søren B; Hansen, Marie N; Jensen, Nini Skovgaard

    2012-01-01

    Turtles of the genus Trachemys show a remarkable ability to survive prolonged anoxia. This is achieved by a strong metabolic depression, redistribution of blood flow and high levels of antioxidant defence. To understand whether nitric oxide (NO), a major regulator of vasodilatation and oxygen...... consumption, may be involved in the adaptive response of Trachemys to anoxia, we measured NO metabolites (nitrite, S-nitroso, Fe-nitrosyl and N-nitroso compounds) in the plasma and red blood cells of venous and arterial blood of Trachemys scripta turtles during normoxia and after anoxia (3 h......-nitroso compounds were present at high micromolar levels under normoxia and increased further after anoxia and reoxygenation, suggesting NO generation from nitrite catalysed by deoxygenated haemoglobin, which in turtle had a higher nitrite reductase activity than in hypoxia-intolerant species. Taken together...

  8. Cadmium phytoextraction potential of poplar clones (Populus spp.)

    Energy Technology Data Exchange (ETDEWEB)

    Pilipovic, A.; Orlovic, S.; Petrovic, N. [Faculty of Agriculture, Inst. of Lowland Forestry and Environment, Novi Sad (Czechoslovakia); Nikolic, N.; Krstic, B. [Faculty of Natural Sciences, Dept. of Biology and Ecology, Novi Sad (Czechoslovakia)

    2005-04-01

    Biomass production, leaf number and area, photosynthetic and dark respiration rates, leaf concentration of photosynthetic pigments, nitrate reductase activity, as well as cadmium concentrations in leaves, stem, and roots were measured in poplar clones PE 4/68, B-229, 665, and 45/51. Plants were grown hydroponically under controlled conditions and treated with two different cadmium (Cd) concentrations (10{sup -5} and 10{sup -7} M) in the same background solution (Hoagland's solution). The presence of Cd did not cause serious disturbance of growth and physiological parameters in the studied poplar clones. Cd concentrations in plant tissues reflected external concentrations. In treated plants, root contents increased from 38.57 to 511.51 ppm, leaf contents from 0.91 to 7.50, while stem contents ranged from 1.37 to 9.50 ppm. (orig.)

  9. Effects of whole body x-ray irradiation on induction by phenobarbital of rat liver glucose-6-phosphate dehydrogenase and glutathione reductase

    Energy Technology Data Exchange (ETDEWEB)

    Bitny-Szlachto, S.; Szyszko, A. (Wojskowy Inst. Higieny i Epidemiologii, Warsaw (Poland))

    1979-01-01

    In rats treated with phenobarbital (3x100 mg/kg, i.p.), liver G-6-P dehydrogenase activity increased by 70% in the cytosol and in the 9.000xg supernatant, and only by 20% in microsomes. Moreover, the phenobarbital treatment increased rat liver GSSG reductase activity by 30%. On the other hand, activity of the liver microsomal G-6-P dehydrogenase was found to increase by some 20% in whole body irradiated, both control and phenobarbital treated rats. In rats irradiated with 600 R prior to the first dose of the inducer there was not noted any increase in G-6-P dehydrogenase of the 9.000xg supernatant, and increase in the cytosol activity dropped to 38%. Thus, induction of the soluble liver G-6-P dehydrogenase by phenobarbital has turned out to be radiosensitive, whereas phenobarbital induction of GSSG reductase was unaffected by irradiation.

  10. Respiratory arsenate reductase as a bidirectional enzyme

    Science.gov (United States)

    Richey, C.; Chovanec, P.; Hoeft, S.E.; Oremland, R.S.; Basu, P.; Stolz, J.F.

    2009-01-01

    The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encode a putative respiratory arsenate reductase (Arr). Here we show that one homolog is expressed under chemolithoautotrophic conditions and exhibits both arsenite oxidase and arsenate reductase activity. We also demonstrate that Arr from two arsenate respiring bacteria, Alkaliphilus oremlandii and Shewanella sp. strain ANA-3, is also biochemically reversible. Thus Arr can function as a reductase or oxidase. Its physiological role in a specific organism, however, may depend on the electron potentials of the molybdenum center and [Fe–S] clusters, additional subunits, or constitution of the electron transfer chain. This versatility further underscores the ubiquity and antiquity of microbial arsenic metabolism.

  11. Seasonal pattern of metal bioaccumulation and their toxicity on Sphagnum squarrosum.

    Science.gov (United States)

    Saxena, Anuj

    2006-01-01

    Present study was undertaken as an attempt to study the effect of pollutants on biological responses of Sphagnum growing at Kainchi, Kumaon hills (Uttranchal). Sphagnum plants of almost identical size, collected from the marked sites of Kainchi in different seasons viz., monsoon, winter, summer and again in monsoon, were analysed for chlorophyll, protein, shoot length and nitrate reductase and peroxidase activities. Maximum chlorophyll, protein, shoots length and nitrate reductase activities were observed during the monsoon while minimum in summers. The abundance of Sphagnum and two other bryophytes, Marchantia and Plagiochasma was also higher in monsoon than in other seasons. The study also indicated that Sphagnum has more bioaccumulation and tolerance potential for heavy metals than Marchantia and Plagiochasma.

  12. Bacteria, hypertolerant to arsenic in the rocks of an ancient gold mine, and their potential role in dissemination of arsenic pollution.

    Science.gov (United States)

    Drewniak, Lukasz; Styczek, Aleksandra; Majder-Lopatka, Malgorzata; Sklodowska, Aleksandra

    2008-12-01

    The aim of the present study was to find out if bacteria present in ancient gold mine could transform immobilized arsenic into its mobile form and increase its dissemination in the environment. Twenty-two arsenic-hypertolerant cultivable bacterial strains were isolated. No chemolithoautotrophs, which could use arsenite as an electron donor as well as arsenate as an electron acceptor, were identified. Five isolates exhibited hypertolerance to arsenic: up to 500mM of arsenate. A correlation between the presence of siderophores and high resistance to arsenic was found. The results of this study show that detoxification processes based on arsenate reductase activity might be significant in dissemination of arsenic pollution. It was concluded that the activity of the described heterotrophic bacteria contributes to the mobilization of arsenic in the more toxic As(III) form and a new mechanism of arsenic mobilization from a scorodite was proposed.

  13. Effects of commonly consumed fruit juices and carbohydrates on redox status and anticancer biomarkers in female rats

    DEFF Research Database (Denmark)

    Breinholt, Vibeke M.; Nielsen, Salka E.; Knuthsen, Pia

    2003-01-01

    /kg of diet. However, no effects were observed on hepatic glutathione S-transferase or quinone reductase activities, plasma redox status, or the activity of red blood cell antioxidant enzymes. Overall, the results of the present study suggest that commonly consumed fruit juices can alter lipid and protein......Administration of apple juice, black currant juice, ora 1:1 combination of the two juices significantly decreased the level of the lipid peroxidation biomarker malondialdehyde in plasma of female rats, whereas the protein oxidation biomarker 2-amino-adipic semialdehyde, was significantly increased...... following administration of orange juice, black currant juice, or the 1: 1 combination of apple and black currant juice. A significant increase in 2-amino-adipic semialdehyde was also observed in control rats given sucrose, fructose, and glucose in the drinking water at concentrations approximating...

  14. Synthesis of a phosphorothioate derivative of flavin mononucleotide

    International Nuclear Information System (INIS)

    Calhoun, J.P.; Miziorko, H.M.; Otvos, J.D.; Masters, B.S.S.

    1987-01-01

    The synthesis of riboflavin-5'-phosphorothioate (5'-FMNS), an analog of riboflavin-5'-phosphate (FMN), is described. 5'-FMNS is produced from the alkaline hydrolysis of riboflavin-4',5'-cyclic phosphorothioate (cFMNS). The cyclic phosphorothioate is produced upon reaction of riboflavin with thiophosphoryl chloride in trimethyl phosphate. The phosphorothioate compounds have been characterized by 13 C and 31 P NMR and the purified 5'-FMNS is isolated by preparative HPLC. Preliminary results indicate that this analog of FMN is capable of replacing FMN in at least on flavoprotein, NADPH-cytochrome P-450 reductase, and is competent in reconstituting the cytochrome c reductase activity of this enzyme. Full characterization of this derivatized flavoprotein is in progress

  15. Structural basis for target protein recognition by the protein disulfide reductase thioredoxin

    DEFF Research Database (Denmark)

    Maeda, Kenji; Hägglund, Per; Finnie, Christine

    2006-01-01

    Thioredoxin is ubiquitous and regulates various target proteins through disulfide bond reduction. We report the structure of thioredoxin (HvTrxh2 from barley) in a reaction intermediate complex with a protein substrate, barley alpha-amylase/subtilisin inhibitor (BASI). The crystal structure...... of this mixed disulfide shows a conserved hydrophobic motif in thioredoxin interacting with a sequence of residues from BASI through van der Waals contacts and backbone-backbone hydrogen bonds. The observed structural complementarity suggests that the recognition of features around protein disulfides plays...... a major role in the specificity and protein disulfide reductase activity of thioredoxin. This novel insight into the function of thioredoxin constitutes a basis for comprehensive understanding of its biological role. Moreover, comparison with structurally related proteins shows that thioredoxin shares...

  16. Investigations on the effect of flavonoids from banana, Musa paradisiaca L. on lipid metabolism in rats.

    Science.gov (United States)

    Vijayakumar, S; Presannakumar, G; Vijayalakshmi, N R

    2009-01-01

    Oral administration of flavonoids extracted from unripe fruits of Musa paradisiaca showed significant hypolipidemic activities in male rats (Sprague Dawley strain) at a dose of 1 mg/100 g body weight (BW)/day. Concentrations of cholesterol, phospholipids, free fatty acids, and triglycerides showed significant decrease in the serum, liver, kidney, and brain of experimental animals. HMG CoA reductase activity was found to be enhanced, while activities of glucose-6-phosphate dehydrogenase and malate dehydrogenase were significantly reduced. Activities of lipoprotein lipase and plasma LCAT showed significant enhancement. A significant increase in the concentrations of hepatic and fecal bile acids and fecal neutral sterols was also observed indicating a higher rate of degradation of cholesterol. The present study indicates that although there is an increase in the rate of synthesis of cholesterol in the liver, the process of degradation exceeds the rate of synthesis.

  17. Chemical profile of mango (Mangifera indica L.) using electrospray ionisation mass spectrometry (ESI-MS).

    Science.gov (United States)

    Oliveira, Bruno G; Costa, Helber B; Ventura, José A; Kondratyuk, Tamara P; Barroso, Maria E S; Correia, Radigya M; Pimentel, Elisângela F; Pinto, Fernanda E; Endringer, Denise C; Romão, Wanderson

    2016-08-01

    Mangifera indica L., mango fruit, is consumed as a dietary supplement with purported health benefits; it is widely used in the food industry. Herein, the chemical profile of the Ubá mango at four distinct maturation stages was evaluated during the process of growth and maturity using negative-ion mode electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI(-)FT-ICR MS) and physicochemical characterisation analysis (total titratable acidity (TA), total soluble solids (TSS), TSS/TA ratio, and total polyphenolic content). Primary (organic acids and sugars) and secondary metabolites (polyphenolic compounds) were mostly identified in the third maturation stage, thus indicating the best stage for harvesting and consuming the fruit. In addition, the potential cancer chemoprevention of the secondary metabolites (phenolic extracts obtained from mango samples) was evaluated using the induction of quinone reductase activity, concluding that fruit polyphenols have the potential for cancer chemoprevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Cholesterol biosynthesis in polychlorinated biphenyl-treated rats

    International Nuclear Information System (INIS)

    Kling, D.; Gamble, W.

    1982-01-01

    After administration of polychlorinated biphenly (PCB) at 0.055 (w/w) of the diet to Wistar rats for 30 days, followed by intraperitioneal injection of tritiated water, [ 14 C]mevalonate, and [ 14 C]acetate, there was a decrease in cholesterol biosynthesis in rat liver. No significant change in cholesterol formation was observed when PCB was administered at 0.01% (w/w) of the diet. In vitro inhibition of cholesterol synthesis by rat liver microsomes was observed with PCB. Squalene 2,3-oxidocyclase activity of rat liver microsomes was not significantly altered. Desmosterol delta 24 reductase activity was inhibited only at relatively high concentrations of PCB. There was increased incorporation of radioactivity into squalene and lanosterol, in vitro, in the presence of PCB. The primary inhibition of cholesterol biosynthesis appears to be at the demethylation and rearrangement reactions between lanosterol and cholesterol in the biosynthetic pathway

  19. Influence of acute and chronic administration of methadone hydrochloride on NADPH-cytochrome c reductase and cytochrome P-450 of mouse liver microsomes.

    Science.gov (United States)

    Datta, R K; Johnson, E A; Bhattacharjee, G; Stenger, R J

    1976-03-01

    Administration of a single acute dose (20 mg/kg body weight) of methadone hydrochloride to both male and female mice increased the specific activity of NADPH-cytochrome c reductase and did not change much the content of cytochrome P-450 of their liver microsomes. Administration of multiple acute doses of methadone in male mice increased the specific activity of cytochrome c reductase and the content of cytochrome P-450 of their liver microsomes. Chronic administration of progressively increasing doses of methadone (up to 40 mg/kg body weight) to male mice increased the specific activity of c reductase. Similar chronic administration of methadone up to 28 mg/kg body weight also increased the microsomal content of P-450, but with higher doses of methadone, the content of P-450 declined and finally dropped slightly below control levels. The levels of c reductase activity and P-450 content returned to normal about two weeks after discontinuation of methadone administration.

  20. Altered carbohydrate, lipid, and xenobiotic metabolism by liver from rats flown on Cosmos 1887

    Science.gov (United States)

    Merrill, A. H. Jr; Hoel, M.; Wang, E.; Mullins, R. E.; Hargrove, J. L.; Jones, D. P.; Popova, I. A.; Merrill AH, J. r. (Principal Investigator)

    1990-01-01

    To determine the possible biochemical effects of prolonged weightlessness on liver function, samples of liver from rats that had flown aboard Cosmos 1887 were analyzed for protein, glycogen, and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the glycogen content and hydroxymethylglutaryl-CoA (HMG-CoA) reductase activities for the rats flown on Cosmos 1887 and decreases in the amount of microsomal cytochrome P-450 and the activities of aniline hydroxylase and ethylmorphine N-demethylase, cytochrome P-450-dependent enzymes. These results support the earlier finding of differences in these parameters and suggest that altered hepatic function could be important during spaceflight and/or the postflight recovery period.

  1. Binding of 7-dehydrocholesterol to sterol carrier protein and vitamin D3 effect

    International Nuclear Information System (INIS)

    Takase, Sachiko; Oizumi, Kumiko; Moriuchi, Sachiko; Hosoya, Norimasa

    1975-01-01

    It was confirmed that deltasup(5,7)-sterol delta 7 -reductase activity was suppressed by cholecalciferol (vitamin D 3 ) in the enzyme system consisted of microsomes and sterol carrier protein (SCP). The enzyme activity was significantly decreased in the combination with microsomes obtained from either vitamin D-deficient or vitamin D 3 -treated rat liver and with SCP obtained from vitamin D 3 -treated rat. It was also demonstrated by the binding assay of the dextran-charcoal technique that 7-dehydrocholesterol binding to SCP could be specifically displaced by vitamin D 3 . The inhibition of cholecalciferol on 7-dehydro-cholesterol binding to liver SCP was confirmed to be non-competitive inhibition. (auth.)

  2. Inhibition of catalase by aminotriazole in vivo results in reduction of glucose-6-phosphate dehydrogenase activity in Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Bayliak, M; Gospodaryov, D; Semchyshyn, H; Lushchak, V

    2008-04-01

    The inhibitor of catalase 3-amino-1,2,4-triazole (AMT) was used to study the physiological role of catalase in the yeast Saccharomyces cerevisiae under starvation. It was shown that AMT at the concentration of 10 mM did not affect the growth of the yeast. In vivo and in vitro the degree of catalase inhibition by AMT was concentration- and time-dependent. Peroxisomal catalase in bakers' yeast was more sensitive to AMT than the cytosolic one. In vivo inhibition of catalase by AMT in S. cerevisiae caused a simultaneous decrease in glucose-6-phosphate dehydrogenase activity and an increase in glutathione reductase activity. At the same time, the level of protein carbonyls, a marker of oxidative modification, was not affected. Possible mechanisms compensating the negative effects caused by AMT inhibition of catalase are discussed.

  3. Melatonin Regulates Oxidative Stress Initiated by Freund’s Complete Adjuvant

    Directory of Open Access Journals (Sweden)

    Miroslav Pohanka

    2015-07-01

    Full Text Available Melatonin is a hormone with strong antioxidant properties. In this experiment, Freund’s complete adjuvant was used as a stressogenic substance given to laboratory outbred mice, whereas melatonin was investigated as a protectant against the stressogenic effect. Levels of low molecular weight antioxidants, thiobarbituric acid reactive substances, and tumor necrosis factor α and activity of glutathione reductase were determined in blood from the animals. Surprisingly, melatonin was not involved in direct regulation of antioxidants, thiobarbituric acid reactive substances and tumor necrosis factor α. On the other hand, melatonin regulated glutathione reductase activity. We can conclude on regulation of metabolism caused by melatonin in the model. The effect was more important than the expected regulation of immunity and basal oxidative homeostasis.

  4. Metabolism of [14C] testosterone by human foetal and brain tissue

    International Nuclear Information System (INIS)

    Jenkins, J.S.; Hall, C.J.

    1977-01-01

    The metabolism of [ 14 C] testosterone in vitro by various areas of the human foetal brain has been studied and compared with that of an adult brain. The predominant metabolites were 5α-dihydrotestosterone and 5α-androstane-3α,17β-diol, and also androstenedione, and all areas of the foetal brain showed similar activity. In the foetal pituitary gland, the activity of 5α-reductase was less prominent than that of 17β-hydroxysteroid-dehydrogenase. Small quantities of oestradiol-17 β were produced from testosterone by the hypothalamus, temporal lobe and amygdala only, and no aromatization could be detected in the pituitary gland. 5α-Reductase activity was much lower in adult brain tissues and no oestradiol was identified in adult temporal lobe tissue. (author)

  5. Pre-sowing application of ascorbic acid and salicylic acid to seed of pumpkin and seedling response to salt

    International Nuclear Information System (INIS)

    Rafique, N.; Raza, S.H.; Qasim, M.; Iqbal, N.

    2011-01-01

    The effects of seed soaking with salicylic acid or ascorbic acid on pumpkin seedlings growth under saline (10 dS m/sup -1/) conditions were investigated. Seedlings fresh weight, protein contents, protease and nitrate reductase activities were significantly affected by 15 and 30 mg L/sup -1/ salicylic acid and 30 mg L/sup -1/ ascorbic acid priming treatments, under both normal and saline conditions. Priming reduced the severity of the salt stress, the amelioration was better due to 30 mg L/sup -1/ ascorbic acid or 30 mg L/sup -1/ salicylic acid treatments as these treatments showed best results on seedling growth, fresh and dry matter production under non-saline and saline environments. Application of seed priming with ascorbic acid and salicylic acid in pumpkin ameliorate the adverse effects of salt stress. (author)

  6. Extracellular ascorbate stabilization as a result of transplasma electron transfer in Saccharomyces cerevisiae.

    Science.gov (United States)

    Santos-Ocaña, C; Navas, P; Crane, F L; Córdoba, F

    1995-12-01

    The presence of yeast cells in the incubation medium prevents the oxidation of ascrobate catalyzed by copper ions. Ethanol increases ascorbate retention. Pyrazole, an alcohol dehydrogenase inhibitor, prevents ascorbate stabilization by cells. Chelation of copper ions does not account for stabilization, since oxidation rates with broken or boiled cells or conditioned media are similar to control rates in the absence of cells. Protoplast integrity is needed to reach optimal values of stabilization. Chloroquine, a known inhibitor of plasma membrane redox systems, inhibits the ascorbate stabilization, the inhibition being partially reversed by coenzyme Q6. Chloroquine does not inhibit ferricyanide reduction. Growth of yeast in iron-deficient media to increase ferric ion reductase activity also increases the stabilization. In conclusion, extracellular ascorbate stabilization by yeast cells can reflect a coenzyme Q dependent transplasmalemma electron transfer which uses NADH as electron donor. Iron deficiency increases the ascorbate stabilization but the transmembrane ferricyanide reduction system can act independently of ascorbate stabilization.

  7. Effects of Fermented Mushroom of Cordyceps sinensis, Rich in Selenium, on Uterine Cervix Cancer

    Directory of Open Access Journals (Sweden)

    Jing Ji

    2014-01-01

    Full Text Available The purpose of this study was to investigate the effect of fermented mushroom of Cordyceps sinensis (CS, rich in selenium (Se-CS, on uterine cervical cancer in mice. The methylcholanthrene- (MCA- induced tumor model was used in this paper. After the mice were administered Se-CS, the animals showed 40% tumor incidence (P<0.05. Se-CS also enhanced the immune functions. Se-CS treatment showed significant (P<0.05–0.01 restoration in the level of glutathione content, lipid peroxidation, glutathione peroxidase activity, glutathione reductase activity, catalase activity, Na+/K+-ATPase activity, and glutathione S transferase activity. This finding suggested that the concomitant use of Se and CS could be a potential therapeutic approach to improve the efficacy of therapy for uterine cervical cancer.

  8. Nitric oxide formation from the reaction of nitrite with carp and rabbit hemoglobin at intermediate oxygen saturations

    DEFF Research Database (Denmark)

    Jensen, Frank Bo

    2008-01-01

    The nitrite reductase activity of deoxyhemoglobin has received much recent interest because the nitric oxide produced in this reaction may participate in blood flow regulation during hypoxia. The present study used spectral deconvolution to characterize the reaction of nitrite with carp and rabbit...... hemoglobin at different constant oxygen tensions that generate the full range of physiological relevant oxygen saturations. Carp is a hypoxia-tolerant species with very high hemoglobin oxygen affinity, and the high R-state character and low redox potential of the hemoglobin is hypothesized to promote...... NO generation from nitrite. The reaction of nitrite with deoxyhemoglobin leads to a 1 : 1 formation of nitrosylhemoglobin and methemoglobin in both species. At intermediate oxygen saturations, the reaction with deoxyhemoglobin is clearly favored over that with oxyhemoglobin, and the oxyhemoglobin reaction...

  9. Biological indication of nitric oxides; Zum bioindikativen Nachweis von Stickoxiden

    Energy Technology Data Exchange (ETDEWEB)

    Belotti, E.; Kaemmerer, D.; Mangold, U.; Tempes, D.; Arndt, U.

    1992-12-31

    The authors demonstrate the need for a nitrogen oxide bio-indicator and suggest to use nitrate reductase activity in exposed plant leaves to be established in vivo as the action criterium. Studies on the suitability of different plants and cultivation conditions are presented. Their results are taken to show that large-leaved plants like sunflower or tomato grown with ammonia as the only nitrogen source are best suited for bio-indication of nitric oxides. (orig.) [Deutsch] Der Beitrag zeigt die Notwendigkeit eines Bioindikators fuer Stickoxide auf und schlaegt als Wirkungskriterium die Nitratreduktase-Aktivitaet in den Blaettern exponierter Pflanzen, ermittelt mit der in-vivo-Methode, vor. Untersuchungen zur Eignung verschiedener Pflanzen und Anzuchtbedingungen werden vorgestellt. Aus ihnen ist abzuleiten, dass mit Ammonium als einziger Stickstoffquelle angezogene grossblaettrige Kulturpflanzen, etwa Sonnenblume oder Tomate, am ehesten fuer den bioindikativen Nachweis von Stickoxiden geeignet sind. (orig.)

  10. Antifungal Activity from Leaves of Acacia Nilotica against Pythium Aphanidermatum

    Directory of Open Access Journals (Sweden)

    A. J. Khan

    1996-01-01

    Full Text Available Gallic acid and methyl ester of gallic acid has been identified as antifungal compounds against the mycelial growth of Pythium aphanidermatum from acetone-water extracts of Acacia nilotica leaves. The growth of fungus was completely ceased by gallic acid and its methyl ester at 1000 ppm and 750 ppm, respectively. Antifungal properties of both compounds were found to be higher in combination than alone. The minimum inhibitory concentration for both compounds was 1000 ppm. No phytotoxic effect of the compounds was observed on watermelon seed germination. The growth of roots and shoots of watermelon seedlings was promoted by gallic acid but decreased with methyl ester of gallic acid. Nitrate reductase activity of the fungus was significantly inhibited by both compounds.

  11. Diabetic neuropathy: structural analysis of nerve hydration by Magnetic Resonance Spectroscopy

    International Nuclear Information System (INIS)

    Griffey, R.H.; Eaton, P.; Sibbitt, R.R.; Sibbitt, W.L. Jr.; Bicknell, J.M.

    1988-01-01

    The water content of the sural nerve of diabetic patients was quantitatively defined by magnetic resonance proton imaging as a putative reflection of activity of the aldose-reductase pathway. Thirty-nine patients were evaluated, comparing group A, symptomatic diabetic men with sensory neuropathy; group B, similarly symptomatic diabetic men treated aldose-reductase inhibition; group C, neurologically asymptomatic diabetic men; and group D, control nondiabetic men. Marked increase in hydration of the sural nerve was seen in more than half of the symptomatic diabetic patients. Two of 11 neurologically asymptomatic diabetics had increased nerve hydration, suggesting a presymptomatic alteration of the nerve. Symptomatic diabetics treated with aldose-reductase inhibitors had normal nerve water levels. Increased level of peripheral nerve water represents a new finding in diabetes mellitus. It seems to be related to aldose-reductase activity, involved in the development of neuropathy, and similar to events that occur in other target tissue in human diabetes

  12. Halomonas maura is a physiologically versatile bacterium of both ecological and biotechnological interest.

    Science.gov (United States)

    Llamas, Inmaculada; del Moral, Ana; Martínez-Checa, Fernando; Arco, Yolanda; Arias, Soledad; Quesada, Emilia

    2006-01-01

    Halomonas maura is a bacterium of great metabolic versatility. We summarise in this work some of the properties that make it a very interesting microorganism both from an ecological and biotechnological point of view. It plays an active role in the nitrogen cycle, is capable of anaerobic respiration in the presence of nitrate and has recently been identified as a diazotrophic bacterium. Of equal interest is mauran, the exopolysaccharide produced by H. maura, which contributes to the formation of biofilms and thus affords the bacterium advantages in the colonisation of its saline niches. Mauran is highly viscous, shows thixotropic and pseudoplastic behaviour, has the capacity to capture heavy metals and exerts a certain immunomodulator effect in medicine. All these attributes have prompted us to make further investigations into its molecular characteristics. To date we have described 15 open reading frames (ORF's) related to exopolysaccharide production, nitrogen fixation and nitrate reductase activity among others.

  13. Endogenous sodium potassium ATPase inhibition related biochemical cascade and the acquired immunodeficiency syndrome -Neural regulation of viral replication and immune response to the virus

    Directory of Open Access Journals (Sweden)

    Ravikumar A

    2001-11-01

    Full Text Available The isoprenoid pathway and its metabolites - digoxin, dolichol and ubiquinone were assessed in acquired immunodeficiency syndrome. Digoxin is an endogenous regulator of membrane Na+-K+ ATPase secreted by the human hypothalamus. The HMG CoA reductase activity was increased with increased digoxin and dolichol levels and reduced ubiquinone levels in AIDS. Membrane Na+-K+ ATPase activity and serum magnesium levels were reduced. The tryptophan catabolites were increased and the tyrosine catabolites were reduced. The glycoconjugate metabolites were increased and lysosomal stability was reduced. There was reduced incorporation of glycoconjugates into membranes and increased membrane cholesterol: phospholipid ratio. Lipid peroxidation products and NO were increased while free radical scavenging enzymes and reduced glutathione were reduced. The role of the isoprenoid pathway related cascade in the pathogenesis of AIDS is discussed.

  14. [Study of enzymes of xenobiotic metabolism in the evaluation of quality of protein-containing wheat germ flakes and wallpaper flour].

    Science.gov (United States)

    Martinchuk, A N; E En Gyn; Safronova, A M; Peskova, E V

    1991-01-01

    Intake of wheat upholstery meal by growing rats was attended by a sharp decrease in the content and activity of xenobiotic metabolism enzymes in the hepatic microsomes, that was caused by the low biological value of the meal proteins. Hepatic microsomes of the rats that were fed with wheat germ flakes showed increased specific content of cytochromes P-450 and b5, but the total blood protein content per 100 g of body mass was lower than during casein consumption. No significant changes were detected in hydroxylation rate of benz(a)pyrene, aniline and ethylmorphine. During consumption of wheat germ flakes induction of UDP-glucuronide-transferase was detected in hepatic microsomes. Wheat germ flakes induced a 5-fold increase of Se-dependent glutathione peroxidase activity. Wheat germ flakes produced no significant effect on glutathione-S-aryltransferase and glutathione reductase activity.

  15. Ameliorative Effects of Herbal Combinations in Hyperlipidemia

    Directory of Open Access Journals (Sweden)

    Nishant P. Visavadiya

    2011-01-01

    Full Text Available The roots of Glycyrrhiza glabra, Withania somnifera, Asparagus racemosus, and Chlorophytum borivilianum and seeds of Sesamum indicum are ayurvedic medicinal plants used in India to treat several ailments. Our previous studies indicated that these plants possess hypolipidemic and antioxidant potential. The present study was aimed at investigating the composite effects of these plants on hypercholesterolemic rats. Three different combinations (5 gm%, given for four weeks used in this study effectively reduced plasma and hepatic lipid profiles and increased fecal excretion of cholesterol, neutral sterol, and bile acid along with increasing the hepatic HMG-CoA reductase activity and bile acid content in hypercholesterolemic rats. Further, all three combinations also improved the hepatic antioxidant status (catalase, SOD, and ascorbic acid levels and plasma total antioxidant capacity with reduced hepatic lipid peroxidation. Overall, combination I had the maximum effect on hypercholesterolemic rats followed by combinations II and III due to varying concentrations of the different classes of phytocomponents.

  16. Proteomic and activity profiles of ascorbate-glutathione cycle enzymes in germinating barley embryo

    DEFF Research Database (Denmark)

    Bønsager, Birgit Christine; Shahpiri, Azar; Finnie, Christine

    2010-01-01

    Enzymes involved in redox control are important during seed germination and seedling growth. Ascorbate-glutathione cycle enzymes in barley embryo extracts were monitored both by 2D-gel electrophoresis and activity measurements from 4 to 144 h post imbibition (PI). Strikingly different activity...... profiles were observed. No ascorbate peroxidase (APX) activity was present in mature seeds but activity was detected after 24 h PI and increased 14-fold up to 144 h PI. In contrast, dehydroascorbate reductase (DHAR) activity was present at 4 h PI and first decreased by 9-fold until 72 h PI followed by a 5......-fold increase at 144 h PI. Glutathione reductase and monodehydroascorbate reductase activities were also detected at 4 h PI, and showed modest increases of 1.8- and 2.7-fold, respectively, by 144 h PI. The combination of functional analysis with the proteomics approach enabled correlation...

  17. Sites of production of sex steroids: secretion of steroids from x-irradiated and polycystic ovaries of rats

    International Nuclear Information System (INIS)

    Sawada, T.; Ichikawa, S.

    1978-01-01

    Ovaries of immature rats and PMS-induced pregnant rats were unilaterally x-irradiated. Ten days later, the concentrations of pregnane compounds in the ovarian venous plasma were measured. LH (2 μg) was injected iv 30 min before bleeding. A comparison of steroid levels in the ovarian venous effluent of rats with and without destruction of selected tissue components by irradiation of the ovaries suggests that the follicles contribute to the secretion of 5α-pregnane-3,20-dione and 3α-hydroxy-5α-pregnan-20-one in the presence of interstitial gland tissue. Because it is known that follicular tissue is involved in the production of estrogens, we studied the interrelationship between the secretion of the two progesterone metabolites and estrogens in follicular polycystic ovaries of androgen-sterilized rats. Normal ovaries of diestrus-2 rats were used as controls for the polycystic ovaries. The injection of LH greatly increased the secretion of 5α-pregnane-3,20-dione and 3α-hydroxy-5α-pregnan-20-one within 1 h in normal ovaries, but the response of polycystic ovaries was low, suggesting low 5α-reductase activity in the cystic ovary. The polycystic ovaries exhibited a marked increase in the secretion of estrogens in response to LH, whereas normal ovaries showed no significant change. These results suggest that low 5α-reductase activity may be causally related to the high level of estrogen secretion in polycystic ovaries of androgen-sterilized rats

  18. Comparison of nitrate accumulation, nitrogen uptake and utilization efficiency among different spinach (Spinacia oleracea L. genotypes

    Directory of Open Access Journals (Sweden)

    Zhou Jianjian

    2017-10-01

    Full Text Available A hydroponic experiment was conducted to study the difference of nitrate accumulation,nitrogen uptake and utilization efficiency between four spinach (Spinacia oleracea L. genotypes (So10,So13,So18 and So57. Results showed that So13 had the highest nitrate contents under two nitrate (NO3--N level (0.5 mmol·L-1,15 mmol·L-1 conditions,whereas So10 had the lowest nitrate contents. So18 had the similar nitrate contents with So13 under low NO3- level,while it showed no significant difference of nitrate contents with So57 under high NO3- treatment. The 15NO3--N uptake rates of So13 were the highest one among four genotypes,while the N utilization efficiency (NutE and N utilization ratio (NUR of So13 were significantly lower than those of So18 and So57. The shoot dry mass,nitrate reductase activity,NutE,NUR of So18 and So57 were higher than those of So13 and So10,while their 15NO3--N uptake rates were lower than those of So13. The shoot dry mass,nitrate reductase activity,NutE,N utilization ratio of So10 were significantly lower than those of So18 and So57,and its 15NO3--N uptake rate was significantly lower than those of So13. Among the four spinach genotypes,the So57 can be selected as elite germplasm using for spinach production for its relatively lower nitrate content and higher N efficiency.

  19. MacA is a second cytochrome c peroxidase of Geobacter sulfurreducens.

    Science.gov (United States)

    Seidel, Julian; Hoffmann, Maren; Ellis, Katie E; Seidel, Antonia; Spatzal, Thomas; Gerhardt, Stefan; Elliott, Sean J; Einsle, Oliver

    2012-04-03

    The metal-reducing δ-proteobacterium Geobacter sulfurreducens produces a large number of c-type cytochromes, many of which have been implicated in the transfer of electrons to insoluble metal oxides. Among these, the dihemic MacA was assigned a central role. Here we have produced G. sulfurreducens MacA by recombinant expression in Escherichia coli and have solved its three-dimensional structure in three different oxidation states. Sequence comparisons group MacA into the family of diheme cytochrome c peroxidases, and the protein indeed showed hydrogen peroxide reductase activity with ABTS(-2) as an electron donor. The observed K(M) was 38.5 ± 3.7 μM H(2)O(2) and v(max) was 0.78 ± 0.03 μmol of H(2)O(2)·min(-1)·mg(-1), resulting in a turnover number k(cat) = 0.46 · s(-1). In contrast, no Fe(III) reductase activity was observed. MacA was found to display electrochemical properties similar to other bacterial diheme peroxidases, in addition to the ability to electrochemically mediate electron transfer to the soluble cytochrome PpcA. Differences in activity between CcpA and MacA can be rationalized with structural variations in one of the three loop regions, loop 2, that undergoes conformational changes during reductive activation of the enzyme. This loop is adjacent to the active site heme and forms an open loop structure rather than a more rigid helix as in CcpA. For the activation of the protein, the loop has to displace the distal ligand to the active site heme, H93, in loop 1. A H93G variant showed an unexpected formation of a helix in loop 2 and disorder in loop 1, while a M297H variant that altered the properties of the electron transfer heme abolished reductive activation.

  20. Overexpression of Iron Superoxide Dismutase in Transformed Poplar Modifies the Regulation of Photosynthesis at Low CO2 Partial Pressures or Following Exposure to the Prooxidant Herbicide Methyl Viologen1

    Science.gov (United States)

    Arisi, Ana-Carolina M.; Cornic, Gabriel; Jouanin, Lise; Foyer, Christine H.

    1998-01-01

    Chloroplast-targeted overexpression of an Fe superoxide dismutase (SOD) from Arabidopsis thaliana resulted in substantially increased foliar SOD activities. Ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase activities were similar in the leaves from all of the lines, but dehydroascorbate reductase activity was increased in the leaves of the FeSOD transformants relative to untransformed controls. Foliar H2O2, ascorbate, and glutathione contents were comparable in all lines of plants. Irradiance-dependent changes in net CO2 assimilation and chlorophyll a fluorescence quenching parameters were similar in all lines both in air (21% O2) and at low (1%) O2. CO2-response curves for photosynthesis showed similar net CO2-exchange characteristics in all lines. In contrast, values of photochemical quenching declined in leaves from untransformed controls at intercellular CO2 (Ci) values below 200 μL L−1 but remained constant with decreasing Ci in leaves of FeSOD transformants. When the O2 concentration was decreased from 21 to 1%, the effect of FeSOD overexpression on photochemical quenching at limiting Ci was abolished. At high light (1000 μmol m−2 s−1) a progressive decrease in the ratio of variable (Fv) to maximal (Fm) fluorescence was observed with decreasing temperature. At 6oC the high-light-induced decrease in the Fv/Fm ratio was partially prevented by low O2 but values were comparable in all lines. Methyl viologen caused decreased Fv/Fm ratios, but this was less marked in the FeSOD transformants than in the untransformed controls. These observations suggest that the rate of superoxide dismutation limits flux through the Mehler-peroxidase cycle in certain conditions. PMID:9625709

  1. Diversity, metabolic properties and arsenic mobilization potential of indigenous bacteria in arsenic contaminated groundwater of West Bengal, India.

    Science.gov (United States)

    Paul, Dhiraj; Kazy, Sufia K; Gupta, Ashok K; Pal, Taraknath; Sar, Pinaki

    2015-01-01

    Arsenic (As) mobilization in alluvial aquifers is caused by a complex interplay of hydro-geo-microbiological activities. Nevertheless, diversity and biogeochemical significance of indigenous bacteria in Bengal Delta Plain are not well documented. We have deciphered bacterial community compositions and metabolic properties in As contaminated groundwater of West Bengal to define their role in As mobilization. Groundwater samples showed characteristic high As, low organic carbon and reducing property. Culture-independent and -dependent analyses revealed presence of diverse, yet near consistent community composition mostly represented by genera Pseudomonas, Flavobacterium, Brevundimonas, Polaromonas, Rhodococcus, Methyloversatilis and Methylotenera. Along with As-resistance and -reductase activities, abilities to metabolize a wide range carbon substrates including long chain and polyaromatic hydrocarbons and HCO3, As3+ as electron donor and As5+/Fe3+ as terminal electron acceptor during anaerobic growth were frequently observed within the cultivable bacteria. Genes encoding cytosolic As5+ reductase (arsC) and As3+ efflux/transporter [arsB and acr3(2)] were found to be more abundant than the dissimilatory As5+ reductase gene arrA. The observed metabolic characteristics showed a good agreement with the same derived from phylogenetic lineages of constituent populations. Selected bacterial strains incubated anaerobically over 300 days using natural orange sand of Pleistocene aquifer showed release of soluble As mostly as As3+ along with several other elements (Al, Fe, Mn, K, etc.). Together with the production of oxalic acid within the biotic microcosms, change in sediment composition and mineralogy indicated dissolution of orange sand coupled with As/Fe reduction. Presence of arsC gene, As5+ reductase activity and oxalic acid production by the bacteria were found to be closely related to their ability to mobilize sediment bound As. Overall observations suggest that

  2. Silencing of NADPH-Dependent Oxidoreductase Genes (yqhD and dkgA) in Furfural-Resistant Ethanologenic Escherichia coli▿

    Science.gov (United States)

    Miller, E. N.; Jarboe, L. R.; Yomano, L. P.; York, S. W.; Shanmugam, K. T.; Ingram, L. O.

    2009-01-01

    Low concentrations of furfural are formed as a side product during the dilute acid hydrolysis of hemicellulose. Growth is inhibited by exposure to furfural but resumes after the complete reduction of furfural to the less toxic furfuryl alcohol. Growth-based selection was used to isolate a furfural-resistant mutant of ethanologenic Escherichia coli LY180, designated strain EMFR9. Based on mRNA expression levels in the parent and mutant in response to furfural challenge, genes encoding 12 oxidoreductases were found to vary by more than twofold (eight were higher in EMFR9; four were higher in the parent). All 12 genes were cloned. When expressed from plasmids, none of the eight genes in the first group increased furfural tolerance in the parent (LY180). Expression of three of the silenced genes (yqhD, dkgA, and yqfA) in EMFR9 was found to decrease furfural tolerance compared to that in the parent. Purified enzymes encoded by yqhD and dkgA were shown to have NADPH-dependent furfural reductase activity. Both exhibited low Km values for NADPH (8 μM and 23 μM, respectively), similar to those of biosynthetic reactions. Furfural reductase activity was not associated with yqfA. Deleting yqhD and dkgA in the parent (LY180) increased furfural tolerance, but not to the same extent observed in the mutant EMFR9. Together, these results suggest that the process of reducing furfural by using an enzyme with a low Km for NADPH rather than a direct inhibitory action is the primary cause for growth inhibition by low concentrations of furfural. PMID:19429550

  3. Sexually dimorphic effects of maternal nutrient reduction on expression of genes regulating cortisol metabolism in fetal baboon adipose and liver tissues.

    Science.gov (United States)

    Guo, Chunming; Li, Cun; Myatt, Leslie; Nathanielsz, Peter W; Sun, Kang

    2013-04-01

    Maternal nutrient reduction (MNR) during fetal development may predispose offspring to chronic disease later in life. Increased regeneration of active glucocorticoids by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in metabolic tissues is fundamental to the developmental programming of metabolic syndrome, but underlying mechanisms are unknown. Hexose-6-phosphate dehydrogenase (H6PD) generates NADPH, the cofactor for 11β-HSD1 reductase activity. CCAAT/enhancer binding proteins (C/EBPs) and the glucocorticoid receptor (GR) regulate 11β-HSD1 expression. We hypothesize that MNR increases expression of fetal C/EBPs, GR, and H6PD, thereby increasing expression of 11β-HSD1 and reductase activity in fetal liver and adipose tissues. Pregnant MNR baboons ate 70% of what controls ate from 0.16 to 0.9 gestation (term, 184 days). Cortisol levels in maternal and fetal circulations increased in MNR pregnancies at 0.9 gestation. MNR increased expression of 11β-HSD1; H6PD; C/EBPα, -β, -γ; and GR in female but not male perirenal adipose tissue and in male but not female liver at 0.9 gestation. Local cortisol level and its targets PEPCK1 and PPARγ increased correspondingly in adipose and liver tissues. C/EBPα and GR were found to be bound to the 11β-HSD1 promoter. In conclusion, sex- and tissue-specific increases of 11β-HSD1, H6PD, GR, and C/EBPs may contribute to sexual dimorphism in the programming of exaggerated cortisol regeneration in liver and adipose tissues and offsprings' susceptibility to metabolic syndrome.

  4. Inhibition of steroid 5 alpha-reductase by specific aliphatic unsaturated fatty acids.

    Science.gov (United States)

    Liang, T; Liao, S

    1992-01-01

    Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells. PMID:1637346

  5. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals.

    Science.gov (United States)

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E; Kristensen, Niels; Giouri, Lea; Jensen, Frank B

    2017-03-01

    The ability of marine mammals to hunt prey at depth is known to rely on enhanced oxygen stores and on selective distribution of blood flow, but the molecular mechanisms regulating blood flow and oxygen transport remain unresolved. To investigate the molecular mechanisms that may be important in regulating blood flow, we measured concentration of nitrite and S-nitrosothiols (SNO), two metabolites of the vasodilator nitric oxide (NO), in the blood of 5 species of marine mammals differing in their dive duration: bottlenose dolphin, South American sea lion, harbor seal, walrus and beluga whale. We also examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals, but unusually high concentrations of red blood cell SNO in bottlenose dolphin, walrus and beluga whale, suggesting enhanced SNO-dependent signaling in these species. Purified Hbs showed similar functional properties in terms of oxygen affinity and sensitivity to DPG, indicating that reported large variations in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken together, these results underscore adaptive variations in circulatory NO metabolism in diving mammals but not in the oxygenation properties of the Hb. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. The cysteine 34 residue of A1M/α1-microglobulin is essential for protection of irradiated cell cultures and reduction of carbonyl groups.

    Science.gov (United States)

    Rutardottir, S; Nilsson, E J C; Pallon, J; Gram, M; Åkerström, B

    2013-07-01

    α1-microglobulin (A1M) is a 26 kDa plasma and a tissue protein belonging to the lipocalin family. The reductase and free radical scavenger A1M has been shown to protect cells and extracellular matrix against oxidative and irradiation-induced damage. The reductase activity was previously shown to depend upon an unpaired cysteinyl side-chain, C34, and three lysyl side-chains, K92, 118, and 130, located around the open end of the lipocalin pocket. The aim of this work was to investigate whether the cell and matrix protection by A1M is a result of its reductase activity by using A1M-variants with site-directed mutations of the C34, K92, K118, and K130 positions. The results show that the C34 side-chain is an absolute requirement for protection of HepG2 cell cultures against alpha-particle irradiation-induced cell death, upregulation of stress response and cell cycle regulation genes. Mutation of C34 also resulted in loss of the reduction capacity toward heme- and hydrogen peroxide-oxidized collagen, and the radical species 2,2´-azino-bis (3-ethyl-benzo-thiazoline-6-sulphonic acid) (ABTS). Furthermore, mutation of C34 significantly suppressed the cell-uptake of A1M. The K92, K118, and K130 side-chains were of minor importance in cell protection and reduction of oxidized collagen but strongly influenced the reduction of the ABTS-radical. It is concluded that antioxidative protection of cells and collagen by A1M is totally dependent on its C34 amino acid residue. A model of the cell protection mechanism of A1M should be based on the redox activity of the free thiolyl group of the C34 side-chain and a regulatory role of the K92, K118, and K130 residues.

  7. Unique regional distribution of delta 4-3-ketosteroid-5 alpha-oxidoreductase and associated epididymal morphology in the marsupial, Didelphis virginiana.

    Science.gov (United States)

    Kelce, W R; Krause, W J; Ganjam, V K

    1987-09-01

    The epididymal epithelial ultrastructure has been described in the adult male North American opossum, Didelphis virginiana. Morphological results have suggested that absorptive activity is prominent in the proximal epididymal region by virtue of numerous microvilli, an endocytotic complex, dense granules, and multivesicular bodies in the apical cytoplasm. In contrast, the middle and distal epididymal regions exhibit ultrastructural features indicative of protein synthesis such as large invaginated euchromatic nuclei, large nucleoli, and increased amounts of granular endoplasmic reticulum. It is in the middle and distal epididymal regions where sperm head rotation and sperm pairing take place. Epididymal delta 4-3-ketosteroid-5 alpha-oxidoreductase (5 alpha-reductase) activity also has been measured. It has been found that the level of enzyme activity differs significantly (p less than 0.01) between the proximal, middle, and distal epididymal regions. Enzyme-specific activity has been found to be highest in the middle region (47.6 +/- 5.4 picomoles 5 alpha-reduced androgens formed/b/mg protein), lower in the distal region (18.3 +/- 0.7 picomoles 5 alpha-reduced androgens formed/b/mg protein), with little activity (2.4 +/- 1.2 picomoles 5 alpha-reduced androgens formed/h/mg protein) found in the proximal epididymal region. This regional distribution of enzyme activity differs markedly from that reported for eutherian mammals. Both the suggested epididymal protein synthetic and secretory activity and the level of epididymal 5 alpha-reductase activity appear to correlate regionally with the morphological changes that occur in the opossum spermatozoa as they transit the epididymis.

  8. Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria.

    Science.gov (United States)

    Filannino, Pasquale; Gobbetti, Marco; De Angelis, Maria; Di Cagno, Raffaella

    2014-12-01

    The metabolism of hydroxycinnamic acids by strictly heterofermentative lactic acid bacteria (19 strains) was investigated as a potential alternative energy route. Lactobacillus curvatus PE5 was the most tolerant to hydroxycinnamic acids, followed by strains of Weissella spp., Lactobacillus brevis, Lactobacillus fermentum, and Leuconostoc mesenteroides, for which the MIC values were the same. The highest sensitivity was found for Lactobacillus rossiae strains. During growth in MRS broth, lactic acid bacteria reduced caffeic, p-coumaric, and ferulic acids into dihydrocaffeic, phloretic, and dihydroferulic acids, respectively, or decarboxylated hydroxycinnamic acids into the corresponding vinyl derivatives and then reduced the latter compounds to ethyl compounds. Reductase activities mainly emerged, and the activities of selected strains were further investigated in chemically defined basal medium (CDM) under anaerobic conditions. The end products of carbon metabolism were quantified, as were the levels of intracellular ATP and the NAD(+)/NADH ratio. Electron and carbon balances and theoretical ATP/glucose yields were also estimated. When CDM was supplemented with hydroxycinnamic acids, the synthesis of ethanol decreased and the concentration of acetic acid increased. The levels of these metabolites reflected on the alcohol dehydrogenase and acetate kinase activities. Overall, some biochemical traits distinguished the common metabolism of strictly heterofermentative strains: main reductase activity toward hydroxycinnamic acids, a shift from alcohol dehydrogenase to acetate kinase activities, an increase in the NAD(+)/NADH ratio, and the accumulation of supplementary intracellular ATP. Taken together, the above-described metabolic responses suggest that strictly heterofermentative lactic acid bacteria mainly use hydroxycinnamic acids as external acceptors of electrons. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. Cell death by SecTRAPs: thioredoxin reductase as a prooxidant killer of cells.

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    Karin Anestål

    Full Text Available BACKGROUND: SecTRAPs (selenium compromised thioredoxin reductase-derived apoptotic proteins can be formed from the selenoprotein thioredoxin reductase (TrxR by targeting of its selenocysteine (Sec residue with electrophiles, or by its removal through C-terminal truncation. SecTRAPs are devoid of thioredoxin reductase activity but can induce rapid cell death in cultured cancer cell lines by a gain of function. PRINCIPAL FINDINGS: Both human and rat SecTRAPs killed human A549 and HeLa cells. The cell death displayed both apoptotic and necrotic features. It did not require novel protein synthesis nor did it show extensive nuclear fragmentation, but it was attenuated by use of caspase inhibitors. The redox active disulfide/dithiol motif in the N-terminal domain of TrxR had to be maintained for manifestation of SecTRAP cytotoxicity. Stopped-flow kinetics showed that NADPH can reduce the FAD moiety in SecTRAPs at similar rates as in native TrxR and purified SecTRAPs could maintain NADPH oxidase activity, which was accelerated by low molecular weight substrates such as juglone. In a cellular context, SecTRAPs triggered extensive formation of reactive oxygen species (ROS and consequently antioxidants could protect against the cell killing by SecTRAPs. CONCLUSIONS: We conclude that formation of SecTRAPs could contribute to the cytotoxicity seen upon exposure of cells to electrophilic agents targeting TrxR. SecTRAPs are prooxidant killers of cells, triggering mechanisms beyond those of a mere loss of thioredoxin reductase activity.

  10. Comparing the Influence of Wildfire and Prescribed Burns on Watershed Nitrogen Biogeochemistry Using 15N Natural Abundance in Terrestrial and Aquatic Ecosystem Components

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    Stephan, Kirsten; Kavanagh, Kathleen L.; Koyama, Akihiro

    2015-01-01

    We evaluated differences in the effects of three low-severity spring prescribed burns and four wildfires on nitrogen (N) biogeochemistry in Rocky Mountain headwater watersheds. We compared paired (burned/unburned) watersheds of four wildfires and three spring prescribed burns for three growing seasons post-fire. To better understand fire effects on the entire watershed ecosystem, we measured N concentrations and δ15N in both the terrestrial and aquatic ecosystems components, i.e., soil, understory plants in upland and riparian areas, streamwater, and in-stream moss. In addition, we measured nitrate reductase activity in foliage of Spiraea betulifolia, a dominant understory species. We found increases of δ15N and N concentrations in both terrestrial and aquatic ecosystem N pools after wildfire, but responses were limited to terrestrial N pools after prescribed burns indicating that N transfer from terrestrial to aquatic ecosystem components did not occur in low-severity prescribed burns. Foliar δ15N differed between wildfire and prescribed burn sites; the δ15N of foliage of upland plants was enriched by 2.9 ‰ (difference between burned and unburned watersheds) in the first two years after wildfire, but only 1.3 ‰ after prescribed burns. In-stream moss δ15N in wildfire-burned watersheds was enriched by 1.3 ‰, but there was no response by moss in prescription-burned watersheds, mirroring patterns of streamwater nitrate concentrations. S. betulifolia showed significantly higher nitrate reductase activity two years after wildfires relative to corresponding unburned watersheds, but no such difference was found after prescribed burns. These responses are consistent with less altered N biogeochemistry after prescribed burns relative to wildfire. We concluded that δ15N values in terrestrial and aquatic plants and streamwater nitrate concentrations after fire can be useful indicators of the magnitude and duration of fire effects and the fate of post

  11. Identification of HMG-CoA Reductase Inhibitor Active Compound in Medicinal Forest Plants

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    Shelly Rahmania

    2017-08-01

    Full Text Available Cardiovascular disease is a leading cause of death worldwide, hypercholesterolemia is one of the causes. Three medicinal forest plants are potential natural resources to be developed as cholesterol-reducing herbal product, but scientific informations on their mechanism is still limited. The objective of this research is to explore the potency of the leaf of Jati Belanda (Guazuma ulmifolia, Jabon (Antocephalus macrophyllus, and Mindi (Melia azedarach as inhibitor of HMG-CoA reductase (HMGR, a key enzyme in the regulation of cholesterol biosynthesis. Samples were macerated in ethanol 96% and the filtrate was partitioned using n-hexane and chloroform to obtain the ethanolic flavonoid extract. The effect of each extracts on the HMG-CoA reductase activity were analyzed using HMGR assay kit. At concentration of 10 ppm the G.ulmifolia ethanolic extract showed the highest inhibitory activity as well as pravastatin control inhibitor.  The phenolic content of the ethanolic extracts of G.ulmifolia, A.macrophyllus, and M.azedarach were: 11.00, 34.83, and 13.67 mg gallic acid AE/g dried leaves, respectively. The flavonoid content of the ethanolic extracts of G.ulmifolia, A.macrophyllus, and M.azedarach were: 0.22, 0.64, and 0.78 mg QE/g dried leaves, respectively. Interestingly, G.ulmifolia extract the lowest concentration of phenolic and flavonoid content. HPLC analysis showed that all samples contain quercetin at similiar small concentrations (6.7%, 6.6%, and 7.0% for G.ulmifolia, A.macrophyllus, and M.azedarach, respectively. This indicating other active compounds may play some roles in this inhibitory action on HMG-CoA reductase activity. Further identification using LC-MS/MS showed that G.ulmifolia flavonoid extract contained an unidetified coumpound with molecural weight of 380.0723 Da.  

  12. Global iTRAQ-based proteomic profiling of Toxoplasma gondii oocysts during sporulation.

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    Zhou, Chun-Xue; Zhu, Xing-Quan; Elsheikha, Hany M; He, Shuai; Li, Qian; Zhou, Dong-Hui; Suo, Xun

    2016-10-04

    Toxoplasma gondii is a medically and economically important protozoan parasite. However, the molecular mechanisms of its sporulation remain largely unknown. Here, we applied iTRAQ coupled with 2D LC-MS/MS proteomic analysis to investigate the proteomic expression profile of T. gondii oocysts during sporulation. Of the 2095 non-redundant proteins identified, 587 were identified as differentially expressed proteins (DEPs). Based on Gene Ontology enrichment and KEGG pathway analyses the majority of these DEPs were found related to the metabolism of amino acids, carbon and energy. Protein interaction network analysis generated by STRING identified ATP-citrate lyase (ACL), GMP synthase, IMP dehydrogenase (IMPDH), poly (ADP-ribose) glycohydrolase (PARG), and bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) as the top five hubs. We also identified 25 parasite virulence factors that were expressed at relatively high levels in sporulated oocysts compared to non-sporulated oocysts, which might contribute to the infectivity of mature oocysts. Considering the importance of oocysts in the dissemination of toxoplasmosis these findings may help in the search of protein targets with a key role in infectiousness and ecological success of oocysts, creating new opportunities for the development of better means for disease prevention. The development of new preventative interventions against T. gondii infection relies on an improved understanding of the proteome and chemical pathways of this parasite. To identify proteins required for the development of environmentally resistant and infective T. gondii oocysts, we compared the proteome of non-sporulated (immature) oocysts with the proteome of sporulated (mature, infective) oocysts. iTRAQ 2D-LC-MS/MS analysis revealed proteomic changes that distinguish non-sporulated from sporulated oocysts. Many of the differentially expressed proteins were involved in metabolic pathways and 25 virulence factors were identified

  13. Poly (ADP-ribose) metabolism in alkylated mouse L5178Y cells

    International Nuclear Information System (INIS)

    Boyle, J.M.

    1985-01-01

    Poly ADP-ribosylation of two mouse lymphoma cell lines, L5178Y (LS) and the radiation and alkylating agent resistant derivative AII, was investigated by uptake of [ 3 H]NAD by permeabilised cells into acid-precipitable material that was sensitive to phosphodiesterase but insensitive to DNase and RNase. Basal activities in both lymphoma lines were 3-4-fold greater than in mouse L1210 leukaemia cells. However, total endogenous poly (ADP-R) polymerase activity in both L5178Y cell lines, stimulated by a large excess of DNase in the presence of Triton X-100, was less than half the activity in L1210 cells. Doses of N-methyl-N-nitrosourea (MNU) that produced 20-50% survival of colony-forming units increased poly (ADP-R) in both lymphoma lines by only 25% compared with 377% in L1210 cells when synthesis was measured immediately after a 30-min exposure of MNU. Concentrations of 3-aminobenzamide (3AB) above 2.5 mM inhibited colony-forming ability of lymphoma cells and equally inhibited uptake of [ 14 C]formate into protein, RNA and DNA indicating that 3AB behaves as a general metabolic poison. Non-toxic concentrations of 3AB potentiated cell killing by MNU to a similar degree in both lymphoma cell lines. In conclusion, the authors have found little evidence to support the hypothesis that the differential sensitivity of LS and AII is related to poly ADP-ribosylation. Compared with other mouse cells, L5178Y cells appear deficient in poly (ADP-R) polymerase and poly (ADP-R) glycohydrolase activities

  14. Identification and Characterization of a New Enterotoxin Produced by Clostridium perfringens Isolated from Food Poisoning Outbreaks.

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    Daisuke Irikura

    Full Text Available There is a strain of Clostridium perfringens, W5052, which does not produce a known enterotoxin. We herein report that the strain W5052 expressed a homologue of the iota-like toxin components sa and sb of C. spiroforme, named Clostridium perfringens iota-like enterotoxin, CPILE-a and CPILE-b, respectively, based on the results of a genome sequencing analysis and a systematic protein screening. In the nicotinamide glyco-hydrolase (NADase assay the hydrolysis activity was dose-dependently increased by the concentration of rCPILE-a, as judged by the mass spectrometry analysis. In addition, the actin monomer of the lysates of Vero and L929 cells were radiolabeled in the presence of [32P]NAD and rCPILE-a. These findings indicated that CPILE-a possesses ADP-ribosylation activity. The culture supernatant of W5052 facilitated the rounding and killing of Vero and L929 cells, but the rCPILE-a or a non-proteolyzed rCPILE-b did not. However, a trypsin-treated rCPILE-b did. Moreover, a mixture of rCPILE-a and the trypsin-treated rCPILE-b enhanced the cell rounding and killing activities, compared with that induced by the trypsin-treated rCPILE-b alone. The injection of the mixture of rCPILE-a and the trypsin-treated rCPILE-b into an ileum loop of rabbits evoked the swelling of the loop and accumulation of the fluid dose-dependently, suggesting that CPILE possesses enterotoxic activity. The evidence presented in this communication will facilitate the epidemiological, etiological, and toxicological studies of C. perfringens food poisoning, and also stimulate studies on the transfer of the toxins' gene(s among the Genus Clostridium.

  15. Pyridine nucleotide cycle of Salmonella typhimurium: isolation and characterization of pncA, pncB, and pncC mutants and utilization of exogenous nicotinamide adenine dinucleotide.

    Science.gov (United States)

    Foster, J W; Kinney, D M; Moat, A G

    1979-03-01

    Mutants of Salmonella typhimurium LT-2 deficient in nicotinamidase activity (pncA) or nicotinic acid phosphoribosyltransferase activity (pncB) were isolated as resistant to analogs of nicotinic acid and nicotinamide. Information obtained from interrupted mating experiments placed the pncA gene at 27 units and the pncB gene at 25 units on the S. typhimurium LT-2 linkage map. A major difference in the location of the pncA gene was found between the S. typhimurium and Escherichia coli linkage maps. The pncA gene is located in a region in which there is a major inversion of the gene order in S. typhimurium as compared to that in E. coli. Growth experiments using double mutants blocked in the de novo pathway to nicotinamide adenine dinucleotide (NAD) (nad) and in the pyridine nucleotide cycle (pnc) at either the pncA or pncB locus, or both, have provided evidence for the existence of an alternate recycling pathway in this organism. Mutants lacking this alternate cycle, pncC, have been isolated and mapped via cotransduction at 0 units. Utilization of exogenous NAD was examined through the use of [14C]carbonyl-labeled NAD and [14C]adenine-labeled NAD. The results of these experiments suggest that NAD is degraded to nicotinamide mononucleotide at the cell surface. A portion of this extracellular nicotinamide mononucleotide is then transported across the cell membrane by nicotinamide mononucleotide glycohydrolase and degraded to nicotinamide in the process. The remaining nicotinamide mononucleotide accumulates extracellularly and will support the growth of nadA pncB mutants which cannot utilize the nicotinamide resulting from the major pathway of NAD degradation. A model is presented for the utilization of exogenous NAD by S. typhimurium LT-2.

  16. The involvement of poly(ADP-ribose) polymerase in the degradation of NAD caused by γ-radiation and N-methyl-N-nitrosourea

    International Nuclear Information System (INIS)

    Skidmore, C.J.; Davies, M.I.; Goodwin, P.M.; Halldorsson, H.; Lewis, P.J.; Shall, S.; Zia'ee, A.

    1979-01-01

    Both N-methyl-N-nitrosourea and γ-radiation lower cellular NAD in mouse leukaemia cells (L1210) in a dose-dependent way. The minimum NAD level is reached 2 h after a brief exposure to N-methyl-N-nitrosourea, but within 15 min of γ-irradiation. The cells remain metabolically active; they are able to recover their control NAD levels and are impermeable to trypan blue. Several inhibitors of poly(ADP-ribose) polymerase inhibit the drop in cellular NAD caused by these two agents: 2 mM 5-methylnicotinamide, 1 mM theophylline or 1 mM theobromine inhibit the effect of N-methyl-N-nitrosourea on cellular NAD level; 200 μM thymidine, 500 μM 5-methylnicotinaminde, 500 μM thephylline and 500 μM theobromine prevent the lowering of cellular NAD by γ-irradiation. The extent to which the drop in cellular NAD is inhibited is dependent on both the concentration of cytotoxic agent and of polymerase inhibitor. Caffeine will inhibit the drop in NAD but only at 10 mM, while nicotonic acid is ineffictive even at this dose. The activity of poly(ADP-ribose) polymerase is permeabilized cells immediately after γ-radiation increases with dose up to 12 krad, giving a maximal 3.4-fold stimulation of the enzyme activity, whereas the degradation of NAD under conditions optimal for NAD glycohydrolase does not change. The activity of the polymerase shows a close temporal correlation with the NAD drop following both γ-radiation and N-methyl-N-nitrosourea. The enzyme activity is maximal when the NAD content. (orig./AJ) 891 AJ/orig.- 892 HIS [de

  17. NAD-content and metabolism in the mouse embryo and developing brain

    International Nuclear Information System (INIS)

    Beuningen, M. van; Streffer, C.; Beuningen, D. van

    1986-01-01

    Biochemical studies have shown that NAD is not only the coenzyme of dehydrogenase but also the substrate of poly-(ADPR)-synthetase which is involved in processes of cell proliferation and differentiation. The NAD and protein content was determined in the total embryo and in the CNS 9 to 13 days p.c. The embryos were X-irradiated 9 days p.c. The NAD content increased in the total mouse embryo during the early organogenesis. At the later period a decrease of the NAD content per mg protein was observed. This latter effect was apparently due to an increase of the NAD glycohydrolase activity. This enzyme degrades NAD. A similar development was observed in the developing mouse brain. However, the maximal NAD content per mg protein occurred on day 10 p.c. One of the enzyme activities, which are responsible for NAD synthesis, NMN-pyrophosphorylase, also increased in the brain at the same time. After the injection of C 14-nicotinamide, a precursor of NAD, it was observed that the radioactivity mainly appeared in nicotinamide and NAD. With progressing embryological development less nicotinamide was taken up by the embryonic tissue. When the embryos were X-irradiated on day 9 p.c. with 1.8 Gy the increase of NAD was considerably reduced during the next days, so that also the NAD level per mg protein was reduced. Also the NAD biosynthesis apparently decreased. This was shown again by the reduced NMN-pyrophosphorylase activity. The dose dependance of these effects was studied in the dose range 0.48-1.8 Gy. Two days p.r. most of the radiation effects were normalized again and at later periods even an overshoot of the enzyme activity was observed. The possible relevance of these effects for cell proliferation will be discussed. (orig.)

  18. PARP2 Is the Predominant Poly(ADP-Ribose Polymerase in Arabidopsis DNA Damage and Immune Responses.

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    Junqi Song

    2015-05-01

    Full Text Available Poly (ADP-ribose polymerases (PARPs catalyze the transfer of multiple poly(ADP-ribose units onto target proteins. Poly(ADP-ribosylation plays a crucial role in a variety of cellular processes including, most prominently, auto-activation of PARP at sites of DNA breaks to activate DNA repair processes. In humans, PARP1 (the founding and most characterized member of the PARP family accounts for more than 90% of overall cellular PARP activity in response to DNA damage. We have found that, in contrast with animals, in Arabidopsis thaliana PARP2 (At4g02390, rather than PARP1 (At2g31320, makes the greatest contribution to PARP activity and organismal viability in response to genotoxic stresses caused by bleomycin, mitomycin C or gamma-radiation. Plant PARP2 proteins carry SAP DNA binding motifs rather than the zinc finger domains common in plant and animal PARP1 proteins. PARP2 also makes stronger contributions than PARP1 to plant immune responses including restriction of pathogenic Pseudomonas syringae pv. tomato growth and reduction of infection-associated DNA double-strand break abundance. For poly(ADP-ribose glycohydrolase (PARG enzymes, we find that Arabidopsis PARG1 and not PARG2 is the major contributor to poly(ADP-ribose removal from acceptor proteins. The activity or abundance of PARP2 is influenced by PARP1 and PARG1. PARP2 and PARP1 physically interact with each other, and with PARG1 and PARG2, suggesting relatively direct regulatory interactions among these mediators of the balance of poly(ADP-ribosylation. As with plant PARP2, plant PARG proteins are also structurally distinct from their animal counterparts. Hence core aspects of plant poly(ADP-ribosylation are mediated by substantially different enzymes than in animals, suggesting the likelihood of substantial differences in regulation.

  19. Design, synthesis, and biological evaluation of enantiomeric beta-N-acetylhexosaminidase inhibitors LABNAc and DABNAc as potential agents against Tay-Sachs and Sandhoff disease.

    Science.gov (United States)

    Rountree, J S Shane; Butters, Terry D; Wormald, Mark R; Boomkamp, Stephanie D; Dwek, Raymond A; Asano, Naoki; Ikeda, Kyoko; Evinson, Emma L; Nash, Robert J; Fleet, George W J

    2009-03-01

    N-Acetylhexosaminidases are of considerable importance in mammals and are involved in various significant biological processes. In humans, deficiencies of these enzymes in the lysosome, resulting from inherited genetic defects, cause the glycolipid storage disorders Tay-Sachs and Sandhoff diseases. One promising therapy for these diseases involves the use of beta-N-acetylhexosaminidase inhibitors as chemical chaperones to enhance the enzyme activity above sub-critical levels. Herein we describe the synthesis and biological evaluation of a potent inhibitor, 2-acetamido-1,4-imino-1,2,4-trideoxy-L-arabinitol (LABNAc), in a high-yielding 11-step procedure from D-lyxonolactone. The N-benzyl and N-butyl analogues were also prepared and found to be potent inhibitors. The enantiomers DABNAc and NBn-DABNAc were synthesised from L-lyxonolactone, and were also evaluated. The L-iminosugar LABNAc and its derivatives were found to be potent noncompetitive inhibitors of some beta-N-acetylhexosaminidases, while the D-iminosugar DABNAc and its derivatives were found to be weaker competitive inhibitors. These results support previous work postulating that D-iminosugar mimics inhibit D-glycohydrolases competitively, and that their corresponding L-enantiomers show noncompetitive inhibition of these enzymes. Molecular modelling studies confirm that the spatial organisation in enantiomeric inhibitors leads to a different overlay with the monosaccharide substrate. Initial cell-based studies suggest that NBn-LABNAc can act as a chemical chaperone to enhance the deficient enzyme's activity to levels that may cause a positive pharmacological effect. LABNAc, NBn-LABNAc, and NBu-LABNAc are potent and selective inhibitors of beta-N-acetylhexosaminidase and may be useful as therapeutic agents for treating adult Tay-Sachs and Sandhoff diseases.

  20. Proteomic analysis of apoplastic fluid of Coffea arabica leaves highlights novel biomarkers for resistance against Hemileia vastatrix

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    Leonor eGuerra-Guimarães

    2015-06-01

    Full Text Available A proteomic analysis of the apoplastic fluid (APF of coffee leaves was conducted to investigate the cellular processes associated with incompatible (resistant and compatible (susceptible Coffea arabica-Hemileia vastatrix interactions, during the 24-96 hai period. The APF proteins were extracted by leaf vacuum infiltration and protein profiles were obtained by 2-DE. The comparative analysis of the gels revealed 210 polypeptide spots whose volume changed in abundance between samples (control, resistant and susceptible during the 24-96 hai period. The proteins identified were involved mainly in protein degradation, cell wall metabolism and stress/defense responses, most of them being hydrolases (around 70%, particularly sugar hydrolases and peptidases/proteases. The changes in the APF proteome along the infection process revealed two distinct phases of defense responses, an initial/basal one (24-48 hai and a late/specific one (72-96 hai. Compared to susceptibility, resistance was associated with a higher number of proteins, which was more evident in the late/specific phase. Proteins involved in the resistance response were mainly, glycohydrolases of the cell wall, serine proteases and pathogen related-like proteins (PR-proteins, suggesting that some of these proteins could be putative candidates for resistant markers of coffee to H. vastatrix. Antibodies were produced against chitinase, pectin methylesterase, serine carboxypeptidase, reticuline oxidase and subtilase and by an immunodetection assay it was observed an increase of these proteins in the resistant sample. With this methodology we have identified proteins that are candidate markers of resistance and that will be useful in coffee breeding programs to assist in the selection of cultivars with resistance to H. vastatrix.

  1. Investigation of PARP-1, PARP-2, and PARG interactomes by affinity-purification mass spectrometry

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    Isabelle Maxim

    2010-04-01

    Full Text Available Abstract Background Poly(ADP-ribose polymerases (PARPs catalyze the formation of poly(ADP-ribose (pADPr, a post-translational modification involved in several important biological processes, namely surveillance of genome integrity, cell cycle progression, initiation of the DNA damage response, apoptosis, and regulation of transcription. Poly(ADP-ribose glycohydrolase (PARG, on the other hand, catabolizes pADPr and thereby accounts for the transient nature of poly(ADP-ribosylation. Our investigation of the interactomes of PARP-1, PARP-2, and PARG by affinity-purification mass spectrometry (AP-MS aimed, on the one hand, to confirm current knowledge on these interactomes and, on the other hand, to discover new protein partners which could offer insights into PARPs and PARG functions. Results PARP-1, PARP-2, and PARG were immunoprecipitated from human cells, and pulled-down proteins were separated by gel electrophoresis prior to in-gel trypsin digestion. Peptides were identified by tandem mass spectrometry. Our AP-MS experiments resulted in the identifications of 179 interactions, 139 of which are novel interactions. Gene Ontology analysis of the identified protein interactors points to five biological processes in which PARP-1, PARP-2 and PARG may be involved: RNA metabolism for PARP-1, PARP-2 and PARG; DNA repair and apoptosis for PARP-1 and PARP-2; and glycolysis and cell cycle for PARP-1. Conclusions This study reveals several novel protein partners for PARP-1, PARP-2 and PARG. It provides a global view of the interactomes of these proteins as well as a roadmap to establish the systems biology of poly(ADP-ribose metabolism.

  2. Sexual dimorphism of growth plate prehypertrophic and hypertrophic chondrocytes in response to testosterone requires metabolism to dihydrotestosterone (DHT) by steroid 5-alpha reductase type 1.

    Science.gov (United States)

    Raz, P; Nasatzky, E; Boyan, B D; Ornoy, A; Schwartz, Z

    2005-05-01

    Rat costochondral growth plate chondrocytes exhibit sex-specific and cell maturation dependent responses to testosterone. Only male cells respond to testosterone, although testosterone receptors are present in both male and female cells, suggesting other mechanisms are involved. We examined the hypothesis that the sex-specific response of rat costochondral cartilage cells to testosterone requires further metabolism of the hormone to dihydrotestosterone (DHT). Resting zone (RC) and growth zone (GC, prehypertrophic and upper hypertrophic zones) chondrocytes from male and female Sabra strain rats exhibited sex-specific responses to testosterone and DHT: only male cells were responsive. Testosterone and DHT treatment for 24 h caused a comparable dose-dependent increase in [3H]-thymidine incorporation in quiescent preconfluent cultures of male GC cells, and a comparable increase in alkaline phosphatase specific activity in confluent cultures. RC cells responded in a differential manner to testosterone and DHT. Testosterone decreased DNA synthesis in male RC cells but DHT had no effect and alkaline phosphatase specific activity of male RC cells was unaffected by either hormone. Inhibition of steroid 5alpha-reductase activity with finasteride (1, 5, or 10 microg/ml), reduced the response of male GC cells to testosterone in a dose-dependent manner, indicating that metabolism to DHT was required. RT-PCR showed that both male and female cells expressed mRNAs for steroid 5alpha-reductase type 1 but lacked mRNAs for the type 2 form of the enzyme. Male cells also exhibited 5alpha-reductase activity but activity of this enzyme was undetectable in female cells. These observations show that sex-specific responses of rat growth zone chondrocytes to testosterone requires the further metabolism of the hormone to DHT and that the effect of DHT in the male growth plate is maturation-state dependent. Failure of female chondrocytes to respond to testosterone may reflect differences in

  3. [Effects of controlled release blend bulk urea on soil nitrogen and soil enzyme activity in wheat and rice fields].

    Science.gov (United States)

    Zhang, Jing Sheng; Wang, Chang Quan; Li, Bing; Liang, Jing Yue; He, Jie; Xiang, Hao; Yin, Bin; Luo, Jing

    2017-06-18

    A field experiment was conducted to investigate the effect of controlled-release fertilizer (CRF) combined with urea (UR) on the soil fertility and environment in wheat-rice rotation system. Changes in four forms of nitrogen (total nitrogen, ammonium nitrogen, nitrate nitrogen, and microbial biomass nitrogen) and in activities of three soil enzymes participating in nitrogen transformation (urease, protease, and nitrate reductase) were measured in seven fertilization treatments (no fertilization, routine fertilization, 10%CRF+90%UR, 20%CRF+80%UR, 40%CRF+60%UR, 80%CRF+20%UR, and 100%CRF). The results showed that soil total nitrogen was stable in the whole growth period of wheat and rice. There was no significant difference among the treatments of over 20% CRF in soil total nitrogen content of wheat and rice. The soil inorganic nitrogen content was increased dramatically in treatments of 40% or above CRF during the mid-late growing stages of wheat and rice. With the advance of the growth period, conventional fertilization significantly decreased soil microbial biomass nitrogen, but the treatments of 40% and above CRF increased the soil microbial biomass nitrogen significantly. The soil enzyme activities were increased with over 40% of CRF in the mid-late growing stage of wheat and rice. By increasing the CRF ratio, the soil protease activity and nitrate reductase activity were improved gradually, and peaked in 100% CRF. The treatments of above 20% CRF could decrease the urease activity in tillering stage of rice and delay the peak of ammonium nitrogen, which would benefit nitrogen loss reduction. The treatments of 40% and above CRF were beneficial to improving soil nitrogen supply and enhancing soil urease and protease activities, which could promote the effectiveness of nitrogen during the later growth stages of wheat and rice. The 100% CRF treatment improved the nitrate reductase activity significantly during the later stage of wheat and rice. Compared with the

  4. Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

    Science.gov (United States)

    Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

    2014-06-15

    Recent studies have shown that tolerance to abiotic stress, including water stress, is improved by grafting. In a previous work, we took advantage of the natural variability of Capsicum spp. and selected accessions tolerant and sensitive to water stress as rootstocks. The behavior of commercial cultivar 'Verset' seedlings grafted onto the selected rootstocks at two levels of water stress provoked by adding 3.5 and 7% PEG (polyethylene glycol) was examined over 14 days. The objective was to identify the physiological traits responsible for the tolerance provided by the rootstock in order to determine if the tolerance is based on the maintenance of the water relations under water stress or through the activation of protective mechanisms. To achieve this goal, various physiological parameters were measured, including: water relations; proline accumulation; gas exchange; chlorophyll fluorescence; nitrate reductase activity; and antioxidant capacity. Our results indicate that the effect of water stress on the measured parameters depends on the duration and intensity of the stress level, as well as the rootstock used. Under control conditions (0% PEG) all plant combinations showed similar values for all measured parameters. In general terms, PEG provoked a strong decrease in the gas exchange parameters in the cultivar grafted onto the sensitive accessions, as also observed in the ungrafted plants. This effect was related to lower relative water content in the plants, provoked by an inefficient osmotic adjustment that was dependent on reduced proline accumulation. At the end of the experiment, chronic photoinhibition was observed in these plants. However, the plants grafted onto the tolerant rootstocks, despite the reduction in photosynthetic rate, maintained the protective capacity of the photosynthetic machinery mediated by osmotic adjustment (based on higher proline content). In addition, water stress limited uptake and further NO3(-) transfer to the leaves. Increased

  5. Purification and kinetic analysis of cytosolic and mitochondrial thioredoxin glutathione reductase extracted from Taenia solium cysticerci.

    Science.gov (United States)

    Plancarte, Agustin; Nava, Gabriela

    2015-02-01

    Thioredoxin glutathione reductases (TGRs) (EC 1.8.1.9) were purified to homogeneity from the cytosolic (cTsTGR) and mitochondrial (mTsTGR) fractions of Taenia solium, the agent responsible for neurocysticercosis, one of the major central nervous system parasitic diseases in humans. TsTGRs had a relative molecular weight of 132,000, while the corresponding value per subunit obtained under denaturing conditions, was of 62,000. Specific activities for thioredoxin reductase and glutathione reductase substrates for both TGRs explored were in the range or lower than values obtained for other platyhelminths and mammalian TGRs. cTsTGR and mTsTGR also showed hydroperoxide reductase activity using hydroperoxide as substrate. Km(DTNB) and Kcat(DTNB) values for cTsTGR and mTsTGR (88 µM and 1.9 s(-1); 45 µM and 12.6 s(-1), respectively) and Km(GSSG) and Kcat(GSSG) values for cTsTGR and mTsTGR (6.3 µM and 0.96 s(-1); 4 µM and 1.62 s(-1), respectively) were similar to or lower than those reported for mammalian TGRs. Mass spectrometry analysis showed that 12 peptides from cTsTGR and seven from mTsTGR were a match for gi|29825896 thioredoxin glutathione reductase [Echinococcus granulosus], confirming that both enzymes are TGRs. Both T. solium TGRs were inhibited by the gold compound auranofin, a selective inhibitor of thiol-dependent flavoreductases (I₅₀ = 3.25, 2.29 nM for DTNB and GSSG substrates, respectively for cTsTGR; I₅₀ = 5.6, 25.4 nM for mTsTGR toward the same substrates in the described order). Glutathione reductase activity of cTsTGR and mTsTGR exhibited hysteretic behavior with moderate to high concentrations of GSSG; this result was not observed either with thioredoxin, DTNB or NADPH. However, the observed hysteretic kinetics was suppressed with increasing amounts of both parasitic TGRs. These data suggest the existence of an effective substitute which may account for the lack of the detoxification enzymes glutathione reductase

  6. Cyclobenzaprine Raises ROS Levels in Leishmania infantum and Reduces Parasite Burden in Infected Mice.

    Directory of Open Access Journals (Sweden)

    Edézio Ferreira Cunha-Júnior

    2017-01-01

    Full Text Available The leishmanicidal action of tricyclic antidepressants has been studied and evidences have pointed that their action is linked to inhibition of trypanothione reductase, a key enzyme in the redox metabolism of pathogenic trypanosomes. Cyclobenzaprine (CBP is a tricyclic structurally related to the antidepressant amitriptyline, differing only by the presence of a double bond in the central ring. This paper describes the effect of CBP in experimental visceral leishmaniasis, its inhibitory effect in trypanothione reductase and the potential immunomodulatory activity.In vitro antileishmanial activity was determined in promastigotes and in L. infantum-infected macrophages. For in vivo studies, L. infantum-infected BALB/c mice were treated with CBP by oral gavage for five days and the parasite load was estimated. Trypanothione reductase activity was assessed in the soluble fraction of promastigotes of L. infantum. For evaluation of cytokines, L. infantum-infected macrophages were co-cultured with BALB/c splenocytes and treated with CBP for 48 h. The supernatant was analyzed for IL-6, IL-10, MCP-1, IFN-γ and TNF-α. CBP demonstrated an IC50 of 14.5±1.1μM and an IC90 of 74.5±1.2 μM in promastigotes and an IC50 of 12.6±1.05 μM and an IC90 of 28.7±1.3 μM in intracellular amastigotes. CBP also reduced the parasite load in L. infantum-infected mice by 40.4±10.3% and 66.7±10.5% in spleen at 24.64 and 49.28 mg/kg, respectively and by 85.6±5.0 and 89.3±4.8% in liver at 24.64 and 49.28mg/kg, after a short-term treatment. CBP inhibited the trypanothione reductase activity with a Ki of 86 ± 7.7 μM and increased the ROS production in promastigotes. CBP inhibited in 53% the production of IL-6 in infected macrophages co-culture.To the best of our knowledge, this study is the first report of the in vivo antileishmanial activity of the FDA-approved drug CBP. Modulation of immune response and induction of oxidative stress in parasite seem to contribute to

  7. Purification and characterization of a novel cytosolic NADP(H)-dependent retinol oxidoreductase from rabbit liver.

    Science.gov (United States)

    Huang, D Y; Ichikawa, Y

    1997-03-07

    Rabbit liver cytosol exhibits very high retinol dehydrogenase activity. At least two retinol dehydrogenases were demonstrated to exist in rabbit liver cytosol, and the major one, a cytosolic NADP(H)-dependent retinol dehydrogenase (systematic name: retinol oxidoreductase) was purified about 1795-fold to electrophoretic and column chromatographic homogeneity by a procedure involving column chromatography on AF-Red Toyopearl twice and then hydroxyapatite. Its molecular mass was estimated to be 34 kDa by SDS-PAGE, and 144 kDa by HPLC gel filtration, suggesting that it is a homo-tetramer. The enzyme uses free retinol and retinal, and their complexes with CRBP as substrates in vitro. The optimum pH values for retinol oxidation of free retinol and CRBP-retinol were 8.8-9.2 and 8.0-9.0, respectively, and those for retinal reduction of free retinal and retinal-CRBP were the same, 7.0-7.6. Km for free retinol and Vmax for retinal formation were 2.8 microM and 2893 nmol/min per mg protein at 37 degrees C (pH 9.0) and the corresponding values with retinol-CRBP as a substrate were 2.5 microM and 2428 nmol/min per mg protein at 37 degrees C (pH 8.6); Km for free retinal and Vmax for retinol formation were 6.5 microM and 4108 nmol/min per mg protein, and the corresponding values with retinal-CRBP as a substrate were 5.1 microM and 3067 nmol/min per mg protein at 37 degrees C, pH 7.4. NAD(H) was not effective as a cofactor. 4-Methylpyrazole was a weak inhibitor (IC50 = 28 mM) of the enzyme, and ethanol was neither a substrate nor an inhibitor of the enzyme. This enzyme exhibits relatively broad aldehyde reductase activity and some ketone reductase activity, the activity for aromatic substitutive aldehydes being especially high and effective. Whereas, except in the case of retinol, oxidative activity toward the corresponding alcohols was not detected. This novel cytosolic enzyme may play an important role in vivo in maintaining the homeostasis of retinal, the substrate of retinoic

  8. Thioredoxin-1 Negatively Modulates ADAM17 Activity Through Direct Binding and Indirect Reductive Activity.

    Science.gov (United States)

    Granato, Daniela C; E Costa, Rute A P; Kawahara, Rebeca; Yokoo, Sami; Aragão, Annelize Z; Domingues, Romênia R; Pauletti, Bianca A; Honorato, Rodrigo V; Fattori, Juliana; Figueira, Ana Carolina M; Oliveira, Paulo S L; Consonni, Silvio R; Fernandes, Denise; Laurindo, Francisco; Hansen, Hinrich P; Paes Leme, Adriana F

    2018-02-27

    A disintegrin and metalloprotease 17 (ADAM17) modulates signaling events by releasing surface protein ectodomains such as TNFa and the EGFR-ligands. We have previously characterized cytoplasmic thioredoxin-1 (Trx-1) as a partner of ADAM17 cytoplasmic domain. Still, the mechanism of ADAM17 regulation by Trx-1 is unknown, and it has become of paramount importance to assess the degree of influence that Trx-1 has on metalloproteinase ADAM17. Combining discovery and targeted proteomic approaches, we uncovered that Trx-1 negatively regulates ADAM17 by direct and indirect effect. We performed cell-based assays with synthetic peptides and site-directed mutagenesis, and we demonstrated that the interaction interface of Trx-1 and ADAM17 is important for the negative regulation of ADAM17 activity. However, both Trx-1 K72A and catalytic site mutant Trx-1 C32/35S rescued ADAM17 activity, although the interaction with Trx-1 C32/35S was unaffected, suggesting an indirect effect of Trx-1. We confirmed that the Trx-1 C32/35S mutant showed diminished reductive capacity, explaining this indirect effect on increasing ADAM17 activity through oxidant levels. Interestingly, Trx-1 K72A mutant showed similar oxidant levels to Trx-1 C32/35S , even though its catalytic site was preserved. We further demonstrated that the general reactive oxygen species inhibitor, Nacetylcysteine (NAC), maintained the regulation of ADAM17 dependent of Trx-1 reductase activity levels; whereas the electron transport chain modulator, rotenone, abolished Trx-1 effect on ADAM17 activity. We show for the first time that the mechanism of ADAM17 regulation, Trx-1 dependent, can be by direct interaction and indirect effect, bringing new insights into the cross-talk between isomerases and mammalian metalloproteinases. This unexpected Trx-1 K72A behavior was due to more dimer formation and, consequently, the reduction of its Trx-1 reductase activity, evaluated through dimer verification, by gel filtration and mass

  9. Identification and functional evaluation of the reductases and dehydrogenases from Saccharomyces cerevisiae involved in vanillin resistance.

    Science.gov (United States)

    Wang, Xinning; Liang, Zhenzhen; Hou, Jin; Bao, Xiaoming; Shen, Yu

    2016-04-01

    Vanillin, a type of phenolic released during the pre-treatment of lignocellulosic materials, is toxic to microorganisms and therefore its presence inhibits the fermentation. The vanillin can be reduced to vanillyl alcohol, which is much less toxic, by the ethanol producer Saccharomyces cerevisiae. The reducing capacity of S. cerevisiae and its vanillin resistance are strongly correlated. However, the specific enzymes and their contribution to the vanillin reduction are not extensively studied. In our previous work, an evolved vanillin-resistant strain showed an increased vanillin reduction capacity compared with its parent strain. The transcriptome analysis suggested the reductases and dehydrogenases of this vanillin resistant strain were up-regulated. Using this as a starting point, 11 significantly regulated reductases and dehydrogenases were selected in the present work for further study. The roles of these reductases and dehydrogenases in the vanillin tolerance and detoxification abilities of S. cerevisiae are described. Among the candidate genes, the overexpression of the alcohol dehydrogenase gene ADH6, acetaldehyde dehydrogenase gene ALD6, glucose-6-phosphate 1-dehydrogenase gene ZWF1, NADH-dependent aldehyde reductase gene YNL134C, and aldo-keto reductase gene YJR096W increased 177, 25, 6, 15, and 18 % of the strain μmax in the medium containing 1 g L(-1) vanillin. The in vitro detected vanillin reductase activities of strain overexpressing ADH6, YNL134C and YJR096W were notably higher than control. The vanillin specific reduction rate increased by 8 times in ADH6 overexpressed strain but not in YNL134C and YJR096W overexpressed strain. This suggested that the enzymes encoded by YNL134C and YJR096W might prefer other substrate and/or could not show their effects on vanillin on the high background of Adh6p in vivo. Overexpressing ALD6 and ZWF1 mainly increased the [NADPH]/[NADP(+)] and [GSH]/[GSSG] ratios but not the vanillin reductase activities. Their

  10. Physiological effects of magnetic iron oxide nanoparticles towards watermelon.

    Science.gov (United States)

    Li, Junli; Chang, Peter R; Huang, Jin; Wang, Yunqiang; Yuan, Hong; Ren, Hongxuan

    2013-08-01

    Nanoparticles (NPs) have been exploited in a diverse range of products in the past decade or so. However, the biosafety/environmental impact or legislation pertaining to this newly created, highly functional composites containing NPs (otherwise called nanomaterials) is generally lagging behind their technological innovation. To advance the agenda in this area, our current primary interest is focused on using crops as model systems as they have very close relationship with us. Thus, the objective of the present study was to evaluate the biological effects of magnetic iron oxide nanoparticles towards watermelon seedlings. We have systematically studied the physiological effects of Fe2O3 nanoparticles (nano-Fe2O3) on watermelon, and present the first evidence that a significant amount of Fe2O3 nanoparticles suspended in a liquid medium can be taken up by watermelon plants and translocated throughout the plant tissues. Changes in important physiological indicators, such as root activity, activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), chlorophyll and malondialdehyde (MDA) contents, ferric reductase activity, root apoplastic iron content were clearly presented. Different concentrations of nano-Fe2O3 all increased seed germination, seedling growth, and enhanced physiological function to some degree; and the positive effects increased quickly and then slowed with an increase in the treatment concentrations. Changes in CAT, SOD and POD activities due to nano-Fe2O3 were significantly larger than that of the control. The 20 mg/L treatment had the most obvious effect on the increase of root activity. Ferric reductase activity, root apoplastic iron content, and watermelon biomass were significantly affected by exposure to nano-Fe2O3. Results of statistical analysis showed that there were significant differences in all the above indexes between the treatment at optimal concentration and the control. This proved that the proper concentration of nano

  11. Redução de nitrato em plantas jovens de café cultivadas em diferentes níveis de luz e de nitrogênio Nitrate reduction in young coffee trees grown under different levels of light and nitrogen

    Directory of Open Access Journals (Sweden)

    Maria Luiza Carvalho Carelli

    1990-01-01

    Full Text Available Foi estudado o efeito de níveis de luz e de nitrogênio na atividade da enzima redutase de nitrato e nos teores de nitrato e de açúcares nas folhas de plantas jovens de café (Coffea arabica L, assim como as possíveis relações entre a disponibilidade desses compostos e a atividade enzimática. Foram utilizadas plantas de dez meses de idade cultivadas em vasos contendo uma mistura de terra mais composto, e mantidas em condições ambientais em pleno sol e em 50% da luz solar. Metade das plantas de cada tratamento de luz foi suplementada semanalmente com nitrogênio. Os resultados mostraram que a atividade da redutase de nitrato, nos dois tratamentos de luz, foi maior nas plantas suplementadas com nitrogênio. Para um mesmo nível de nitrogênio, as plantas cultivadas em pleno sol apresentaram menor atividade da redutase de nitrato, maiores teores de nitrato e de açúcares e maiores taxas de transpiração, do que as cultivadas na sombra. Tais resultados indicam que a menor atividade da redutase de nitrato nas plantas cultivadas em pleno sol aparentemente não foi devida a limitações na disponibilidade de nitrato e de açúcares para fornecer a energia necessária para a redução de nitrato.The effect of levels of light and nitrogen on the activity of the enzyme nitrate reductase and its relationship with the availability of sugars and nitrate was studied in leaves of coffee plants (Coffea arabica L. cv. Catual. Ten month old plants were grown on pots containing a mixture of soil and compost, and were kept at full or 50% sunlight. Half of the plants of each light treatment received nitrogen supply. The results showed that the activity of nitrate reductase was higher on plants supplied with nitrogen at both light treatments. For the same nitrogen level, plants grown under full sunlight presented lower nitrate reductase activity, higher nitrate and sugars concentrations, and higher transpiration rates than plants kept at 50% sunlight

  12. Elucidation of mechanisms of actions of thymoquinone-enriched methanolic and volatile oil extracts from Nigella sativa against cardiovascular risk parameters in experimental hyperlipidemia.

    Science.gov (United States)

    Ahmad, Shafeeque; Beg, Zafarul H

    2013-06-13

    Nigella sativa belonging to the Ranunculaceae family has been reported to use for thousands of years as protective and curative traditional medicine against a number of diseases. GC-MS analysis of methanolic extract (ME) and volatile oil (VO) extracted from Nigella sativa seed oil was performed by two different mass spectrometry libraries, WIlEY8 and NIST05s. The cholesterol lowering and antioxidant actions of VO and ME fractions were investigated in atherogenic suspension fed rats. In this study, four groups of male Wistar rats were used: normolipidemic control (NLP-C), hyperlipidemic control (HLP-C), methanolic extract (HLP-ME) and volatile oil treated (HLP-VO) groups for 30 days of duration. P value < 0.05 was assumed as significant data in groups. Administration of atherogenic suspension to male Wistar rats for 30 days resulted in a marked increase of plasma triglycerides and total cholesterol, and significant change in plasma lipoprotein levels along with a decrease in antioxidant arylesterase activity in hyperlipidemic control (HLP-C) group. The oral feeding of 100 mg ME or 20 mg VO per rat/day effectively reduced the plasma triglycerides to near normal level, while high density lipoprotein cholesterol and its subfraction along with arylesterase activity levels were significantly increased. The test fractions elicited a significant decrease in hepatic HMG-CoA reductase activity. The fractions significantly blocked the ex vivo basal and in vitro maximal formation of conjugated diene and malondialdehyde, and lengthened the lag times of low density lipoprotein, small dense low density lipoprotein and large buoyant low density lipoprotein. ME possessing ω-6 linoleic acid along with palmitic acid active compounds was more effective than VO extract containing thymol and isothymol phenolic antioxidant compounds, thymoquinone phenolic compound common to the both extracts, via reduction in hepatic HMG-CoA reductase activity as well as antioxidant mechanisms. The both

  13. Sterylglucoside catabolism in Cryptococcus neoformans with endoglycoceramidase-related protein 2 (EGCrP2), the first steryl-β-glucosidase identified in fungi.

    Science.gov (United States)

    Watanabe, Takashi; Ito, Tomoharu; Goda, Hatsumi M; Ishibashi, Yohei; Miyamoto, Tomofumi; Ikeda, Kazutaka; Taguchi, Ryo; Okino, Nozomu; Ito, Makoto

    2015-01-09

    Cryptococcosis is an infectious disease caused by pathogenic fungi, such as Cryptococcus neoformans and Cryptococcus gattii. The ceramide structure (methyl-d18:2/h18:0) of C. neoformans glucosylceramide (GlcCer) is characteristic and strongly related to its pathogenicity. We recently identified endoglycoceramidase-related protein 1 (EGCrP1) as a glucocerebrosidase in C. neoformans and showed that it was involved in the quality control of GlcCer by eliminating immature GlcCer during the synthesis of GlcCer (Ishibashi, Y., Ikeda, K., Sakaguchi, K., Okino, N., Taguchi, R., and Ito, M. (2012) Quality control of fungus-specific glucosylceramide in Cryptococcus neoformans by endoglycoceramidase-related protein 1 (EGCrP1). J. Biol. Chem. 287, 368-381). We herein identified and characterized EGCrP2, a homologue of EGCrP1, as the enzyme responsible for sterylglucoside catabolism in C. neoformans. In contrast to EGCrP1, which is specific to GlcCer, EGCrP2 hydrolyzed various β-glucosides, including GlcCer, cholesteryl-β-glucoside, ergosteryl-β-glucoside, sitosteryl-β-glucoside, and para-nitrophenyl-β-glucoside, but not α-glucosides or β-galactosides, under acidic conditions. Disruption of the EGCrP2 gene (egcrp2) resulted in the accumulation of a glycolipid, the structure of which was determined following purification to ergosteryl-3β-glucoside, a major sterylglucoside in fungi, by mass spectrometric and two-dimensional nuclear magnetic resonance analyses. This glycolipid accumulated in vacuoles and EGCrP2 was detected in vacuole-enriched fraction. These results indicated that EGCrP2 was involved in the catabolism of ergosteryl-β-glucoside in the vacuoles of C. neoformans. Distinct growth arrest, a dysfunction in cell budding, and an abnormal vacuole morphology were detected in the egcrp2-disrupted mutants, suggesting that EGCrP2 may be a promising target for anti-cryptococcal drugs. EGCrP2, classified into glycohydrolase family 5, is the first steryl

  14. Effects of Trans-Resveratrol on hyperglycemia-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase signaling in rat testis

    Energy Technology Data Exchange (ETDEWEB)

    Abdelali, Ala [Department of Anatomy, Faculty of Medicine, Kuwait University (Kuwait); Al-Bader, Maie [Department of Physiology, Faculty of Medicine, Kuwait University (Kuwait); Kilarkaje, Narayana, E-mail: knarayana@hsc.edu.kw [Department of Anatomy, Faculty of Medicine, Kuwait University (Kuwait)

    2016-11-15

    Diabetes induces oxidative stress, DNA damage and alters several intracellular signaling pathways in organ systems. This study investigated modulatory effects of Trans-Resveratrol on type 1 diabetes mellitus (T1DM)-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase (PARP) signaling in rat testis. Trans-Resveratrol administration (5mg/kg/day, ip) to Streptozotocin-induced T1DM adult male Wistar rats from day 22–42 resulted in recovery of induced oxidative stress, abnormal spermatogenesis and inhibited DNA synthesis, and led to mitigation of 8-hydroxy-2'-deoxyguanosine formation in the testis and spermatozoa, and DNA double-strand breaks in the testis. Trans-Resveratrol aggravated T1DM-induced up-regulation of aminoacyl tRNA synthetase complex-interacting multifunctional protein 2 expression; however, it did not modify the up-regulated total PARP and down-regulated PARP1 expressions, but recovered the decreased SirT1 (Sirtuin 1) levels in T1DM rat testis. Trans-Resveratrol, when given alone, reduced the poly (ADP-ribosyl)ation (pADPr) process in the testis due to an increase in PAR glycohydrolase activity, but when given to T1DM rats it did not affect the pADPr levels. T1DM with or without Trans-Resveratrol did not induce nuclear translocation of apoptosis-inducing factor and the formation of 50 kb DNA breaks, suggesting to the lack of caspase-3-independent cell death called parthanatos. T1DM with or without Trans-Resveratrol did not increase necrotic cell death in the testis. Primary spermatocytes, Sertoli cells, Leydig cells and intra-testicular vessels showed the expression of PARP pathway related proteins. In conclusion, Trans-Resveratrol mitigates T1DM-induced sperm abnormality and DNA damage, but does not significantly modulate PARP signaling pathway, except the SirT1 expression, in the rat testis. - Highlights: • Resveratrol inhibits diabetes-induced abnormal sperm morphogenesis • Resveratrol recovers

  15. Radiosensitivity modulating factors: Role of PARP-1, PARP-2 and Cdk5 proteins and chromatin implication

    International Nuclear Information System (INIS)

    Boudra, M.T.

    2011-12-01

    The post-translational modifications of DNA repair proteins and histone remodeling factors by poly(ADP-ribose)ylation and phosphorylation are essential for the maintenance of DNA integrity and chromatin structure, and in particular in response to DNA damaging produced by ionizing radiation (IR). Amongst the proteins implicated in these two processes are the poly(ADP-ribose) polymerase -1 (PARP-1) and PARP-2, and the cyclin-dependent kinase Cdk5: PARP-1 and 2 are involved in DNA single strand break (SSB) repair (SSBR) and Cdk5 depletion has been linked with increased cell sensitivity to PARP inhibition. We have shown by using HeLa cells stably depleted for either CdK5 or PARP-2, that the recruitment profile of PARP-1 and XRCC-1, two proteins involved in the short-patch (SP) SSBR sub-pathway, to DNA damage sites is sub-maximal and that of PCNA, a protein involved in the long-patch (LP) repair pathway, is increased in the absence of Cdk5 and decreased in the absence of PARP-2 suggesting that both Cdk5 and PARP-2 are involved in both SSBR sub-pathways. PARP-2 and Cdk5 also impact on the poly(ADP-ribose) levels in cells as in the absence of Cdk5 a hyper-activation of PARP-1 was found and in the absence of PARP-2 a reduction in poly(ADP-ribose) glyco-hydrolase (PARG) activity was seen. However, in spite of these changes no impact on the repair of SSBs induced by IR was seen in either the Cdk5 or PARP-2 depleted cells (Cdk5 KD or PARP-2 KD cells) but, interestingly, increased radiation sensitivity in terms of cell killing was noted in the Cdk5 depleted cells. We also found that Cdk5, PARP-2 and PARG were all implicated in the regulation of the recruitment and the dissociation of the chromatin-remodeling factor ALC1 from DNA damage sites suggesting a role for these three proteins in changes in chromatin structure after DNA photo-damage. These results, taken together with the observation that PARP-1 recruitment is sub-optimal in both Cdk5 KD and PARP-2 KD cells, show that

  16. Parallel metatranscriptome analyses of host and symbiont gene expression in the gut of the termite Reticulitermes flavipes

    Directory of Open Access Journals (Sweden)

    Zhou Xuguo

    2009-10-01

    Full Text Available Abstract Background Termite lignocellulose digestion is achieved through a collaboration of host plus prokaryotic and eukaryotic symbionts. In the present work, we took a combined host and symbiont metatranscriptomic approach for investigating the digestive contributions of host and symbiont in the lower termite Reticulitermes flavipes. Our approach consisted of parallel high-throughput sequencing from (i a host gut cDNA library and (ii a hindgut symbiont cDNA library. Subsequently, we undertook functional analyses of newly identified phenoloxidases with potential importance as pretreatment enzymes in industrial lignocellulose processing. Results Over 10,000 expressed sequence tags (ESTs were sequenced from the 2 libraries that aligned into 6,555 putative transcripts, including 171 putative lignocellulase genes. Sequence analyses provided insights in two areas. First, a non-overlapping complement of host and symbiont (prokaryotic plus protist glycohydrolase gene families known to participate in cellulose, hemicellulose, alpha carbohydrate, and chitin degradation were identified. Of these, cellulases are contributed by host plus symbiont genomes, whereas hemicellulases are contributed exclusively by symbiont genomes. Second, a diverse complement of previously unknown genes that encode proteins with homology to lignase, antioxidant, and detoxification enzymes were identified exclusively from the host library (laccase, catalase, peroxidase, superoxide dismutase, carboxylesterase, cytochrome P450. Subsequently, functional analyses of phenoloxidase activity provided results that were strongly consistent with patterns of laccase gene expression. In particular, phenoloxidase activity and laccase gene expression are mostly restricted to symbiont-free foregut plus salivary gland tissues, and phenoloxidase activity is inducible by lignin feeding. Conclusion To our knowledge, this is the first time that a dual host-symbiont transcriptome sequencing effort

  17. Effects of Trans-Resveratrol on hyperglycemia-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase signaling in rat testis

    International Nuclear Information System (INIS)

    Abdelali, Ala; Al-Bader, Maie; Kilarkaje, Narayana

    2016-01-01

    Diabetes induces oxidative stress, DNA damage and alters several intracellular signaling pathways in organ systems. This study investigated modulatory effects of Trans-Resveratrol on type 1 diabetes mellitus (T1DM)-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase (PARP) signaling in rat testis. Trans-Resveratrol administration (5mg/kg/day, ip) to Streptozotocin-induced T1DM adult male Wistar rats from day 22–42 resulted in recovery of induced oxidative stress, abnormal spermatogenesis and inhibited DNA synthesis, and led to mitigation of 8-hydroxy-2'-deoxyguanosine formation in the testis and spermatozoa, and DNA double-strand breaks in the testis. Trans-Resveratrol aggravated T1DM-induced up-regulation of aminoacyl tRNA synthetase complex-interacting multifunctional protein 2 expression; however, it did not modify the up-regulated total PARP and down-regulated PARP1 expressions, but recovered the decreased SirT1 (Sirtuin 1) levels in T1DM rat testis. Trans-Resveratrol, when given alone, reduced the poly (ADP-ribosyl)ation (pADPr) process in the testis due to an increase in PAR glycohydrolase activity, but when given to T1DM rats it did not affect the pADPr levels. T1DM with or without Trans-Resveratrol did not induce nuclear translocation of apoptosis-inducing factor and the formation of 50 kb DNA breaks, suggesting to the lack of caspase-3-independent cell death called parthanatos. T1DM with or without Trans-Resveratrol did not increase necrotic cell death in the testis. Primary spermatocytes, Sertoli cells, Leydig cells and intra-testicular vessels showed the expression of PARP pathway related proteins. In conclusion, Trans-Resveratrol mitigates T1DM-induced sperm abnormality and DNA damage, but does not significantly modulate PARP signaling pathway, except the SirT1 expression, in the rat testis. - Highlights: • Resveratrol inhibits diabetes-induced abnormal sperm morphogenesis • Resveratrol recovers

  18. Lifelong endurance training attenuates age-related genotoxic stress in human skeletal muscle.

    Science.gov (United States)

    Cobley, James N; Sakellariou, George K; Murray, Scott; Waldron, Sarah; Gregson, Warren; Burniston, Jatin G; Morton, James P; Iwanejko, Lesley A; Close, Graeme L

    2013-07-12

    The aim of the present study was to determine the influence of age and habitual activity level, at rest and following a single bout of high-intensity exercise, on the levels of three proteins poly(ADP-ribose) polymerase-1 (PARP-1), cleaved-PARP-1 and poly(ADP-ribose) glycohydrolase (PARG), involved in the DNA repair and cell death responses to stress and genotoxic insults. Muscle biopsies were obtained from the vastus lateralis of young trained (22 ± 3 years, n = 6), young untrained (24 ± 4 years, n = 6), old trained (64 ± 3 years, n = 6) and old untrained (65 ± 6 years, n = 6) healthy males before, immediately after and three days following a high-intensity interval exercise bout. PARP-1, which catalyzes poly(ADP-ribosyl)ation of proteins and DNA in response to a range of intrinsic and extrinsic stresses, was increased at baseline in old trained and old untrained compared with young trained and young untrained participants (P ≤ 0.05). Following exercise, PARP-1 levels remained unchanged in young trained participants, in contrast to old trained and old untrained where levels decreased and young untrained where levels increased (P ≤ 0.05). Interestingly, baseline levels of the cleaved PARP-1, a marker of apoptosis, and PARG, responsible for polymer degradation, were both significantly elevated in old untrained compared with old trained, young trained and young untrained (P ≤ 0.05). Despite this baseline difference in PARG, there was no change in any group following exercise. There was a non-significant statistical trend (P = 0.072) towards increased cleaved-PARP-1 expression post-exercise in younger but not old persons, regardless of training status. Collectively, these results show that exercise slows the progression towards a chronically stressed state but has no impact on the age-related attenuated response to acute exercise. Our findings provide valuable insight into how habitual exercise training could protect skeletal muscle from chronic damage to

  19. Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non-hyperaccumulating ferns

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Nandita [Soil and Water Science Department, University of Florida, Gainesville, Fl 32611-0290 (United States); Eco-Auditing group, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001 (India); Ma, Lena Q., E-mail: lqma@ufl.ed [Soil and Water Science Department, University of Florida, Gainesville, Fl 32611-0290 (United States); Vu, Joseph C. [Chemistry Research Unit, CMAVE, USDA-ARS, Gainesville, FL 32608-1069 and Agronomy Department, University of Florida, Gainesville, FL 32611-0500 (United States); Raj, Anshita [Eco-Auditing group, National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001 (India)

    2009-08-15

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of four-month old Pteris vittata (arsenic - hyperaccumulator) and Pteris ensiformis (non-arsenic--hyperaccumulator) plants. The arsenic treatments (0, 150, and 300 muM as sodium arsenate) in hydroponics had adverse effects on the root and frond dry weights, and this effect was more evident in P. ensiformis than in P. vittata. Nitrate reductase and nitrite reductase activities of arsenate-treated plants were reduced more in P. ensiformis than in P. vittata. This effect was accompanied by similar decreases in tissue NO{sub 3}{sup -} concentrations. Therefore, this decrease is interpreted as being indirect, i.e., the consequence of the reduced NO{sub 3}{sup -} uptake and translocation in the plants. The study shows the difference in the tolerance level of the two Pteris species with varying sensitivity to arsenic. - Arsenic reduced the activity of nitrate and nitrite reductase more in Pteris ensiformis than Pteris vittata.

  20. Members of the LBD family of transcription factors repress anthocyanin synthesis and affect additional nitrogen responses in Arabidopsis.

    Science.gov (United States)

    Rubin, Grit; Tohge, Takayuki; Matsuda, Fumio; Saito, Kazuki; Scheible, Wolf-Rüdiger

    2009-11-01

    Nitrogen (N) and nitrate (NO(3)(-)) per se regulate many aspects of plant metabolism, growth, and development. N/NO(3)(-) also suppresses parts of secondary metabolism, including anthocyanin synthesis. Molecular components for this repression are unknown. We report that three N/NO(3)(-)-induced members of the LATERAL ORGAN BOUNDARY DOMAIN (LBD) gene family of transcription factors (LBD37, LBD38, and LBD39) act as negative regulators of anthocyanin biosynthesis in Arabidopsis thaliana. Overexpression of each of the three genes in the absence of N/NO(3)(-) strongly suppresses the key regulators of anthocyanin synthesis PAP1 and PAP2, genes in the anthocyanin-specific part of flavonoid synthesis, as well as cyanidin- but not quercetin- or kaempferol-glycoside production. Conversely, lbd37, lbd38, or lbd39 mutants accumulate anthocyanins when grown in N/NO(3)(-)-sufficient conditions and show constitutive expression of anthocyanin biosynthetic genes. The LBD genes also repress many other known N-responsive genes, including key genes required for NO(3)(-) uptake and assimilation, resulting in altered NO(3)(-) content, nitrate reductase activity/activation, protein, amino acid, and starch levels, and N-related growth phenotypes. The results identify LBD37 and its two close homologs as novel repressors of anthocyanin biosynthesis and N availability signals in general. They also show that, besides being developmental regulators, LBD genes fulfill roles in metabolic regulation.

  1. Novel ETF dehydrogenase mutations in a patient with mild glutaric aciduria type II and complex II-III deficiency in liver and muscle.

    Science.gov (United States)

    Wolfe, Lynne A; He, Miao; Vockley, Jerry; Payne, Nicole; Rhead, William; Hoppel, Charles; Spector, Elaine; Gernert, Kim; Gibson, K Michael

    2010-12-01

    We describe a 22-year-old male who developed severe hypoglycemia and lethargy during an acute illness at 4 months of age and subsequently grew and developed normally. At age 4 years he developed recurrent vomiting with mild hyperammonemia and dehydration requiring frequent hospitalizations. Glutaric aciduria Type II was suspected based upon biochemical findings and managed with cornstarch, carnitine and riboflavin supplements. He did not experience metabolic crises between ages 4-12 years. He experienced recurrent vomiting, mild hyperammonemia, and generalized weakness associated with acute illnesses and growth spurts. At age 18 years, he developed exercise intolerance and proximal muscle weakness leading to the identification of multiple acyl-CoA dehydrogenase and complex II/III deficiencies in both skeletal muscle and liver. Subsequent molecular characterization of the ETFDH gene revealed novel heterozygous mutations, p.G274X:c.820 G > T (exon 7) and p.P534L: c.1601 C > T (exon 12), the latter within the iron sulfur-cluster and predicted to affect ubiquinone reductase activity of ETFDH and the docking of ETF to ETFDH. Our case supports the concept of a structural interaction between ETFDH and other enzyme partners, and suggests that the conformational change upon ETF binding to ETFDH may play a key role in linking ETFDH to II/III super-complex formation.

  2. Overexpression of PSP1 enhances growth of transgenic Arabidopsis plants under ambient air conditions.

    Science.gov (United States)

    Han, Xiaofang; Peng, Keli; Wu, Haixia; Song, Shanshan; Zhu, Yerong; Bai, Yanling; Wang, Yong

    2017-07-01

    The importance of the phosphorylated pathway (PPSB) of L-serine (Ser) biosynthesis in plant growth and development has been demonstrated, but its specific role in leaves and interaction with photorespiration, the main leaf Ser biosynthetic pathway at daytime, are still unclear. To investigate whether changes in biosynthesis of Ser by the PPSB in leaves could have an impact on photorespiration and plant growth, we overexpressed PSP1, the last enzyme of this pathway, under control of the Cauliflower Mosaic Virus 35S promoter in Arabidopsis thaliana. Overexpressor plants grown in normal air displayed larger rosette diameter and leaf area as well as higher fresh and dry weight than the wild type. By contrast, no statistically significant differences to the wild type were observed when the overexpressor seedlings were transferred to elevated CO 2 , indicating a relationship between PSP1 overexpression and photorespiration. Additionally, the transgenic plants displayed higher photorespiration, an increase in CO 2 net-uptake and stronger expression in the light of genes encoding enzymes involved in photorespiration. We further demonstrated that expression of many genes involved in nitrogen assimilation was also promoted in leaves of transgenic plants and that leaf nitrate reductase activity increased in the light, too, although not in the dark. Our results suggest a close correlation between the function of PPSB and photorespiration, and also nitrogen metabolism in leaves.

  3. The distribution and utilization of nitrogen in developing zea mays L. seedlings

    International Nuclear Information System (INIS)

    Watt, M.P.M. de O.C.

    1987-01-01

    During the first five days of germination, in the presence of NO - 3 - 15 N and N-SERVE, the nitrogen reserves of Zea mays L. caryopses accounted for 75% of the total nitrogen content of the seedlings. By day 7, exogenous nitrate contributed to all the inorganic nitrogen measured in the plant. Although NO - 3 - 15 N (94,2 atom % 15 N) was supplied throughout the germination process, and increasing pool of unlabelled nitrate was detected in both the grain and the seedling during this period. It appears that during germination in maize there is an oxidative pathway from reduced nitrogen in the reserve proteins to nitrate-nitrogen which is then supplied to the developing embryo. The levels of nitrate in the leaf increased towards the sheath, whereas other forms of nitrogen, nitrate reductase activity and capacity for nitrate accumulation increased in the opposite direction. Studies with mesophyll and bundle sheath protoplasts showed that the mesophyll tissue contributes over 80% of the total leaf content of inorganic nitrogen. Leaf tissue of Zea mays was found to have the capacity to assimilate nitrate in the dark, but at a lower rate than in the light. Oxygen did not restrict the initial rate of nitrate reduction in the dark. The rate of the in vivo nitrate reduction declined during the second hour of dark anaerobiosis, and was only restored upon supply of oxygen. Under dark anaerobic conditions nitrite accumulated and, on transfer to oxygen, the accumulate nitrite was reduced

  4. Stability of cytochromes P450 and phase II conjugation systems in precision-cut rat lung slices cultured up to 72 h.

    Science.gov (United States)

    Umachandran, Meera; Ioannides, Costas

    2006-07-05

    The objective of the present study was to evaluate the stability of cytochrome P450 enzymes and of the conjugation enzyme systems epoxide hydrolase, glucuronosyl transferase, sulphotransferase and glutathione S-transferase in precision-cut rat lung slices incubated in RPMI media for different time periods up to 72 h. Moreover, the effect of culturing of lung slices on total glutathione levels and glutathione reductase was also investigated. Monitoring of cytochrome P450 activity was achieved using established diagnostic probes, but when activity in the lung was low the maintenance of the various enzymes in culture was determined immunologically using Western blotting. The dealkylation of pentoxyresorufin declined markedly during the first 4h of incubation but in the case of ethoxyresorufin loss of activity was more gradual and less severe. Western blot analysis revealed that the rate of decrease in cytochrome P450 apoprotein levels was isoform-specific with CYP2E1 being the most stable and CYP3A the least stable. Generally, phase II activities, especially cytosolic sulphotransferase, were relatively more stable throughout the incubation period compared with cytochromes P450. Finally, glutathione reductase activity and total glutathione levels were maintained throughout the 72 h incubation. The present studies indicate that xenobiotic-metabolising enzymes in precision-cut rat lung slices decline in culture, but the rate of loss differs and depends on the nature of the enzyme.

  5. Acid azo dye remediation in anoxic-aerobic-anoxic microenvironment under periodic discontinuous batch operation: bio-electro kinetics and microbial inventory.

    Science.gov (United States)

    Venkata Mohan, S; Suresh Babu, P; Naresh, K; Velvizhi, G; Madamwar, Datta

    2012-09-01

    Functional behavior of anoxic-aerobic-anoxic microenvironment on azo dye (C.I. Acid black 10B) degradation was evaluated in a periodic discontinuous batch mode operation for 26 cycles. Dye removal efficiency and azo-reductase activity (30.50 ± 1 U) increased with each feeding event until 13th cycle and further stabilized. Dehydrogenase activity also increased gradually and stabilized (2.0 ± 0.2 μg/ml) indicating the stable proton shuttling between metabolic intermediates providing higher number of reducing equivalents towards dye degradation. Voltammetric profiles showed drop in redox catalytic currents during stabilized phase also supports the consumption of reducing equivalents towards dye removal. Change in Tafel slopes, polarization resistance and other bioprocess parameters correlated well with the observed dye removal and biocatalyst behavior. Microbial community analysis documented the involvement of specific organism pertaining to aerobic and facultative functions with heterotrophic and autotrophic metabolism. Integrating anoxic microenvironment with aerobic operation might have facilitated effective dye mineralization due to the possibility of combining redox functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Ecotoxicological effects of copper and selenium combined pollution on soil enzyme activities in planted and unplanted soils.

    Science.gov (United States)

    Hu, Bin; Liang, Dongli; Liu, Juanjuan; Xie, Junyu

    2013-04-01

    The present study explored the joint effects of Cu and Se pollution mechanisms on soil enzymes to provide references for the phytoremediation of contaminated areas and agricultural environmental protection. Pot experiments and laboratory analyses were carried out to study the individual and combined influences of Cu and Se on soil enzyme activities. The activities of four soil enzymes (urease, catalase, alkaline phosphatase, and nitrate reductase) were chosen. All soil enzyme activities tested were inhibited by Cu and Se pollution, either individually or combined, in varying degrees, following the order nitrate reductase>urease>catalase>alkaline phosphatase. Growing plants stimulated soil enzyme activity in a similar trend compared with treatments without plants. The joint effects of Cu and Se on catalase activity showed synergism at low concentrations and antagonism at high concentrations, whereas the opposite was observed for urease activity. However, nitrate reductase activity showed synergism both with and without plant treatments. The half maximal effective concentration (EC50) of exchangeable fractions had a similar trend with the EC50 of total content and was lower than that of total content. The EC50 values of nitrate reductase and urease activities were significantly lower for both Se and Cu (p<0.05), which indicated that they were more sensitive than the other two enzymes. Copyright © 2013 SETAC.

  7. Failure of isolated rat tibial periosteal cells to 5 alpha reduce testosterone to 5 alpha-dihydrotestosterone

    Energy Technology Data Exchange (ETDEWEB)

    Turner, R.T.; Bleiberg, B.; Colvard, D.S.; Keeting, P.E.; Evans, G.; Spelsberg, T.C. (Mayo Clinic, Rochester, MN (USA))

    1990-07-01

    Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-alpha 2(I) chain of type 1 precollagen. The isolated periosteal cells were incubated with 1 nM (3H)testosterone (({sup 3}H)T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. ({sup 3}H)5 alpha-dihydrotestosterone (({sup 3}H)DHT) was not detected in extracts of periosteal cell incubations. In contrast, ({sup 3}H)DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5 alpha-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT.

  8. Hydrocarbons and energy from plants: Final report, 1984-1987

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, M.; Otvos, J.; Taylor, S.E.; Nemethy, E.K.; Skrukrud, C.L.; Hawkins, D.R.; Lago, R.

    1988-08-01

    Plant hydrocarbon (isoprenoid) production was investigated as an alternative source to fossil fuels. Because of their high triterpenoid (hydrocarbon) content of 4--8%, Euphorbia lathyris plants were used as a model system for this study. The structure of the E. lathyris triterpenoids was determined, and triterpenoid biosynthesis studied to better understand the metabolic regulation of isoprenoid production. Triterpenoid biosynthesis occurs in two distinct tissue types in E. lathyris plants: in the latex of the laticifer cells; and in the mesophyll cells of the leaf and stem. The latex has been fractionated by centrifugation, and it has been determined that the later steps of isoprenoid biosynthesis, the conversion of mevalonic acid to the triterpenes, are compartmentized within a vacuole. Also identified was the conversion of hydroxymethyl glutaryl-CoA to mevalonic acid, catalyzed by the enzyme Hydroxymethyl glutaryl-CoA Reductase, as a key rate limiting step in isoprenoid biosynthesis. At least two isozymes of this enzyme, one in the latex and another in the leaf plastids, have been identified. Environmental stress has been applied to plants to study changes in carbon allocation. Salinity stress caused a large decrease in growth, smaller decreases in photosynthesis, resulting in a larger allocation of carbon to both hydrocarbon and sugar production. An increase in Hydroxymethyl glutaryl-CoA Reductase activity was also observed when isoprenoid production increased. Other species where also screened for the production of hydrogen rich products such as isoprenoids and glycerides, and their hydrocarbon composition was determined.

  9. Effects of dietary saw palmetto on the prostate of transgenic adenocarcinoma of the mouse prostate model (TRAMP).

    Science.gov (United States)

    Wadsworth, Teri L; Worstell, Teresa R; Greenberg, Norman M; Roselli, Charles E

    2007-05-01

    Several of the proposed mechanisms for the actions of the liposterolic extract of saw palmetto (SPE) are exerted on known risk factors for prostate cancer (CaP). This study investigated whether SPE could prevent the progression of CaP in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Two different doses of SPE designed to deliver 50 mg/kg/day SPE and 300 mg/kg/day SPE were administered in a custom diet to TRAMP mice for 12 or 24 weeks. Body and organ weights were used to evaluate toxicity, and radioimmunoassay was used to measure plasma and tissue androgen levels to monitor effects of SPE on 5alpha reductase activity. Prostate tissues were evaluated histologically to determine the effect of treatment on tumor grade, cell proliferation, and apoptosis. Treatment with 300 mg/kg/day SPE from 4 to 24 weeks of age significantly reduced the concentration of 5alpha-dihydrotestosterone (DHT) in the prostate and resulted in a significant increase in apoptosis and significant decrease in pathological tumor grade and frank tumor incidence. Dietary supplementation with SPE may be effective in controlling CaP tumorigenesis. SPE suppression of prostatic DHT levels lends support to the hypothesis that inhibition of the enzyme 5alpha-reductase is a mechanism of action of this substance. (c) 2007 Wiley-Liss, Inc.

  10. Flomoxef, a new oxacephem antibiotic, does not cause hemostatic defects.

    Science.gov (United States)

    Cazzola, M; Brancaccio, V; De Giglio, C; Paternò, E; Matera, M G; Rossi, F

    1993-03-01

    Antibiotics of the beta-lactam class may cause coagulation defects and bleeding. It has been suggested that N-methyltetrazolethiol (NMTT), a common side chain group at the 3'-position of the cephem or 1-oxacephem frame, could be responsible for the hypoprothrombinemic effect of the antibiotics and that it could inhibit the liver vitamin K-epoxide reductase activity. Flomoxef (6315-S) is a new oxacephem antibiotic which differs from latamoxef because it has [1-(2-hydroxethyl)-1H-tetrazol-5-yl] thiomethyl (HTT) as a side chain at the 3'-position of cephem group instead of NMTT and an extensive modification of 7 beta-acylamino side chain. The present study was carried out to study its effects on vitamin K-dependent blood coagulation parameters in human volunteers. Ten adult patients (6 men and 4 women), suffering from chronic bronchitis, entered into the study. Each patient received ten 1 g i.m. injections of flomoxef at 12-hourly intervals. Apparently, the treatment with this oxacephem antibiotic had no significant effect. PT, PTT and fibrinogen remained in the normal range in all patients and factors II+VII+X, protein C, protein S and AT III were not depleted. The trend was similar both in men and women. Based on the results of the present study, we conclude that flomoxef is an antibiotic that does not exhibit an effect on blood coagulation, even in males.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Certain growth related attributes of micropropagated banana under different salinity levels

    International Nuclear Information System (INIS)

    Haq, I.U.; Soomro, F.

    2011-01-01

    The effect of salinity (NaCl) was assessed on banana (Musa spp.) cv., Sindhri Banana (Basrai) propagating plantlets in aseptic condition. Four different NaCl levels [0 (control) 50, 100 and 150 mM] were maintained at shoot multiplication stage for 6-weeks. Salinity reduced the number of plantlets per explants and plant biomass significantly. A proportional relationship was observed for Na/sup +/ and Cl/sub -/ but K/sup +/, Ca/sup 2+/and NO/sub 3/ were observed to be inversely proportioned with NaCl stress. Similarly, total proteins as well as carbohydrate contents were decreased significantly. Increasing mode of secondary metabolites (proline, betaine contents and reducing sugars) were showing a negative relationship of saline stress with plant micro-propagation efficiency. Among photosynthetic pigments, total carotenoids were increased while chlorophyll contents (Chl a and b) decreased. Similarly, nitrate reductase activity also reduced. Overall, vegetative propagation of banana was affected significantly by NaCl stress under in-vitro conditions. (author)

  12. Photoaffinity labeling of steroid 5 alpha-reductase of rat liver and prostate microsomes

    International Nuclear Information System (INIS)

    Liang, T.; Cheung, A.H.; Reynolds, G.F.; Rasmusson, G.H.

    1985-01-01

    21-Diazo-4-methyl-4-aza-5 alpha-pregnane-3,20-dione (Diazo-MAPD) inhibits steroid 5 alpha-reductase in liver microsomes of female rats with a K/sub i/ value of 8.7 +/- 1.7 nM, and the inhibition is competitive with testosterone. It also inhibits the binding of a 5 alpha-reductase inhibitor, [ 3 H] 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([ 3 H]4-MA), to the enzyme in liver microsomes. The inhibition of 5 alpha-reductase activity and of inhibitor binding activity by diazo-MAPD becomes irreversible upon UV irradiation. [1,2- 3 H]Diazo-MAPD binds to a single high affinity site in liver microsomes of female rats, and this binding requires NADPH. Without UV irradiation, this binding is reversible, and it becomes irreversible upon UV irradiation. Both the initial reversible binding and the subsequent irreversible conjugation after UV irradiation are inhibited by inhibitors (diazo-MAPD and 4-MA) and substrates (progesterone and testosterone) of 5 alpha-reductase, but they are not inhibited by 5 alpha-reduced steroids. Photoaffinity labeled liver microsomes of female rats were solubilized and fractionated by high performance gel filtration. The radioactive conjugate eluted in one major peak at Mr 50,000

  13. Body Composition, Lipid Profile, Adipokine Concentration, and Antioxidant Capacity Changes during Interventions to Treat Overweight with Exercise Programme and Whole-Body Cryostimulation

    Directory of Open Access Journals (Sweden)

    Anna Lubkowska

    2015-01-01

    Full Text Available The aim of this study was to determine the effect of six-month-long physical exercise programme with a two-time exposure to whole-body cryostimulation (WBC in 20 sessions on antioxidant enzyme activities, lipid profile, and body composition changes in obese people (30 adult subjects; BMI = 30.39 ± 4.31 kg/m2. Blood samples were taken before the programme, one month following the exercise programme, before and after the first WBC treatment, six months following the exercise programme, after the second WBC treatment, and finally one month after the intervention. Six months of moderate aerobic activity combined with WBC did not change body mass or fat and lean body mass percentages, or circulating adiponectin, leptin, and resistin concentrations. In response to intervention a significant decrease in the level of low-density lipoprotein and triglycerides was observed, with a slight increase in high-density lipoprotein concentration. The nature of changes in the activity of respective antioxidant enzymes was not identical. After one month of increased physical activity, a significant decrease in superoxide dismutase, catalase, and glutathione reductase activities was observed (13%, 8%, and 70%, resp.. The SOD activity increased significantly after successive whole-body cryostimulation sessions. As regards catalase, a significant progressive decrease in its activity was observed.

  14. Foliar-applied urea modulates nitric oxide synthesis metabolism and glycinebetaine accumulation in drought-stressed maize

    International Nuclear Information System (INIS)

    Zhang, L.; Tian, L.; Lai, J.; Zheng, P.; Liang, Z.; Alva, A

    2014-01-01

    Foliar urea has been proved to play a better positive role in enhancing accumulation of nitric oxide (NO) and glycinebetaine (GB) in maize (Zea mays L.) under drought stress (DS). However, it is unclear how foliar urea affects biosynthetic metabolism of NO and its relationship with GB accumulation. This study was on investigating the effect of foliar- applied urea on seedlings of maize cultivar Zhengdan 958 grown in a hydroponic medium under DS or No DS. Contents of NO and GB and nitric oxide synthase (NOS) activity increased and peaked 12 h after the treatment. Nitrate reductase activity (NRA) followed the similar pattern 6h after the treatment. Under DS foliar urea application increased NR and NOS activity and, thereby, increased NO formation. Therefore, enhancement in activities of both NRA and NOS resulted in an increase of NO accumulation. Foliar- applied urea could induce an increased NO burst by enhanced NO synthesis metabolism as a nitrogen signal, possibly resulting in GB accumulation under DS. (author)

  15. Decline of plasma 5alpha-dihydrotestosterone (DHT) levels upon testosterone administration to elderly men with subnormal plasma testosterone and high DHT levels.

    Science.gov (United States)

    Gooren, L J; Saad, F; Haide, A; Yassin, A

    2008-10-01

    The study was performed to measure the impact of testosterone (T) administration on circulating levels of 5alpha-dihydrotestosterone (DHT). Group 1 (32 men; mean age 61 years; mean T 6.9 +/- 1.9 nmol l(-1)) were treated for 15 months with long-acting T undecanoate. Group 2 (23 men, mean age 60 years, mean T 7.6 +/- 2.0 nmol l(-1)) were treated for 9 months with T gel. Plasma T and DHT were measured before and after 9 months T administration. In the men treated with T undecanoate plasma T and DHT were also measured after 12 and 15 months. Before T administration, plasma DHT ranged from 0.39 to 1.76 nmol l(-1) (0.30-1.90 nmol l(-1)). Mean DHT declined upon T administration from 0.95 +/- 0.50 to 0.55 +/- 0.30 nmol l(-1) (P DHT > 0.60 nmol l(-1) had fallen from 1.29 +/- 0.50 to 0.70 +/- 0.60 nmol l(-1) (P DHT levels declined upon T administration when they were in the higher range of normal (>0.6 nmol l(-1)), with a profound shift of DHT/T ratios presumed to be an indicator of a reduced 5alpha-reductase activity. Below plasma DHT levels of 0.6 nmol l(-1), responses of plasma DHT to T administration varied.

  16. Metabolism in vitro 3H-testosterone in testis, epididymis and sex accessories of the rhesus monkey

    International Nuclear Information System (INIS)

    Arora-Dinkar, Renu; Dinakar, N.; Prasad, M.R.N.

    1977-01-01

    Metabolism of 3 H-testosterone in the reproductive organs of intact, castrated and cyproterone acetate treated rhesus monkeys was studied in vitro. The main androgen metabolite in the epididymis, ductus deferens, seminal vesicles, prostate and bulb-urethral glands of the intact monkeys was 5-α-dihydrotestosterone (DHT). Testosterone was not metabolized in slices of the testis, indicating very little 5-α-reductase activity in this organ. Bilateral castration caused a decrease in the metabolism of 3 H-testosterone in all tissues studied. The decrease was greater in the caput than in the corpus and cauda epididymides. Treatment with cyproterone acetate did not affect the formation of DHT in the ductus deferens and accessory glands. Azoospermia, following administration of cyproterone acetate, had little effect on the metabolism of 3 H-testosterone in the corpus and cauda epididymides; however, in the caput region the extent of formation of DHT was markedly reduced. These results are discussed in relation to the influence of spermatozoa, testicular fluid and testicular and peripheral androgens on the metabolism of 3 H-testosterone in epididymis of the monkey. (author)

  17. Adjustment of growth and central metabolism to a mild but sustained nitrogen-limitation in Arabidopsis.

    Science.gov (United States)

    Tschoep, Hendrik; Gibon, Yves; Carillo, Petronia; Armengaud, Patrick; Szecowka, Marek; Nunes-Nesi, Adriano; Fernie, Alisdair R; Koehl, Karin; Stitt, Mark

    2009-03-01

    We have established a simple soil-based experimental system that allows a small and sustained restriction of growth of Arabidopsis by low nitrogen (N). Plants were grown in a large volume of a peat-vermiculite mix that contained very low levels of inorganic N. As a control, inorganic N was added in solid form to the peat-vermiculite mix, or plants were grown in conventional nutrient-rich solids. The low N growth regime led to a sustained 20% decrease of the relative growth rate over a period of 2 weeks, resulting in a two- to threefold decrease in biomass in 35- to 40-day-old plants. Plants in the low N regime contained lower levels of nitrate, lower nitrate reductase activity, lower levels of malate, fumarate and other organic acids and slightly higher levels of starch, as expected from published studies of N-limited plants. However, their rosette protein content was unaltered, and total and many individual amino acid levels increased compared with N-replete plants. This metabolic phenotype reveals that Arabidopsis responds adaptively to low N by decreasing the rate of growth, while maintaining the overall protein content, and maintaining or even increasing the levels of many amino acids.

  18. Chromium VI administration induces oxidative stress in hypothalamus and anterior pituitary gland from male rats.

    Science.gov (United States)

    Nudler, Silvana I; Quinteros, Fernanda A; Miler, Eliana A; Cabilla, Jimena P; Ronchetti, Sonia A; Duvilanski, Beatriz H

    2009-03-28

    Hexavalent chromium (Cr VI)-containing compounds are known carcinogens which are present in industrial settings and in the environment. The major route of chromium exposure for the general population is oral intake. Previously we have observed that Cr VI affects anterior pituitary secretion and causes oxidative stress in vitro. The aim of the present work was to investigate if in vivo Cr VI treatment (100 ppm of Cr VI in drinking water for up 30 days) causes oxidative stress in hypothalamus and anterior pituitary gland from male rats. This treatment produced a 4-fold increase of chromium content in hypothalamus and 10-fold increase in anterior pituitary gland. Lipid peroxidation showed a significant increase in hypothalamus and anterior pituitary. Cr VI augmented superoxide dismutase activity in anterior pituitary gland and glutathione reductase activity in hypothalamus, but glutathione peroxidase and catalase activities remained unchanged in both tissues. Heme oxygenase-1 mRNA expression significantly rose in both tissues. Metallothionein 1 mRNA content increased in anterior pituitary and metallothionein 3 mRNA increased in hypothalamus. These results show, for the first time, that oral chronic administration of Cr VI produces oxidative stress on the hypothalamus and anterior pituitary gland which may affect normal endocrine function.

  19. Differential Responses of Two Lactuca sativa Varieties to Bicarbonate-Induced Iron Deficiency

    Directory of Open Access Journals (Sweden)

    Mohamed Chebbi

    2013-11-01

    Full Text Available Iron chlorosis induced by bicarbonate is very common in calcareous soils, where bicarbonate (HCO3- ions are present at high concentrations. In this study, morpho-physiological and biochemical responses of two Lactuca sativa varieties (Romaine and Vista to bicarbonate induced iron deficiency were investigated. The culture was conducted on nutrient solution containing 5 µM Fe and 10 mM NaHCO3, in a growth chamber with controlled conditions. After 14 days of bicarbonate treatment, the two varieties seedling showed a slight yellowing of young leaves associated with a significant decline of plant biomass, leaf number and area. Furthermore, the concentrations of the nutrient elements (potassium, magnesium, iron and calcium in leaves and roots of two lettuce varieties were modified. In roots of bicarbonate treated plants, the Fe-chelate reductase activity was increased as compared to control in both varieties. PEPC activity was enhanced only in Vista variety. Moreover, Fe deficiency induced a small change in the photosynthetic parameters and chlorophyll fluorescence, especially in Romaine variety. These changes are accompanied by decreases in ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco activity. These findings indicated that Vista variety could survive at low iron supply.

  20. Hydroxyurea-resistant vaccinia virus: overproduction of ribonucleotide reductase

    International Nuclear Information System (INIS)

    Slabaugh, M.B.; Mathews, C.K.

    1986-01-01

    Repeated passage of vaccinia virus in increasing concentrations of hydroxyurea followed by plaque purification resulted in the isolation of variants capable of growth in 5 mM hydroxyurea, a drug concentration which inhibited the reproduction of wild-type vaccinia virus 1000-fold. Analyses of viral protein synthesis by using [ 35 S]methionine pulse-labeling at intervals throughout the infection cycle revealed that all isolates overproduced a 34,000-molecular-weight (MW) early polypeptide. Measurement of ribonucleoside-diphosphate reductase activity after infection indicated that 4- to 10-fold more activity was induced by hydroxyurea-resistant viruses than by the wild-type virus. A two-step partial purification resulted in a substantial enrichment for the 34,000-MW protein from extracts of wild-type and hydroxyurea-resistant-virus-infected, but not mock-infected, cells. In the presence of the drug, the isolates incorporated [ 3 H]thymidine into DNA earlier and a rate substantially greater than that of the wild type, although the onset of DNA synthesis was delayed in both cases. The drug resistance trait was markedly unstable in all isolates. In the absence of selective pressure, plaque-purified isolated readily segregated progeny that displayed a wide range of resistance phenotypes. The results of this study indicate that vaccinia virus encodes a subunit of ribonucleotide reductase which is 34,000-MW early protein whose overproduction confers hydroxyurea resistance on reproducing viruses

  1. Phytoremediation of arsenic-contaminated water: the role of antioxidant metabolism of Azolla caroliniana Willd. (Salviniales

    Directory of Open Access Journals (Sweden)

    Gabriela Alves Leão

    Full Text Available ABSTRACT Phytoremediation has proven to be an efficient technology for removing arsenic (As from water, but the plants used in this process need to be tolerant to the damage caused by As. The toxic effect of As on growth and functioning of the antioxidant system was studied in individual plants of Azolla caroliniana exposed to five concentrations of As (0.0, 0.25, 0.5, 1.0 and 1.5 mg L-1 for the course of five days. Growth, As absorption, enzymatic activity, total and non-protein thiols and anthocyanin content were assessed. Azolla caroliniana was able to take up large amounts of the pollutant, reaching As concentrations of 386.1 µg g-1 dry weight without saturating the absorption mechanism. The tolerance index and the growth of A. caroliniana decreased with the increased As uptake. Superoxide dismutase, peroxidases, catalases and glutathione reductase activities increased at lower doses of As and subsequently declined with higher concentrations, whereas ascorbate peroxidase activity was reduced in all treatments. Unlike the enzymatic defence system, anthocyanin and thiol content increased consistently in all treatments and showed a positive correlation with As concentration. Therefore, the increased synthesis of non-enzymatic antioxidants is most likely the main factor responsible for the high As tolerance of A. caroliniana.

  2. Physiological and transcriptional approaches reveal connection between nitrogen and manganese cycles in Shewanella algae C6G3

    Science.gov (United States)

    Aigle, Axel; Bonin, Patricia; Iobbi-Nivol, Chantal; Méjean, Vincent; Michotey, Valérie

    2017-03-01

    To explain anaerobic nitrite/nitrate production at the expense of ammonium mediated by manganese oxide (Mn(IV)) in sediment, nitrate and manganese respirations were investigated in a strain (Shewanella algae C6G3) presenting these features. In contrast to S. oneidensis MR-1, a biotic transitory nitrite accumulation at the expense of ammonium was observed in S. algae during anaerobic growth with Mn(IV) under condition of limiting electron acceptor, concomitantly, with a higher electron donor stoichiometry than expected. This low and reproducible transitory accumulation is the result of production and consumption since the strain is able to dissimilative reduce nitrate into ammonium. Nitrite production in Mn(IV) condition is strengthened by comparative expression of the nitrate/nitrite reductase genes (napA, nrfA, nrfA-2), and rates of the nitrate/nitrite reductase activities under Mn(IV), nitrate or fumarate conditions. Compared with S. oneidensis MR-1, S. algae contains additional genes that encode nitrate and nitrite reductases (napA-α and nrfA-2) and an Outer Membrane Cytochrome (OMC)(mtrH). Different patterns of expression of the OMC genes (omcA, mtrF, mtrH and mtrC) were observed depending on the electron acceptor and growth phase. Only gene mtrF-2 (SO1659 homolog) was specifically expressed under the Mn(IV) condition. Nitrate and Mn(IV) respirations seem connected at the physiological and transcriptional levels.

  3. Hypothalamic digoxin, hemispheric chemical dominance, and eating behavior.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in eating disorders. The patterns were compared in those with right hemispheric and left hemispheric dominance. The serum HMG CoA reductase activity, RBC membrane Na+-K+ ATPase activity, serum digoxin, magnesium, tryptophan catabolites (serotonin, quinolinic acid, strychnine, and nicotine), and tyrosine catabolites (morphine, dopamine, and noradrenaline) were measured in anorexia nervosa, bulimia nervosa, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. Digoxin synthesis was increased with upregulated tryptophan catabolism and downregulated tyrosine catabolism in those with anorexia nervosa and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism and upregulated tyrosine catabolism in those with bulimia nervosa and left hemispheric chemical dominance. The membrane Na+-K+ ATPase activity and serum magnesium were decreased in anorexia nervosa and right hemispheric chemical dominance while they were increased in bulimia nervosa and left hemispheric chemical dominance. Hypothalamic digoxin and hemispheric chemical dominance play a central role in the regulation of eating behavior. Anorexia nervosa represents the right hemispheric chemically dominant/hyperdigoxinemic state and bulimia nervosa the left hemispheric chemically dominant/hypodigoxinemic state.

  4. Chaperone-like properties of tobacco plastid thioredoxins f and m

    Science.gov (United States)

    Sanz-Barrio, Ruth; Fernández-San Millán, Alicia; Carballeda, Jon; Corral-Martínez, Patricia; Seguí-Simarro, José M.; Farran, Inmaculada

    2012-01-01

    Thioredoxins (Trxs) are ubiquitous disulphide reductases that play important roles in the redox regulation of many cellular processes. However, some redox-independent functions, such as chaperone activity, have also been attributed to Trxs in recent years. The focus of our study is on the putative chaperone function of the well-described plastid Trxs f and m. To that end, the cDNA of both Trxs, designated as NtTrxf and NtTrxm, was isolated from Nicotiana tabacum plants. It was found that bacterially expressed tobacco Trx f and Trx m, in addition to their disulphide reductase activity, possessed chaperone-like properties. In vitro, Trx f and Trx m could both facilitate the reactivation of the cysteine-free form of chemically denatured glucose-6 phosphate dehydrogenase (foldase chaperone activity) and prevent heat-induced malate dehydrogenase aggregation (holdase chaperone activity). Our results led us to infer that the disulphide reductase and foldase chaperone functions prevail when the proteins occur as monomers and the well-conserved non-active cysteine present in Trx f is critical for both functions. By contrast, the holdase chaperone activity of both Trxs depended on their oligomeric status: the proteins were functional only when they were associated with high molecular mass protein complexes. Because the oligomeric status of both Trxs was induced by salt and temperature, our data suggest that plastid Trxs could operate as molecular holdase chaperones upon oxidative stress, acting as a type of small stress protein. PMID:21948853

  5. How does the greater white-toothed shrew, Crocidura russula, responds to long-term heavy metal contamination? - A case study

    International Nuclear Information System (INIS)

    Marques, Carla Cristina; Sanchez-Chardi, Alejandro; Gabriel, Sofia Isabel; Nadal, Jacint; Viegas-Crespo, Ana Maria; Luz Mathias, Maria da

    2007-01-01

    Heavy metals accumulation in parallel with the evaluation of physiological and biochemical effects resulting from continued metal exposure were considered here using for the first time the great white-toothed shrew Crocidura russula as an in vivo model. Shrews were originated from an abandoned lead/zinc mining area and from a reference area, both in Alentejo, southern Portugal. Hepatic contents of nickel, copper, zinc, cadmium, mercury and lead were quantified by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Haematological parameters (white blood cells, red blood cells, haemoglobin and haematocrit) were obtained in a Coulter Counter Analyser and biochemical markers of the redox balance (glutathione S-transferase, glutathione peroxidase, and glutathione reductase) activities were measured spectrophotometrically using a Duo-50 spectrophotometer. Compared with control animals, significantly higher concentration of hepatic cadmium (9.29 vs. 1.18 μg/g dry weight) and nickel (1.56 vs. 0.343 μg/g dry weight) were detected in the shrews collected in the mining area. However, no significant changes were observed on haematological or enzymatic parameters in animals exposed to metal pollution. The obtained results show that shrews are good bioaccumulators of toxic heavy metals, but very tolerant to their effects, revealing an interesting long-term adaptation to polluted environments. In addition, this study provides reference values for haematological parameters and antioxidant enzymes levels in C. russula, which may be relevant for comparative purposes in further studies

  6. Effect of Cuscuta reflexa Roxb on androgen-induced alopecia.

    Science.gov (United States)

    Pandit, Shweta; Chauhan, Nagendra Singh; Dixit, V K

    2008-09-01

    Alopecia is a psychologically distressing condition. Androgenetic alopecia, which affects millions of men and women, is an androgen-driven disorder. Here, Cuscuta reflexa Roxb is evaluated for hair growth activity in androgen-induced alopecia. Petroleum ether extract of C. reflexa was studied for its hair growth-promoting activity. Alopecia was induced in albino mice by testosterone administration for 20 days. Its inhibition by simultaneous administration of extract was evaluated using follicular density, anagen/telogen ratio, and microscopic observation of skin sections. To investigate the mechanism of observed activity, in vitro experiments were performed to study the effect of extract and its major component on activity of 5alpha-reductase enzyme. Petroleum ether extract of C. reflexa exhibited promising hair growth-promoting activity as reflected from follicular density, anagen/telogen ratio, and skin sections. Inhibition of 5alpha-reductase activity by extract and isolate suggest that the extract reversed androgen-induced alopecia by inhibiting conversion of testosterone to dihydrotestosterone. The petroleum ether extract of C. reflexa and its isolate is useful in treatment of androgen-induced alopecia by inhibiting the enzyme 5alpha-reductase.

  7. Effects of 3G cell phone exposure on the structure and function of the human cytochrome P450 reductase.

    Science.gov (United States)

    Tanvir, Shazia; Thuróczy, György; Selmaoui, Brahim; Silva Pires Antonietti, Viviane; Sonnet, Pascal; Arnaud-Cormos, Delia; Lévêque, Philippe; Pulvin, Sylviane; de Seze, René

    2016-10-01

    Cell phones increase exposure to radiofrequency (RF) electromagnetic fields (EMFs). Whether EMFs exert specific effects on biological systems remains debatable. This study investigated the effect of cell phone exposure on the structure and function of human NADPH-cytochrome P450 reductase (CPR). CPR plays a key role in the electron transfer to cytochrome P450, which takes part in a wide range of oxidative metabolic reactions in various organisms from microbes to humans. Human CPR was exposed for 60min to 1966-MHz RF inside a transverse electromagnetic cell (TEM-cell) placed in an incubator. The specific absorption rate (SAR) was 5W·kg(-1). Conformation changes have been detected through fluorescent spectroscopy of flavin and tryptophan residues, and investigated through circular dichroism, dynamic light scattering and microelectrophoresis. These showed that CPR was narrowed. By using cytochrome C reductase activity to assess the electron flux through the CPR, the Michaelis Menten constant (Km) and the maximum initial velocity (Vmax) decreased by 22% as compared with controls. This change was due to small changes in the tertiary and secondary structures of the protein at 37°C. The relevance of these findings to an actual RF exposure scenario demands further biochemical and in-vivo confirmation. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Urinary excretion of androgen metabolites, comparison with excretion of radioactive metabolites after injection of [4-14C]testosterone

    International Nuclear Information System (INIS)

    Deslypere, J.P.; Sayed, A.; Vermeulen, A.; Wiers, P.W.

    1981-01-01

    The influence of age on the metabolic pattern of [4- 14 C]testosterone was studied in 20 young and 8 elderly males and compared to the metabolic pattern of endogenous androgens; the latter was also studied in 16 young and 8 elderly women. In both young and elderly males, androsterone and aetiocholanolone glucuronide represent 65% of [4- 14 C]testosterone metabolites: together with their suephoconjugates as well as with 5α- and 5β-androstane-3α, 17β-diol they represent even more than 75% of total urinary metabolites. The 5α/5β ratio of metabolites of [4- 14 C]testosterone was significantly (P 14 C]testosterone metabolites was generally higher than the ratio of metabolites of endogenous androgens, suggesting that the transformation of T to ring A saturated metabolites occurs at least partially in another compartment than the transformation of DHEA to these metabolites. For both [4- 14 C]testosterone and endogenous androgen metabolites we observed a statistically significant reduction of the 5α/5β ratio with age, a general phenomenon in both males and females. This reduction concern also 11-OH-androst-4-ene-3.17-dione metabolism. Neither sex hormone levels, nor specific binding seems to determine this age dependent shift; neither is there convincing evidence for latent hypothyroisism or liver dysfunction in the elderly. An age associated primary decrease of the 5α-reductase activity seems the most likely explanation. (author)

  9. Comparative Analysis of the Interaction between Different Flavonoids and PDIA3

    Science.gov (United States)

    Giamogante, Flavia; Marrocco, Ilaria; Romaniello, Donatella; Eufemi, Margherita; Chichiarelli, Silvia

    2016-01-01

    Flavonoids, plant secondary metabolites present in fruits, vegetables, and products such as tea and red wine, show antioxidant, anti-inflammatory, antithrombotic, antiviral, and antitumor activity. PDIA3 is a member of the protein disulfide isomerase family mainly involved in the correct folding of newly synthetized glycoproteins. PDIA3 is associated with different human pathologies such as cancer, prion disorders, Alzheimer's disease, and Parkinson's diseases and it has the potential to be a pharmacological target. The interaction of different flavonoids with PDIA3 was investigated by quenching fluorescence analysis and the effects on protein activity were evaluated. A higher affinity was observed for eupatorin-5-methyl ether and eupatorin which also inhibit reductase activity of PDIA3 but do not significantly affect its DNA binding activity. The use of several flavonoids differing in chemical structure and functional groups allows us to make some consideration about the relationship between ligand structure and the affinity for PDIA3. The specific flavone backbone conformation and the degree of polarity seem to play an important role for the interaction with PDIA3. The binding site is probably similar but not equivalent to that of green tea catechins, which, as previously demonstrated, can bind to PDIA3 and prevent its interaction with DNA. PMID:28044092

  10. Antisense Suppression of 2-Cysteine Peroxiredoxin in Arabidopsis Specifically Enhances the Activities and Expression of Enzymes Associated with Ascorbate Metabolism But Not Glutathione Metabolism1

    Science.gov (United States)

    Baier, Margarete; Noctor, Graham; Foyer, Christine H.; Dietz, Karl-Josef

    2000-01-01

    The aim of this study was to characterize the effect of decreased 2-cysteine peroxiredoxin (2-CP) on the leaf anti-oxidative system in Arabidopsis. At three stages of leaf development, two lines of transgenic Arabidopsis mutants with decreased contents of chloroplast 2-CP were compared with wild type and a control line transformed with an empty vector. Glutathione contents and redox state were similar in all plants, and no changes in transcript levels for enzymes involved in glutathione metabolism were observed. Transcript levels for chloroplastic glutathione peroxidase were much lower than those for 2-CP, and both cytosolic and chloroplastic glutathione peroxidase were not increased in the mutants. In contrast, the foliar ascorbate pool was more oxidized in the mutants, although the difference decreased with plant age. The activities of thylakoid and stromal ascorbate peroxidase and particularly monodehydroascorbate reductase were increased as were transcripts for these enzymes. No change in dehydroascorbate reductase activity was observed, and effects on transcript abundance for glutathione reductase, catalase, and superoxide dismutase were slight or absent. The results demonstrate that 2-CP forms an integral part of the anti-oxidant network of chloroplasts and is functionally interconnected with other defense systems. Suppression of 2-CP leads to increased expression of other anti-oxidative genes possibly mediated by increased oxidation state of the leaf ascorbate pool. PMID:11027730

  11. Changes in Salicylic Acid and Antioxidants during Induced Thermotolerance in Mustard Seedlings

    Science.gov (United States)

    Dat, James F.; Foyer, Christine H.; Scott, Ian M.

    1998-01-01

    Heat-acclimation or salicylic acid (SA) treatments were previously shown to induce thermotolerance in mustard (Sinapis alba L.) seedlings from 1.5 to 4 h after treatment. In the present study we investigated changes in endogenous SA and antioxidants in relation to induced thermotolerance. Thirty minutes into a 1-h heat-acclimation treatment glucosylated SA had increased 5.5-fold and then declined during the next 6 h. Increases in free SA were smaller (2-fold) but significant. Changes in antioxidants showed the following similarities after either heat-acclimation or SA treatment. The reduced-to-oxidized ascorbate ratio was 5-fold lower than the controls 1 h after treatment but recovered by 2 h. The glutathione pool became slightly more oxidized from 2 h after treatment. Glutathione reductase activity was more than 50% higher during the first 2 h. Activities of dehydroascorbate reductase and monodehydroascorbate reductase decreased by at least 25% during the first 2 h but were 20% to 60% higher than the control levels after 3 to 6 h. One hour after heat acclimation ascorbate peroxidase activity was increased by 30%. Young leaves appeared to be better protected by antioxidant enzymes following heat acclimation than the cotyledons or stem. Changes in endogenous SA and antioxidants may be involved in heat acclimation. PMID:9847121

  12. Bezafibrate induces a mitochondrial derangement in human cell lines: a PPAR-independent mechanism for a peroxisome proliferator.

    Science.gov (United States)

    Scatena, R; Bottoni, P; Vincenzoni, F; Messana, I; Martorana, G E; Nocca, G; De Sole, P; Maggiano, N; Castagnola, M; Giardina, B

    2003-11-01

    Bezafibrate is a hypolipidemic drug that belongs to the group of peroxisome proliferators because it binds to peroxisome proliferator-activated receptors type alpha (PPARs). Peroxisome proliferators produce a myriad of extraperoxisomal effects, which are not necessarily dependent on their interaction with PPARs. An investigation on the peculiar activities of bezafibrate could clarify some of the molecular events and the relationship with the biochemical and pharmacological properties of this class of compounds. In this view, the human acute promyelocytic leukemia HL-60 cell line and human rabdomiosarcoma TE-671 cell line were cultured in media containing bezafibrate and a number of observations such as spectrophotometric analysis of mitochondrial respiratory chain enzymes, NMR metabolite determinations, phosphofructokinase enzymatic analysis, and differentiation assays were carried on. Bezafibrate induced a derangement of NADH cytochrome c reductase activity accompanied by metabolic alterations, mainly a shift to anaerobic glycolysis and an increase of fatty acid oxidation, as shown by NMR analysis of culture supernatants where acetate, lactate, and alanine levels increased. On the whole, the present results suggest a biochemical profile and a therapeutic role of this class of PPARs ligands more complex than those previously proposed.

  13. Stress-Induced Cytokinin Synthesis Increases Drought Tolerance through the Coordinated Regulation of Carbon and Nitrogen Assimilation in Rice1[C][W][OPEN

    Science.gov (United States)

    Reguera, Maria; Peleg, Zvi; Abdel-Tawab, Yasser M.; Tumimbang, Ellen B.; Delatorre, Carla A.; Blumwald, Eduardo

    2013-01-01

    The effects of water deficit on carbon and nitrogen metabolism were investigated in flag leaves of wild-type and transgenic rice (Oryza sativa japonica ‘Kitaake’) plants expressing ISOPENTENYLTRANSFERASE (IPT; encoding the enzyme that mediates the rate-limiting step in cytokinin synthesis) under the control of PSARK, a maturation- and stress-induced promoter. While the wild-type plants displayed inhibition of photosynthesis and nitrogen assimilation during water stress, neither carbon nor nitrogen assimilation was affected by stress in the transgenic PSARK::IPT plants. In the transgenic plants, photosynthesis was maintained at control levels during stress and the flag leaf showed increased sucrose (Suc) phosphate synthase activity and reduced Suc synthase and invertase activities, leading to increased Suc contents. The sustained carbon assimilation in the transgenic PSARK::IPT plants was well correlated with enhanced nitrate content, higher nitrate reductase activity, and sustained ammonium contents, indicating that the stress-induced cytokinin synthesis in the transgenic plants played a role in maintaining nitrate acquisition. Protein contents decreased and free amino acids increased in wild-type plants during stress, while protein content was preserved in the transgenic plants. Our results indicate that the stress-induced cytokinin synthesis in the transgenic plants promoted sink strengthening through a cytokinin-dependent coordinated regulation of carbon and nitrogen metabolism that facilitates an enhanced tolerance of the transgenic plants to water deficit. PMID:24101772

  14. Stress-induced cytokinin synthesis increases drought tolerance through the coordinated regulation of carbon and nitrogen assimilation in rice.

    Science.gov (United States)

    Reguera, Maria; Peleg, Zvi; Abdel-Tawab, Yasser M; Tumimbang, Ellen B; Delatorre, Carla A; Blumwald, Eduardo

    2013-12-01

    The effects of water deficit on carbon and nitrogen metabolism were investigated in flag leaves of wild-type and transgenic rice (Oryza sativa japonica 'Kitaake') plants expressing ISOPENTENYLTRANSFERASE (IPT; encoding the enzyme that mediates the rate-limiting step in cytokinin synthesis) under the control of P(SARK), a maturation- and stress-induced promoter. While the wild-type plants displayed inhibition of photosynthesis and nitrogen assimilation during water stress, neither carbon nor nitrogen assimilation was affected by stress in the transgenic P(SARK)::IPT plants. In the transgenic plants, photosynthesis was maintained at control levels during stress and the flag leaf showed increased sucrose (Suc) phosphate synthase activity and reduced Suc synthase and invertase activities, leading to increased Suc contents. The sustained carbon assimilation in the transgenic P(SARK)::IPT plants was well correlated with enhanced nitrate content, higher nitrate reductase activity, and sustained ammonium contents, indicating that the stress-induced cytokinin synthesis in the transgenic plants played a role in maintaining nitrate acquisition. Protein contents decreased and free amino acids increased in wild-type plants during stress, while protein content was preserved in the transgenic plants. Our results indicate that the stress-induced cytokinin synthesis in the transgenic plants promoted sink strengthening through a cytokinin-dependent coordinated regulation of carbon and nitrogen metabolism that facilitates an enhanced tolerance of the transgenic plants to water deficit.

  15. Identification and characterization of an archaeal ketopantoate reductase and its involvement in regulation of coenzyme A biosynthesis.

    Science.gov (United States)

    Tomita, Hiroya; Imanaka, Tadayuki; Atomi, Haruyuki

    2013-10-01

    Coenzyme A (CoA) biosynthesis in bacteria and eukaryotes is regulated primarily by feedback inhibition towards pantothenate kinase (PanK). As most archaea utilize a modified route for CoA biosynthesis and do not harbour PanK, the mechanisms governing regulation of CoA biosynthesis are unknown. Here we performed genetic and biochemical studies on the ketopantoate reductase (KPR) from the hyperthermophilic archaeon Thermococcus kodakarensis. KPR catalyses the second step in CoA biosynthesis, the reduction of 2-oxopantoate to pantoate. Gene disruption of TK1968, whose product was 20-29% identical to previously characterized KPRs from bacteria/eukaryotes, resulted in a strain with growth defects that were complemented by addition of pantoate. The TK1968 protein (Tk-KPR) displayed reductase activity specific for 2-oxopantoate and preferred NADH as the electron donor, distinct to the bacterial/eukaryotic NADPH-dependent enzymes. Tk-KPR activity decreased dramatically in the presence of CoA and KPR activity in cell-free extracts was also inhibited by CoA. Kinetic studies indicated that CoA inhibits KPR by competing with NADH. Inhibition of ketopantoate hydroxymethyltransferase, the first enzyme of the pathway, by CoA was not observed. Our results suggest that CoA biosynthesis in T. kodakarensis is regulated by feedback inhibition of KPR, providing a feasible regulation mechanism of CoA biosynthesis in archaea. © 2013 John Wiley & Sons Ltd.

  16. Long-term effect of medium-chain triglyceride on hepatic enzymes catalyzing lipogenesis and cholesterogenesis in rats

    International Nuclear Information System (INIS)

    Takase, Sachiko; Morimoto, Ayami; Nakanishi, Mayumi; Muto, Yasutoshi.

    1977-01-01

    This study was conducted to investigate the long-term effect of dietary medium-chain triglyceride (MCT) as compared with that of corn oil feeding on lipid metabolism in rats. Both serum cholesterol and triglyceride levels in MCT-fed rats showed significant decrease during the experimental period of eight weeks, although liver cholesterol and triglyceride contents were not distinguishable between the two groups. Significant elevation of the activity of lipogenic enzymes, such as fatty acid synthetase (FAS) and malic enzyme (ME) of the liver, was observed in MCT-fed rats without any fat accumulation of the liver (fatty liver). The increase of lipogenic enzyme activity was accompanied by a significant reduction of essential fatty acids (EFA) such as 18:2 (ωsigma) and 20:4 (ωsigma) in total liver lipid. In contrast, hepatic β-hydroxy-β-methylglutaryl CoA(HMG-CoA) reductase activity was significantly decreased in MCT-fed rats, that would play an important role in achieving hypocholesterolemia. From these results obtained in a long-term experiment, it is concluded that exogenous MCT depresses the key enzyme catalyzing cholesterol synthesis with a concomitant elevation of lipogenic enzyme activity in the rat liver. (auth.)

  17. Compact conformations of human protein disulfide isomerase.

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    Shang Yang

    Full Text Available Protein disulfide isomerase (PDI composed of four thioredoxin-like domains a, b, b', and a', is a key enzyme catalyzing oxidative protein folding in the endoplasmic reticulum. Large scale molecular dynamics simulations starting from the crystal structures of human PDI (hPDI in the oxidized and reduced states were performed. The results indicate that hPDI adopts more compact conformations in solution than in the crystal structures, which are stabilized primarily by inter-domain interactions, including the salt bridges between domains a and b' observed for the first time. A prominent feature of the compact conformations is that the two catalytic domains a and a' can locate close enough for intra-molecular electron transfer, which was confirmed by the characterization of an intermediate with a disulfide between the two domains. Mutations, which disrupt the inter-domain interactions, lead to decreased reductase activity of hPDI. Our molecular dynamics simulations and biochemical experiments reveal the intrinsic conformational dynamics of hPDI and its biological impact.

  18. Graphene oxide amplifies the phytotoxicity of arsenic in wheat

    Science.gov (United States)

    Hu, Xiangang; Kang, Jia; Lu, Kaicheng; Zhou, Ruiren; Mu, Li; Zhou, Qixing

    2014-08-01

    Graphene oxide (GO) is widely used in various fields and is considered to be relatively biocompatible. Herein, ``indirect'' nanotoxicity is first defined as toxic amplification of toxicants or pollutants by nanomaterials. This work revealed that GO greatly amplifies the phytotoxicity of arsenic (As), a widespread contaminant, in wheat, for example, causing a decrease in biomass and root numbers and increasing oxidative stress, which are thought to be regulated by its metabolisms. Compared with As or GO alone, GO combined with As inhibited the metabolism of carbohydrates, enhanced amino acid and secondary metabolism and disrupted fatty acid metabolism and the urea cycle. GO also triggered damage to cellular structures and electrolyte leakage and enhanced the uptake of GO and As. Co-transport of GO-loading As and transformation of As(V) to high-toxicity As(III) by GO were observed. The generation of dimethylarsinate, produced from the detoxification of inorganic As, was inhibited by GO in plants. GO also regulated phosphate transporter gene expression and arsenate reductase activity to influence the uptake and transformation of As, respectively. Moreover, the above effects of GO were concentration dependent. Given the widespread exposure to As in agriculture, the indirect nanotoxicity of GO should be carefully considered in food safety.

  19. Reconstitution of FMN-free NADPH-cytochrome P-450 reductase with a phosphorothioate analog of FMN: 31P NMR studies of the reconstituted protein

    International Nuclear Information System (INIS)

    Krum, D.P.; Otvos, J.D.; Calhoun, J.P.; Miziorko, H.M.; Masters, B.S.S.

    1987-01-01

    A phosphorothioate analog of FMN (FMNS) has been synthesized and shown to be completely competent in reconstituting the FMN-free form of NADPH-cytochrome P-450 reductase as evidenced by flavin determinations and cytochrome c reductase activity assays. The FMNS-reconstituted FMN-free reductase gives rise to an air-stable semiquinone, and the fluorescence of FMNS is quenched upon addition of FMN-free reductase. 31 P NMR spectra of the FMN-free reductase reveal only two resonances (-7.3 and -11.3 ppm), which are attributable to FAD. This result confirms the assignments of Otvos et al, and demonstrates unequivocally that there are no phosphate residues other than those of FMN and FAD attached to the steapsin-solubilized reductase. The addition of FMN to the FMN-free reductase resulted in the appearance of one additional resonance at 3.9 ppm. Addition of FMNS to the FMN-free reductase caused no change, surprisingly, in the 31 P NMR spectrum until Mn(II) was added, after which a peak centered at ∼ 45 ppm was observed. This unexpected result may be explained if the T 1 for the phosphate of FMNS is significantly longer than that of FMN, and suggests that the sulfur atom of FMNS may perturb the interaction of the phosphate with its protein environment. These results demonstrate the utility of phosphorothioate analogs as mechanistic probes for proteins containing nucleotide cofactors

  20. Evaluation of Neonatal Streptozotocin Induced Diabetic Rat Model for the Development of Cataract

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    Madhoosudan A. Patil

    2014-01-01

    Full Text Available Type 2 diabetes (T2D generally follows prediabetes (PD conditions such as impaired fasting glucose (IFG and/or impaired glucose tolerance (IGT. Although studies reported an association of IGT or IFG with cataract, the experimental basis for PD associated cataract is not known. Hence, we evaluated neonatal streptozotocin (nSTZ induced rat model to study PD associated cataractogenesis by injecting STZ to two-day old rats. While majority (70% of nSTZ injected pups developed IGT (nSTZ-PD by two months but not cataract even after seven months, remaining (30% nSTZ rats developed hyperglycemia (nSTZ-D by two months and mature cataract by seven months. Lens biochemical analysis indicated increased oxidative stress as indicated by increased SOD activity, lipid peroxidation, and protein carbonyl levels in nSTZ-D cataractous lens. There was also increased polyol pathway as assessed by aldose reductase activity and sorbitol levels. Though nSTZ-PD animals have not shown any signs of lenticular opacity, insolubilization of proteins along with enhanced polyol pathway was observed in the lens. Further there was increased oxidative stress in lens of IGT animals. These results suggest that oxidative stress along with increased polyol pathway might play a role in IGT-associated lens abnormalities. In conclusion, nSTZ-PD rat model could aid to investigate IGT-associated lens abnormalities.

  1. Effect of petroleum ether and ethanol fractions of seeds of Abrus precatorius on androgenic alopecia

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    Sukirti Upadhyay

    2012-04-01

    Full Text Available Seeds of Abrus precatorius L., Fabaceae, are commonly used as purgative, emetic, aphrodisiac and in nervous disorder in traditional and folk medicines. In present study petroleum ether and ethanolic extracts of A. precatorius seeds are evaluated for reversal of androgen (testosterone by i.m route induced alopecia in male albino wistar rats and compared to topical administration of standard antiandrogenic drug finasteride for 21 days. The results were reflected from visual observation and histological study of several skin sections via various parameters as anagen to telogen ratio and follicle density/mm area of skin surface. The animal of group 1 who were treated with only testosterone became alopecic on visual observation. Animals of Group 2, 3 and 4 who were treated with finasteride, petroleum ether and ethanolic extract of seed respectively topically along with testosterone (i.m did not developed alopecia. To investigate the mechanism of observed activity, in vitro experiments were performed. Inhibition of 5α-reductase activity by extracts and finasteride suggest that they reversed androgen induced alopecia by inhibiting conversion of testosterone to dihydrotestosterone (potent androgen responsible for androgenic alopecia. So it may be concluded that petroleum ether and ethanolic extract of A. precatorius seed posses anti androgenic alopecia activity due to inhibition of 5α-reductase enzyme.

  2. Effect of petroleum ether and ethanol fractions of seeds of Abrus precatorius on androgenic alopecia

    Directory of Open Access Journals (Sweden)

    Sukirti Upadhyay

    2011-12-01

    Full Text Available Seeds of Abrus precatorius L., Fabaceae, are commonly used as purgative, emetic, aphrodisiac and in nervous disorder in traditional and folk medicines. In present study petroleum ether and ethanolic extracts of A. precatorius seeds are evaluated for reversal of androgen (testosterone by i.m route induced alopecia in male albino wistar rats and compared to topical administration of standard antiandrogenic drug finasteride for 21 days. The results were reflected from visual observation and histological study of several skin sections via various parameters as anagen to telogen ratio and follicle density/mm area of skin surface. The animal of group 1 who were treated with only testosterone became alopecic on visual observation. Animals of Group 2, 3 and 4 who were treated with finasteride, petroleum ether and ethanolic extract of seed respectively topically along with testosterone (i.m did not developed alopecia. To investigate the mechanism of observed activity, in vitro experiments were performed. Inhibition of 5α-reductase activity by extracts and finasteride suggest that they reversed androgen induced alopecia by inhibiting conversion of testosterone to dihydrotestosterone (potent androgen responsible for androgenic alopecia. So it may be concluded that petroleum ether and ethanolic extract of A. precatorius seed posses anti androgenic alopecia activity due to inhibition of 5α-reductase enzyme.

  3. Novel Study on N-Nitrosamines as Risk Factors of Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Salah A. Sheweita

    2014-01-01

    Full Text Available Millions of people are exposed daily to N-nitrosamines from different environmental sources. The present study aims at investigating the role of N-nitrosamines in the alteration of homocysteine, lipid profile, oxidative stress, paraoxonase activity, antioxidant enzymes, and free radicals which are important risk factors for CVD. In addition, biomarkers of cardiovascular diseases such as creatine kinase MB activity (CK-MB and lactate dehydrogenase (LDH as well as protein expression of both glutathione peroxidase and glutathione S-transferase π isozyme were assayed after treatment of rats with 0.2 mg/kg body weight of N-nitrosodibutylamine (NDBA, N-nitrosoethylbutylamine (NEBA, N-nitrosobutylpropylamine (NBPA, N-nitrosodiethylamine (NDEA, N-nitrosodimethylamine (NDMA, and N-nitrosodiphenylamine (NDPA as a daily dose for two weeks. LDL levels, paraoxonase activity, reduced glutathione levels, and glutathione reductase activities were increased, whereas HDL levels decreased after treatment of rats with most of N-nitrosamines compared to control group. Moreover, levels of free radicals and catalase activity increased, whereas protein expression of both glutathione peroxidase and glutathione S-transferase decreased after treatment of rats with some N-nitrosamines. The data showed that most N-nitrosamines increased CK-MB and LDH activities. It is concluded that N-nitrosamines increased levels of free radicals, and decreased the activity of antioxidant enzymes which may consequently increase the incidence of CVDs.

  4. Prognosis of physiological disorders in physic nut to N, P, and K deficiency during initial growth.

    Science.gov (United States)

    Santos, Elcio Ferreira; Macedo, Fernando Giovannetti; Zanchim, Bruno José; Lima, Giuseppina Pace Pereira; Lavres, José

    2017-06-01

    The description of physiological disorders in physic nut plants deficient in nitrogen (N), phosphorus (P) and potassium (K) may help to predict nutritional imbalances before the appearance of visual symptoms and to guide strategies for early nutrient supply. The aim of this study was to evaluate the growth of physic nuts (Jatropha curcas L.) during initial development by analyzing the gas exchange parameters, nutrient uptake and use efficiency, as well as the nitrate reductase and acid phosphatase activities and polyamine content. Plants were grown in a complete nutrient solution and solutions from which N, P or K was omitted. The nitrate reductase activity, phosphatase acid activity, polyamine content and gas exchange parameters from leaves of N, P and K-deficient plants indicates earlier imbalances before the appearance of visual symptoms. Nutrient deficiencies resulted in reduced plant growth, although P- and K-deficient plants retained normal net photosynthesis (A), stomatal conductance (g s ) and instantaneous carboxylation efficiency (k) during the first evaluation periods, as modulated by the P and K use efficiencies. Increased phosphatase acid activity in P-deficient plants may also contribute to the P use efficiency and to A and gs during the first evaluations. Early physiological and biochemical evaluations of N-, P- and K-starved plants may rely on reliable, useful methods to predict early nutritional imbalances. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Induction of sesquiterpenoid biosynthesis in tobacco cell suspension cultures by fungal elicitor

    International Nuclear Information System (INIS)

    Chappell, J.; Nable, R.

    1987-01-01

    Large amounts of the sesquiterpenoid capsidiol accumulated in the media of tobacco (Nicotiana tabacum L. cv KY14) cell suspension cultures upon addition of fungal elicitor. Capsidiol accumulation was proportional to the amount of elicitor added. The accumulation of capsidiol was preceded by a transient increase in the capsidiol de novo synthesis rate as measured by the incorporation of exogenous [ 14 C]acetate. Changes in 3-hydroxy-3-methylglutaryl-CoA reductase activity, an enzyme of general isoprenoid metabolism, paralleled the changes in [ 14 C]acetate incorporation into capsidiol. Incubation of the cell cultures with mevinolin, a potent in vitro inhibitor of the tobacco HMGR enzyme activity, inhibited the elicitor-induced capsidiol accumulation in a concentration dependent manner. [ 14 C]Acetate incorporation into capsidiol was likewise inhibited by mevinolin treatment. Unexpectedly, [ 3 H] mevalonate incorporation into capsidiol was also partially inhibited by mevinolin, suggesting that mevinolin may effect secondary sites of sesquiterpenoid biosynthesis in vivo beyond HMGR. The data indicated the importance of the induced HMGR activity for capsidiol production in elicitor-treated tobacco cell suspension cultures

  6. Effect of salinity on Brassica rapa var. toria (BRSRT under selenium defence: A trial to assess the protective role of selenium

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    Akanksha SAO

    2017-12-01

    Full Text Available The present study assesses the role of selenium, an antioxidant in salt-stressed plants. A hydroponic trial of sodium selenate (Na2SeO4 on the growth, oxidative stress and antioxidant protection system of Brassica rapa var. toria (BRSRT plant was studied. 40 µmol and 100 µmol of Na2SeO4 were hydroponically applied to BRSRT roots with 50 mmol and 100 mmol sodium chloride (NaCl for 12 days. Plant growth, biomass production and photosynthetic pigments at 100 mmol salt stress was inhibited while oxidative stress indicators, for example, hydrogen peroxide and lipid peroxidation were stimulated. Supplementation of 40 µmol Na2SeO4 with 50 mmol and 100 mmol NaCl improved growth, photosynthetic pigments and acted as an antioxidant by inhibiting lipid peroxidation and increasing superoxide dismutase, ascorbate peroxidase, catalase, glutathione peroxidase, glutathione reductase activities. The in-gel assays also showed enhanced activities of these enzymes. At 100 µmol concentration, selenium under salt stress, repressed growth and expression of antioxidant enzymes and stimulated oxidative stress with enhanced glutathione peroxidase activity. Under consolidated stress treatment, an addition of 40 µmol Na2SeO4 was the most effective for both NaCl concentrations. The finding reveals that the optimal selenium supplementation presents a promising potential for use in conditions of relatively high levels of NaCl stress for BRSRT seedlings.

  7. The memory of iron stress in strawberry plants.

    Science.gov (United States)

    Gama, Florinda; Saavedra, Teresa; da Silva, José Paulo; Miguel, Maria Graça; de Varennes, Amarilis; Correia, Pedro José; Pestana, Maribela

    2016-07-01

    To provide information towards optimization of strategies to treat Fe deficiency, experiments were conducted to study the responses of Fe-deficient plants to the resupply of Fe. Strawberry (Fragaria × ananassa Duch.) was used as model plant. Bare-root transplants of strawberry (cv. 'Diamante') were grown for 42 days in Hoagland's nutrient solutions without Fe (Fe0) and containing 10 μM of Fe as Fe-EDDHA (control, Fe10). For plants under Fe0 the total chlorophyll concentration of young leaves decreased progressively on time, showing the typical symptoms of iron chlorosis. After 35 days the Fe concentration was 6% of that observed for plants growing under Fe10. Half of plants growing under Fe0 were then Fe-resupplied by adding 10 μM of Fe to the Fe0 nutrient solution (FeR). Full Chlorophyll recovery of young leaves took place within 12 days. Root ferric chelate-reductase activity (FCR) and succinic and citric acid concentrations increased in FeR plants. Fe partition revealed that FeR plants expressively accumulated this nutrient in the crown and flowers. This observation can be due to a passive deactivation mechanism of the FCR activity, associated with continuous synthesis of succinic and citric acids at root level, and consequent greater uptake of Fe. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Tobacco Nectarin III is a bifunctional enzyme with monodehydroascorbate reductase and carbonic anhydrase activities.

    Science.gov (United States)

    Carter, Clay J; Thornburg, Robert W

    2004-02-01

    Tobacco plants secrete a limited array of proteins (nectarins) into their floral nectar. N-terminal sequencing of the Nectarin II ( NEC2; 35kD) and the Nectarin III ( NEC3; 40kD) proteins revealed that they both share identity with dioscorin, the major soluble protein of yam tubers. These sequences also revealed that NEC2 is a breakdown product of NEC3. Using these N-terminal peptide sequences, degenerate oligonucleotides were designed that permitted the isolation of a partial NEC3 cDNA. This cDNA was then used to probe a nectary specific cDNA library and a full-length NEC3 cDNA clone was isolated. Complete sequence analysis confirmed the identity of NEC3 as a dioscorin-like protein. MALDI-TOF mass spectrometric fingerprinting of tryptic peptides derived from the purified NEC3 confirmed that this protein was encoded by the isolated cDNA. NEC3 was shown to possess both carbonic anhydrase and monodehydroascorbate reductase activities. RT-PCR based expression analyses demonstrated that NEC3 transcript is expressed throughout nectary development as well as in other floral organs. A proposed function in the maintenance of pH and oxidative balance in nectar is discussed.

  9. Gold nanoparticles synthesized by Geobacillus sp. strain ID17 a thermophilic bacterium isolated from Deception Island, Antarctica

    Science.gov (United States)

    2013-01-01

    Background The use of microorganisms in the synthesis of nanoparticles emerges as an eco-friendly and exciting approach, for production of nanoparticles due to its low energy requirement, environmental compatibility, reduced costs of manufacture, scalability, and nanoparticle stabilization compared with the chemical synthesis. Results The production of gold nanoparticles by the thermophilic bacterium Geobacillus sp. strain ID17 is reported in this study. Cells exposed to Au3+ turned from colourless into an intense purple colour. This change of colour indicates the accumulation of intracellular gold nanoparticles. Elemental analysis of particles composition was verified using TEM and EDX analysis. The intracellular localization and particles size were verified by TEM showing two different types of particles of predominant quasi-hexagonal shape with size ranging from 5–50 nm. The mayority of them were between 10‒20 nm in size. FT-IR was utilized to characterize the chemical surface of gold nanoparticles. This assay supports the idea of a protein type of compound on the surface of biosynthesized gold nanoparticles. Reductase activity involved in the synthesis of gold nanoparticles has been previously reported to be present in others microorganisms. This reduction using NADH as substrate was tested in ID17. Crude extracts of the microorganism could catalyze the NADH-dependent Au3+ reduction. Conclusions Our results strongly suggest that the biosynthesis of gold nanoparticles by ID17 is mediated by enzymes and NADH as a cofactor for this biological transformation. PMID:23919572

  10. Seasonal changes in physiological performance in wild Clarkia xantiana populations: Implications for the evolution of a compressed life cycle and self-fertilization.

    Science.gov (United States)

    Dudley, Leah S; Hove, Alisa A; Emms, Simon K; Verhoeven, Amy S; Mazer, Susan J

    2015-06-01

    One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season drought. Here, we test two fundamental assumptions of this hypothesis in Clarkia xantiana: (1) that a seasonal decline in precipitation causes an increase in drought stress and (2) that this results in changes in physiological performance, reflecting these deteriorating conditions. We examined seasonal and interannual variation in abiotic environmental conditions (estimated by ambient temperature, relative humidity, predawn leaf water potentials, and carbon isotope ratios) and physiological traits (photosynthesis, conductance, transpiration, instantaneous water-use efficiency, ascorbate peroxidase and glutathione reductase activities, quantum yield of photosystem II, PSII potential efficiency) in field populations of C. xantiana in 2009 and 2010. In both years, plants experienced intensifying drought across the growing season. Gas exchange rates decreased over the growing season and were lower in 2009 (a relatively dry year) than in 2010, suggesting that the temporal changes from early to late spring were directly linked to the deteriorating environmental conditions. Seasonal declines in transpiration rate may have increased survival by protecting plants from desiccation. Concomitant declines in photosynthetic rate likely reduced the availability of resources for seed production late in the season. Thus, the physiological patterns observed are consistent with the conditions required for the drought escape hypothesis. © 2015 Botanical Society of America, Inc.

  11. Crystal Structure of Saccharomyces cerevisiae ECM4, a Xi-Class Glutathione Transferase that Reacts with Glutathionyl-(hydro)quinones

    Science.gov (United States)

    Schwartz, Mathieu; Didierjean, Claude; Hecker, Arnaud; Girardet, Jean-Michel; Morel-Rouhier, Mélanie; Gelhaye, Eric; Favier, Frédérique

    2016-01-01

    Glutathionyl-hydroquinone reductases (GHRs) belong to the recently characterized Xi-class of glutathione transferases (GSTXs) according to unique structural properties and are present in all but animal kingdoms. The GHR ScECM4 from the yeast Saccharomyces cerevisiae has been studied since 1997 when it was found to be potentially involved in cell-wall biosynthesis. Up to now and in spite of biological studies made on this enzyme, its physiological role remains challenging. The work here reports its crystallographic study. In addition to exhibiting the general GSTX structural features, ScECM4 shows extensions including a huge loop which contributes to the quaternary assembly. These structural extensions are probably specific to Saccharomycetaceae. Soaking of ScECM4 crystals with GS-menadione results in a structure where glutathione forms a mixed disulfide bond with the cysteine 46. Solution studies confirm that ScECM4 has reductase activity for GS-menadione in presence of glutathione. Moreover, the high resolution structures allowed us to propose new roles of conserved residues of the active site to assist the cysteine 46 during the catalytic act. PMID:27736955

  12. Crystal Structure of Saccharomyces cerevisiae ECM4, a Xi-Class Glutathione Transferase that Reacts with Glutathionyl-(hydroquinones.

    Directory of Open Access Journals (Sweden)

    Mathieu Schwartz

    Full Text Available Glutathionyl-hydroquinone reductases (GHRs belong to the recently characterized Xi-class of glutathione transferases (GSTXs according to unique structural properties and are present in all but animal kingdoms. The GHR ScECM4 from the yeast Saccharomyces cerevisiae has been studied since 1997 when it was found to be potentially involved in cell-wall biosynthesis. Up to now and in spite of biological studies made on this enzyme, its physiological role remains challenging. The work here reports its crystallographic study. In addition to exhibiting the general GSTX structural features, ScECM4 shows extensions including a huge loop which contributes to the quaternary assembly. These structural extensions are probably specific to Saccharomycetaceae. Soaking of ScECM4 crystals with GS-menadione results in a structure where glutathione forms a mixed disulfide bond with the cysteine 46. Solution studies confirm that ScECM4 has reductase activity for GS-menadione in presence of glutathione. Moreover, the high resolution structures allowed us to propose new roles of conserved residues of the active site to assist the cysteine 46 during the catalytic act.

  13. Efficacy of curcumin to reduce hepatic damage induced by alcohol and thermally treated oil in rats

    Directory of Open Access Journals (Sweden)

    Nasr A.M.N. El-Deen

    2010-03-01

    Full Text Available The authors investigated the effect of curcumin on markers of oxidative stress and liver damage in rats that chronically ingested alcohol and heated oil. Nine groups of ten Wistar male rats received combinations of curcumin 100 mg/kg body weight daily, ethanol 5 mg/kg, 15% dietary sunflower oil and 15% heated sunflower oil for 12 weeks. Serum and liver tissue were collected. Groups 4-6, which had received compounds causing oxidative stress, showed increased serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, cholesterol, triglycerides, low density lipoprotein, very low density lipoprotein and reduced high density lipoprotein, protein and albumin, compared with the controls. Reductions were observed in glutathione peroxidase and reductase gene expression, superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione concentration and catalase enzyme activity. Groups 7, 8 and 9 which received curcumin with heated oil, ethanol or both, showed lower elevations in serum and oxidative damage markers compared with the corresponding non-curcumin treated groups.It can be concluded that curcumin reduces markers of liver damage in rats treated with heated sunflower oil or ethanol.

  14. Antioxidant Properties and Flavonoid Profile in Leaves of Calabrian Lavandula multifida L., an Autochthon Plant of Mediterranean Southern Regions.

    Science.gov (United States)

    Panuccio, Maria Rosaria; Fazio, Angela; Papalia, Teresa; Barreca, Davide

    2016-04-01

    Lavandula multifida is a rare short-lived plant characteristic of Mediterranean basin able to survive in hot and arid climatic conditions on poorly evolved limestone soils. In this work, we characterize the enzymatic antioxidant system and phenolic composition, as well as the antioxidant properties of L. multifida fresh leaves. Enzymatic patterns show high level of peroxidases, ascorbate peroxidase, and dehydroascorbate reductase activities, when compared with L. angustifolia. The same trend is evident in total carotenoids, ascorbic acid, and reduced glutathione, and in the total antioxidant capacity assay. Moreover, RP-DAD-HPLC analyses of EtOH extract, obtained from fresh leaves, reveal main components, carvacrol, vitexin, and 7- or 8-glucoside derivatives of hypolaetin, scutellarein, luteolin, isoscutellarein, apigenin, and chrysoeriol. The analysis of this autochthon plant depicted a series of strategies adopted by L. multifida to survive in its stressful natural habitat and richness in health-promoting compounds that can be a resource for the preservation of this variety in dangerous of extinction. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Testosterone metabolism in the estuarine mysid Neomysis integer (Crustacea; Mysidacea) following tributyltin exposure.

    Science.gov (United States)

    Verslycke, Tim; Poelmans, Sofie; De Wasch, Katia; Vercauteren, Jordy; Devos, Christophe; Moens, Luc; Sandra, Patrick; De Brabander, Hubert F; Janssen, Colin R

    2003-09-01

    Current evidence suggests that the biocide tributyltin (TBT) causes the development of imposex, a state of pseudohermaphrodism in which females exhibit functional secondary male characteristics, by altering the biotransformation or elimination of testosterone. Imposex in gastropods following TBT exposure is the most complete example of the effects of an endocrine disrupter on marine invertebrates. Previous studies have demonstrated that the estuarine mysid Neomysis integer converts testosterone into multiple polar and nonpolar metabolites resulting from both phase I and phase II biotransformations. In this study, the effects of TBT chloride (TBTCl) on the phase I and II testosterone metabolism of N. integer were evaluated. The TBTCl was highly toxic to N. integer (96-h median lethal concentration [LC50] of 164 ng/L). To assess the effects on testosterone metabolism, mysids were exposed for 96 h to different concentrations of TBTCl (control, 10, 100, and 1,000 ng/L), and testosterone elimination as polar hydroxylated, nonpolar oxido-reduced, and glucose- and sulfate-conjugated metabolites was examined. The TBTCl differentially affected testosterone metabolism. The effect of TBTCl on phase I metabolism was unclear and has been shown to vary among species, likely depending on the inducibility or presence of certain P450 isozyme families. Reductase activity and metabolic androgenization were induced in the 10-ng/L treatment, whereas higher concentrations resulted in a reduction of sulfate conjugation. The exact mechanisms underlying TBT-induced imposex and alterations in the steroid metabolism need to be further elucidated.

  16. Sexual dimorphism in cortisol secretion starts after age 10 in healthy children: urinary cortisol metabolite excretion rates during growth.

    Science.gov (United States)

    Wudy, Stefan A; Hartmann, Michaela F; Remer, Thomas

    2007-10-01

    Detailed data on the physiological pattern of adrenocortical activity during normal growth are lacking. An established method to determine adrenocortical glucocorticoid secretion is the measurement of 24-h excretion rates of major urinary cortisol metabolites (C21). To test the hypothesis that the frequently reported higher cortisol secretion in men than in women develops during puberty, we examined C21 together with excretions of combined urinary free and conjugated cortisol (F(comb)) in 400 healthy boys and girls aged 3-18 yr using GC-MS. Daily excretion rates of C21, F(comb), and body surface area (BSA)-corrected F(comb) significantly increased with age in both sexes. In contrast, C21/BSA (microgxm(-2).day(-1)) declined from the age of 3-4 yr to 7-8 yr in boys and girls (P activity (allotetrahydrocortisol/tetrahydrocortisol) in females compared with males. Our results demonstrate dynamic changes in adrenocortical activity in healthy children resulting in an emerging sexual dimorphism in cortisol secretion after age 11. The latter can be explained, at least partly, by diverging 5alpha-reductase activities in boys and girls. F(comb), a frequently analyzed GC-MS parameter, proved not to reflect dynamic changes in cortisol secretion. In conclusion, the varying metabolic need for cortisol during normal growth may have implications for future improvements in glucocorticoid replacement therapy.

  17. Constitutive synthesis of a transport function encoded by the Thiobacillus ferrooxidans merC gene cloned in Escherichia coli

    International Nuclear Information System (INIS)

    Kusano, Tomonobu; Ji, Guangyong; Silver, S.; Inoue, Chihiro

    1990-01-01

    Mercuric reductase activity determined by the Thiobacillus ferrooxidans merA gene (cloned and expressed constitutively in Escherichia coli) was measured by volatilization of 203 Hg 2+ . (The absence of a merR regulatory gene in the cloned Thiobacillus mer determinant provides a basis for the constitutive synthesis of this system.) In the absence of the Thiobacillus merC transport gene, the mercury volatilization activity was cryptic and was not seen with whole cells but only with sonication-disrupted cells. The Thiobacillus merC transport function was compared with transport via the merT-merP system of plasmid pDU1358. Both systems, cloned and expressed in E. coli, governed enhanced uptake of 203 Hg 2+ in a temperature- and concentration-dependent fashion. Uptake via MerT-MerP was greater and conferred greater hypersensitivity to Hg 2+ than did uptake with MerC. Mercury uptake was inhibited by N-ethylmaleimide but not by EDTA. Ag + salts inhibited mercury uptake by the MerT-MerP system but did not inhibit uptake via MerC. Radioactive mercury accumulated by the MerT-MerP and by the MerC systems was exchangeable with nonradioactive Hg 2+

  18. Differential effect of ultraviolet-B radiation on certain metabolic processes in a chromatically adapting Nostoc

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, R.; Srinivas, G.; Vyas, D.; Kumar, A.; Kumar, H.D. (Banaras Hindu Univ., Varanasi (India))

    1992-03-01

    The impact of UV-B radiation on growth, pigmentation and certain physiological processes was studied in a N{sub 2}-fixing chromatically adapting cyanobacterium, Nostoc spongiaeforme. A brownish form (phycoerythrin rich) was found to be more tolerant to UV-B than the blue-green (phycocyanin rich) form of N. spongiaeforme. Continuous exposure to UV-B (5.5 W m{sup -2}) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. Pigment content was more strongly inhibited in the blue-green strain than in the brown. Nitrogenase activity was completely abolished in both strains within 35 min of UV-B treatment. Restoration of nitrogenase occurred upon transfer to fluorescent or incandescent light after a lag of 5-6 h, suggesting fresh synthesis of nitrogenase. In vivo nitrate reductase activity was stimulated by UV-B treatment, the degree of enhancement being significantly higher in the blue-green strain. {sup 14}CO{sub 2} uptake was also completely abolished by UV-B treatment in both strains. (author).

  19. Differential effect of ultraviolet-B radiation on certain metabolic processes in a chromatically adapting Nostoc

    International Nuclear Information System (INIS)

    Tyagi, R.; Srinivas, G.; Vyas, D.; Kumar, A.; Kumar, H.D.

    1992-01-01

    The impact of UV-B radiation on growth, pigmentation and certain physiological processes was studied in a N 2 -fixing chromatically adapting cyanobacterium, Nostoc spongiaeforme. A brownish form (phycoerythrin rich) was found to be more tolerant to UV-B than the blue-green (phycocyanin rich) form of N. spongiaeforme. Continuous exposure to UV-B (5.5 W m -2 ) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. Pigment content was more strongly inhibited in the blue-green strain than in the brown. Nitrogenase activity was completely abolished in both strains within 35 min of UV-B treatment. Restoration of nitrogenase occurred upon transfer to fluorescent or incandescent light after a lag of 5-6 h, suggesting fresh synthesis of nitrogenase. In vivo nitrate reductase activity was stimulated by UV-B treatment, the degree of enhancement being significantly higher in the blue-green strain. 14 CO 2 uptake was also completely abolished by UV-B treatment in both strains. (author)

  20. Ethylene response factor AtERF72 negatively regulates Arabidopsis thaliana response to iron deficiency.

    Science.gov (United States)

    Liu, Wei; Li, Qiwei; Wang, Yi; Wu, Ting; Yang, Yafei; Zhang, Xinzhong; Han, Zhenhai; Xu, Xuefeng

    2017-09-23

    Ethylene regulates the plant's response to stress caused by iron (Fe) deficiency. However, specific roles of ERF proteins in response to Fe deficiency remain poorly understood. Here, we investigated the role of ERF72 in response to iron deficiency in Arabidopsis thaliana. In this study, the levels of the ethylene response factor AtERF72 increased in leaves and roots induced under the iron deficient conditions. erf72 mutant plants showed increased growth compared to wild type (WT) when grown in iron deficient medium for 5 d. erf72 mutants had increased root H + velocity and the ferric reductase activity, and increase in the expression of the iron deficiency response genes iron-regulated transporter 1 (IRT1) and H + -ATPase (HA2) levels in iron deficient conditions. Compared to WT plants, erf72 mutants retained healthy chloroplast structure with significantly higher Fe and Mg content, and decreased chlorophyll degradation gene pheophorbide a oxygenase (PAO) and chlorophyllase (CLH1) expression when grown in iron deficient media. Yeast one-hybrid analysis showed that ERF72 could directly bind to the promoter regions of iron deficiency responses genes IRT1, HA2 and CLH1. Based on our results, we suggest that ethylene released from plants under iron deficiency stress can activate the expression of ERF72, which responds to iron deficiency in the negative regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Adaptation of anaerobic cultures of E scherichia coli  K‐12 in response to environmental trimethylamine‐N‐oxide

    Science.gov (United States)

    Denby, Katie J.; Rolfe, Matthew D.; Crick, Ellen; Sanguinetti, Guido; Poole, Robert K.

    2015-01-01

    Summary Systematic analyses of transcriptional and metabolic changes occurring when E scherichia coli  K‐12 switches from fermentative growth to anaerobic respiratory growth with trimethylamine‐N‐oxide (TMAO) as the terminal electron acceptor revealed: (i) the induction of torCAD, but not genes encoding alternative TMAO reductases; (ii) transient expression of frmRAB, encoding formaldehyde dehydrogenase; and (iii) downregulation of copper resistance genes. Simultaneous inference of 167 transcription factor (TF) activities implied that transcriptional re‐programming was mediated by 20 TFs, including the transient inactivation of the two‐component system ArcBA; a prediction validated by direct measurement of phosphorylated ArcA. Induction of frmRAB, detection of dimethylamine in culture medium and formaldehyde production when cell‐free extracts were incubated with TMAO suggested the presence of TMAO demethylase activity. Accordingly, the viability of an frmRAB mutant was compromised upon exposure to TMAO. Downregulation of genes involved in copper resistance could be accounted for by TMAO inhibition of Cu(II) reduction. The simplest interpretation of the data is that during adaptation to the presence of environmental TMAO, anaerobic fermentative cultures of E . coli respond by activating the TorTSR regulatory system with consequent induction of TMAO reductase activity, resulting in net oxidation of menaquinone and inhibition of Cu(II) reduction, responses that are sensed by ArcBA and CusRS respectively. PMID:25471524

  2. The Antimicrobial Properties of Silver Nanoparticles in Bacillus subtilis Are Mediated by Released Ag+ Ions

    Science.gov (United States)

    Hsueh, Yi-Huang; Lin, Kuen-Song; Ke, Wan-Ju; Hsieh, Chien-Te; Chiang, Chao-Lung; Tzou, Dong-Ying; Liu, Shih-Tung

    2015-01-01

    The superior antimicrobial properties of silver nanoparticles (Ag NPs) are well-documented, but the exact mechanisms underlying Ag-NP microbial toxicity remain the subject of intense debate. Here, we show that Ag-NP concentrations as low as 10 ppm exert significant toxicity against Bacillus subtilis, a beneficial bacterium ubiquitous in the soil. Growth arrest and chromosomal DNA degradation were observed, and flow cytometric quantification of propidium iodide (PI) staining also revealed that Ag-NP concentrations of 25 ppm and above increased membrane permeability. RedoxSensor content analysis and Phag-GFP expression analysis further indicated that reductase activity and cytosolic protein expression decreased in B. subtilis cells treated with 10–50 ppm of Ag NPs. We conducted X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) analyses to directly clarify the valence and fine structure of Ag atoms in B. subtilis cells placed in contact with Ag NPs. The results confirmed the Ag species in Ag NP-treated B. subtilis cells as Ag2O, indicating that Ag-NP toxicity is likely mediated by released Ag+ ions from Ag NPs, which penetrate bacterial cells and are subsequently oxidized intracellularly to Ag2O. These findings provide conclusive evidence for the role of Ag+ ions in Ag-NP microbial toxicity, and suggest that the impact of inappropriately disposed Ag NPs to soil and water ecosystems may warrant further investigation. PMID:26669836

  3. Preconditioning with subneurotoxic allyl nitrile: protection against allyl nitrile neurotoxicity.

    Science.gov (United States)

    Tanii, H; Higashi, T; Saijoh, K

    2010-02-01

    High-dose cruciferous allyl nitrile can induce behavioral abnormalities in rodents, while repeated exposure to allyl nitrile at subneurotoxic levels can increase phase 2 detoxification enzymes in many tissues, although the brain has not been investigated yet. In the present study, we examined the effect of 5 days repeated exposure to subneurotoxic allyl nitrile (0-400 micromol/kg/day) on the brain. Elevated glutathione S-transferase activity was recorded in the striatum, hippocampus, medulla oblongata plus pons, and cortex. Enhancement of quinone reductase activity was observed in the medulla oblongata plus pons, hippocampus, and cortex. In the medulla oblongata plus pons, elevated glutathione levels were recorded. Following repeated subneurotoxic allyl nitrile exposure (0-400 micromol/kg/day), mice were administered a high-dose allyl nitrile (1.2 mmol/kg) which alone led to appearance of behavioral abnormalities. Compared with the 0 micromol/kg/day group, animals in the 200 and 400 micromol/kg/day pre-treatment groups exhibited decreased behavioral abnormalities and elevated GABA-positive cell counts in the substantia nigra pars reticulata and the interpeduncular nucleus. These data suggest that repeated exposure to subneurotoxic levels of allyl nitrile can induce phase 2 enzymes in the brain, which together with induction in other tissues, may contribute to protection against allyl nitrile neurotoxicity. Copyright 2009 Elsevier Ltd. All rights reserved.

  4. Coenzyme Q10 and alpha-tocopherol protect against amitriptyline toxicity

    International Nuclear Information System (INIS)

    Cordero, Mario D.; Moreno-Fernandez, Ana Maria; Gomez-Skarmeta, Jose Luis; Miguel, Manuel de; Garrido-Maraver, Juan; Oropesa-Avila, Manuel; Rodriguez-Hernandez, Angeles; Navas, Placido; Sanchez-Alcazar, Jose Antonio

    2009-01-01

    Since amitriptyline is a very frequently prescribed antidepressant drug, it is not surprising that amitriptyline toxicity is relatively common. Amitriptyline toxic systemic effects include cardiovascular, autonomous nervous, and central nervous systems. To understand the mechanisms of amitriptyline toxicity we studied the cytotoxic effects of amitriptyline treatment on cultured primary human fibroblasts and zebrafish embryos, and the protective role of coenzyme Q 10 and alpha-tocopherol, two membrane antioxidants. We found that amitriptyline treatment induced oxidative stress and mitochondrial dysfunction in primary human fibroblasts. Mitochondrial dysfunction in amitriptyline treatment was characterized by reduced expression levels of mitochondrial proteins and coenzyme Q 10 , decreased NADH:cytochrome c reductase activity, and a drop in mitochondrial membrane potential. Moreover, and as a consequence of these toxic effects, amitriptyline treatment induced a significant increase in apoptotic cell death activating mitochondrial permeability transition. Coenzyme Q 10 and alpha-tocopherol supplementation attenuated ROS production, lipid peroxidation, mitochondrial dysfunction, and cell death, suggesting that oxidative stress affecting cell membrane components is involved in amitriptyline cytotoxicity. Furthermore, amitriptyline-dependent toxicity and antioxidant protection were also evaluated in zebrafish embryos, a well established vertebrate model to study developmental toxicity. Amitriptyline significantly increased embryonic cell death and apoptosis rate, and both antioxidants provided a significant protection against amitriptyline embryotoxicity

  5. Bacteria, hypertolerant to arsenic in the rocks of an ancient gold mine, and their potential role in dissemination of arsenic pollution

    International Nuclear Information System (INIS)

    Drewniak, Lukasz; Styczek, Aleksandra; Majder-Lopatka, Malgorzata; Sklodowska, Aleksandra

    2008-01-01

    The aim of the present study was to find out if bacteria present in ancient gold mine could transform immobilized arsenic into its mobile form and increase its dissemination in the environment. Twenty-two arsenic-hypertolerant cultivable bacterial strains were isolated. No chemolithoautotrophs, which could use arsenite as an electron donor as well as arsenate as an electron acceptor, were identified. Five isolates exhibited hypertolerance to arsenic: up to 500 mM of arsenate. A correlation between the presence of siderophores and high resistance to arsenic was found. The results of this study show that detoxification processes based on arsenate reductase activity might be significant in dissemination of arsenic pollution. It was concluded that the activity of the described heterotrophic bacteria contributes to the mobilization of arsenic in the more toxic As(III) form and a new mechanism of arsenic mobilization from a scorodite was proposed. - The activity of the described heterotrophic bacteria leads to mobilization of arsenic and in this way contributes to the dissemination of arsenic pollution

  6. Effect of riboflavin supply on student body's provision in north-western Poland with riboflavin measured by activity of glutathione reductase considering daily intake of other nutrients.

    Science.gov (United States)

    Szczuko, Małgorzata; Seidler, Teresa; Mierzwa, Mariusz; Stachowska, Ewa; Chlubek, Dariusz

    2011-06-01

    The riboflavin nutritional status of 120 people, age 22-25, studying in Szczecin, Poland, together with contents of their daily food servings were studied. Body's provision with riboflavin was determined using the erythrocyte glutathione reductase activity coefficient (EGRAC) and was compared with a sample in which the enzyme activity was stimulated with flavin adenine dinucleotide. The information concerning diets was collected with the method of a 7-day food record prior to blood collection. Biochemical deficiency in riboflavin was observed in 33.7% of women and 25% of men. The resulting average EGRAC value was 1.02 for women and 0.88 for men. Assessment of significant differences in riboflavin provision between the sexes revealed better provision in the male group. The comparison of EGRAC values with riboflavin content in 7-day diets of the respondents showed that the average intake of this vitamin in the female group, in which biochemical deficiency was observed, amounted to 1.05 mg, whereas in the male group it was, on average, 1.39 mg. In the group of people in which the potential risk of riboflavin deficiency in the body was not observed, the level of this vitamin consumption was, on average, 1.43 mg and 1.8 mg in the female and male groups, respectively. Women with biochemical riboflavin deficiency consumed significantly less of all the analyzed nutrients in comparison with the people without riboflavin deficiency.

  7. Urinary 5α-androstane-3α,17β-diol radioimmunoassay: a new clinical evaluation

    International Nuclear Information System (INIS)

    Wright, F.; Mowszowicz, I.; Mauvais-Jarvis, P.

    1978-01-01

    A rapid specific and reliable RIA for urinary 5α-androstane-3α, 17β-diol (Adiol) is described using chromatographical purification and a specific antibody. Values are reported under some physiological and pathological conditions in 179 individuals. In 43 normal adult men the mean (+- SD) urinary Adiol excretion was 193 +- 77 μg/24 h, and in 29 normal women it was 44 +- 23 μg/24 h. These values are significantly different (P < 0.01). In 49 hirsute women, urinary Adiol Excretion was elevated (137 +- 51 μg/24 h) and significantly different from this value in normal women (P < 0.01). The urinary Adiol excretion in 10 postmenopausal women was very low (< 5 μg/24 h). In normal adult subjects, the theoretical contribution to urinary Adiol of the major secreted androgens was calculated. Whereas dehydroisoandrosterone and dehydroisoandrosterone sulfate yield the same amount of urinary Adiol in both sexes, testosterone is the main precursor of Adiol in men and androstenedione is the main precursor in normal premenopausal and hirsute women. However, the amount of Adiol recovered in the 24-h urine depends not only on the secretion rate of androstenedione and testosterone but is also related to the testosterone 5α-reductase activity present in androgen target cells, especially in sexual skin

  8. The influence of supplementation with artichoke (Cynara scolymus L.) extract on selected redox parameters in rowers.

    Science.gov (United States)

    Skarpanska-Stejnborn, Anna; Pilaczynska-Szczesniak, Lucia; Basta, Piotr; Deskur-Smielcka, Ewa; Horoszkiewicz-Hassan, Magorzata

    2008-06-01

    High-intensity physical exercise decreases intracellular antioxidant potential. An enhanced antioxidant defense system is desirable in people subjected to exhaustive exercise. The aim of this study was to investigate the influence of supplementation with artichoke-leaf extract on parameters describing balance between oxidants and antioxidants in competitive rowers. This double-blinded study was carried out in 22 members of the Polish rowing team who were randomly assigned to a supplemented group (n = 12), receiving 1 gelatin capsule containing 400 mg of artichoke-leaf extract 3 times a day for 5 wk, or a placebo group (n = 10). At the beginning and end of the study participants performed a 2,000-m maximal test on a rowing ergometer. Before each exercise test, 1 min after the test completion, and after a 24-hr restitution period blood samples were taken from antecubital vein. The following redox parameters were assessed in red blood cells: superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione levels, and thiobarbituric-acid-reactive-substances concentrations. Creatine kinase activity and total antioxidant capacity (TAC) were measured in plasma samples, lactate levels were determined in capillary blood samples, and serum lipid profiles were assessed. During restitution, plasma TAC was significantly higher (p artichoke-leaf extract, a natural vegetable preparation of high antioxidant potential, resulted in higher plasma TAC than placebo but did not limit oxidative damage to erythrocytes in competitive rowers subjected to strenuous training.

  9. Responses of the sea anemone, Exaiptasia pallida, to ocean acidification conditions and zinc or nickel exposure.

    Science.gov (United States)

    Duckworth, Christina G; Picariello, Codie R; Thomason, Rachel K; Patel, Krina S; Bielmyer-Fraser, Gretchen K

    2017-01-01

    Ocean acidification, caused by increasing atmospheric carbon dioxide (CO 2 ), is a growing concern in marine environments. Land-based sources of pollution, such as metals, have also been a noted problem; however, little research has addressed the combined exposure of both pollutants to coral reef organisms. In this study we examined tissue metal accumulation and physiological effects (activity of anti-oxidant enzymes, catalase and glutathione reductase) in the sea anemone, Exaiptasia pallida after exposure to increased CO 2 , as well as zinc (Zn) or nickel (Ni). After exposure to four concentrations (nominal values=control, 10, 50, 100μg/L) of Zn or Ni over 7days, both metals accumulated in the tissues of E. pallida in a concentration-dependent manner. Anemones exposed to elevated CO 2 (1000ppm) accumulated significant tissue burdens of Zn or Ni faster (by 48h) than those exposed to the same metal concentrations at ambient CO 2 . No differences were observed in catalase activity due to Zn exposure; however, 50μg/L Ni caused a significant increase in catalase activity at ambient CO 2 . No significant effect on catalase activity from CO 2 exposure alone was observed. Glutathione reductase activity was affected by increased Zn or Ni exposure and those effects were influenced by increased CO 2 . Results of this study provide insight into the toxic mechanisms and environmental implications of CO 2 and Zn or Ni exposure to the cnidarian E. pallida. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Fullerenol C{sub 60}(OH){sub 24} nanoparticles decrease relaxing effects of dimethyl sulfoxide on rat uterus spontaneous contraction

    Energy Technology Data Exchange (ETDEWEB)

    Slavic, Marija, E-mail: marija17@ibiss.bg.ac.rs [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Djordjevic, Aleksandar [University of Novi Sad, Department of Chemistry, Biochemistry and the Environment, Faculty of Sciences (Serbia); Radojicic, Ratko [University of Belgrade, Faculty of Biology (Serbia); Milovanovic, Slobodan [University of East Sarajevo, Department of Pharmacology, Faculty of Medicine at Foca (Bosnia and Herzegowina); Orescanin-Dusic, Zorana [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Rakocevic, Zlatko [University of Belgrade, Institute for Nuclear Sciences ' Vinca' (Serbia); Spasic, Mihajlo B.; Blagojevic, Dusko [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia)

    2013-05-15

    Dimethyl sulfoxide (DMSO) is a widely used solvent and cryoprotectant that can cause impaired blood flow, reduction in intracranial pressure, tissue edema, inflammatory reactions, inhibition of vascular smooth muscle cell migration and proliferation, processes which can lead to atherosclerosis of the coronary, peripheral and cerebral circulation. Although the adverse effects are rare when DMSO is administered in clinically established concentrations, there is no safe antagonist for an overdose. In this work, we treated isolated spontaneous and calcium-induced contractile active rat uteri (Wistar, virgo intacta), with DMSO and fullerenol C{sub 60}(OH){sub 24} nanoparticle (FNP) in DMSO. FNP is a water-soluble derivative of fullerene C{sub 60}. Its size is a 1.1 nm in diameter and is a very promising candidate for a drug carrier in nanomedicine. FNP also displays free radical scavenging activity. DMSO decreased both spontaneous and calcium-induced contractions. In contrast, FNP only decreased spontaneous contraction. FNP decreased copper-zinc superoxide dismutase activity and prevented the DMSO-induced increase in glutathione reductase activity. Atomic force microscopy detected that FNP aggregated with calcium ions. Our results indicate that FNP has properties that make it a good candidate to be a modulator of DMSO activity which could minimize side effects of the latter.

  11. Cotesia vestalis parasitization suppresses expression of a Plutella xylostella thioredoxin.

    Science.gov (United States)

    Shi, M; Zhao, S; Wang, Z-H; Stanley, D; Chen, X-X

    2016-12-01

    Thioredoxins (Trxs) are a family of small, highly conserved and ubiquitous proteins involved in protecting organisms against toxic reactive oxygen species. In this study, a typical thioredoxin gene, PxTrx, was isolated from Plutella xylostella. The full-length cDNA sequence is composed of 959 bp containing a 321 bp open reading frame that encodes a predicted protein of 106 amino acids, a predicted molecular weight of 11.7 kDa and an isoelectric point of 5.03. PxTrx was mainly expressed in larval Malpighian tubules and the fat body. An enriched recombinant PxTrx had insulin disulphide reductase activity and stimulated Human Embryonic Kidney 293 (HEK293) cell proliferation. It also protected supercoiled DNA and living HEK293 cells from H 2 O 2 -induced damage. Parasitization by Cotesia vestalis and injections of 0.05 and 0.01 equivalents of C. vestalis Bracovirus (CvBv), the symbiotic virus carried by the parasitoid, led to down-regulation of PxTrx expression in host fat body. Taken together, our results indicate that PxTrx contributes to the maintenance of P. xylostella cellular haemostasis. Host fat body expression of PxTrx is strongly attenuated by parasitization and by injections of CvBv. © 2016 The Royal Entomological Society.

  12. The influence of single application of paracetamol and/or N-acetylcysteine on rats subchronic exposed to trichloroethylene vapours. I. Effect on hepatic moonooxygenase system dependent of cytochrome P450

    Directory of Open Access Journals (Sweden)

    Andrzej Plewka

    2012-06-01

    Full Text Available Background: There is a number of factors which potentially affect occurrence of toxic change in liver after overdosing of paracetamol. Hepatic metabolism of trichloroethylene has primary impact on hepatotoxic effect of this solvent. This means that the combined exposure to these xenobiotics can be particularly harmful for human. The influence of N-acetylcysteine (NAC as a protective factor after paracetamol intoxication was studies. Materials and method: Tests were carried out on rats which were treated with trichloroethylene, paracetamol and/or N-acetylcysteine. In the hepatic microsomal fraction activity of the components of cytochrome P450- dependent monooxygenases was determined Results: Paracetamol slightly stimulated cytochrome P450 having no effect on reductase activity cooperating with it. Cytochrome b5 and its reductase were inhibited by this compound. Trichloroethylene was the inhibitor of compounds of II microsomal electron transport chain. N-acetylcysteine inhibited activity of reductase of NADH-cytochrome b5. Conclusions: Tested doses of the xenobiotics influenced on II microsomal electron transport chain. Protective influence of N-acetylcysteine was better if this compound was applied 2 hours after exposure on xenobiotics

  13. Relationship between organochlorine pesticides and stress indicators in hawksbill sea turtle (Eretmochelys imbricata) nesting at Punta Xen (Campeche), Southern Gulf of Mexico.

    Science.gov (United States)

    Tremblay, Nelly; Ortíz Arana, Alejandro; González Jáuregui, Mauricio; Rendón-von Osten, Jaime

    2017-03-01

    Data on the impact of environmental pollution on the homeostasis of sea turtles remains scarce, particularly in the Southern Gulf of Mexico. As many municipalities along the coastline of the Yucatan Peninsula do not rely on a waste treatment plant, these organisms could be particularly vulnerable. We searched for relationships between the presence of organochlorine pesticides (OCP) and the level of several oxidative and pollutant stress indicators of the hawksbill sea turtle (Eretmochelys imbricata) during the 2010 nesting season at Punta Xen (Campeche, Mexico). Of the 30 sampled sea turtles, endosulfans, aldrin related (aldrin, endrin, dieldrin, endrin ketone, endrin aldehyde) and dichlorodiphenyldichloroethylene (DDT) families were detected in 17, 21 and 26, respectively. Significant correlation existed between the size of sea turtles with the concentration of methoxychlor, cholinesterase activity in plasma and heptachlors family, and catalase activity and hexachlorohexane family. Cholinesterase activity in washed erythrocytes and lipid peroxidation were positively correlated with glutathione reductase activity. Antioxidant enzyme actions seem adequate as no lipids damages were correlated with any OCPs. Future studies are necessary to evaluate the effect of OCPs on males of the area due to the significant detection of methoxychlor, which target endocrine functioning and increases its concentration with sea turtles size.

  14. Rapid upregulation of heart antioxidant enzymes during arousal from estivation in the Giant African snail (Achatina fulica).

    Science.gov (United States)

    Salway, Kurtis D; Tattersall, Glenn J; Stuart, Jeffrey A

    2010-11-01

    Estivation is an adaptive response to environments characterized by elevated temperatures and desiccative stress, as may occur during summer dry seasons. Similar to diapause and hibernation, it is characterized by low levels of activity, a drastically suppressed metabolic rate and enhanced stress resistance. We tested the hypothesis that Achatina fulica, a pulmonate land snail, enhances stress resistance during estivation and/or arousal by upregulating intracellular antioxidant defenses in the heart, kidney, hepatopancreas and foot tissues. No statistically significant changes in mitochondrial or cytosolic superoxide dismutase levels or activities, or glutathione peroxidase, glutathione reductase or catalase activities were associated with estivation in any tissue, however. In contrast, during arousal from estivation, activities of several antioxidant enzymes increased in heart, hepatopancreas and foot. In heart, a rapid increase in MnSOD protein levels was observed that peaked at 2h post arousal, but no such change was observed in CuZnSOD protein levels. Glutathione peroxidase activity was upregulated at 1h post arousal and remained elevated until 8h post arousal in heart tissue. Glutathione peroxidase was also upregulated at 24h post arousal in foot tissue. Glutathione reductase activity was upregulated at 4h post arousal in heart and foot tissues whereas catalase activity showed no changes. Markers of lipid peroxidation and protein damage revealed no significant increases during estivation or arousal. Therefore, antioxidant enzymes may play a role in oxidative stress defense specifically during arousal from estivation in A. fulica. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Mutational analysis of the respiratory nitrate transporter NarK2 of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Michelle M Giffin

    Full Text Available Mycobacterium tuberculosis induces nitrate reductase activity in response to decreasing oxygen levels. This is due to regulation of both the transcription and the activity of the nitrate transporter NarK2. A model of NarK2 structure is proposed containing 12 membrane spanning regions consistent with other members of the major facilitator superfamily. The role of the proton gradient was determined by exposing M. tuberculosis to uncouplers. Nitrite production decreased indicating that the importation of nitrate involved an H(+/nitrate symporter. The addition of nitrite before nitrate had no effect, suggesting no role for a nitrate/nitrite antiporter. In addition the NarK2 knockout mutant showed no defect in nitrite export. NarK2 is proposed to be a Type I H(+/nitrate symporter. Site directed mutagenesis was performed changing 23 amino acids of NarK2. This allowed the identification of important regions and amino acids of this transporter. Five of these mutants were inactive for nitrate transport, seven produced reduced activity and eleven mutants retained wild type activity. NarK2 is inactivated in the presence of oxygen by an unknown mechanism. However none of the mutants, including those with mutated cysteines, were altered in their response to oxygen levels. The assimilatory nitrate transporter NasA of Bacillus subtilis was expressed in the M. tuberculosis NarK2 mutant. It remained active during aerobic incubation showing that the point of oxygen control is NarK2.

  16. In vitro metabolism of radioactive progesterone and testosterone by the gonads of the protandrous Rhabdosargus sarba at various sexual phases

    International Nuclear Information System (INIS)

    Yeung, W.S.; Chan, S.T.

    1985-01-01

    The in vitro steroidogenic capacity of the gonadal tissue in the protandrous Rhabdosargus sarba was studied. Testicular and ovarian tissues from various sexual phases were used either separately or combined. With progesterone as precursor, high yield of 5 beta-reduced metabolites, and no 11-ketotestosterone or 11 beta-hydroxytestosterone were found. The production of 5 beta-pregnan-3 alpha-ol-20-one and 5 beta-pregnane-3,20-dione was very high in incubations with testicular tissue from intersexes or males and was low in those with ovarian tissue only. The production of 17 alpha-hydroxyprogesterone was high in the female but was low in other sexual phases. With testosterone as precursor, 11-ketotestoterone and 11 beta-hydroxytestosterone were identified. 5 beta-Reductase activity was high in the male and relatively low in the female. 5 alpha-Reduced products, however, were absent. There was an increase in the production of androstenedione as the animal underwent sex reversal. The significance of this change in steroidogenesis in this protandrous fish is at present under investigation. Experimental results also indicated that in the intersexual gonad there may be interaction between the testicular component and the ovarian component in steroidgenesis

  17. Co-utilization of L-arabinose and D-xylose by laboratory and industrial Saccharomyces cerevisiae strains

    Directory of Open Access Journals (Sweden)

    Boles Eckhard

    2006-04-01

    Full Text Available Abstract Background Fermentation of lignocellulosic biomass is an attractive alternative for the production of bioethanol. Traditionally, the yeast Saccharomyces cerevisiae is used in industrial ethanol fermentations. However, S. cerevisiae is naturally not able to ferment the pentose sugars D-xylose and L-arabinose, which are present in high amounts in lignocellulosic raw materials. Results We describe the engineering of laboratory and industrial S. cerevisiae strains to co-ferment the pentose sugars D-xylose and L-arabinose. Introduction of a fungal xylose and a bacterial arabinose pathway resulted in strains able to grow on both pentose sugars. Introduction of a xylose pathway into an arabinose-fermenting laboratory strain resulted in nearly complete conversion of arabinose into arabitol due to the L-arabinose reductase activity of the xylose reductase. The industrial strain displayed lower arabitol yield and increased ethanol yield from xylose and arabinose. Conclusion Our work demonstrates simultaneous co-utilization of xylose and arabinose in recombinant strains of S. cerevisiae. In addition, the co-utilization of arabinose together with xylose significantly reduced formation of the by-product xylitol, which contributed to improved ethanol production.

  18. Inhibition of Glutathione and Thioredoxin Metabolism Enhances Sensitivity to Perifosine in Head and Neck Cancer Cells

    Directory of Open Access Journals (Sweden)

    Andrean L. Simons

    2009-01-01

    Full Text Available The hypothesis that the Akt inhibitor, perifosine (PER, combined with inhibitors of glutathione (GSH and thioredoxin (Trx metabolism will induce cytotoxicity via metabolic oxidative stress in human head and neck cancer (HNSCC cells was tested. PER induced increases in glutathione disulfide (%GSSG in FaDu, Cal-27, and SCC-25 HNSCCs as well as causing significant clonogenic cell killing in FaDu and Cal-27, which was suppressed by simultaneous treatment with N-acetylcysteine (NAC. An inhibitor of GSH synthesis, buthionine sulfoximine (BSO, sensitized Cal-27 and SCC-25 cells to PER-induced clonogenic killing as well as decreased total GSH and increased %GSSG. Additionally, inhibition of thioredoxin reductase activity (TrxRed with auranofin (AUR was able to induce PER sensitization in SCC-25 cells that were initially refractory to PER. These results support the conclusion that PER induces oxidative stress and clonogenic killing in HNSCC cells that is enhanced with inhibitors of GSH and Trx metabolism.

  19. Oligo-carrageenan kappa-induced reducing redox status and activation of TRR/TRX system increase the level of indole-3-acetic acid, gibberellin A3 and trans-zeatin in Eucalyptus globulus trees.

    Science.gov (United States)

    González, Alberto; Contreras, Rodrigo A; Zúiga, Gustavo; Moenne, Alejandra

    2014-08-20

    Eucalyptus globulus trees treated with oligo-carrageenan (OC) kappa showed an increase in NADPH, ascorbate and glutathione levels and activation of the thioredoxin reductase (TRR)/thioredoxin (TRX) system which enhance photosynthesis, basal metabolism and growth. In order to analyze whether the reducing redox status and the activation of thioredoxin reductase (TRR)/thioredoxin (TRX) increased the level of growth-promoting hormones, trees were treated with water (control), with OC kappa, or with inhibitors of ascorbate synthesis, lycorine, glutathione synthesis, buthionine sulfoximine (BSO), NADPH synthesis, CHS-828, and thioredoxin reductase activity, auranofine, and with OC kappa, and cultivated for four additional months. Eucalyptus trees treated with OC kappa showed an increase in the levels of the auxin indole 3-acetic acid (IAA), gibberellin A3 (GA3) and the cytokinin trans-zeatin (t-Z) as well as a decrease in the level of the brassinosteroid epi-brassinolide (EB). In addition, treatment with lycorine, BSO, CHS-828 and auranofine inhibited the increase in IAA, GA3 and t-Z as well as the decrease in EB levels. Thus, the reducing redox status and the activation of TRR/TRX system induced by OC kappa increased the levels of IAA, GA3 and t-Z levels determining, at least in part, the stimulation of growth in Eucalyptus trees.

  20. The Cholesterol-Lowering Effect of Alisol Acetates Based on HMG-CoA Reductase and Its Molecular Mechanism

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2016-01-01

    Full Text Available This study measured the impact of alisol B 23-acetate and alisol A 24-acetate, the main active ingredients of the traditional Chinese medicine Alismatis rhizoma, on total cholesterol (TC, triglyceride (TG, high density lipoprotein-cholesterol (HDL-C, and low density lipoprotein-cholesterol (LDL-C levels of hyperlipidemic mice. The binding of alisol B 23-acetate and alisol A 24-acetate to the key enzyme involved in the metabolism of TC, 3-hydroxy-3-methylglutary-coenzyme A (HMG-CoA reductase, was studied using the reagent kit method and the western blotting technique combined with a molecular simulation technique. According to the results, alisol acetates significantly lower the TC, TG, and LDL-C concentrations of hyperlipidemic mice, while raising HDL-C concentrations. Alisol acetates lower HMG-CoA reductase activity in a dose-dependent fashion, both in vivo and in vitro. Neither of these alisol acetates significantly lower the protein expression of HMG-CoA. This suggests that alisol acetates lower the TC level via inhibiting the activity of HMG-CoA reductase by its prototype drug, which may exhibit an inhibition effect via directly and competitively binding to HMG-CoA. The side chain of the alisol acetate was the steering group via molecular simulation.

  1. Monooxygenase system in Guerin’s carcinoma of rats under conditions of ω-3 polyunsaturated fatty acids administration

    Directory of Open Access Journals (Sweden)

    M. M. Marchenko

    2016-08-01

    Full Text Available The aim of the study was to determine the variations of function in components of monooxygenase system (MOS of rat Guerin’s carcinoma under ω-3 polyunsaturated fatty acids (PUFAs administration. The activity of Guerin’s carcinoma microsomal NADH-cytochrome b5 reductase, the content and the rate of cytochrome b5 oxidation-reduction, the content and the rate of cytochrome Р450 oxidation-reduction have been investigated in rats with tumor under conditions of ω-3 PUFAs administration. ω-3 PUFAs supplementation before and after transplantation of Guerin’s carcinoma resulted in the increase of NADH-cytochrome b5 reductase activity and decrease of cytochrome b5 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of carcinogenesis as compared to the tumor-bearing rats. Increased activity of NADH-cytochrome b5 reductase facilitates higher electron flow in redox-chain of MOS. Under decreased cytochrome b5 levels the electrons are transferred to oxygen, which leads to heightened generation of superoxide (O2•- in comparison to control. It was shown, that the decrease of cytochrome P450 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of oncogenesis under ω-3 PUFAs administration may be associated with its transition into an inactive form – cytochrome P420. This decrease in cytochrome P450 coincides with increased generation of superoxide by MOS oxygenase chain.

  2. Crystallization and preliminary X-ray crystallographic analysis of dioscorin from Dioscorea japonica

    International Nuclear Information System (INIS)

    Xue, You-Lin; Miyakawa, Takuya; Sawano, Yoriko; Tanokura, Masaru

    2012-01-01

    Dioscorin from D. japonica was expressed, purified and crystallized using the sitting-drop vapour-diffusion method. The dioscorin crystal diffracted X-rays to 2.11 Å resolution. Dioscorin, the major tuber storage protein in yam, has been reported to possess carbonic anhydrase, trypsin inhibitor, angiotensin-converting enzyme (ACE) inhibitor, free-radical scavenger, dehydroascorbate reductase and monodehydroascorbate reductase activities. Recent research has also found that dioscorin can enhance immune modulation via the toll-like receptor 4 (TLR-4) signal transduction pathway in RAW 264.7 cells, murine bone-marrow cells and human monocytes ex vivo. Resolving the structure of dioscorin would help in better understanding its activities and would provide clues to understanding the mechanism of its multiple functions. The full-length protein (residues 1–246) with an additional His 6 tag at the N-terminus was expressed in Escherichia coli Rosetta (DE3) cells. After His-tag cleavage and purification, the protein was crystallized by the sitting-drop vapour-diffusion method at 278 K. An X-ray diffraction data set was collected to a resolution of 2.11 Å using a synchrotron X-ray source. The crystal belonged to space group C222 1 , with unit-cell parameters a = 83.5, b = 156.8, c = 83.6 Å, and was estimated to contain two protein molecules per asymmetric unit

  3. Crystallization and preliminary X-ray crystallographic analysis of dioscorin from Dioscorea japonica.

    Science.gov (United States)

    Xue, You-Lin; Miyakawa, Takuya; Sawano, Yoriko; Tanokura, Masaru

    2012-02-01

    Dioscorin, the major tuber storage protein in yam, has been reported to possess carbonic anhydrase, trypsin inhibitor, angiotensin-converting enzyme (ACE) inhibitor, free-radical scavenger, dehydroascorbate reductase and monodehydroascorbate reductase activities. Recent research has also found that dioscorin can enhance immune modulation via the toll-like receptor 4 (TLR-4) signal transduction pathway in RAW 264.7 cells, murine bone-marrow cells and human monocytes ex vivo. Resolving the structure of dioscorin would help in better understanding its activities and would provide clues to understanding the mechanism of its multiple functions. The full-length protein (residues 1-246) with an additional His(6) tag at the N-terminus was expressed in Escherichia coli Rosetta (DE3) cells. After His-tag cleavage and purification, the protein was crystallized by the sitting-drop vapour-diffusion method at 278 K. An X-ray diffraction data set was collected to a resolution of 2.11 Å using a synchrotron X-ray source. The crystal belonged to space group C222(1), with unit-cell parameters a = 83.5, b = 156.8, c = 83.6 Å, and was estimated to contain two protein molecules per asymmetric unit.

  4. Caloric restriction counteracts age-related changes in the activities of sorbitol metabolizing enzymes from mouse liver

    Science.gov (United States)

    Hagopian, Kevork; Ramsey, Jon J.; Weindruch, Richard

    2009-01-01

    The influence of caloric restriction (CR) on hepatic sorbitol-metabolizing enzyme activities was investigated in young and old mice. Aldose reductase and sorbitol dehydrogenase activities were significantly lower in old CR mice than in old controls. Young CR mice showed decreased aldose reductase activity and a trend towards decreased sorbitol dehydrogenase when compared to controls. Metabolites of the pathway, namely sorbitol, glucose and fructose were decreased by CR in young and old mice. Pyruvate levels were decreased by CR in both young and old mice, while lactate decreased only in old CR. Malate levels increased in old CR but remained unchanged in young CR, when compared with controls. Accordingly, the lactae/pyruvate and malate/pyruvate ratios in young and old CR mice were increased, indicating increased NADH/NAD and NADPH/NADP redox couples, respectively. The results indicate that decreased glucose levels under CR conditions lead to decreased sorbitol pathway enzyme activities and metabolite levels, and could contribute to the beneficial effects of long-term CR through decreased sorbitol levels and NADPH sparing. PMID:18953666

  5. Comparative Analysis of the Interaction between Different Flavonoids and PDIA3

    Directory of Open Access Journals (Sweden)

    Flavia Giamogante

    2016-01-01

    Full Text Available Flavonoids, plant secondary metabolites present in fruits, vegetables, and products such as tea and red wine, show antioxidant, anti-inflammatory, antithrombotic, antiviral, and antitumor activity. PDIA3 is a member of the protein disulfide isomerase family mainly involved in the correct folding of newly synthetized glycoproteins. PDIA3 is associated with different human pathologies such as cancer, prion disorders, Alzheimer’s disease, and Parkinson’s diseases and it has the potential to be a pharmacological target. The interaction of different flavonoids with PDIA3 was investigated by quenching fluorescence analysis and the effects on protein activity were evaluated. A higher affinity was observed for eupatorin-5-methyl ether and eupatorin which also inhibit reductase activity of PDIA3 but do not significantly affect its DNA binding activity. The use of several flavonoids differing in chemical structure and functional groups allows us to make some consideration about the relationship between ligand structure and the affinity for PDIA3. The specific flavone backbone conformation and the degree of polarity seem to play an important role for the interaction with PDIA3. The binding site is probably similar but not equivalent to that of green tea catechins, which, as previously demonstrated, can bind to PDIA3 and prevent its interaction with DNA.

  6. Influence of thiourea application on some physiological and molecular criteria of sunflower (Helianthus annuus L.) plants under conditions of heat stress.

    Science.gov (United States)

    Akladious, Samia Ageeb

    2014-05-01

    High temperature is a major factor limiting the growth of plant species during summer. Understanding the mechanisms of plant tolerance to high temperature would help in developing effective management practices and heat-tolerant cultivars through breeding or biotechnology. The present investigation was carried out to study the role of thiourea in enhancing the tolerance of sunflower plants to heat stress. Sunflower plants were subjected to temperature stress by exposing plants to 35 or 45 °C for 12 h. Two levels of thiourea (10 and 20 mM) were applied before sowing (seed treatment). The results indicated that the plants exposed to temperature stress exhibited a significant decline in growth parameters, chlorophylls, relative leaf water content, oil content, leaf nutrient status, and nitrate reductase activity. Treatment with thiourea, especially when applied at 10 mM, improved the above parameters and induced non-enzymatic and enzymatic antioxidants responsible for antioxidation. SDS-PAGE of protein revealed that high-temperature treatments alone or in combination with thiourea were associated with the disappearance of some bands or the appearance of unique ones. The result of RAPD analysis using five primers showed variable qualitative and quantitative changes. These findings confirm the effectiveness of applying thiourea on alleviating heat injuries in sunflower plants.

  7. The Drosophila carbonyl reductase sniffer prevents oxidative stress-induced neurodegeneration.

    Science.gov (United States)

    Botella, Jose A; Ulschmid, Julia K; Gruenewald, Christoph; Moehle, Christoph; Kretzschmar, Doris; Becker, Katja; Schneuwly, Stephan

    2004-05-04

    A growing body of evidence suggests that oxidative stress is a common underlying mechanism in the pathogenesis of neurodegenerative disorders such as Alzheimer's, Huntington's, Creutzfeld-Jakob and Parkinson's diseases. Despite the increasing number of reports finding a causal relation between oxidative stress and neurodegeneration, little is known about the genetic elements that confer protection against the deleterious effects of oxidation in neurons. We have isolated and characterized the Drosophila melanogaster gene sniffer, whose function is essential for preventing age-related neurodegeneration. In addition, we demonstrate that oxidative stress is a direct cause of neurodegeneration in the Drosophila central nervous system and that reduction of sniffer activity leads to neuronal cell death. The overexpression of the gene confers neuronal protection against oxygen-induced apoptosis, increases resistance of flies to experimental normobaric hyperoxia, and improves general locomotor fitness. Sniffer belongs to the family of short-chain dehydrogenase/reductase (SDR) enzymes and exhibits carbonyl reductase activity. This is the first in vivo evidence of the direct and important implication of this enzyme as a neuroprotective agent in the cellular defense mechanisms against oxidative stress.

  8. The arbuscular mycorrhizal fungus Rhizophagus irregularis differentially regulates the copper response of two maize cultivars differing in copper tolerance.

    Science.gov (United States)

    Merlos, Miguel A; Zitka, Ondrej; Vojtech, Adam; Azcón-Aguilar, Concepción; Ferrol, Nuria

    2016-12-01

    Arbuscular mycorrhiza can increase plant tolerance to heavy metals. The effects of arbuscular mycorrhiza on plant metal tolerance vary depending on the fungal and plant species involved. Here, we report the effect of the arbuscular mycorrhizal fungus Rhizophagus irregularis on the physiological and biochemical responses to Cu of two maize genotypes differing in Cu tolerance, the Cu-sensitive cv. Orense and the Cu-tolerant cv. Oropesa. Development of the symbiosis confers an increased Cu tolerance to cv. Orense. Root and shoot Cu concentrations were lower in mycorrhizal than in non-mycorrhizal plants of both cultivars. Shoot lipid peroxidation increased with soil Cu content only in non-mycorrhizal plants of the Cu-sensitive cultivar. Root lipid peroxidation increased with soil Cu content, except in mycorrhizal plants grown at 250mg Cu kg -1 soil. In shoots of mycorrhizal plants of both cultivars, superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities were not affected by soil Cu content. In Cu-supplemented soils, total phytochelatin content increased in shoots of mycorrhizal cv. Orense but decreased in cv. Oropesa. Overall, these data suggest that the increased Cu tolerance of mycorrhizal plants of cv. Orense could be due to an increased induction of shoot phytochelatin biosynthesis by the symbiosis in this cultivar. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Telmisartan enhances mitochondrial activity and alters cellular functions in human coronary artery endothelial cells via AMP-activated protein kinase pathway.

    Science.gov (United States)

    Kurokawa, Hirofumi; Sugiyama, Seigo; Nozaki, Toshimitsu; Sugamura, Koichi; Toyama, Kensuke; Matsubara, Junichi; Fujisue, Koichiro; Ohba, Keisuke; Maeda, Hirofumi; Konishi, Masaaki; Akiyama, Eiichi; Sumida, Hitoshi; Izumiya, Yasuhiro; Yasuda, Osamu; Kim-Mitsuyama, Shokei; Ogawa, Hisao

    2015-04-01

    Mitochondrial dysfunction plays an important role in cellular senescence and impaired function of vascular endothelium, resulted in cardiovascular diseases. Telmisartan is a unique angiotensin II type I receptor blocker that has been shown to prevent cardiovascular events in high risk patients. AMP-activated protein kinase (AMPK) plays a critical role in mitochondrial biogenesis and endothelial function. This study assessed whether telmisartan enhances mitochondrial function and alters cellular functions via AMPK in human coronary artery endothelial cells (HCAECs). In cultured HCAECs, telmisartan significantly enhanced mitochondrial activity assessed by mitochondrial reductase activity and intracellular ATP production and increased the expression of mitochondria related genes. Telmisartan prevented cellular senescence and exhibited the anti-apoptotic and pro-angiogenic properties. The expression of genes related anti-oxidant and pro-angiogenic properties were increased by telmisartan. Telmisartan increased endothelial NO synthase and AMPK phosphorylation. Peroxisome proliferator-activated receptor gamma signaling was not involved in telmisartan-induced improvement of mitochondrial function. All of these effects were abolished by inhibition of AMPK. Telmisartan enhanced mitochondrial activity and exhibited anti-senescence effects and improving endothelial function through AMPK in HCAECs. Telmisartan could provide beneficial effects on vascular diseases via enhancement of mitochondrial activity and modulating endothelial function through AMPK activation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. 3-Amino-1,2,4-triazole Limits the Oxidative Damage in UVA-Irradiated Dysplastic Keratinocytes

    Directory of Open Access Journals (Sweden)

    Marina Tamara Nechifor

    2017-01-01

    Full Text Available Reactive oxygen species (ROS generated by UVA irradiation affect the keratinocyte cell membrane, DNA, and proteins and may cause serious injury to the skin. Treating human dysplastic keratinocytes (DOK with 3-amino-1,2,4-triazole (AMT, a common catalase inhibitor, induced a compensatory mechanism for the hydrogen peroxide detoxification, which included a rise in glutathione peroxidase and glutathione reductase activities. Here, we examined a possible role of AMT in protecting a human DOK cell line against UVA-induced damage. In DOK cells exposed to UVA irradiation, we observed a substantial decrease in antioxidant enzymatic activities, such as catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase and an increase in lipid peroxidation and protein oxidation levels. Treating DOK cells with AMT prior to UVA exposure enhanced the activities of glutathione peroxidase, glutathione reductase, and glutathione-S-transferase, relative to nontreated cells. The enhanced antioxidant activities were correlated with decreased protein oxidation levels. Based on these results, we suggest that AMT may protect dysplastic keratinocytes against the harmful effects of UVA radiation.

  11. Overexpression of Soybean Isoflavone Reductase (GmIFR) Enhances Resistance to Phytophthora sojae in Soybean.

    Science.gov (United States)

    Cheng, Qun; Li, Ninghui; Dong, Lidong; Zhang, Dayong; Fan, Sujie; Jiang, Liangyu; Wang, Xin; Xu, Pengfei; Zhang, Shuzhen

    2015-01-01

    Isoflavone reductase (IFR) is an enzyme involved in the biosynthetic pathway of isoflavonoid phytoalexin in plants. IFRs are unique to the plant kingdom and are considered to have crucial roles in plant response to various biotic and abiotic environmental stresses. Here, we report the characterization of a novel member of the soybean isoflavone reductase gene family GmIFR. Overexpression of GmIFR transgenic soybean exhibited enhanced resistance to Phytophthora sojae. Following stress treatments, GmIFR was significantly induced by P. sojae, ethephon (ET), abscisic acid (placeCityABA), salicylic acid (SA). It is located in the cytoplasm when transiently expressed in soybean protoplasts. The daidzein levels reduced greatly for the seeds of transgenic plants, while the relative content of glyceollins in transgenic plants was significantly higher than that of non-transgenic plants. Furthermore, we found that the relative expression levels of reactive oxygen species (ROS) of transgenic soybean plants were significantly lower than those of non-transgenic plants after incubation with P. sojae, suggesting an important role of GmIFR might function as an antioxidant to reduce ROS in soybean. The enzyme activity assay suggested that GmIFR has isoflavone reductase activity.

  12. [Control levels of Sin3 histone deacetylase for spontaneous and UV-induced mutagenesis in yeasts Saccharomyces cerevisiae].

    Science.gov (United States)

    Lebovka, I Iu; Kozhina, T N; Fedorova, I V; Peshekhonov, V T; Evstiukhina, T A; Chernenkov, A Iu; Korolev, V G

    2014-01-01

    SIN3 gene product operates as a repressor for a huge amount of genes in Saccharomyces cerevisiae. Sin3 protein with a mass of about 175 kDa is a member of the RPD3 protein complex with an assessed mass of greater than 2 million Da. It was previously shownthat RPD3 gene mutations influence recombination and repair processes in S. cerevisiae yeasts. We studied the impacts of the sin3 mutation on UV-light sensitivity and UV-induced mutagenesis in budding yeast cells. The deletion ofthe SIN3 gene causes weak UV-sensitivity of mutant budding cells as compared to the wild-type strain. These results show that the sin3 mutation decreases both spontaneous and UV-induced levels of levels. This fact is hypothetically related to themalfunction of ribonucleotide reductase activity regulation, which leads to a decrease in the dNTP pool and the inaccurate error-prone damage bypass postreplication repair pathway, which in turn provokes a reduction in the incidence of mutations.

  13. Antioxidant defense parameters as predictive biomarkers for fermentative capacity of active dried wine yeast.

    Science.gov (United States)

    Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

    2014-08-01

    The production of active dried yeast (ADY) is a common practice in industry for the maintenance of yeast starters and as a means of long term storage. The process, however, causes multiple cell injuries, with oxidative damage being one of the most important stresses. Consequentially, dehydration tolerance is a highly appreciated property in yeast for ADY production. In this study we analyzed the cellular redox environment in three Saccharomyces cerevisiae wine strains, which show markedly different fermentative capacities after dehydration. To measure/quantify the effect of dehydration on the S. cerevisiae strains, we used: (i) fluorescent probes; (ii) antioxidant enzyme activities; (ii) intracellular damage; (iii) antioxidant metabolites; and (iv) gene expression, to select a minimal set of biochemical parameters capable of predicting desiccation tolerance in wine yeasts. Our results show that naturally enhanced antioxidant defenses prevent oxidative damage after wine yeast biomass dehydration and improve fermentative capacity. Based on these results we chose four easily assayable parameters/biomarkers for the selection of industrial yeast strains of interest for ADY production: trehalose and glutathione levels, and glutathione reductase and catalase enzymatic activities. Yeast strains selected in accordance with this process display high levels of trehalose, low levels of oxidized glutathione, a high induction of glutathione reductase activity, as well as a high basal level and sufficient induction of catalase activity, which are properties inherent in superior ADY strains. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Overexpression of amyloid precursor protein increases copper content in HEK293 cells

    International Nuclear Information System (INIS)

    Suazo, Miriam; Hodar, Christian; Morgan, Carlos; Cerpa, Waldo; Cambiazo, Veronica; Inestrosa, Nibaldo C.; Gonzalez, Mauricio

    2009-01-01

    Amyloid precursor protein (APP) is a transmembrane glycoprotein widely expressed in mammalian tissues and plays a central role in Alzheimer's disease. However, its physiological function remains elusive. Cu 2+ binding and reduction activities have been described in the extracellular APP135-156 region, which might be relevant for cellular copper uptake and homeostasis. Here, we assessed Cu 2+ reduction and 64 Cu uptake in two human HEK293 cell lines overexpressing APP. Our results indicate that Cu 2+ reduction increased and cells accumulated larger levels of copper, maintaining cell viability at supra-physiological levels of Cu 2+ ions. Moreover, wild-type cells exposed to both Cu 2+ ions and APP135-155 synthetic peptides increased copper reduction and uptake. Complementation of function studies in human APP751 transformed Fre1 defective Saccharomyces cerevisiae cells rescued low Cu 2+ reductase activity and increased 64 Cu uptake. We conclude that Cu 2+ reduction activity of APP facilitates copper uptake and may represent an early step in cellular copper homeostasis.

  15. The Antimicrobial Properties of Silver Nanoparticles in Bacillus subtilis Are Mediated by Released Ag+ Ions.

    Directory of Open Access Journals (Sweden)

    Yi-Huang Hsueh

    Full Text Available The superior antimicrobial properties of silver nanoparticles (Ag NPs are well-documented, but the exact mechanisms underlying Ag-NP microbial toxicity remain the subject of intense debate. Here, we show that Ag-NP concentrations as low as 10 ppm exert significant toxicity against Bacillus subtilis, a beneficial bacterium ubiquitous in the soil. Growth arrest and chromosomal DNA degradation were observed, and flow cytometric quantification of propidium iodide (PI staining also revealed that Ag-NP concentrations of 25 ppm and above increased membrane permeability. RedoxSensor content analysis and Phag-GFP expression analysis further indicated that reductase activity and cytosolic protein expression decreased in B. subtilis cells treated with 10-50 ppm of Ag NPs. We conducted X-ray absorption near-edge structure (XANES and extended X-ray absorption fine structure (EXAFS analyses to directly clarify the valence and fine structure of Ag atoms in B. subtilis cells placed in contact with Ag NPs. The results confirmed the Ag species in Ag NP-treated B. subtilis cells as Ag2O, indicating that Ag-NP toxicity is likely mediated by released Ag+ ions from Ag NPs, which penetrate bacterial cells and are subsequently oxidized intracellularly to Ag2O. These findings provide conclusive evidence for the role of Ag+ ions in Ag-NP microbial toxicity, and suggest that the impact of inappropriately disposed Ag NPs to soil and water ecosystems may warrant further investigation.

  16. Lamin B Receptor: Interplay between Structure, Function and Localization

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    Eleni Nikolakaki

    2017-08-01

    Full Text Available Lamin B receptor (LBR is an integral protein of the inner nuclear membrane, containing a hydrophilic N-terminal end protruding into the nucleoplasm, eight hydrophobic segments that span the membrane and a short, nucleoplasmic C-terminal tail. Two seemingly unrelated functions have been attributed to LBR. Its N-terminal domain tethers heterochromatin to the nuclear periphery, thus contributing to the shape of interphase nuclear architecture, while its transmembrane domains exhibit sterol reductase activity. Mutations within the transmembrane segments result in defects in cholesterol synthesis and are associated with diseases such as the Pelger–Huët anomaly and Greenberg skeletal dysplasia, whereas no such harmful mutations related to the anchoring properties of LBR have been reported so far. Recent evidence suggests a dynamic regulation of LBR expression levels, structural organization, localization and function, in response to various signals. The molecular mechanisms underlying this dynamic behavior have not yet been fully unraveled. Here, we provide an overview of the current knowledge of the interplay between the structure, function and localization of LBR, and hint at the interconnection of the two distinct functions of LBR.

  17. An 15N study of the effects of nitrate, ammonium, and nitrate + ammonium nutrition on nitrogen assimilation in Zea mays L

    International Nuclear Information System (INIS)

    Murphy, A.T.

    1984-10-01

    A brief review of the literature on the effects of nitrate and ammonium nitrogen sources on plant growth, and the assimilation of those nitrogen sources, has been presented. It was concluded that ammonium nutrition produces optimum growth, with nitrate + ammonium being a better nitrogen source than only nitrate. Leaf blade nitrate reductase activity exceeded that of the root in nitrate-fed plants, suggesting that the shoot is the major region of nitrate assimilation. This is further supported by the results of xylem exudate analysis, where 93% of the newly-absorbed nitrogen exported by the roots was detected as nitrate. Evidence in support of this hypothesis was also obtained by studying the distribution of 15 N in the various nitrogenous compounds. The effects of nitrogen source on plant growth, organic nitrogen and inorganic nitrogen contents, and the rates of incorporation into nitrogenous compounds were studied. The observed differences were explained with reference to the effects of the various nitrogen sources on the physiology of the plants. The experimental techniques included assays of the enzymes nitrate reductase and glutamine synthetase, whole plant growth studies, and the analysis of nitrogenous compounds of xylem exudate and those extracted from the leaf blade, leaf base, and root regions of maize plants after feeding with a nutrient solution containing nitrogen as 15 N

  18. Mixed arbuscular mycorrhizal (AM) fungal application to improve growth and arsenic accumulation of Pteris vittata (As hyperaccumulator) grown in As-contaminated soil.

    Science.gov (United States)

    Leung, H M; Leung, A O W; Ye, Z H; Cheung, K C; Yung, K K L

    2013-08-01

    A greenhouse pot experiment was conducted to study the effects of three types of single inoculum [indigenous mycorrhizas (IM) isolated from As mine, Glomus mosseae (GM) and Glomus intraradices (GI)] and two types of mixed inoculum (mixed with IM and either GM or GI) on the growth response of Pteris vittata (hyperaccumulator) and Cynodon dactylon (non-hyperaccumulator) at three levels of As concentrations (0, 100 and 200mgkg(-1)). Both mycorrhizal plants exhibited significantly higher biomass, and N and P accumulation in its tissue than the control. Among the mycorrhizal inoculum, the mixed inoculum IM/GM promoted substantially higher mycorrhizal colonization and arsenate reductase activity in P. vittata than C. dactylon, among all As levels. The portion of Paris arbuscular mycorrhizal structure (observed in colonized roots) together with the highest As translocation factor of 10.2 in P. vittata inoculated with IM/GM was also noted. It was deduced that IM/GM inoculum may be the best choice for field inoculation at any contaminated lands as the inoculum exhibited better adaptation to variable environmental conditions and hence benefited the host plants. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  19. Furfural-tolerant Zymomonas mobilis derived from error-prone PCR-based whole genome shuffling and their tolerant mechanism.

    Science.gov (United States)

    Huang, Suzhen; Xue, Tingli; Wang, Zhiquan; Ma, Yuanyuan; He, Xueting; Hong, Jiefang; Zou, Shaolan; Song, Hao; Zhang, Minhua

    2018-04-01

    Furfural-tolerant strain is essential for the fermentative production of biofuels or chemicals from lignocellulosic biomass. In this study, Zymomonas mobilis CP4 was for the first time subjected to error-prone PCR-based whole genome shuffling, and the resulting mutants F211 and F27 that could tolerate 3 g/L furfural were obtained. The mutant F211 under various furfural stress conditions could rapidly grow when the furfural concentration reduced to 1 g/L. Meanwhile, the two mutants also showed higher tolerance to high concentration of glucose than the control strain CP4. Genome resequencing revealed that the F211 and F27 had 12 and 13 single-nucleotide polymorphisms. The activity assay demonstrated that the activity of NADH-dependent furfural reductase in mutant F211 and CP4 was all increased under furfural stress, and the activity peaked earlier in mutant than in control. Also, furfural level in the culture of F211 was also more rapidly decreased. These indicate that the increase in furfural tolerance of the mutants may be resulted from the enhanced NADH-dependent furfural reductase activity during early log phase, which could lead to an accelerated furfural detoxification process in mutants. In all, we obtained Z. mobilis mutants with enhanced furfural and high concentration of glucose tolerance, and provided valuable clues for the mechanism of furfural tolerance and strain development.

  20. Ethanol Extract of Evodia rutaecarpa Attenuates Cell Growth through Caspase-Dependent Apoptosis in Benign Prostatic Hyperplasia-1 Cells

    Directory of Open Access Journals (Sweden)

    Eunsook Park

    2018-04-01

    Full Text Available The dried fruits of Evodia rutaecarpa Bentham have been used widely as a herbal medicine for the treatment of inflammatory disorders and abdominal pain. Benign prostatic hyperplasia (BPH is a nonmalignant disease characterized by overgrowth of prostates. Despite the pharmacological efficacy of the fruits of E. rutaecarpa against various diseases, their effects against BPH have not been reported. Here, we investigated the inhibitory activity of a 70% ethanol extract of E. rutaecarpa (EEER against BPH, and its underlying mechanisms regarding cell growth of BPH using BPH-1 cells. An in vitro 5α-reductase activity assay showed that EEER exhibited inhibitory activity against 5α-reductase. In BPH-1 cells, EEER treatment inhibited cell viability and reduced the expression of the proliferating cell nuclear antigen proliferating cell nuclear antigen (PCNA, cyclin D1, and phosphor-ERK1/2 proteins. Moreover, EEER also induced apoptosis, with chromatin condensation, apoptotic bodies, and internucleosomal DNA fragmentation. Regarding its underlying mechanisms, EEER exacerbated the activation of caspase-8 and caspase-3 in a concentration-dependent manner and eventually caused the cleavage of PARP. Taken together, these data demonstrated that EEER had a potent 5α-reductase inhibitory activity and that EEER treatment in BPH-1 cells inhibited cell viability via caspase-8- and caspase-3-dependent apoptosis. Therefore, EEER may be a potential phytotherapeutic agent for the treatment of BPH.

  1. Poor thiamin and riboflavin status is common among women of childbearing age in rural and urban Cambodia.

    Science.gov (United States)

    Whitfield, Kyly C; Karakochuk, Crystal D; Liu, Yazheng; McCann, Adrian; Talukder, Aminuzzaman; Kroeun, Hou; Ward, Mary; McNulty, Helene; Lynd, Larry D; Kitts, David D; Li-Chan, Eunice C Y; McLean, Judy; Green, Timothy J

    2015-03-01

    Thiamin deficiency in infancy is the underlying cause of beriberi, which can be fatal without rapid treatment. Reports of thiamin deficiency are common in Cambodia; however, population representative data are unavailable. Because B-complex vitamin deficiencies commonly occur in combination, riboflavin was also investigated. We determined the biomarker status of thiamin and riboflavin in women of childbearing age in rural and urban Cambodia. We measured thiamin (erythrocyte thiamin diphosphate; TDP) and riboflavin (erythrocyte glutathione reductase activity coefficient; EGRac) status in a representative sample of Cambodian women (aged 20-45 y) in urban Phnom Penh (n = 146) and rural Prey Veng (n = 156), Cambodia, and, for comparison purposes, in a convenience sample of women in urban Vancouver, British Columbia, Canada (n = 49). Thiamin insufficiency (TDP ≤ 90 nmol/L) was common among both urban (39%) and rural (59%) Cambodian women (P Cambodia. The unexpected finding of high riboflavin inadequacy status in Vancouver women warrants further investigation. © 2015 American Society for Nutrition.

  2. The Sorghum Gene for Leaf Color Changes upon Wounding (P Encodes a Flavanone 4-Reductase in the 3-Deoxyanthocyanidin Biosynthesis Pathway

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    Hiroyuki Kawahigashi

    2016-05-01

    Full Text Available Upon wounding or pathogen invasion, leaves of sorghum [Sorghum bicolor (L. Moench] plants with the P gene turn purple, whereas leaves with the recessive allele turn brown or tan. This purple phenotype is determined by the production of two 3-deoxyanthocyanidins, apigeninidin and luteolinidin, which are not produced by the tan-phenotype plants. Using map-based cloning in progeny from a cross between purple Nakei-MS3B (PP and tan Greenleaf (pp cultivars, we isolated this gene, which was located in a 27-kb genomic region around the 58.1 Mb position on chromosome 6. Four candidate genes identified in this region were similar to the maize leucoanthocyanidin reductase gene. None of them was expressed before wounding, and only the Sb06g029550 gene was induced in both cultivars after wounding. The Sb06g029550 protein was detected in Nakei-MS3B, but only slightly in Greenleaf, in which it may be unstable because of a Cys252Tyr substitution. A recombinant Sb06g029550 protein had a specific flavanone 4-reductase activity, and converted flavanones (naringenin or eriodictyol to flavan-4-ols (apiforol or luteoforol in vitro. Our data indicate that the Sb06g029550 gene is involved in the 3-deoxyanthocyanidin synthesis pathway.

  3. Possible ecological risk of two pharmaceuticals diclofenac and paracetamol demonstrated on a model plant Lemna minor.

    Science.gov (United States)

    Kummerová, Marie; Zezulka, Štěpán; Babula, Petr; Tříska, Jan

    2016-01-25

    Lemna minor is often used in environmental risk assessment and it can be supposed that usually evaluated parameters will be reliable even for assessing the risk of pharmaceuticals. Subtle changes in duckweed plant number, biomass production, and leaf area size induced by 10-day-exposure to diclofenac (DCF) and paracetamol (PCT) (0.1, 10, and 100 μg/L), excepting 100 μg/L DCF, are in contrast with considerable changes on biochemical and histochemical level. Both drugs caused a decrease in content of photosynthetic pigments (by up to 50%), an increase in non-photochemical quenching (by 65%) and decrease in relative chlorophyll fluorescence decay values (by up to 90% with DCF). Both DCF and especially PCT increased amount of reactive nitrogen and oxygen species in roots. DCF-induced effects included mainly increased lipid peroxidation (by 78%), disturbation in membrane integrity and lowering both oxidoreductase and dehydrogenase activities (by 30%). PCT increased the content of soluble proteins and phenolics. Higher concentrations of both DCF and PCT increased the levels of oxidised ascorbate (by 30%) and oxidised thiols (by up to 84% with DCF). Glutathion-reductase activity was elevated by both pharmaceuticals (nearly by 90%), glutathion-S-transferase activity increased mainly with PCT (by 22%). The early and sensitive indicators of DCF and PCT phytotoxicity stress in duckweed are mainly the changes in biochemical processes, connected with activation of defense mechanisms against oxidative stress. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Organization of the capsule biosynthesis gene locus of the oral streptococcus Streptococcus anginosus.

    Science.gov (United States)

    Tsunashima, Hiroyuki; Miyake, Katsuhide; Motono, Makoto; Iijima, Shinji

    2012-03-01

    The capsular polysaccharide (CPS) of the important oral streptococcus Streptococcus anginosus, which causes endocarditis, and the genes for its synthesis have not been clarified. In this study, we investigated the gene locus required for CPS synthesis in S. anginosus. Southern hybridization using the cpsE gene of the well-characterized bacterium S. agalactiae revealed that there is a similar gene in the genome of S. anginosus. By using the colony hybridization technique and inverse PCR, we isolated the CPS synthesis (cps) genes of S. anginosus. This gene cluster consisted of genes containing typical regulatory genes, cpsA-D, and glycosyltransferase genes coding for glucose, rhamnose, N-acetylgalactosamine, and galactofuranose transferases. Furthermore, we confirmed that the cps locus is required for CPS synthesis using a mutant strain with a defective cpsE gene. The cps cluster was found to be located downstream the nrdG gene, which encodes ribonucleoside triphosphate reductase activator, as is the case in other oral streptococci such as S. gordonii and S. sanguinis. However, the location of the gene cluster was different from those of S. pneumonia and S. agalactiae. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Acrolein-Induced Dyslipidemia and Acute Phase Response Independenly of HMG-CoA Reductase

    Science.gov (United States)

    Conklin, Daniel J.; Prough, Russell A.; Juvan, Peter; Rezen, Tadeja; Rozman, Damjana; Haberzettl, Petra; Srivastava, Sanjay; Bhatnagar, Aruni

    2012-01-01

    Scope Aldehydes are ubiquitous natural constituents of foods, water and beverages. Dietary intake represents the greatest source of exposure to acrolein and related aldehydes. Oral acrolein induces dyslipidemia acutely and chronically increases atherosclerosis in mice, yet the mechanisms are unknown. Because lipid synthesis and trafficking are largely under hepatic control, we examined hepatic genes in murine models of acute and chronic oral acrolein exposure. Methods and results Changes in hepatic gene expression were examined using a Steroltalk microarray. Acute acrolein feeding modified plasma and hepatic proteins and increased plasma triglycerides within 15 min. By 6h, acrolein altered hepatic gene expression including Insig1, Insig2 and Hmgcr genes and stimulated an acute phase response (APR) with up-regulation of serum amyloid A genes (Saa) and systemic hypoalbuminemia. To test if decreased HMG-CoA reductase activity could modify acrolein-induced dyslipidemia or the APR, mice were pretreated with simvastatin. Statin treatment, however, did not alter acrolein-induced dyslipidemia or hypoalbuminemia associated with an APR. Few hepatic genes were dysregulated by chronic acrolein feeding in apoE-null mice. These studies confirmed that acute acrolein exposure altered expression of hepatic genes involved with lipid synthesis and trafficking and APR, and thus, indicated a hepatic locus of acrolein-induced dyslipidemia and APR that was independent of HMG CoA-reductase. Conclusion Dietary intake of acrolein could contribute to cardiovascular disease risk by disturbing hepatic function. PMID:21812109

  6. Ntdin, a tobacco senescence-associated gene, is involved in molybdenum cofactor biosynthesis.

    Science.gov (United States)

    Yang, Seung Hwan; Berberich, Thomas; Miyazaki, Atsushi; Sano, Hiroshi; Kusano, Tomonobu

    2003-10-01

    To date, dozens of genes have been reported to be up-regulated with senescence in higher plants. Radish din1 and its ortholog sen1 of Arabidopsis are known as such, but their function is not clear yet. Here we have isolated their counterpart cDNA from tobacco and designated it as NTDIN: Its product, Ntdin, a 185 amino acid polypeptide with 56.8% and 54.2% identity to Atsen1 and Rsdin1, respectively, is localized in chloroplasts. Transcripts of Ntdin are induced by sulfate or nitrate but not by phosphate, suggesting its involvement in sulfur and nitrogen metabolism. A database search revealed that Ntdin shows similarity with the C-terminal region of Nicotiana plumbaginifolia Cnx5, which functions in molybdenum cofactor (Moco) biosynthesis. Transgenic tobacco plants with suppressed Ntdin are more tolerant to chlorate, a substrate analog of nitrate reductase, than controls, implying low nitrate reductase activity in the transgenic plants due to a deficiency of Moco. Indeed, enzymatic activities of two molybdoenzymes, nitrate reductase and xanthine dehydrogenase, in transgenic plants are found to be significantly lower than in control plants. Direct measurement of Moco contents reveals that those transgenic plants contain about 5% Moco of those of the control plants. Abscisic acid and indole-3-acidic acid, whose biosynthetic pathways require Moco, up-regulated Ntdin expression. Taken together, it is concluded that Ntdin functions in a certain step in Moco biosynthesis.

  7. Cholesterol-lowering properties of Ganoderma lucidum in vitro, ex vivo, and in hamsters and minipigs

    Directory of Open Access Journals (Sweden)

    Hajjaj H

    2004-02-01

    Full Text Available Abstract Introduction There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl, a renowned medicinal species. Results Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC 9.8%, and HDL 11.2%. Gl (2.5 and 5% had effects on several fecal neutral sterols and bile acids. Both Gl doses reduced hepatic microsomal ex-vivo HMG-CoA reductase activity. In minipigs, 2.5 Gl decreased TC, LDL- and HDL cholesterol 20, 27, and 18%, respectively (P Conclusions Overall, Gl has potential to reduce LDL cholesterol in vivo through various mechanisms. Next steps are to: fully characterize bioactive components in lipid soluble/insoluble fractions; evaluate bioactivity of isolated fractions; and examine human cholesterol lowering properties. Innovative new cholesterol-lowering foods and medicines containing Gl are envisioned.

  8. Study on the effect of different fertilizer on the stable nitrogen isotope of soil, leaf and cucumber

    International Nuclear Information System (INIS)

    Yuan Yuwei; Zhang Zhiheng; Xu Mingfei; Yang Guiling; Zheng Jici; Wang Qiang; Zhao Ming

    2010-01-01

    The effect of combined application of organic and chemical fertilizers on stable nitrogen isotope abundance (δ 15 N-%), nitrate and nitrate reductase active was studied for the soil, cucumber and leaf,respectively. The results showed that the δ 15 N of cucumber was with the trend of low, high and low as the application rate of organic manure decreased, and it was significantly different (P 0.05) for the other treatments. The δ 15 N of cucumber was not significantly different during different harvest time (P>0.05) for the same treatment. The correlation of δ 15 N between the cucumber and the leaf was 0.9836 for the different treatment, whose δ 15 N was more affected more by the fertilizer and less by the soil. The content of nitrate in cucumber was reducing with the rate of organic manure decreasing, which had a bad correlation (r=0.6568) with the δ 15 N of cucumber; however the active of nitrate reductase was increasing which had a positive correlation with the treatments of control treatment, 100%, 80% and 60% of organic manure applied (r=0.9187), and a negative correlation with the treatments of 60%, 40%, 20% of organic manure and 100% chemical fertilizer applied (r=-0.9773). To sum up, the δ 15 N can be used as marks to discriminate the cucumbers grown with organic manure and chemical fertilizer, but the pattern of fractionation and distribution of the stable nitrogen isotope should be further studied. (authors)

  9. Apigenin inhibits d-galactosamine/LPS-induced liver injury through upregulation of hepatic Nrf-2 and PPARγ expressions in mice.

    Science.gov (United States)

    Zhou, Rui-Jun; Ye, Hua; Wang, Feng; Wang, Jun-Long; Xie, Mei-Lin

    2017-11-04

    Apigenin is a natural flavonoid compound widely distributed in a variety of vegetables, medicinal plants and health foods. This study aimed to examine the protective effect of apigenin against d-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced mouse liver injury and to investigate the potential biochemical mechanisms. The results showed that after oral administration of apigenin 100-200 mg/kg for 7 days, the levels of serum alanine aminotransferase and aspartate aminotransferase were decreased, and the severity of liver injury was alleviated. Importantly, apigenin pretreatment increased the levels of hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) and peroxisome proliferator-activated receptor γ (PPARγ) protein expressions as well as superoxide dismutase, catalase, glutathione S-transferase and glutathione reductase activities, decreased the levels of hepatic nuclear factor-κB (NF-κB) protein expression and tumor necrosis factor-α. These findings demonstrated that apigenin could prevent the D-GalN/LPS-induced liver injury in mice, and its mechanisms might be associated with the increments of Nrf-2-mediated antioxidative enzymes and modulation of PPARγ/NF-κB-mediated inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Fate and effects of Camembert cheese micro-organisms in the human colonic microbiota of healthy volunteers after regular Camembert consumption.

    Science.gov (United States)

    Firmesse, Olivier; Alvaro, Elise; Mogenet, Agnès; Bresson, Jean-Louis; Lemée, Riwanon; Le Ruyet, Pascale; Bonhomme, Cécile; Lambert, Denis; Andrieux, Claude; Doré, Joël; Corthier, Gérard; Furet, Jean-Pierre; Rigottier-Gois, Lionel

    2008-07-15

    The objective of this study was to determine i) if Camembert cheese micro-organisms could be detected in fecal samples after regular consumption by human subjects and ii) the consequence of this consumption on global metabolic activities of the host colonic microbiota. An open human protocol was designed where 12 healthy volunteers were included: a 2-week period of fermented products exclusion followed by a 4-weeks Camembert ingestion period where 2x40 g/day of Camembert cheese was consumed. Stools were collected from the volunteers before consumption, twice during the ingestion period (2nd and 4th week) and once after a wash out period of 2 weeks. During the consumption of Camembert cheese, high levels of Lactococcus lactis and Leuconostoc mesenteroides were measured in fecal samples using real-time quantitative PCR, reaching median values of 8.2 and 7.5 Log(10) genome equivalents/g of stool. For Ln. mesenteroides, persistence was observed 15 days after the end of Camembert consumption. The survival of Geotrichum candidum was also assessed and the fecal concentration reached a median level of 7.1 Log(10) CFU/g in stools. Except a decreasing trend of the nitrate reductase activity, no significant modification was shown in the metabolic activities during this study.

  11. Hypolipidemic activity of Phellinus rimosus against triton WR-1339 and high cholesterol diet induced hyperlipidemic rats.

    Science.gov (United States)

    Rony, K A; Ajith, T A; Nima, N; Janardhanan, K K

    2014-03-01

    Patients with the risk for atherosclerotic disease will be targeted to reduce the existing hyperlipidemia. The hypolipidemic activity of Phellinus rimosus was studied using triton WR-1339 and high cholesterol diet (HCD) induced models. The triton induced elevated lipid profile was attenuated by P. rimosus or standard drug atorvastatin. Similarly, administration of P. rimosus along with HCD significantly decline serum triglyceride, total cholesterol, low-density lipoprotein, with elevating the high-density lipoprotein. Thiobarbituric acid reacting substances in heart and liver significantly decreased; where as activity of enzymatic antioxidants and level of reduced glutathione were significantly increased. In both models, P. rimosus extract showed a significant ameliorative effect on the elevated atherogenic index as well as LDL/HDL-C ratio. The hypolipidemic activity of P. rimosus can be ascribed to its inhibitory effect on the liver HMG CoA reductase activity. The results suggest the possible therapeutic potential of this fungus as hypolipidemic agent. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Tacrine is implicated in oxidative stress in the laboratory guinea pig model.

    Science.gov (United States)

    Kracmarova, Alzbeta; Bandouchova, Hana; Pikula, Jiri; Pohanka, Miroslav

    2012-01-01

    Tacrine was the first acetylcholinesterase inhibitor approved for the treatment of Alzheimer disease. The compound is not available for therapeutic purposes as it was withdrawn due to hepatotoxicity of its metabolites. The hepatotoxicity can be decreased by alternative ways of drug administration avoiding thus the first pass effect. The present study is aimed to investigate the influence of intramuscularly administrated tacrine on oxidative stress. Laboratory guinea pigs were exposed to tacrine at doses of 0-800 μg/kg. The animals were euthanized 1 and 24 hours after the exposure. Parameters such as ferric reducing antioxidant power (FRAP), thiobarbituric acid reactive substances (TBARS), carbonylated proteins, caspase 3 activity, superoxide dismutase activity and glutathione reductase activity were assessed in the frontal, temporal and occipital lobe, cerebellum, liver, spleen, heart, and kidney. Moreover, levels of glucose, total and HDL cholesterol forms, triglycerides, blood urea nitrogen, creatinine, total bilirubin, total protein, albumin and activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase were assessed in plasma samples. Activities of the enzymatic markers, level of carbonylated proteins in organs and levels of biochemical markers in plasma were only slightly influenced by tacrine. Dose-dependent elevation of the FRAP value was recognized in the brain tissues and the liver. The TBARS value was increased in the kidney and heart 1 and 24 hours, respectively, after exposure. In the study, the effect of tacrine on markers of oxidative stress was proved. Possible positive effects of tacrine on the antioxidant defence in the brain tissue were discussed.

  13. Thioacetamide-induced cirrhosis in selenium-adequate mice displays rapid and persistent abnormity of hepatic selenoenzymes which are mute to selenium supplementation

    International Nuclear Information System (INIS)

    Zhang Jinsong; Wang Huali; Yu Hanqing

    2007-01-01

    Selenium reduction in cirrhosis is frequently reported. The known beneficial effect of selenium supplementation on cirrhosis is probably obtained from nutritionally selenium-deficient subjects. Whether selenium supplementation truly improves cirrhosis in general needs additional experimental investigation. Thioacetamide was used to induce cirrhosis in selenium-adequate and -deficient mice. Selenoenzyme activity and selenium content were measured and the influence of selenium supplementation was evaluated. In Se-adequate mice, thioacetamide-mediated rapid onset of hepatic oxidative stress resulted in an increase in thioredoxin reductase activity and a decrease in both glutathione peroxidase activity and selenium content. The inverse activity of selenoenzymes (i.e. TrxR activity goes up and GPx activity goes down) was persistent and mute to selenium supplementation during the progress of cirrhosis; accordingly, cirrhosis was not improved by selenium supplementation in any period. On the other hand, selenium supplementation to selenium-deficient mice always more efficiently increased hepatic glutathione peroxidase activity and selenium content compared with those treated with thioacetamide, indicating that thioacetamide impairs the liver bioavailability of selenium. Although thioacetamide profoundly affects hepatic selenium status in selenium-adequate mice, selenium supplementation does not modify the changes. Selenium supplementation to cirrhotic subjects with a background of nutritional selenium deficiency can improve selenium status but cannot restore hepatic glutathione peroxidase and selenium to normal levels

  14. Anaerobic respiratory growth of Vibrio harveyi, Vibrio fischeri and Photobacterium leiognathi with trimethylamine N-oxide, nitrate and fumarate: ecological implications.

    Science.gov (United States)

    Proctor, L M; Gunsalus, R P

    2000-08-01

    Two symbiotic species, Photobacterium leiognathi and Vibrio fischeri, and one non-symbiotic species, Vibrio harveyi, of the Vibrionaceae were tested for their ability to grow by anaerobic respiration on various electron acceptors, including trimethylamine N-oxide (TMAO) and dimethylsulphoxide (DMSO), compounds common in the marine environment. Each species was able to grow anaerobically with TMAO, nitrate or fumarate, but not with DMSO, as an electron acceptor. Cell growth under microaerophilic growth conditions resulted in elevated levels of TMAO reductase, nitrate reductase and fumarate reductase activity in each strain, whereas growth in the presence of the respective substrate for each enzyme further elevated enzyme activity. TMAO reductase specific activity was the highest of all the reductases. Interestingly, the bacteria-colonized light organs from the two squids, Euprymna scolopes and Euprymna morsei, and the light organ of the ponyfish, Leiognathus equus, also had high levels of TMAO reductase enzyme activity, in contrast to non-symbiotic tissues. The ability of these bacterial symbionts to support cell growth by respiration with TMAO may conceivably eliminate the competition for oxygen needed for both bioluminescence and metabolism.

  15. Ammonia Assimilation in Zea mays L. Infected with a Vesicular-Arbuscular Mycorrhizal Fungus Glomus fasciculatum.

    Science.gov (United States)

    Cliquet, J. B.; Stewart, G. R.

    1993-03-01

    To investigate nitrogen assimilation and translocation in Zea mays L. colonized by the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thax. sensu Gerd.), we measured key enzyme activities, 15N incorporation into free amino acids, and 15N translocation from roots to shoots. Glutamine synthetase and nitrate reductase activities were increased in both roots and shoots compared with control plants, and glutamate dehydrogenase activity increased in roots only. In the presence of [15N]ammonium, glutamine amide was the most heavily labeled product. More label was incorporated into amino acids in VAM plants. The kinetics of 15N labeling and effects of methionine sulfoximine on distribution of 15N-labeled products were entirely consistent with the operation of the glutamate synthase cycle. No evidence was found for ammonium assimilation via glutamate dehydrogenase. 15N translocation from roots to shoots through the xylem was higher in VAM plants compared with control plants. These results establish that, in maize, VAM fungi increase ammonium assimilation, glutamine production, and xylem nitrogen translocation. Unlike some ectomycorrhizal fungi, VAM fungi do not appear to alter the pathway of ammonium assimilation in roots of their hosts.

  16. Arsenic biotransformation and release by bacteria indigenous to arsenic contaminated groundwater.

    Science.gov (United States)

    Paul, Dhiraj; Kazy, Sufia K; Banerjee, Tirtha Das; Gupta, Ashok K; Pal, Taraknath; Sar, Pinaki

    2015-01-01

    Arsenic (As) biotransformation and release by indigenous bacteria from As rich groundwater was investigated. Metabolic landscape of 173 bacterial isolates indicated broad catabolic repertoire including abundance of As(5+) reductase activity and abilities in utilizing wide ranges of organic and inorganic respiratory substrates. Abundance of As homeostasis genes and utilization of hydrocarbon as carbon/electron donor and As(5+) as electron acceptor were noted within the isolates. Sediment microcosm study (for 300 days) showed a pivotal role of metal reducing facultative anaerobic bacteria in toxic As(3+) release in aqueous phase. Inhabitant bacteria catalyze As transformation and facilitate its release through a cascade of reactions including mineral bioweathering and As(5+) and/or Fe(3+) reduction activities. Compared to anaerobic incubation with As(5+) reducing strains, oxic state and/or incubation with As(3+) oxidizing bacteria resulted in reduced As release, thus indicating a strong role of such condition or biocatalytic mechanism in controlling in situ As contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Dietary Supplementation with the Microalga Galdieria sulphuraria (Rhodophyta Reduces Prolonged Exercise-Induced Oxidative Stress in Rat Tissues

    Directory of Open Access Journals (Sweden)

    Simona Carfagna

    2015-01-01

    Full Text Available We studied the effects of ten-day 1% Galdieria sulphuraria dietary supplementation on oxidative damage and metabolic changes elicited by acute exercise (6-hour swimming determining oxygen consumption, lipid hydroperoxides, protein bound carbonyls in rat tissue (liver, heart, and muscle homogenates and mitochondria, tissue glutathione peroxidase and glutathione reductase activities, glutathione content, and rates of H2O2 mitochondrial release. Exercise increased oxidative damage in tissues and mitochondria and decreased tissue content of reduced glutathione. Moreover, it increased State 4 and decreased State 3 respiration in tissues and mitochondria. G. sulphuraria supplementation reduced the above exercise-induced variations. Conversely, alga supplementation was not able to modify the exercise-induced increase in mitochondrial release rate of hydrogen peroxide and in liver and heart antioxidant enzyme activities. The alga capacity to reduce lipid oxidative damage without reducing mitochondrial H2O2 release can be due to its high content of C-phycocyanin and glutathione, which are able to scavenge peroxyl radicals and contribute to phospholipid hydroperoxide metabolism, respectively. In conclusion, G. sulphuraria ability to reduce exercise-linked oxidative damage and mitochondrial dysfunction makes it potentially useful even in other conditions leading to oxidative stress, including hyperthyroidism, chronic inflammation, and ischemia/reperfusion.

  18. Dietary supplementation with the microalga Galdieria sulphuraria (Rhodophyta) reduces prolonged exercise-induced oxidative stress in rat tissues.

    Science.gov (United States)

    Carfagna, Simona; Napolitano, Gaetana; Barone, Daniela; Pinto, Gabriele; Pollio, Antonino; Venditti, Paola

    2015-01-01

    We studied the effects of ten-day 1% Galdieria sulphuraria dietary supplementation on oxidative damage and metabolic changes elicited by acute exercise (6-hour swimming) determining oxygen consumption, lipid hydroperoxides, protein bound carbonyls in rat tissue (liver, heart, and muscle) homogenates and mitochondria, tissue glutathione peroxidase and glutathione reductase activities, glutathione content, and rates of H2O2 mitochondrial release. Exercise increased oxidative damage in tissues and mitochondria and decreased tissue content of reduced glutathione. Moreover, it increased State 4 and decreased State 3 respiration in tissues and mitochondria. G. sulphuraria supplementation reduced the above exercise-induced variations. Conversely, alga supplementation was not able to modify the exercise-induced increase in mitochondrial release rate of hydrogen peroxide and in liver and heart antioxidant enzyme activities. The alga capacity to reduce lipid oxidative damage without reducing mitochondrial H2O2 release can be due to its high content of C-phycocyanin and glutathione, which are able to scavenge peroxyl radicals and contribute to phospholipid hydroperoxide metabolism, respectively. In conclusion, G. sulphuraria ability to reduce exercise-linked oxidative damage and mitochondrial dysfunction makes it potentially useful even in other conditions leading to oxidative stress, including hyperthyroidism, chronic inflammation, and ischemia/reperfusion.

  19. CHANGES IN THE GLUTATHIONE SYSTEM IN P19 EMBRYONAL CARCINOMA CELLS UNDER HYPOXIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    D. S. Orlov

    2015-01-01

    Full Text Available Introduction. According to modern perceptions, tumor growth, along with oxidative stress formation, is accompanied by hypoxia. Nowadays studying the regulation of cellular molecular system functioning by conformational changes in proteins appears to be a topical issue. Research goal was to evaluate the state of the glutathione system and the level of protein glutathionylation in P19 embryonal carcinoma (EC cells under hypoxic conditions.Material and methods. P19 EC cells (mouse embryonal carcinoma cultured under normoxic and hypox-ic conditions served the research material.The concentration of total, oxidized, reduced and protein-bound glutathione, the reduced to oxidized thiol ratio as well as glutathione peroxidase and glutathione reductase activity were determined by spectropho-tometry.Results. Glutathione imbalance was accompanied by a decrease in P19 EC cell redox status under hypox-ic conditions against the backdrop of a rise in protein-bound glutathione.Conclusions. As a result of the conducted study oxidative stress formation was identified when modeling hypoxia in P19 embryonal carcinoma cells. The rise in the concentration of protein-bound glutathione may indicate the role of protein glutathionylation in regulation of P19 cell metabolism and functions un-der hypoxia. 

  20. Antioxidative Activity of Colostrum and Human Milk: Effects of Pasteurization and Storage.

    Science.gov (United States)

    Marinković, Vesna; Ranković-Janevski, Milica; Spasić, Snežana; Nikolić-Kokić, Aleksandra; Lugonja, Nikoleta; Djurović, Dijana; Miletić, Srdjan; Vrvić, Miroslav M; Spasojević, Ivan

    2016-06-01

    Milk banks collect, pasteurize, and freeze/store human milk. The processing may alter redox properties of milk, but the effects have not been fully examined. We collected 10 mature milk and 10 colostrum samples and applied a battery of biochemical assays and electron paramagnetic resonance spectroscopy to inspect changes that milk undergoes with pasteurization and 30 days storage at -20°C. Pasteurization and storage of raw milk did not affect total nonenzymatic antioxidative capacity, but specific components and features were altered. Urate radical and ascorbyl radical emerge as products of exposure of milk to hydroxyl radical-generating system. Processing shifted the load of antioxidative activity from ascorbate to urate and lowered the capacity of milk to diminish hydroxyl radical. Pasteurization caused a significant drop in the activity of 2 major antioxidative enzymes-superoxide dismutase and glutathione peroxidase, whereas freezing/storage of raw milk affected only superoxide dismutase. Colostrum showed drastically higher total nonenzymatic antioxidative capacity, hydroxyl radical scavenging ability, and glutathione reductase activity compared with mature milk. Pasteurization and storage affect nonenzymatic and enzymatic antioxidative agents in human milk. It appears that nonenzymatic antioxidative systems in colostrum and milk are different. The effects of processing may be partially compensated by fortification/spiking with ascorbate before use.

  1. [Effects of diurnal warming on soil N2O emission in soybean field].

    Science.gov (United States)

    Hu, Zheng-Hua; Zhou, Ying-Ping; Cui, Hai-Ling; Chen, Shu-Tao; Xiao, Qi-Tao; Liu, Yan

    2013-08-01

    To investigate the impact of experimental warming on N2O emission from soil of soybean field, outdoor experiments with simulating diurnal warming were conducted, and static dark chamber-gas chromatograph method was used to measure N2O emission fluxes. Results indicated that: the diurnal warming did not change the seasonal pattern of N2O emissions from soil. In the whole growing season, comparing to the control treatment (CK), the warming treatment (T) significantly enhanced the N2O flux and the cumulative amount of N2O by 17.31% (P = 0.019), and 20.27% (P = 0.005), respectively. The significant correlations were found between soil N2O emission and soil temperature, moisture. The temperature sensitivity values of soil N2O emission under CK and T treatments were 3.75 and 4.10, respectively. In whole growing stage, T treatment significantly increased the crop aboveground and total biomass, the nitrate reductase activity, and total nitrogen in leaves, while significantly decreased NO3(-) -N content in leaves. T treatment significantly increased soil NO3(-) -N content, but had no significant effect on soil organic carbon and total nitrogen contents. The results of this study suggested that diurnal warming enhanced N2O emission from soil in soybean field.

  2. Pulsed magnetic field: a contemporary approach offers to enhance plant growth and yield of soybean.

    Science.gov (United States)

    Radhakrishnan, Ramalingam; Ranjitha Kumari, Bollipo Diana

    2012-02-01

    The possible involvement of pulsed magnetic field (PMF) pretreatment in development and yield of soybean was investigated. Seeds were subjected to 20 days with 1500 nT at 10.0 Hz of PMF for 5 h per day. PMF pretreatment increased the plant height, fresh and dry weight, and protein content with the changes of protein profile in 8 days old seedlings. In addition, activity of enzymes such as β-amylase, acid phosphatase, polyphenol oxidase and catalase was enhanced while α-amylase, alkaline phosphatase, protease and nitrate reductase activities declined due to PMF exposure. However, a considerable increment of Fe, Cu, Mn, Zn, Mg, K and Na contents with reduced level of Ca was found in PMF treated seedlings. The number of leaves, pods, seeds and length of pods, and weight of seeds were also remarkably higher in PMF treatment in contrast to controls. The results suggest that pretreatment of PMF plays important roles in improvement of crop productivity of soybean through the enhancement of protein, mineral accumulation and enzyme activities which leads to increase the growth and yield. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  3. Major depressive disorder mediates accelerated aging in rats subjected to chronic mild stress.

    Science.gov (United States)

    Xie, Xiaoxian; Chen, Yangyang; Ma, Lingyan; Shen, Qichen; Huang, Liangfeng; Zhao, Binggong; Wu, Tao; Fu, Zhengwei

    2017-06-30

    Major depressive disorder (MDD) has a complex etiology and is characterized by a change in mood and psychophysiological state. MDD has been shown to mediate accelerated biological aging in patients, although the underlying mechanism is not well understood. In the present study, we used a chronic mild stress (CMS) paradigm to induce anhedonia, one of the main symptoms of MDD. CMS induced depression-like symptoms in rats, including reduced sucrose preference and increased immobility time in the forced swim test. Moreover, stressed rats travelled a shorter total distance, had fewer grid line crossings, and spent less time in the outer zone in the open field test than controls. CMS altered the levels of 5-hydroxytryptophan, dopamine, and corticosterone in the serum and hippocampus (P<0.05); these rats also exhibited impaired liver function, decreased telomerase activity, and telomere shortening, which was associated with increased oxidative damage along with decreased superoxide dismutase and glutathione reductase activities. Mitochondria in CMS-treated rats showed ultrastructural damage as well as reduced DNA content and integrity. These findings provide physiological and cellular evidence that the MDD can mediate accelerated aging in rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus.

    Science.gov (United States)

    Kalloniati, Chrysanthi; Krompas, Panagiotis; Karalias, Georgios; Udvardi, Michael K; Rennenberg, Heinz; Herschbach, Cornelia; Flemetakis, Emmanouil

    2015-09-01

    We combined transcriptomic and biochemical approaches to study rhizobial and plant sulfur (S) metabolism in nitrogen (N) fixing nodules (Fix(+)) of Lotus japonicus, as well as the link of S-metabolism to symbiotic nitrogen fixation and the effect of nodules on whole-plant S-partitioning and metabolism. Our data reveal that N-fixing nodules are thiol-rich organs. Their high adenosine 5'-phosphosulfate reductase activity and strong (35)S-flux into cysteine and its metabolites, in combination with the transcriptional upregulation of several rhizobial and plant genes involved in S-assimilation, highlight the function of nodules as an important site of S-assimilation. The higher thiol content observed in nonsymbiotic organs of N-fixing plants in comparison to uninoculated plants could not be attributed to local biosynthesis, indicating that nodules are an important source of reduced S for the plant, which triggers whole-plant reprogramming of S-metabolism. Enhanced thiol biosynthesis in nodules and their impact on the whole-plant S-economy are dampened in plants nodulated by Fix(-) mutant rhizobia, which in most respects metabolically resemble uninoculated plants, indicating a strong interdependency between N-fixation and S-assimilation. © 2015 American Society of Plant Biologists. All rights reserved.

  5. Investigation of Baseline Antioxidant Enzyme Expression in Pocillopora damicornis

    Science.gov (United States)

    Murphy, J.; Richmond, R. H.

    2016-02-01

    Coral reefs are some of the most diverse and valuable ecosystems in the world. Vital for maintaining ecological balance in coastal tropical environments, they also stand as the foundation for enormous cultural and economic resources. However, the continued degradation of coral reefs around the world, particularly within NOAA's Hawaii Marine Sanctuary, is an alarming call for action towards the identification of stressors and subsequent rehabilitation of these national treasures. Aligned with the goals of NOAA's National Marine Sanctuary to protect areas of the marine environment that are of special national significance to cultural, scientific, educational, and ecological values, this research targets addressing and standardizing antioxidant enzyme stress levels in Hawaiian coral over reproductive cycles in order to increase management aptitude and efficiency. By developing a greater understanding for biochemical biomarkers of stress in corals, specifically through the study of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity and expression, my research will aid in the adaptation and further development of biochemical tests to understand baseline thresholds of stress on coral reefs within Sanctuary waters. Slight, but significant variations in enzyme expression over reproductive time points alert us to modifications that must be made to consider fluctuating levels of coral susceptibility when sampling corals under stress. These findings will be applied to diagnostic tests describing the effect of different chemical pollutants on coral health in order to identify ecological issues and expand the knowledge of local communities and NOAA, so that steps can be taken to mitigate human Sanctuary impacts.

  6. Infestation of potato (Solanum tuberosum L.) by the peach-potato aphid (Myzus persicae Sulzer) alters cellular redox status and is influenced by ascorbate.

    Science.gov (United States)

    Kerchev, Pavel I; Fenton, Brian; Foyer, Christine H; Hancock, Robert D

    2012-02-01

    The peach-potato aphid (Myzus persicae Sulzer) is a major pest of potato (Solanum tuberosum L.) but the molecular characterization of this interaction particularly with regard to oxidants and antioxidants remains to be undertaken. Aphid colonies reared on potato leaves containing high ascorbate were twice the size of those grown on leaves with low ascorbate. Infestation-dependent decreases in the abundance of key transcripts such as chloroplastic FeSOD, peroxisomal catalase 2, PR1 and JAZ1 preceded detectable leaf H(2)O(2) or polyphenol accumulation. The leaf glutathione pool was increased 48 h after infestation, but the amount of ascorbate was unchanged. The ascorbate/dehydroacorbate (DHA) ratio was lower at 48 h but the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) was unchanged. While DHA reductase and GSSG reductase activities were unaffected by aphid feeding, non-specific peroxidase activities were enhanced 48 h following aphid infestation. Brown ethanol-insoluble deposits were observed close to leaf veins following aphid infestation. Taken together, the results demonstrate that high ascorbate favours aphid colony expansion and that perturbations in the leaf antioxidant system are intrinsic to the potato leaf response to aphids. Moreover, these changes together with the induction of hormone-related transcripts precede the deposition of defence-associated oxidized polyphenols along the stylet track. © 2011 Blackwell Publishing Ltd.

  7. The effector AWR5 from the plant pathogen Ralstonia solanacearum is an inhibitor of the TOR signalling pathway.

    Science.gov (United States)

    Popa, Crina; Li, Liang; Gil, Sergio; Tatjer, Laura; Hashii, Keisuke; Tabuchi, Mitsuaki; Coll, Núria S; Ariño, Joaquín; Valls, Marc

    2016-06-03

    Bacterial pathogens possess complex type III effector (T3E) repertoires that are translocated inside the host cells to cause disease. However, only a minor proportion of these effectors have been assigned a function. Here, we show that the T3E AWR5 from the phytopathogen Ralstonia solanacearum is an inhibitor of TOR, a central regulator in eukaryotes that controls the switch between cell growth and stress responses in response to nutrient availability. Heterologous expression of AWR5 in yeast caused growth inhibition and autophagy induction coupled to massive transcriptomic changes, unmistakably reminiscent of TOR inhibition by rapamycin or nitrogen starvation. Detailed genetic analysis of these phenotypes in yeast, including suppression of AWR5-induced toxicity by mutation of CDC55 and TPD3, encoding regulatory subunits of the PP2A phosphatase, indicated that AWR5 might exert its function by directly or indirectly inhibiting the TOR pathway upstream PP2A. We present evidence in planta that this T3E caused a decrease in TOR-regulated plant nitrate reductase activity and also that normal levels of TOR and the Cdc55 homologues in plants are required for R. solanacearum virulence. Our results suggest that the TOR pathway is a bona fide T3E target and further prove that yeast is a useful platform for T3E function characterisation.

  8. The protective effect of N-acetylcysteine on oxidative stress in the brain caused by the long-term intake of aspartame by rats.

    Science.gov (United States)

    Finamor, Isabela A; Ourique, Giovana M; Pês, Tanise S; Saccol, Etiane M H; Bressan, Caroline A; Scheid, Taína; Baldisserotto, Bernardo; Llesuy, Susana F; Partata, Wânia A; Pavanato, Maria A

    2014-09-01

    Long-term intake of aspartame at the acceptable daily dose causes oxidative stress in rodent brain mainly due to the dysregulation of glutathione (GSH) homeostasis. N-Acetylcysteine provides the cysteine that is required for the production of GSH, being effective in treating disorders associated with oxidative stress. We investigated the effects of N-acetylcysteine treatment (150 mg kg(-1), i.p.) on oxidative stress biomarkers in rat brain after chronic aspartame administration by gavage (40 mg kg(-1)). N-Acetylcysteine led to a reduction in the thiobarbituric acid reactive substances, lipid hydroperoxides, and carbonyl protein levels, which were increased due to aspartame administration. N-Acetylcysteine also resulted in an elevation of superoxide dismutase, glutathione peroxidase, glutathione reductase activities, as well as non-protein thiols, and total reactive antioxidant potential levels, which were decreased after aspartame exposure. However, N-acetylcysteine was unable to reduce serum glucose levels, which were increased as a result of aspartame administration. Furthermore, catalase and glutathione S-transferase, whose activities were reduced due to aspartame treatment, remained decreased even after N-acetylcysteine exposure. In conclusion, N-acetylcysteine treatment may exert a protective effect against the oxidative damage in the brain, which was caused by the long-term consumption of the acceptable daily dose of aspartame by rats.

  9. Inorganic Polyphosphates Regulate Hexokinase Activity and Reactive Oxygen Species Generation in Mitochondria of Rhipicephalus (Boophilus) microplus Embryo

    Science.gov (United States)

    Fraga, Amanda; Moraes, Jorge; da Silva, José Roberto; Costa, Evenilton P.; Menezes, Jackson; da Silva Vaz Jr, Itabajara; Logullo, Carlos; da Fonseca, Rodrigo Nunes; Campos, Eldo

    2013-01-01

    The physiological roles of polyphosphates (poly P) recently found in arthropod mitochondria remain obscure. Here, the possible involvement of poly P with reactive oxygen species generation in mitochondria of Rhipicephalus microplus embryos was investigated. Mitochondrial hexokinase and scavenger antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione reductase were assayed during embryogenesis of R. microplus. The influence of poly P3 and poly P15 were analyzed during the period of higher enzymatic activity during embryogenesis. Both poly Ps inhibited hexokinase activity by up to 90% and, interestingly, the mitochondrial membrane exopolyphosphatase activity was stimulated by the hexokinase reaction product, glucose-6-phosphate. Poly P increased hydrogen peroxide generation in mitochondria in a situation where mitochondrial hexokinase is also active. The superoxide dismutase, catalase and glutathione reductase activities were higher during embryo cellularization, at the end of embryogenesis and during embryo segmentation, respectively. All of the enzymes were stimulated by poly P3. However, superoxide dismutase was not affected by poly P15, catalase activity was stimulated only at high concentrations and glutathione reductase was the only enzyme that was stimulated in the same way by both poly Ps. Altogether, our results indicate that inorganic polyphosphate and mitochondrial membrane exopolyphosphatase regulation can be correlated with the generation of reactive oxygen species in the mitochondria of R. microplus embryos. PMID:23983617

  10. Increased occupational coal dust toxicity in blood of central heating system workers.

    Science.gov (United States)

    Tuluce, Yasin; Ozkol, Halil; Koyuncu, Ismail; Ine, Hatice

    2011-02-01

    Coal dust causes lung diseases in occupational exposure. Reactive oxygen species have been implicated in the pathogenesis of its toxicity. In this study, serum enzymes, lipid profile and other biochemical values with oxidant/antioxidant status in whole blood and serum of central heating system workers (CHSW; the persons responsible for heating the apartment with coal) were determined to reflect the cell injury. Blood samples were obtained from CHSW (n = 25) and healthy individuals (n = 25). All values were measured in whole blood and serum. ANOVA was used for the estimation of statistical data. In the group of CHSW, creatinine, ferritin, alanin aminotransferase, aspartate aminotransferase, creatine phosphokinase, gamma glutamyl transferase, lactate dehydrogenase and glutathione reductase activities as well as triglyceride, very low density lipoprotein, protein carbonyl and malondialdehide were significantly higher, while transferrin, high density lipoprotein and catalase (CAT) activities were lower than the group of healthy individuals. This result is consistent with hypothesis that respirable coal dust generates lipid and protein oxidation and induces leakage of serum enzymes by cell damage. It also leads to imbalance in antioxidant defense system, lipid profile and other biochemical parameters.

  11. EFFECT OF POLYPHENOLIC COMPLEX FROM WINE ON RATS ANTIOXIDANT ENZYMES ACTIVITY AT X-RAY IRRADIATION LOW DOSES

    Directory of Open Access Journals (Sweden)

    U. V. Datsyuk

    2014-04-01

    Full Text Available It is shown that the consumption of natural polyphenolic complex from grape wine in drinking water in the daily dose 2.5 ± 1.1 mg polyphenols/kg body mass of rats during the 10 day before exposure to radiation leads to increased of superoxide dismutase and gluthathione reductase activities in peripheral blood on 24 and 48 hours after full body X-ray irradiation (30 cGy. The of catalase, gluthathione peroxidase activities and the of the reactive thiobarbituric acid substances content in total lysates of peripheral blood within 72 hours after exposure are comparable to those in control rats. Marked decreased of catalase and superoxide dismutase activities at 24, 48 and 24 hours, respectively, was observed after exposure to ionizing radiation and increased content of lipid peroxidation products in all above mentioned time points. The decreased of superoxide dismutase and gluthathione peroxidase activities in lysates of rats aorta at 48 hour and increased content of the reactive thiobarbituric acid substances during 72 hours after radiation exposure were observed. The consumption of polyphenolic complex from wine did not change the superoxide dismutase and catalase activities in lysates of aorta rats treated with ionizing radiation, whereas gluthathione reductase and gluthathione peroxidase activities was increased during 72 hours after radiation influence. The content of TBA reactive substances was significantly decreased in lysates of aorta rats that were exposed to radiation and polyphenols of grape wine, compared with those of animals that were exposed to radiation alone.

  12. Effects of replacing fish meal with rubber seed meal on growth, nutrient utilization, and cholesterol metabolism of tilapia (Oreochromis niloticus × O. aureus).

    Science.gov (United States)

    Deng, Junming; Wang, Kun; Mai, Kangsen; Chen, Liqiao; Zhang, Lu; Mi, Haifeng

    2017-08-01

    A feeding trial was conducted to evaluate the effects of replacing fish meal with rubber seed meal (RSM) on growth, nutrient utilization, and cholesterol metabolism of tilapia (Oreochromis niloticus × Oreochromis aureus). Five experimental diets were formulated with 0, 150, 300, 450, and 600 g kg -1 RSM replacing graded levels of fish meal, respectively. Each diet was randomly assigned to triplicate groups of 25 fish (initial average weight 65.3 g) per aquarium in a rearing system maintained at 29 ± 1 °C for 8 weeks. Dietary 150 g kg -1 RSM inclusion did not affect the weight gain and daily growth coefficient, whereas these were depressed by a further inclusion. Additionally, feed efficiency ratio and protein efficiency ratio were not affected by dietary RSM inclusion regardless of inclusion level. However, the inclusion of 450 and 600 g kg -1 RSM decreased the mid-intestinal trypsin, lipase, and amylase activities; the hepatic acyl-CoA/cholesterol acyl transferase; low-density lipoprotein receptor; and 3-hydroxy-3-methyl-glutaryl-CoA reductase activities. Similarly, dietary 600 g kg -1 RSM inclusion inhibited the plasma catalase and hepatic glutathione peroxidase activities. These results indicated that 150 g kg -1 RSM can be included in tilapia diets, whereas higher inclusion of RSM inhibited the growth rate, digestive enzyme activity, antioxidant capacity, and cholesterol metabolism.

  13. Deciphering Molecular Mechanism Underlying Hypolipidemic Activity of Echinocystic Acid

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    Li Han

    2014-01-01

    Full Text Available Our previous study showed that a triterpene mixture, consisting of echinocystic acid (EA and oleanolic acid (OA at a ratio of 4 : 1, dose-dependently ameliorated the hyperlipidemia and atherosclerosis in rabbits fed with high fat/high cholesterol diets. This study was aimed at exploring the mechanisms underlying antihyperlipidemic effect of EA. Molecular docking simulation of EA was performed using Molegro Virtual Docker (version: 4.3.0 to investigate the potential targets related to lipid metabolism. Based on the molecular docking information, isotope labeling method or spectrophotometry was applied to examine the effect of EA on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA reductase, acyl-CoA:cholesterol acyltransferase (ACAT, and diacylglycerol acyltransferase (DGAT in rat liver microsomes. Our results revealed a strong affinity of EA towards ACAT and DGAT in molecular docking analysis, while low binding affinity existed between EA and HMG-CoA reductase as well as between EA and cholesteryl ester transfer protein. Consistent with the results of molecular docking, in vitro enzyme activity assays showed that EA inhibited ACAT and DGAT, with IC50 values of 103 and 139 μM, respectively, and exhibited no significant effect on HMG-CoA reductase activity. The present findings suggest that EA may exert hypolipidemic effect by inhibiting the activity of ACAT and DGAT.

  14. Effects of high dose olive leaf extract on haemodynamic and oxidative stress parameters in normotensive and spontaneously hypertensive rats

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    Dekanski Dragana

    2014-01-01

    Full Text Available Antihypertensive activity of natural antioxidant, olive leaf extract (OLE is known, but its influence on cardiovascular system when administered in a high dose has not been investigated yet. Our aim was to determine the acute effects of excessive intake of standardized OLE on blood pressure, heart rate and oxidative status in both spontaneously hypertensive rats and normotensive Wistar rats. Systolic arterial pressure and heart rate were measured using a tail-cuff, pneumatic pulse detector, before, 60 and 120 minutes after intragastric OLE administration. Activities of catalase, glutathione peroxidase, superoxide dismutase (SOD and glutathione reductase in erythrocytes, as well as lipid peroxidation in plasma (pTBARS were measured at the same time points, spectrophotometrically. High-dose OLE did not influence blood pressure, heart rate and pTBARS in normotensive rats, while SOD, catalase, and glutathione reductase activities significantly increased. The same dose significantly decreased blood pressure in hypertensive rats, but increased pTBARS and SOD activity. Excessive oral intake of OLE induced moderate hypotensive effects in spontaneously hypertensive rats only, suggesting absence of harmful haemodynamic effects after oral overdose in both rats strain. However, its prooxidative role when given in high dose in hypertensive organism should not be neglected. [Projekat Ministarstva nauke Republike Srbije, br. 175096

  15. Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism.

  16. EFFECT OF FERMENTED CHUB MACKEREL EXTRACT ON LIPID METABOLISM OF DIABETIC RATS

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    U. Santoso

    2014-10-01

    Full Text Available The present study was conducted to evaluate the effect of fermented chub mackerel extract(FCME on lipid metabolism in diabetic rats. Four week-old male Wistar rats were divided into threegroups based on weight. All rats were induced with diabetes mellitus by single intraperitoneal injectionof streptozotocin at 45 mg/kg body weight. Thereafter, they were randomly distributed to threetreatments with 7 rats assigned to each treatment. One group was the control with no additive, and twotreatmentgroups were given the purified diets supplemented with 1% or 2% FCME. Experimentalresults showed that in comparison to the control, diabetic rats fed FCME increased feed intake (P<0.01and body weight gain (P<0.05. FCME inclusion significantly reduced the activities of acetyl-CoAcarboxylase (P<0.01 and fatty acid synthetase (P<0.05 in diabetic rats. FCME significantly increasedcholesterol 7 -hydroxylase with no effect on HMG-CoA reductase activity. FCME had no effect onhepatic triglyceride, free cholesterol and phospholipid. FCME inclusion at 1% level significantlyreduced serum triglyceride. FCME significantly increased HDL-cholesterol (P<0.05 with no effect onLDL + VLDL-cholesterol, and significantly reduced atherogenic index. FCME did not significantlyaffect serum insulin and glucose concentration. In conclusion, FCME supplementation altered lipidmetabolism in diabetic rats. FCME supplementation reduced the risk of atherosclerosis in diabetic rats.

  17. NMR studies of transmembrane electron transport in human erythrocytes

    International Nuclear Information System (INIS)

    Kennett, E.C.; Bubb, W.A.; Kuchel, P.W.

    2002-01-01

    Full text: Electron transport systems exist in the plasma membranes of all cells. These systems appear to play a role in cell growth and proliferation, intracellular signalling, hormone responses, apoptotic events, cell defence and perhaps most importantly they enable the cell to respond to changes in the redox state of both the intra- and extracellular environments. Previously, 13 C NMR has been used to study transmembrane electron transport in human erythrocytes, specifically the reduction of extracellular 13 C-ferricyanide. NMR is a particularly useful tool for studying such systems as changes in the metabolic state of the cell can be observed concomitantly with extracellular reductase activity. We investigated the oxidation of extracellular NADH by human erythrocytes using 1 H and 31 P NMR spectroscopy. Recent results for glucose-starved human erythrocytes indicate that, under these conditions, extracellular NADH can be oxidised at the plasma membrane with the electron transfer across the membrane resulting in reduction of intracellular NAD + . The activity is inhibited by known trans-plasma membrane electron transport inhibitors (capsaicin and atebrin) and is unaffected by inhibition of the erythrocyte Band 3 anion transporter. These results suggest that electron import from extracellular NADH allows the cell to re-establish a reducing environment after the normal redox balance is disturbed

  18. Uptake of Eudragit Retard L (Eudragit® RL Nanoparticles by Human THP-1 Cell Line and Its Effects on Hematology and Erythrocyte Damage in Rats

    Directory of Open Access Journals (Sweden)

    Mosaad A. Abdel-Wahhab

    2014-02-01

    Full Text Available The aim of this study was to prepare Eudragit Retard L (Eudragit RL nanoparticles (ENPs and to determine their properties, their uptake by the human THP-1 cell line in vitro and their effect on the hematological parameters and erythrocyte damage in rats. ENPs showed an average size of 329.0 ± 18.5 nm, a positive zeta potential value of +57.5 ± 5.47 mV and nearly spherical shape with a smooth surface. THP-1 cell lines could phagocyte ENPs after 2 h of incubation. In the in vivo study, male Sprague-Dawley rats were exposed orally or intraperitoneally (IP with a single dose of ENP (50 mg/kg body weight. Blood samples were collected after 4 h, 48 h, one week and three weeks for hematological and erythrocytes analysis. ENPs induced significant hematological disturbances in platelets, red blood cell (RBC total and differential counts of white blood cells (WBCs after 4 h, 48 h and one week. ENP increased met-Hb and Co-Hb derivatives and decreased met-Hb reductase activity. These parameters were comparable to the control after three weeks when administrated orally. It could be concluded that the route of administration has a major effect on the induction of hematological disturbances and should be considered when ENPs are applied for drug delivery systems.

  19. Revegetating fly ash landfills with Prosopis juliflora L.: impact of different amendments and Rhizobium inoculation.

    Science.gov (United States)

    Rai, U N; Pandey, K; Sinha, S; Singh, A; Saxena, R; Gupta, D K

    2004-05-01

    A revegetation trial was conducted to evaluate the feasibility of growing a legume species, Prosopis juliflora L., on fly ash ameliorated with combination of various organic amendments, blue-green algal biofertilizer and Rhizobium inoculation. Significant enhancements in plant biomass, photosynthetic pigments, protein content and in vivo nitrate reductase activity were found in the plants grown on ameliorated fly ash in comparison to the plants growing in unamended fly ash or garden soil. Higher growth was obtained in fly ash amended with blue-green algae (BGA) than farmyard manure or press mud (PM), a waste from sugar-processing industry, due to the greater contribution of plant nutrients, supply of fixed nitrogen and increased availability of phosphorus. Nodulation was suppressed in different amendments of fly ash with soil in a concentration-duration-dependent manner, but not with other amendments. Plants accumulated higher amounts of Fe, Mn, Cu, Zn and Cr in various fly ash amendments than in garden soil. Further, inoculation of the plant with a fly ash tolerant Rhizobium strain conferred tolerance for the plant to grow under fly ash stress conditions with more translocation of metals to the above ground parts. The results showed the potential of P. juliflora to grow in plantations on fly ash landfills and to reduce the metal contents of fly ash by bioaccumulation in its tissues.

  20. Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Buc-Calderon, P.; Roberfroid, M. (Universite Catholique de Louvain, Brussels (Belgium))

    1989-09-01

    Captodative substituted olefins are radical scavengers which react with free radicals to form stabilized radical adducts. One of those compounds, N-(paramethoxyphenylacetyl)dehydroalanine (AD-5), may react and scavenge both superoxide anion (O-2) and alk-oxyl radicals (RO.), and in this way prevent the appearance of their mediated biological effects. Nitrofurantoin and tert-butyl hydroperoxide were used as model compounds to stimulate free radical production and their mediated lipid peroxidation in rat liver microsomes. In addition, lipid peroxidation was also initiated by exposure of rat liver microsomal suspensions to ionizing radiation (gamma rays). The microsomal lipid peroxidation induced by these chemicals and physical agents was inhibited by the addition of AD-5. These effects were dose-dependent in a millimolar range of concentration. In addition, AD-5 has no effect on microsomal electron transport, showing that NADPH-cytochrome P450 reductase activity was not modified. These data, together with the comparisons of the effects of AD-5 and some antioxidant molecules such as superoxide dismutase, uric acid, and mannitol, support the conclusion that inhibition of lipid peroxidation by AD-5 is the result of its free radical scavenger activity. In addition, the inhibitory effect of AD-5 on microsomal lipid peroxidation was dependent of the nature of the free radical species involved in the initiation of the process, suggesting that O-2 is scavenged more efficiently than RO.

  1. HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Baskaran G

    2015-01-01

    Full Text Available Gunasekaran Baskaran,1 Shamala Salvamani,1 Siti Aqlima Ahmad,1 Noor Azmi Shaharuddin,1 Parveen Devi Pattiram,2 Mohd Yunus Shukor1 1Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, 2Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia Abstract: The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl, 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and a-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases. Keywords: HMG-CoA reductase, Basella alba, phytochemical, GC-MS/MS, RP-HPLC, hypercholesterolemia

  2. Effect of vermicompost on some physiological attributes involved in carbon and nitrogen metabolism as well as nutrient status in leaves of tobacco (nicotiana tabacum L.)

    International Nuclear Information System (INIS)

    Qin, C.; Zheng, P.; Akram, N.A.

    2016-01-01

    A pot experiment was carried out to examine the influence of vermicompost application on some key enzymes and metabolites involved in carbon (C) and nitrogen (N) metabolism as well as nutrient status in the leaves of tobacco (Nicotiana tabacum L.). Two types of vermicompost with two application rates were used in this study. Regardless of application rate, both types of vermicompost significantly increased total N, phosphorus (P) and potassium (K) contents in the leaves. They also caused enhancements in contents of total soluble carbohydrates, reducing sugars, starch and total organic C as well as amylase and invertase activities involved in C metabolism, contents of soluble protein and nicotine in N metabolism in the leaves. With an increase in application rate, each vermicompost type had an increasing effect on almost all measured parameters except nitrate reductase activity. Regardless of vermicompost type, the high rate (50%) of application showed the best effects compared with controls. The effects of V1 type vermicompost were superior to those of V2 at the same application rate. Therefore, the above effects might appear to be dependent on both type and dose. Vermicompost could be considered as an effective organic matter for attaining improved plant nutrition as well as C and N metabolism. (author)

  3. Pre-harvest methyl jasmonate treatment enhances cauliflower chemoprotective attributes without a loss in postharvest quality.

    Science.gov (United States)

    Ku, Kang Mo; Choi, Jeong-Hee; Kushad, Mosbah M; Jeffery, Elizabeth H; Juvik, John A

    2013-06-01

    Methyl jasmonate (MeJA) treatment can significantly increase glucosinolate (GS) concentrations in Brassica vegetables and potentially enhance anticancer bioactivity. Although MeJA treatment may promote ethylene biosynthesis, which can be detrimental to postharvest quality, there are no previous reports of its effect on cauliflower postharvest quality. To address this, cauliflower curds in field plots were sprayed with either 0.1 % Triton X-100 (control) or 500 μM MeJA solutions four days prior to harvest, then stored at 4 °C. Tissue subsamples were collected after 0, 10, 20, and 30 days of postharvest storage and assayed for visual color change, ethylene production, GS concentrations, and extract quinone reductase inductive activity. MeJA treatment increased curd GS concentrations of glucoraphanin, glucobrassicin, and neoglucobrassicin by 1.5, 2.4, and 4.6-fold over controls, respectively. MeJA treated cauliflower showed significantly higher quinone reductase activity, a biomarker for anticancer bioactivity, without reducing visual color and postharvest quality for 10 days at 4 °C storage.

  4. Comparative biochemistry and physiology of iron-respiring bacteria from acidic and neutral-pH environments: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Magnuson, T S

    2009-04-07

    Acidophilic dissimilatory iron-reducing bacteria (DIRB) are now being detected in a variety of ‘extreme’ low-pH, radionuclide- and heavy-metal contaminated habitats where Fe(III) reduction is taking place, and may represent a significant proportion of metal-transforming organisms in these environments. Acidiphilium cryptum is our model organism, a facultative iron-respiring Alphaproteobacterium. Major findings of this project have been 1) Discovery of novel outer-membrane and periplasmic cytochromes c in acidophiles that are reactive with Fe and Cr, 2) Discovery of Cr(VI) reduction mechanisms in acidophiles, mediated by c-type cytochromes and other reductase activity, 3) Development of enzyme detection methods specific for Cr-reducing enzymes, 4) Characterization of biofilm formation in A. cryptum, and 5) Annotation of the Acidiphilium cryptum genome (Magnuson, Kusel, and Cummings, DOE-JGI 2005-2006). Two manuscripts and one book chapter have been published, and several more mauscripts are prepared for submission.

  5. Allelopathic Stress Produced by Bitter Gourd (Momordica charantia L.

    Directory of Open Access Journals (Sweden)

    N.B. Singh

    2014-05-01

    Full Text Available The present study deals with in vitro effects of allelochemicals present in leaf and fruit leachate of Momordica charantia in vitro on plant growth and metabolism of Lycopersicon esculentum. Momordica was selected as a donor plant and tomato as recipient. Seeds of tomato were shown in pots and after germination different concentrations viz. 25, 50, 75 and 100% of leaf and fruit leachates were applied as treatment. Twenty days old seedlings were harvested for biophysical and biochemical analyses. The root and shoot length, fresh and dry weight of the seedlings decreased in dose dependent manner. The reduction in pigment and protein contents and nitrate reductase activity was concentration dependent. Membrane leakage increased as the concentration of leachates increased. Activities of antioxidant enzymes viz. superoxide dismutase (SOD, catalase (CAT and peroxidase (POX activities significantly enhanced under allelopathic stress. Inhibition of various metabolic activities under allelopathic stress resulted in decreased plant growth and development. The fruit leachate of Momordica was more inhibitory than leaf leachate.

  6. Functional characterization of the Bradyrhizobium japonicum modA and modB genes involved in molybdenum transport.

    Science.gov (United States)

    Delgado, María J; Tresierra-Ayala, Alvaro; Talbi, Chouhra; Bedmar, Eulogio J

    2006-01-01

    A modABC gene cluster that encodes an ABC-type, high-affinity molybdate transporter from Bradyrhizobium japonicum has been isolated and characterized. B. japonicum modA and modB mutant strains were unable to grow aerobically or anaerobically with nitrate as nitrogen source or as respiratory substrate, respectively, and lacked nitrate reductase activity. The nitrogen-fixing ability of the mod mutants in symbiotic association with soybean plants grown in a Mo-deficient mineral solution was severely impaired. Addition of molybdate to the bacterial growth medium or to the plant mineral solution fully restored the wild-type phenotype. Because the amount of molybdate required for suppression of the mutant phenotype either under free-living or under symbiotic conditions was dependent on sulphate concentration, it is likely that a sulphate transporter is also involved in Mo uptake in B. japonicum. The promoter region of the modABC genes has been characterized by primer extension. Reverse transcription and expression of a transcriptional fusion, P(modA)-lacZ, was detected only in a B. japonicum modA mutant grown in a medium without molybdate supplementation. These findings indicate that transcription of the B. japonicum modABC genes is repressed by molybdate.

  7. The potential protective effect of Physalis peruviana L. against carbon tetrachloride-induced hepatotoxicity in rats is mediated by suppression of oxidative stress and downregulation of MMP-9 expression.

    Science.gov (United States)

    Al-Olayan, Ebtisam M; El-Khadragy, Manal F; Aref, Ahmed M; Othman, Mohamed S; Kassab, Rami B; Abdel Moneim, Ahmed E

    2014-01-01

    The active constituent profile in Cape gooseberry (Physalis peruviana L.) juice was determined by GC-MS. Quercetin and kaempferol were active components in the juice. In this study we have evaluated its potential protective effect on hepatic injury and fibrosis induced by carbon tetrachloride (CCl4). Twenty-eight rats divided into 4 groups: Group I served as control group, and Group II received weekly i.p. injection of 2 mL CCl4/kg bwt for 12 weeks. Group III were supplemented with Physalis juice via the drinking water. The animals of Group IV received Physalis juice as Group III and also were intraperitoneally injected weekly with 2 mL CCl4/kg bwt for 12 weeks. Hepatoprotective effect was evaluated by improvement in liver enzymes serum levels, reduction in collagen areas, downregulation in expression of the fibrotic marker MMP-9, reduction in the peroxidative marker malonaldehyde and the inflammatory marker nitric oxide, and restoration of the activity of antioxidant enzymatic and nonenzymatic systems, namely, glutathione content, superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, and glutathione reductase activities. The results show that the potential hepatoprotective effects of Physalis peruviana may be due to physalis acts by promotion of processes that restore hepatolobular architecture and through the inhibition of oxidative stress pathway.

  8. Deficiências de macronutrientes no estado nutricional da mamoneira cultivar Iris Deficiencies of macronutrients on nutritional status of castor bean cultivar Iris

    Directory of Open Access Journals (Sweden)

    José Lavres Junior

    2005-02-01

    Full Text Available Os objetivos deste trabalho foram avaliar o efeito da deficiência dos macronutrientes no crescimento e estado nutricional da mamoneira (Ricinus communis L. e a obtenção do quadro sintomatológico das deficiências de N, P, K, Ca, Mg e S. Cultivou-se Ricinus communis L. cultivar Iris em solução nutritiva, tendo como tratamentos soluções completa e deficientes em N, P, K, Ca, Mg e S. Foram determinadas a concentração indireta de clorofila, a atividade da redutase do nitrato, os teores solúveis de N (NO3-, P (H2PO4- e K+ e realizados testes rápidos para N, P e K. As deficiências de N, Ca, S e Mg foram as que mais restringiram a produção de massa de matéria seca, na ordem decrescente: N>Ca>S>Mg>K>P. Os maiores acúmulos de macronutrientes, no tratamento completo, foram observados nas raízes e no limbo das folhas inferiores. As concentrações críticas para N e Ca, ambas no limbo das folhas superiores e, Mg, no pecíolo das inferiores foram, respectivamente, 46,7, 13,8 e 6,5 g kg-1. As deficiências influenciaram as leituras do clorofilômetro. A atividade da redutase do nitrato guardou relação direta com a determinação da clorofila. Os teores de N (NO3-, P (H2PO4- e K+ foram menores nas folhas deficientes em N, P e K, respectivamente, o mesmo acontecendo quando avaliadas pela análise de toque.The objectives of this work were to evaluate the effect of macronutrient deficiencies on growth and on nutritional status of castor beans (Ricinus communis L., and to obtain the symptoms of the lack of N, P, K, Ca, Mg and S. Nutrient solutions containing all macronutrients and those from which one of these elements was omitted were the treatments used. The following determinations were made: chlorophyll (indirectly, nitrate reductase activity, NO3--N, H2PO4--P and K+, both on soluble fractions, and by spot tests. Deficiencies of N, Ca, S and Mg were the most limiting for dry matter production, followed in decreasing order by those of K and

  9. Induction of the Nitrate Assimilation nirA Operon and Protein-Protein Interactions in the Maturation of Nitrate and Nitrite Reductases in the Cyanobacterium Anabaena sp. Strain PCC 7120.

    Science.gov (United States)

    Frías, José E; Flores, Enrique

    2015-07-01

    Nitrate is widely used as a nitrogen source by cyanobacteria, in which the nitrate assimilation structural genes frequently constitute the so-called nirA operon. This operon contains the genes encoding nitrite reductase (nirA), a nitrate/nitrite transporter (frequently an ABC-type transporter; nrtABCD), and nitrate reductase (narB). In the model filamentous cyanobacterium Anabaena sp. strain PCC 7120, which can fix N2 in specialized cells termed heterocysts, the nirA operon is expressed at high levels only in media containing nitrate or nitrite and lacking ammonium, a preferred nitrogen source. Here we examined the genes downstream of the nirA operon in Anabaena and found that a small open reading frame of unknown function, alr0613, can be cotranscribed with the operon. The next gene in the genome, alr0614 (narM), showed an expression pattern similar to that of the nirA operon, implying correlated expression of narM and the operon. A mutant of narM with an insertion mutation failed to produce nitrate reductase activity, consistent with the idea that NarM is required for the maturation of NarB. Both narM and narB mutants were impaired in the nitrate-dependent induction of the nirA operon, suggesting that nitrite is an inducer of the operon in Anabaena. It has previously been shown that the nitrite reductase protein NirA requires NirB, a protein likely involved in protein-protein interactions, to attain maximum activity. Bacterial two-hybrid analysis confirmed possible NirA-NirB and NarB-NarM interactions, suggesting that the development of both nitrite reductase and nitrate reductase activities in cyanobacteria involves physical interaction of the corresponding enzymes with their cognate partners, NirB and NarM, respectively. Nitrate is an important source of nitrogen for many microorganisms that is utilized through the nitrate assimilation system, which includes nitrate/nitrite membrane transporters and the nitrate and nitrite reductases. Many cyanobacteria

  10. Camphene, a Plant Derived Monoterpene, Exerts Its Hypolipidemic Action by Affecting SREBP-1 and MTP Expression.

    Directory of Open Access Journals (Sweden)

    Ioanna Vallianou

    Full Text Available The control of hyperlipidemia plays a central role in cardiovascular disease. Previously, we have shown that camphene, a constituent of mastic gum oil, lowers cholesterol and triglycerides (TG in the plasma of hyperlipidemic rats without affecting HMG-CoA reductase activity, suggesting that its hypocholesterolemic and hypotriglyceridemic effects are associated with a mechanism of action different than that of statins. In the present study, we examine the mechanism by which camphene exerts its hypolipidemic action. We evaluated the effect of camphene on the de novo synthesis of cholesterol and TG from [14C]-acetate in HepG2 cells, along with the statin mevinolin. Camphene inhibited the biosynthesis of cholesterol in a concentration-dependent manner, and a maximal inhibition of 39% was observed at 100 μM while mevinolin nearly abolished cholesterol biosynthesis. Moreover, treatment with camphene reduced TG by 34% and increased apolipoprotein AI expression. In contrast, mevinolin increased TG by 26% and had a modest effect on apolipoprotein AI expression. To evaluate the mode of action of camphene, we examined its effects on the expression of SREBP-1, which affects TG biosynthesis and SREBP-2, which mostly affects sterol synthesis. Interestingly, camphene increased the nuclear translocation of the mature form of SREBP-1 while mevinolin was found to increase the amount of the mature form of SREBP-2. The effect of camphene is most likely regulated through SREBP-1 by affecting MTP levels in response to a decrease in the intracellular cholesterol. We propose that camphene upregulates SREBP-1 expression and MTP inhibition is likely to be a probable mechanism whereby camphene exerts its hypolipidemic effect.

  11. Impact of mutations on the midpoint potential of the [4Fe-4S]+1,+2 cluster and on catalytic activity in electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO).

    Science.gov (United States)

    Usselman, Robert J; Fielding, Alistair J; Frerman, Frank E; Watmough, Nicholas J; Eaton, Gareth R; Eaton, Sandra S

    2008-01-08

    Electron-transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is an iron-sulfur flavoprotein that accepts electrons from electron-transfer flavoprotein (ETF) and reduces ubiquinone from the Q-pool. ETF-QO contains a single [4Fe-4S]2+,1+ cluster and one equivalent of FAD, which are diamagnetic in the isolated oxidized enzyme and can be reduced to paramagnetic forms by enzymatic donors or dithionite. Mutations were introduced by site-directed mutagenesis of amino acids in the vicinity of the iron-sulfur cluster of Rhodobacter sphaeroides ETF-QO. Y501 and T525 are equivalent to Y533 and T558 in the porcine ETF-QO. In the porcine protein, these residues are within hydrogen-bonding distance of the Sgamma of the cysteine ligands to the iron-sulfur cluster. Y501F, T525A, and Y501F/T525A substitutions were made to determine the effects on midpoint potential, activity, and EPR spectral properties of the cluster. The integrity of the mutated proteins was confirmed by optical spectra, EPR g-values, and spin-lattice relaxation rates, and the cluster to flavin point-dipole distance was determined by relaxation enhancement. Potentiometric titrations were monitored by changes in the CW EPR signals of the cluster and semiquinone. Single mutations decreased the midpoint potentials of the iron-sulfur cluster from +37 mV for wild type to -60 mV for Y501F and T525A and to -128 mV for Y501F/T525A. Lowering the midpoint potential resulted in a decrease in steady-state ubiquinone reductase activity and in ETF semiquinone disproportionation. The decrease in activity demonstrates that reduction of the iron-sulfur cluster is required for activity. There was no detectable effect of the mutations on the flavin midpoint potentials.

  12. Impact of Mutations on the Midpoint Potential of the [4Fe-4S]+1,+2 Cluster and on Catalytic Activity in Electron Transfer Flavoprotein-ubiquinone Oxidoreductase (ETF-QO)†

    Science.gov (United States)

    Usselman, Robert J.; Fielding, Alistair J.; Frerman, Frank E.; Watmough, Nicholas J.; Eaton, Gareth R.; Eaton, Sandra S.

    2011-01-01

    Electron transfer flavoprotein - ubiquinone oxidoreductase (ETF-QO) is an iron-sulfur flavoprotein that accepts electrons from electron-transfer flavoprotein (ETF) and reduces ubiquinone from the Q-pool. ETF-QO contains a single [4Fe-4S]2+,1+ cluster and one equivalent of FAD, which are diamagnetic in the isolated oxidized enzyme and can be reduced to paramagnetic forms by enzymatic donors or dithionite. Mutations were introduced by site-directed mutagenesis of amino acids in the vicinity of the iron-sulfur cluster of Rhodobacter sphaeroides ETF-QO. Y501 and T525 are equivalent to Y533 and T558 in the porcine ETF-QO. In the porcine protein, these residues are within hydrogen bonding distance of the Sγ of the cysteine ligands to the iron-sulfur cluster. Y501F, T525A, and Y501F/T525A substitutions were made to determine the effects on midpoint potential, activity, and EPR spectral properties of the cluster. The integrity of the mutated proteins was confirmed by optical spectra, EPR g-values, and spin-lattice relaxation rates, and the cluster to flavin point-dipole distance was determined by relaxation enhancement. Potentiometric titrations were monitored by changes in the CW EPR signals of the cluster and semiquinone. Single mutations decreased the mid-point potentials of the iron-sulfur cluster from +37 mV for wild type to −60 mV for Y501F and T525A and to −128 mV for Y501F/T525A. Lowering the midpoint potential resulted in a decrease in steady-state ubiquinone reductase activity and in ETF semiquinone disproportionation. The decrease in activity demonstrates that reduction of the iron-sulfur cluster is required for activity. There was no detectable effect of the mutations on the flavin midpoint potentials. PMID:18069858

  13. Proliferation of maize (Zea mays L.) roots in response to localized supply of nitrate

    Science.gov (United States)

    Granato, T. C.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    Maize (Zea mays L.) plants with two primary nodal root axes were grown for 8 d in flowing nutrient culture with each axis independently supplied with NO3-. Dry matter accumulation by roots was similar whether 1.0 mol m-3 NO3- was supplied to one or both axes. When NO3- was supplied to only one axis, however, accumulation of dry matter within the root system was significantly greater in the axis supplied with NO3-. The increased dry matter accumulation by the +N-treated axis was attributable entirely to increased density and growth of lateral branches and not to a difference in growth of the primary axis. Proliferation of lateral branches for the +N axis was associated with the capacity for in situ reduction and utilization of a portion of the absorbed NO3-, especially in the apical region where lateral primordia are initiated. Although reduced nitrogen was translocated to the -N axis, concentrations in the -N axis remained significantly lower than in the +N axis. The concentration of reduced nitrogen, as well as in vitro NO3- reductase activity, was greater in apical than in more basal regions of the +N axis. The enhanced proliferation of lateral branches in the +N axis was accompanied by an increase in total respiration rate of the axis. Part of the increased respiration was attributable to increased mass of roots. The specific respiration rate (micromoles CO2 evolved per hour per gram root dry weight) was also greater for the +N than for the -N axis. If respiration rate is taken as representative of sink demand, stimulation of initiation and growth of laterals by in situ utilization of a localized exogenous supply of NO3- establishes an increased sink demand through enhanced metabolic activity and the increased partitioning of assimilates to the +N axis responds to the difference in sink demand between +N and -N axes.

  14. Regulation of assimilatory sulfate reduction by cadmium in Zea mays L

    International Nuclear Information System (INIS)

    Nussbaum, S.; Schmutz, D.; Brunold, C.

    1988-01-01

    Plants cultivated with Cd can produce large amounts of phytochelatins. Since these compounds contain much cysteine, these plants should have an increased rate of assimilatory sulfate reduction, the biosynthetic pathway leading to cysteine. To test this prediction, the effect of Cd on growth, sulfate assimilation in vivo and extractable activity of two enzymes of sulfate reduction, ATP-sulfurylase (EC 2.7.7.4) and adenosine 5'-phosphosulfate sulfotransferase were measured in maize (Zea mays L.) seedlings. For comparison, nitrate reductase activity was determined. In 9-day-old cultures, the increase in fresh and dry weight was significantly inhibited by 50 micromolar and more Cd in the roots and by 100 and 200 micromolar in the shoots. Seedlings cultivated with 50 micromolar Cd for 5 days incorporated more label from 35 SO 4 2- into higher molecular weight compounds than did controls, indicating that the predicted increase in the rate of assimilatory sulfate reduction took place. Consistent with this finding, an increased level of the extractable activity of both ATP-sulfurylase and adenosine 5'-phosphosulfate sulfotransferase was measured in the roots of these plants at 50 micromolar Cd and at higher concentrations. This effect was reversible after removal of Cd from the nutrient solution. In the leaves, a significant positive effect of Cd was detected at 5 micromolar for ATP-sulfurylase and at 5 and 20 micromolar for adenosine 5'-phosphosulfate sulfotransferase. At higher Cd concentrations, both enzyme activities were at levels below the control. Nitrate reductase (EC 1.6.6.1) activity decreased at 50 micromolar or more Cd in the roots and was similarly affected at ATP-sulfurylase activity in the primary leaves

  15. Up-regulation of cytochrome P450 and phase II enzyme systems in rat precision-cut rat lung slices by the intact glucosinolates, glucoraphanin and glucoerucin.

    Science.gov (United States)

    Abdull Razis, Ahmad Faizal; Bagatta, Manuela; De Nicola, Gina Rosalinda; Iori, Renato; Ioannides, Costas

    2011-03-01

    It is believed that the chemopreventive activity of cruciferous vegetables in the lung and other tissues is exclusively the result of exposure to degradation products of glucosinolates, such as the isothiocyanates, and that the parent glucosinolates make no contribution. In the present study, evidence is presented for the first time that, in rat lung, the intact glucosinolates, glucoraphanin and glucoerucin, can modulate carcinogen-metabolising enzyme systems. The glucosinolates were isolated from cruciferous vegetables and incubated (1-25 μM) with precision-cut rat lung slices for 24h. Both glucosinolates, at concentrations as low as 1 μM, up-regulated the O-deethylation of ethoxyresorufin and the apoprotein levels of CYP1A1 and CYP1B1; supplementation of the incubation medium with myrosinase, the enzyme that converts glucosinolates to their corresponding isothiocyanates, abolished the rise in ethoxyresorufin O-deethylase activity. In contrast, neither glucosinolate, at the concentrations studied, influenced quinone reductase activity in the lung slices, but addition of myrosinase to the glucosinolate incubations led to a marked rise in activity. Glutathione S-transferase activity, monitored using 1-chloro-2,4-dinitrobenzene as the accepting substrate, was elevated in lung slices exposed to glucoraphanin. GSTα protein levels were increased by glucoraphanin and, to a much lesser extent, glucoerucin. It may be concluded that intact glucosinolates can modulate the activity of pulmonary carcinogen-metabolising enzyme systems, and can thus contribute to the documented chemopreventive activity of cruciferous vegetables in the lung. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Cucurbita ficifolia Bouché (Cucurbitaceae) and D-chiro-inositol modulate the redox state and inflammation in 3T3-L1 adipocytes.

    Science.gov (United States)

    Fortis-Barrera, Ángeles; Alarcón-Aguilar, Francisco Javier; Banderas-Dorantes, Tania; Díaz-Flores, Margarita; Román-Ramos, Rubén; Cruz, Miguel; García-Macedo, Rebeca

    2013-10-01

    Cucurbita ficifolia (characterised by its D chiro inositol (DCI) content) and of synthetic DCI on the redox state, mRNA expression and secretions of proinflammatory cytokines. Additionally, we evaluated the insulin-mimetic action of both treatments by assessing protein kinase B (PKB) activation in 3T3-L1 adipocytes. Adipocytes were treated with C. ficifolia and synthetic DCI. The redox state was determined by spectrophotometry as changes in the reduced glutathione/oxidised glutathione (GSH/GSSG) ratio, glutathione peroxidase and glutathione reductase activities; H2 O2 levels were measured by flow cytometry. The mRNA expression and the protein level of cytokines were determinate by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activation of PKB activation was detected by Western blot. C. ficifolia extract and synthetic DCI reduced oxidative stress by decreased H2 O2 levels, increased glutathione peroxidase activity and changes in the GSH/GSSG ratio. Furthermore, DCI decreased the mRNA expression and secretion of tumour necrosis factor-α, interleukin 6 (IL-6) and resistin, while C. ficifolia reduced protein levels of resistin and increased IL-6 levels. Only DCI demonstrated insulin-mimetic action. The antioxidant and anti-inflammatory effects of C. ficifolia extract can be explained in part by its DCI content, which modulates the GSH/GSSG ratio and contributes to a reduced proinflammatory state. C. ficifolia and DCI treatments may reduce the disturbances caused by oxidative stress. Additionally, DCI may improve insulin sensitivity through its insulin-mimetic effects. © 2013 Royal Pharmaceutical Society.

  17. Bioreactor with Ipomoea hederifolia adventitious roots and its endophyte Cladosporium cladosporioides for textile dye degradation

    International Nuclear Information System (INIS)

    Patil, Swapnil M.; Chandanshive, Vishal V.; Rane, Niraj R.; Khandare, Rahul V.; Watharkar, Anuprita D.; Govindwar, Sanjay P.

    2016-01-01

    In vitro grown untransformed adventitious roots (AR) culture of Ipomoea hederifolia and its endophytic fungus (EF) Cladosporium cladosporioides decolorized Navy Blue HE2R (NB-HE2R) at a concentration of 20 ppm up to 83.3 and 65%, respectively within 96 h. Whereas the AR-EF consortium decolorized the dye more efficiently and gave 97% removal within 36 h. Significant inductions in the enzyme activities of lignin peroxidase, tyrosinase and laccase were observed in roots, while enzymes like tyrosinase, laccase and riboflavin reductase activities were induced in EF. Metabolites of dye were analyzed using UV—vis spectroscopy, FTIR and gas chromatography-mass spectrometry. Possible metabolic pathways of NB-HE2R were proposed with AR, EF and AR-EF systems independently. Looking at the superior efficacy of AR-EF system, a rhizoreactor was developed for the treatment of NB-HE2R at a concentration of 1000 ppm. Control reactor systems with independently grown AR and EF gave 94 and 85% NB-HE2R removal, respectively within 36 h. The AR-EF rhizoreactor, however, gave 97% decolorization. The endophyte colonization additionally increased root and shoot lengths of candidate plants through mutualism. Combined bioreactor strategies can be effectively used for future eco-friendly remediation purposes. - Highlights: • Endophytic fungus on Ipomoea hederifolia promotes root growth and shoot development • Endophytic Cladosporium cladosporioides synergistically degrade Navy Blue-HE2R dye • Endophyte colonized I. hederifolia roots proved superior in dye decolorization • Dye stress and toxicity was efficiently dealt by root-endophyte consortium • Root-endophyte consortium can be used as a sustainable remediation strategy

  18. Bioreactor with Ipomoea hederifolia adventitious roots and its endophyte Cladosporium cladosporioides for textile dye degradation

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Swapnil M. [Department of Biotechnology, Shivaji University, Kolhapur-416004 (India); Chandanshive, Vishal V. [Department of Biochemistry, Shivaji University, Kolhapur-416004 (India); Rane, Niraj R.; Khandare, Rahul V. [Department of Biotechnology, Shivaji University, Kolhapur-416004 (India); Watharkar, Anuprita D. [Department of Biochemistry, Shivaji University, Kolhapur-416004 (India); Govindwar, Sanjay P., E-mail: spg_biochem@unishivaji.ac.in [Department of Biochemistry, Shivaji University, Kolhapur-416004 (India)

    2016-04-15

    In vitro grown untransformed adventitious roots (AR) culture of Ipomoea hederifolia and its endophytic fungus (EF) Cladosporium cladosporioides decolorized Navy Blue HE2R (NB-HE2R) at a concentration of 20 ppm up to 83.3 and 65%, respectively within 96 h. Whereas the AR-EF consortium decolorized the dye more efficiently and gave 97% removal within 36 h. Significant inductions in the enzyme activities of lignin peroxidase, tyrosinase and laccase were observed in roots, while enzymes like tyrosinase, laccase and riboflavin reductase activities were induced in EF. Metabolites of dye were analyzed using UV—vis spectroscopy, FTIR and gas chromatography-mass spectrometry. Possible metabolic pathways of NB-HE2R were proposed with AR, EF and AR-EF systems independently. Looking at the superior efficacy of AR-EF system, a rhizoreactor was developed for the treatment of NB-HE2R at a concentration of 1000 ppm. Control reactor systems with independently grown AR and EF gave 94 and 85% NB-HE2R removal, respectively within 36 h. The AR-EF rhizoreactor, however, gave 97% decolorization. The endophyte colonization additionally increased root and shoot lengths of candidate plants through mutualism. Combined bioreactor strategies can be effectively used for future eco-friendly remediation purposes. - Highlights: • Endophytic fungus on Ipomoea hederifolia promotes root growth and shoot development • Endophytic Cladosporium cladosporioides synergistically degrade Navy Blue-HE2R dye • Endophyte colonized I. hederifolia roots proved superior in dye decolorization • Dye stress and toxicity was efficiently dealt by root-endophyte consortium • Root-endophyte consortium can be used as a sustainable remediation strategy.

  19. Exclusion of solar UV radiation improves photosynthetic performance and yield of wheat varieties.

    Science.gov (United States)

    Kataria, Sunita; Guruprasad, K N

    2015-12-01

    Field studies were conducted to determine the potential for alterations in photosynthetic performance and grain yield of four wheat (Triticum aestivum) varieties of India- Vidisha, Purna, Swarna and Naveen Chandausi by ambient ultraviolet radiation (UV). The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (solar UV exclusion increased the leaf mass per area ratio, leaf weight ratio and chlorophylls per unit area of flag leaves in all the four varieties of wheat. Polyphasic chlorophyll a fluorescence transients from the flag leaves of UV excluded wheat plants gave a higher fluorescence yield. Exclusion of solar UV significantly enhanced photosynthetic performance as a consequence of increased efficiency of PS II, performance index (PIABS) and rate of photosynthesis in the flag leaves of wheat varieties along with a remarkable increase in carbonic anhydrase, Rubisco and nitrate reductase activities. This additional fixation of carbon and nitrogen by exclusion of UV was channelized towards the improvement in grain yield of wheat varieties as there was a decrease in the UV-B absorbing substances and an increase in soluble protein content in flag leaves of all the four varieties of wheat. The magnitude of response for UV exclusion for all the measured parameters was higher in two varieties of wheat Vidisha and Purna as compared to Swarna and Naveen Chandausi. Cumulative stress response index (CSRI) for each variety was developed from the cumulative sum of physiological and yield parameters such as leaf mass area ratio of flag leaf, total chlorophyll content, performance index at absorption basis, rate of photosynthesis and grain yield. All the varieties had a negative CSRI, demonstrating a negative impact of ambient UV radiation. Naveen Chandausi and Swarna are less sensitive to ambient UV radiation; Vidisha is more sensitive to both UV-A and UV-B and Purna is more sensitive to ambient UV-B radiation. Copyright

  20. The Mancozeb-containing carbamate fungicide tattoo induces mild oxidative stress in goldfish brain, liver, and kidney.

    Science.gov (United States)

    Atamaniuk, Tetiana M; Kubrak, Olga I; Husak, Viktor V; Storey, Kenneth B; Lushchak, Volodymyr I

    2014-11-01

    Tattoo belongs to the group of carbamate fungicides and contains Mancozeb (ethylene(bis)dithiocarbamate) as its main constituent. The toxicity of Mancozeb to living organisms, particularly fish, is not resolved. This work investigated the effects of 96 h of exposure to 3, 5, or 10 mg L(-1) of Tattoo (corresponding to 0.9, 1.5, or 3 mg L(-1) of Mancozeb) on the levels of oxidative stress markers and the antioxidant enzyme system of brain, liver, and kidney of goldfish, Carassius auratus). In liver, Tattoo exposure resulted in increased activities of superoxide dismutase (SOD) by 70%-79%, catalase by 23%-52% and glutathione peroxidase (GPx) by 49%. The content of protein carbonyls (CP) in liver was also enhanced by 92%-125% indicating extensive damage to proteins. Similar increases in CP levels (by 98%-111%) accompanied by reduced glucose-6-phosphate dehydrogenase activity (by 13%-15%) was observed in kidney of fish exposed to Tattoo; however, SOD activity increased by 37% in this tissue after treatment with 10 mg L(-1) Tattoo. In brain, a rise in lipid peroxide level (by 29%) took place after exposure to 10 mg L(-1) Tattoo and was accompanied by elevation of high-molecular mass thiols (by 14%). Tattoo exposure also resulted in a concentration-dependent decrease in glutathione reductase activity (by 26%-37%) in brain. The data collectively show that exposure of goldfish to 3-10 mg L(-1) of the carbamate fungicide Tattoo resulted in the development of mild oxidative stress and activation of antioxidant defense systems in goldfish tissues. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  1. Mechanistic studies with solubilized rat liver steroid 5 alpha-reductase: Elucidation of the kinetic mechanism

    International Nuclear Information System (INIS)

    Levy, M.A.; Brandt, M.; Greway, A.T.

    1990-01-01

    A solubilized preparation of steroid 5 alpha-reductase from rat liver has been used in studies focused toward an understanding of the kinetic mechanism associated with enzyme catalysis. From the results of analyses with product and dead-end inhibitors, a preferentially ordered binding of substrates and release of products from the surface of the enzyme is proposed. The observations from these experiments were identical with those using the steroid 5 alpha-reductase activity associated with rat liver microsomes. The primary isotope effects on steady-state kinetic parameters when [4S-2H]NADPH was used also were consistent with an ordered kinetic mechanism. Normal isotope effects were observed for all three kinetic parameters (Vm/Km for both testosterone and NADPH and Vm) at all substrate concentrations used experimentally. Upon extrapolation to infinite concentration of testosterone, the isotope effect on Vm/Km for NADPH approached unity, indicating that the nicotinamide dinucleotide phosphate is the first substrate binding to and the second product released from the enzyme. The isotope effects on Vm/Km for testosterone at infinite concentration of cofactor and on Vm were 3.8 +/- 0.5 and 3.3 +/- 0.4, respectively. Data from the pH profiles of these three steady-state parameters and the inhibition constants (1/Ki) of competitive inhibitors versus both substrates indicate that the binding of nicotinamide dinucleotide phosphate involves coordination of its anionic 2'-phosphate to a protonated enzyme-associated base with an apparent pK near 8.0. From these results, relative limits have been placed on several of the internal rate constants used to describe the ordered mechanism of the rat liver steroid 5 alpha-reductase

  2. Heavy Metals Induce Iron Deficiency Responses at Different Hierarchic and Regulatory Levels1[OPEN

    Science.gov (United States)

    2017-01-01

    In plants, the excess of several heavy metals mimics iron (Fe) deficiency-induced chlorosis, indicating a disturbance in Fe homeostasis. To examine the level at which heavy metals interfere with Fe deficiency responses, we carried out an in-depth characterization of Fe-related physiological, regulatory, and morphological responses in Arabidopsis (Arabidopsis thaliana) exposed to heavy metals. Enhanced zinc (Zn) uptake closely mimicked Fe deficiency by leading to low chlorophyll but high ferric-chelate reductase activity and coumarin release. These responses were not caused by Zn-inhibited Fe uptake via IRON-REGULATED TRANSPORTER (IRT1). Instead, Zn simulated the transcriptional response of typical Fe-regulated genes, indicating that Zn affects Fe homeostasis at the level of Fe sensing. Excess supplies of cobalt and nickel altered root traits in a different way from Fe deficiency, inducing only transient Fe deficiency responses, which were characterized by a lack of induction of the ethylene pathway. Cadmium showed a rather inconsistent influence on Fe deficiency responses at multiple levels. By contrast, manganese evoked weak Fe deficiency responses in wild-type plants but strongly exacerbated chlorosis in irt1 plants, indicating that manganese antagonized Fe mainly at the level of transport. These results show that the investigated heavy metals modulate Fe deficiency responses at different hierarchic and regulatory levels and that the interaction of metals with physiological and morphological Fe deficiency responses is uncoupled. Thus, this study not only emphasizes the importance of assessing heavy metal toxicities at multiple levels but also provides a new perspective on how Fe deficiency contributes to the toxic action of individual heavy metals. PMID:28500270

  3. The Suitability and the Bio-chemical Characteristics of Soils from the Northwest Region of Development from Romania, for Blueberry Crop

    Directory of Open Access Journals (Sweden)

    Amalia Ioana BOȚ

    2017-11-01

    Full Text Available We conducted several bio-chemical analyses on soil samples collected from eight blueberry plantations from Northwest Region of Development, using such as Kjeldahl method for total N, Perucci, Krawczyński, Hoffman and Teicher methodology for determine soil enzyme. The bio-chemical analyses conducted provide a better qualitative characterization of soils, providing significant information regarding their fertility degree and favourability for blueberries. For instance, the higher amount of total organic carbon found in four of the eight studied plantation, can be correlated with the same higher amount of enzyme present in soil which have an influence on them, xanthine oxidase and peroxidase activity. Taking into account the requirements needed for a blueberry plantation, we demonstrate that organic soils have also had the highest amount of bio-chemical compounds, such as cambisoil, met in Galații Bistriței, where were also found the highest amounts of different forms of nitrogen (1.755 g/kg total N; 0.0189 g/kg NH4 + and 0.0231g/kg NO3 in Galații Bistriței, comparing to 1.344 g/kg of total nitrogen; 0.0126 g/kg NH4+ and 0.0119 g/kg NO3- in Ulmeni, different forms of carbon and the enzymes that influence this compounds in soil, xanthine oxidase activity, peroxidase activity and nitrate reductase activity.

  4. Lead toxicity in Brassica pekinensis Rupr.: effect on nitrate assimilation and growth.

    Science.gov (United States)

    Xiong, Zhi-Ting; Zhao, Fei; Li, Min-jing

    2006-04-01

    Lead is a major heavy-metal contaminant in the environment that has various anthropogenic and natural sources. To study the phytotoxic effects of Pb on the popular vegetable Chinese cabbage (Brassica pekinensis Rupr.) via depression of nitrogen assimilation, pot culture experiments with three concentrations of treatment with Pb (0, 4, and 8 mmol/kg dry soil) were carried out. Our results demonstrated adverse effects of Pb on nitrogen assimilation and plant growth. The addition of Pb in the soil resulted in elevated accumulation of Pb in the shoots of the plants: Pb concentrations of 14.3, 202.3, and 418.2 mg/kg (DW) in the shoots were detected with the 0, 4, and 8 mmol/kg treatments, respectively. Compared to the control, Pb exposure (4 and 8 mmol/kg) significantly decreased shoot nitrate content (71% and 80% of the control), nitrate reductase activity (104% and 49% of the control), and free amino acid content (81% and 82% of the control), indicating decreased nitrogen assimilation in the plants. The effect of Pb also was shown by the progressive decline in shoot biomass with increasing Pb concentration in plant shoots and in the soil. However, at the treatment levels used in this study, lead did not induce visible toxic symptoms. The lowest-concentration Pb treatment (4 mmol/kg) stimulated chlorophyll b content but did not influence chlorophyll a content. The results suggested that the toxicity of Pb to the plants occurred at least partly via depression of nitrogen assimilation. Copyright 2006 Wiley Periodicals, Inc.

  5. Hair growth promoting effect of white wax and policosanol from white wax on the mouse model of testosterone-induced hair loss.

    Science.gov (United States)

    Wang, Zhan-di; Feng, Ying; Ma, Li-Yi; Li, Xian; Ding, Wei-Feng; Chen, Xiao-Ming

    2017-05-01

    White wax (WW) has been traditionally used to treat hair loss in China. However there has been no reporter WW and its extract responsible for hair growth-promoting effect on androgenetic alopecia. In this paper, we examined the hair growth-promoting effects of WW and policosanol of white wax (WWP) on model animal of androgenetic alopecia and the potential target cell of WW and WWP. WW (1, 10 and 20%) and WWP (0.5, 1 and 2%) were applied topically to the backs of mice. Finasteride (2%) was applied topically as a positive control. MTS assays were performed to evaluate cell proliferation in culture human follicle dermal papilla cells (HFDPCs). The inhibition of WW and WWP for 5α- reductase were tested in Vitro. Results showed more lost hairs were clearly seen in mice treated with TP only and TP plus vehicle. Mice which received TP plus WW and WWP showed less hair loss. WW and WWP showed an outstanding hair growth-promoting activity as reflected by the follicular length, follicular density, A/T ratio, and hair bulb diameter. The optimal treatment effect was observed at 10% WW and 1% WWP, which were better than 2% finasteride treatment. MTS assay results suggested that WW and WWP remarkably increased the proliferation of HFDPCs. Inhibitor assay of 5α- reductase showed that WW and WWP inhibited significantly the conversion of testosterone to dihydrotesterone, and the IC 50 values of WW and WWP were higher than that of finasteride. In Conclusion, WW and WWP could act against testosterone-induced alopecia in mice, and they promoted hair growth by inhibiting 5α-reductase activity and HFDPCs proliferation. DPCs is the target cell of WW and WWP. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Seasonal mercury exposure and oxidant-antioxidant status of James Bay sport fishermen.

    Science.gov (United States)

    Bélanger, Marie-Claire; Mirault, Marc-Edouard; Dewailly, Eric; Plante, Michel; Berthiaume, Line; Noël, Micheline; Julien, Pierre

    2008-05-01

    The effects of a moderate seasonal exposure to methylmercury on plasma low-density lipoprotein (LDL) oxidation and cardiovascular risk indices are not known. The objective of the study was to assess the effects of a seasonal exposure to mercury at similar dose reported to increase cardiovascular risk through fish consumption. Effects on lipoprotein cholesterol and fatty acid profiles, LDL oxidation, and blood oxidant-antioxidant balance were to be assessed in sport fishermen presenting normal blood selenium and omega-3 fatty acid contents. Thirty-one healthy James Bay sport fishermen were assessed for within-subject longitudinal seasonal variations in hair and blood mercury, plasma oxidized LDL, lipophilic antioxidants, homocysteine, blood selenium, and glutathione peroxidase and reductase activities determined before and after the fishing season and compared by matched-pair tests. Hair mercury doubled during the fishing season (2.8+/-0.4 microg/g, P<.0001). Baseline blood selenium, homocysteine, and erythrocyte fatty acid profiles did not change. Plasma high-density lipoprotein cholesterol increased (+5%, P=.05), whereas very low-density lipoprotein cholesterol and oxidized LDL decreased (-8%, P=.05; -18%, P=.008). Blood glutathione peroxidase (+9.7%, P=.001), glutathione reductase (+7.2%, P<.0001), and total glutathione (+45% P<.0001) increased during the fishing season. Plasma total coenzyme Q10 (+13%, P=.02), ubiquinone-10 (+67%, P=.03), and beta-carotene (+46%, P=.01) also increased, whereas vitamin E status was unaffected. Pairwise correlations revealed no association between mercury exposure and any of the biomarkers investigated. In contrast, strong predictors of cardiovascular risk such as high-density lipoprotein cholesterol, oxidized LDL, and glutathione peroxidase improved during the fishing season despite elevated methylmercury exposure. The beneficial effects of seasonal fishing activity and fish consumption on cardiovascular health may suppress

  7. Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Aslankoohi, Elham; Verstrepen, Kevin J; Courtin, Christophe M

    2015-07-02

    Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Molecular mechanisms of drug resistance and tumor promotion involving mammalian ribonucleotide reductase

    Energy Technology Data Exchange (ETDEWEB)

    Choy, B.B.K.

    1991-01-01

    Mammalian ribonucleotide reductase is a highly regulated, rate-limiting activity responsible for converting ribonucleoside diphosphates to the deoxyribonucleotide precursors of DNA. The enzyme consists of two nonidentical proteins called M1 and M2, both of which are required for activity. Hydroxyurea is an antitumor agent which inhibits ribonucleotide reductase by interacting with the M2 component specifically at a unique tyrosyl free radical. Studies were conducted on a series of drug resistant mouse cell lines, selected by a step-wise procedure for increasing levels of resistance to the cytotoxic effects of hydroxyurea. Each successive drug selection step leading to the isolation of highly resistant cells was accompanied by stable elevations in cellular resistance and ribonucleotide reductase activity. The drug resistant cell lines exhibited gene amplification of the M2 gene, elevated M2 mRNA, and M2 protein. In addition to M2 gene amplification, posttranscriptional modulation also occurred during the drug selection. Studies of the biosynthesis rates with exogenously added iron suggest a role for iron in regulating the level of M2 protein when cells are cultured in the presence of hydroxyurea. The hydroxyurea-inactivated ribonucleotide reductase protein M2 has a destabilized iron centre, which readily releases iron. Altered expression of ferritin appears to be required for the development of hydroxyurea resistance in nammalian cells. The results show an interesting relationship between the expressions of ribonucleotide reductase and ferritin. The phorbol ester tumor promoter, TPA, is also able to alter the expression of M2. TPA was able to induce M2 mRNA levels transiently up to 18-fold within 1/2 hour. This rapid and large elevation of ribonucleotide reductase suggests that the enzyme may play a role in tumor promotion. Studies of the M2 promoter region were undertaken to better understand the mechanism of TPA induction of M2.

  9. Selenium bioavailability from soy protein isolate and tofu in rats fed a torula yeast-based diet.

    Science.gov (United States)

    Yan, Lin; Graef, George L; Reeves, Philip G; Johnson, LuAnn K

    2009-12-23

    Selenium (Se) is an essential nutrient, and soy is a major plant source of dietary protein to humans. The United States produces one-third of the world's soybeans, and the Se-rich Northern Plains produce a large share of the nation's soybeans. The present study used a rat model to determine the bioavailability of Se from a protein isolate and tofu (bean curd) prepared from a soybean cultivar we recently developed specifically for food grade markets. The soybean seeds contained 2.91 mg Se/kg. Male Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet containing 5 microg Se/kg; after 56 days, they were replenished of Se for an additional 50 days by feeding them the same diet supplemented with 20, 30, or 40 microg Se/kg from soy protein isolate or tofu. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the responses of Se-dependent enzyme activities and tissue Se contents, comparing those responses for each soy product to those for SeMet using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in dose-dependent increases in glutathione peroxidase activities in blood and liver and thioredoxin reductase activity in liver, as well as dose-dependent increases in the Se contents of plasma, liver, muscle, and kidneys. These responses indicated an overall bioavailability of approximately 97% for Se from both the protein isolate and tofu, relative to SeMet. These results demonstrate that Se from this soybean cultivar is highly bioavailable in this model and that high-Se soybeans can be good dietary sources of Se.

  10. Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats.

    Science.gov (United States)

    Yan, Lin; Reeves, Philip G; Johnson, LuAnn K

    2010-10-01

    We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2±0.2, 11.4±0.1 and 7.4±0.1mg/kg, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se. Published by Elsevier GmbH.

  11. Effect of selenodiglutathione on the metabolism of canine mammary tumor cells

    International Nuclear Information System (INIS)

    Fico-Santoro, M.; Lebowitz, A.; Milner, J.A.

    1986-01-01

    Selenodiglutathione (SDG) has been shown to be an effective inhibitor of tumor growth. The present studies were designed to evaluate altered metabolism in canine mammary tumor cells (CMT-13) exposed to various concentrations of SDG. Addition of SDG at 0.025 μg Se/ml did not inhibit growth of CMT-13 cells after 24 h of incubation. At this concentration of SDG, approximately 25% of 75 Se- 35 S-SDG was retained in these tumor cells after 24 h of incubation. The nuclear fraction contained 96% of the 75 Se and 35 S radioactivity. The ratio of 75 Se to 35 S was 1 to 4.5 in the whole cell and in the nuclear fraction. SDG increased glutathione peroxidase activity by 40% compared to CMT-13 cells not exposed to SDG. Glutathione reductase activity was decreased by 63% by the addition of SDG. In addition, supplemental SDG resulted in a 55% decrease in GSH content but did not alter GSSG concentrations. After 4d of incubation, SDG at 0.1 and 0.5 μg Se/ml caused a 43 and 58% inhibition of growth of CMT-13 cells. Addition of GSH (100μM) partially prevented, 68% and 54%, the growth inhibition caused by SDG at concentrations of 0.1 and 0.5 μg Se per ml respectively during the 4d incubation period. Preincubation of CMT-13 cells with GSH for 48 h before addition of SDG (0.5 μg Se/ml) completely prevented the growth inhibition caused by this seleno-compound

  12. Identification of miR-185 as a regulator of de novo cholesterol biosynthesis and low density lipoprotein uptake

    Science.gov (United States)

    Yang, Muhua; Liu, Weidong; Pellicane, Christina; Sahyoun, Christine; Joseph, Biny K.; Gallo-Ebert, Christina; Donigan, Melissa; Pandya, Devanshi; Giordano, Caroline; Bata, Adam; Nickels, Joseph T.

    2014-01-01

    Dysregulation of cholesterol homeostasis is associated with various metabolic diseases, including atherosclerosis and type 2 diabetes. The sterol response element binding protein (SREBP)-2 transcription factor induces the expression of genes involved in de novo cholesterol biosynthesis and low density lipoprotein (LDL) uptake, thus it plays a crucial role in maintaining cholesterol homeostasis. Here, we found that overexpressing microRNA (miR)-185 in HepG2 cells repressed SREBP-2 expression and protein level. miR-185-directed inhibition caused decreased SREBP-2-dependent gene expression, LDL uptake, and HMG-CoA reductase activity. In addition, we found that miR-185 expression was tightly regulated by SREBP-1c, through its binding to a single sterol response element in the miR-185 promoter. Moreover, we found that miR-185 expression levels were elevated in mice fed a high-fat diet, and this increase correlated with an increase in total cholesterol level and a decrease in SREBP-2 expression and protein. Finally, we found that individuals with high cholesterol had a 5-fold increase in serum miR-185 expression compared with control individuals. Thus, miR-185 controls cholesterol homeostasis through regulating SREBP-2 expression and activity. In turn, SREBP-1c regulates miR-185 expression through a complex cholesterol-responsive feedback loop. Thus, a novel axis regulating cholesterol homeostasis exists that exploits miR-185-dependent regulation of SREBP-2 and requires SREBP-1c for function. PMID:24296663

  13. Nitrite uptake by nitrogen-depleted wheat seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, W A; Johnson, R E; Volk, R J

    1974-01-01

    Intact, 14-day-old nitrogen-depleted wheat (Triticum vulgare cv. Blueboy) seedlings were exposed to solutions of 0.5 mM KNO/sub 2/, 0.05 mM CaSO/sub 4/ and 1 mM sodium 2-(N-morpholino)-ethanesulfonate, pH 6.1. Nitrite uptake was determined from depletion of the ambient solution or from incorporation of /sup 15/N in the tissue. An initial nitrite uptake shoulder was followed by a relatively slow uptake rate which subsequently increased to a substantially greater rate. This accelerated phase was maintained through 24 h. Nitrite accumulated to a slight extent in the root tissues during the first few hours but declined to low values when the accelerated rate was fully developed, indicating an increase in nitrite reductase activity paralleling the increase in nitrite uptake capacity. About 50% of the nitrogen absorbed as nitrite was translocated to the shoots by 9 to 12 h. Development of the accelerated nitrite uptake rate was restricted in excised roots, in intact plants kept in darkness, by 400 ..mu..g puromycin ml/sup -1/ and by 1 mM L-ethionine. When puromycin and L-ethionine were added after the accelerated phase had been initiated, their effects were not as detrimental as when they were added at first exposure to KNO/sub 2/. The two inhibitors restricted translocation more than uptake. The data indicate an involvement of protein synthesis and a requirement for movement of a substance from shoots to roots for maximal development of the accelerated nitrite uptake phase. A requirement for protein synthesis in the transport of soluble organic nitrogen from roots to shoots is also suggested.

  14. Ameliorative Effects of Grape Seed Proanthocyanidin Extract on Growth Performance, Immune Function, Antioxidant Capacity, Biochemical Constituents, Liver Histopathology and Aflatoxin Residues in Broilers Exposed to Aflatoxin B₁.

    Science.gov (United States)

    Ali Rajput, Shahid; Sun, Lvhui; Zhang, Niya; Mohamed Khalil, Mahmoud; Gao, Xin; Ling, Zhao; Zhu, Luoyi; Khan, Farhan Anwar; Zhang, Jiacai; Qi, Desheng

    2017-11-15

    Aflatoxicosis is a grave threat to the poultry industry. Dietary supplementation with antioxidants showed a great potential in enhancing the immune system; hence, protecting animals against aflatoxin B₁-induced toxicity. Grape seed proanthocyanidin extract (GSPE) one of the most well-known and powerful antioxidants. Therefore, the purpose of this research was to investigate the effectiveness of GSPE in the detoxification of AFB₁ in broilers. A total of 300 one-day-old Cobb chicks were randomly allocated into five treatments of six replicates (10 birds per replicate), fed ad libitum for four weeks with the following dietary treatments: 1. Basal diet (control); 2. Basal diet + 1 mg/kg AFB₁ contaminated corn (AFB₁); 3. Basal diet + GSPE 250 mg/kg; (GSPE 250 mg/kg) 4. Basal diet + AFB₁ (1 mg/kg) + GSPE 250 mg/kg; (AFB₁ + GSPE 250 mg/kg) 5. Basal diet + AFB₁ (1mg/kg) + GSPE 500 mg/kg, (AFB₁ + GSPE 500 mg/kg). When compared with the control group, feeding broilers with AFB₁ alone significantly reduced growth performance, serum immunoglobulin contents, negatively altered serum biochemical contents, and enzyme activities, and induced histopathological lesion in the liver. In addition, AFB₁ significantly increased malondialdehyde content and decreased total superoxide dismutase, catalase, glutathione peroxide, glutathione-S transferase, glutathione reductase activities, and glutathione concentration within the liver and serum. The supplementation of GSPE (250 and 500 mg/kg) to AFB₁ contaminated diet reduced AFB₁ residue in the liver and significantly mitigated AFB₁ negative effects. From these results, it can be concluded that dietary supplementation of GSPE has protective effects against aflatoxicosis caused by AFB₁ in broiler chickens.

  15. Rhodobacter capsulatus gains a competitive advantage from respiratory nitrate reduction during light-dark transitions.

    Science.gov (United States)

    Ellington, M J K; Richardson, D J; Ferguson, S J

    2003-04-01

    Rhodobacter capsulatus N22DNAR(+) possesses a periplasmic nitrate reductase and is capable of reducing nitrate to nitrite under anaerobic conditions. In the absence of light this ability cannot support chemoheterotrophic growth in batch cultures. This study investigated the effect of nitrate reduction on the growth of R. capsulatus N22DNAR(+) during multiple light-dark cycles of anaerobic photoheterotrophic/dark chemoheterotrophic growth conditions in carbon-limited continuous cultures. The reduction of nitrate did not affect the photoheterotrophic growth yield of R. capsulatus N22DNAR(+). After a transition from photoheterotrophic to dark chemoheterotrophic growth conditions, the reduction of nitrate slowed the initial washout of a R. capsulatus N22DNAR(+) culture. Towards the end of a period of darkness nitrate-reducing cultures maintained higher viable cell counts than non-nitrate-reducing cultures. During light-dark cycling of a mixed culture, the strain able to reduce nitrate (N22DNAR(+)) outcompeted the strain which was unable to reduce nitrate (N22). The evidence indicates that the periplasmic nitrate reductase activity supports slow growth that retards the washout of a culture during anaerobic chemoheterotrophic conditions, and provides a protonmotive force for cell maintenance during the dark period before reillumination. This translates into a selective advantage during repeated light-dark cycles, such that in mixed culture N22DNAR(+) outcompetes N22. Exposure to light-dark cycles will be a common feature for R. capsulatus in its natural habitats, and this study shows that nitrate respiration may provide a selective advantage under such conditions.

  16. Ameliorative Effects of Grape Seed Proanthocyanidin Extract on Growth Performance, Immune Function, Antioxidant Capacity, Biochemical Constituents, Liver Histopathology and Aflatoxin Residues in Broilers Exposed to Aflatoxin B1

    Science.gov (United States)

    Sun, Lvhui; Zhang, Niya; Ling, Zhao; Zhu, Luoyi; Khan, Farhan Anwar; Zhang, Jiacai; Qi, Desheng

    2017-01-01

    Aflatoxicosis is a grave threat to the poultry industry. Dietary supplementation with antioxidants showed a great potential in enhancing the immune system; hence, protecting animals against aflatoxin B1-induced toxicity. Grape seed proanthocyanidin extract (GSPE) one of the most well-known and powerful antioxidants. Therefore, the purpose of this research was to investigate the effectiveness of GSPE in the detoxification of AFB1 in broilers. A total of 300 one-day-old Cobb chicks were randomly allocated into five treatments of six replicates (10 birds per replicate), fed ad libitum for four weeks with the following dietary treatments: 1. Basal diet (control); 2. Basal diet + 1 mg/kg AFB1 contaminated corn (AFB1); 3. Basal diet + GSPE 250 mg/kg; (GSPE 250 mg/kg) 4. Basal diet + AFB1 (1 mg/kg) + GSPE 250 mg/kg; (AFB1 + GSPE 250 mg/kg) 5. Basal diet + AFB1 (1mg/kg) + GSPE 500 mg/kg, (AFB1 + GSPE 500 mg/kg). When compared with the control group, feeding broilers with AFB1 alone significantly reduced growth performance, serum immunoglobulin contents, negatively altered serum biochemical contents, and enzyme activities, and induced histopathological lesion in the liver. In addition, AFB1 significantly increased malondialdehyde content and decreased total superoxide dismutase, catalase, glutathione peroxide, glutathione-S transferase, glutathione reductase activities, and glutathione concentration within the liver and serum. The supplementation of GSPE (250 and 500 mg/kg) to AFB1 contaminated diet reduced AFB1 residue in the liver and significantly mitigated AFB1 negative effects. From these results, it can be concluded that dietary supplementation of GSPE has protective effects against aflatoxicosis caused by AFB1 in broiler chickens. PMID:29140290

  17. Inter-relationships between light and respiration in the control of ascorbic acid synthesis and accumulation in Arabidopsis thaliana leaves.

    Science.gov (United States)

    Bartoli, Carlos G; Yu, Jianping; Gómez, Facundo; Fernández, Laura; McIntosh, Lee; Foyer, Christine H

    2006-01-01

    The effects of growth irradiance and respiration on ascorbic acid (AA) synthesis and accumulation were studied in the leaves of wild-type and transformed Arabidopsis thaliana with modified amounts of the mitochondrial alternative oxidase (AOX) protein. Plants were grown under low (LL; 50 micromol photons m(-2) s(-1)), intermediate (IL; 100 micromol photons m(-2) s(-1)), or high (HL; 250 micromol photons m(-2) s(-1)) light. Increasing growth irradiance progressively elevated leaf AA content and hence the values of dark-induced disappearance of leaf AA, which were 11, 55, and 89 nmol AA lost g(-1) fresh weight h(-1), from LL-, IL-, and HL-grown leaves, respectively. When HL leaves were supplied with L-galactone-1,4-lactone (L-GalL; the precursor of AA), they accumulated twice as much AA and had double the maximal L-galactone-1,4-lactone dehydrogenase (L-GalLDH) activities of LL leaves. Growth under HL enhanced dehydroascorbate reductase and monodehydroascorbate reductase activities. Leaf respiration rates were highest in the HL leaves, which also had higher amounts of cytochrome c and cytochrome c oxidase (CCO) activities, as well as enhanced capacity of the AOX and CCO electron transport pathways. Leaves of the AOX-overexpressing lines accumulated more AA than wild-type or antisense leaves, particularly at HL. Intact mitochondria from AOX-overexpressing lines had higher AA synthesis capacities than those from the wild-type or antisense lines even though they had similar L-GalLDH activities. AOX antisense lines had more cytochrome c protein than wild-type or AOX-overexpressing lines. It is concluded that regardless of limitations on L-GalL synthesis by regulation of early steps in the AA synthesis pathway, the regulation of L-GalLDH activity via the interaction of light and respiratory controls is a crucial determinant of the overall ability of leaves to produce and accumulate AA.

  18. Ascorbate oxidase-dependent changes in the redox state of the apoplast modulate gene transcript accumulation leading to modified hormone signaling and orchestration of defense processes in tobacco.

    Science.gov (United States)

    Pignocchi, Cristina; Kiddle, Guy; Hernández, Iker; Foster, Simon J; Asensi, Amparo; Taybi, Tahar; Barnes, Jeremy; Foyer, Christine H

    2006-06-01

    The role of the redox state of the apoplast in hormone responses, signaling cascades, and gene expression was studied in transgenic tobacco (Nicotiana tabacum) plants with modified cell wall-localized ascorbate oxidase (AO). High AO activity specifically decreased the ascorbic acid (AA) content of the apoplast and altered plant growth responses triggered by hormones. Auxin stimulated shoot growth only when the apoplastic AA pool was reduced in wild-type or AO antisense lines. Oxidation of apoplastic AA in AO sense lines was associated with loss of the auxin response, higher mitogen-activated protein kinase activities, and susceptibility to a virulent strain of the pathogen Pseudomonas syringae. The total leaf glutathione pool, the ratio of reduced glutathione to glutathione disulfide, and glutathione reductase activities were similar in the leaves of all lines. However, AO sense leaves exhibited significantly lower dehydroascorbate reductase and ascorbate peroxidase activities than wild-type and antisense leaves. The abundance of mRNAs encoding antioxidant enzymes was similar in all lines. However, the day/night rhythms in the abundance of transcripts encoding the three catalase isoforms were changed in response to the AA content of the apoplast. Other transcripts influenced by AO included photorespiratory genes and a plasma membrane Ca(2+) channel-associated gene. We conclude that the redox state of the apoplast modulates plant growth and defense responses by regulating signal transduction cascades and gene expression patterns. Hence, AO activity, which modulates the redox state of the apoplastic AA pool, strongly influences the responses of plant cells to external and internal stimuli.

  19. Effect of the nitrogen fertilizer type on the enzyme activity in the rhizosphere of calcic chernozem and soybean production

    Science.gov (United States)

    Emnova, E. E.; Daraban, O. V.; Bizgan, Ya. V.; Toma, S. I.; Vozian, V. I.; Iacobuta, M. D.

    2015-05-01

    Three varieties (Aura, Magie, and Indra) of soybean ( Glycine max [L.] Merr.) were grown in a small-plot experiment on a calcic chernozem with the application of two types of nitrogen fertilizers: ammonium nitrate (Nan) or carbamide (Nc). These fertilizers at the rate of 20 kg N/ha were applied before sowing together with potassium phosphate (60 kg P2O5/ha). The microbial nitrification capacity and the activity of enzymes related to the nitrogen cycle (urease and nitrate reductase) were measured in the rhizosphere (0-20 cm) at the stage of soybean flowering. It was determined that the biological (enzyme) activity of the calcic chernozem in the soybean rhizosphere was more intense on the plots with the Nan fertilizer than on the plots with the Nc fertilizer. The urease activity depended on the type of nitrogen fertilizer (Nan or Nc) under the conditions of soil water deficiency. In the soil under the Aura variety, the urease activity was significantly lower in the treatments with Nc application, and this was accompanied by a decrease in the crop yield. The nitrification capacity of the calcic chernozem was generally low; in the case of the Nc fertilizer, it was significantly lower than in the case of the Nan fertilizer. The nitrate reductase activity of the soil was also lower in the case of the Nc fertilizer. Each of the three soybean varieties had its own response to changes in the nitrogen nutrition aimed at improving the soybean tolerance to fluctuations in the soil water content during the growing season.

  20. Antioxidant ameliorating effects against H2O2-induced cytotoxicity in primary endometrial cells.

    Science.gov (United States)

    Zal, F; Khademi, F; Taheri, R; Mostafavi-Pour, Z

    2018-02-01

    Oxidative stress and a disrupted antioxidant system are involved in a variety of pregnancy complications. In the present study, the role of vitamin E (Vit E) and folate as radical scavengers on the GSH homeostasis in stress oxidative induced in rat endometrial cells was investigated. Primary endometrial stromal cell cultures treated with 50 and 200 µM of H 2 O 2 and evaluated the cytoprotective effects of Vit E (5 µM) and folate (0.01 µM) in H 2 O 2 -treated cells for 24 h. Following the exposure of endometrial cells to H 2 O 2 alone and in the presence of Vit E and/or folate, cell survival, glutathione peroxidase (GPx) and glutathione reductase activities and the level of reduced glutathione (GSH) were measured. Cell adhesions comprise of cell attachment and spreading on collagen were determined. Flow cytometric analysis using annexin V was used to measure apoptosis. H 2 O 2 treatment showed a marked decrease in cell viability, GPx and GR activities and the level of GSH. Although Vit E or folate had some protective effect, combination therapy with Vit E and folate attenuated all the changes due to H 2 O 2 toxicity. An increasing number of alive cells was showed in the cells exposed to H 2 O 2 (50 µM) accompanied by co-treatment with Vit E and folic acid. The present findings indicate that co-administration of Vit E and folate before and during pregnancy may maintain a viable pregnancy and contribute to its clinical efficacy for the treatment of some idiopathic infertility.

  1. Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield

    International Nuclear Information System (INIS)

    Kumari, Sumita; Agrawal, Madhoolika; Tiwari, Supriya

    2013-01-01

    The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO 2 and O 3 , alone and in combination. As compared to the plants grown in charcoal filtered air (ACO 2 ), growth and yield of the plants increased under elevated CO 2 (ECO 2 ) and decreased under combination of ECO 2 with elevated O 3 (ECO 2 + EO 3 ), ambient O 3 (ACO 2 + AO 3 ) and elevated O 3 (EO 3 ). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO 3. Foliar starch and organic carbon contents increased under ECO 2 and ECO 2 + EO 3 and reduced under EO 3 and ACO 2 + AO 3. Foliar N content declined in all treatments compared to ACO 2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO 2 is not enough to counteract O 3 impact, but elevated CO 2 has potential to counteract the negative effects of future O 3 level. -- Highlights: ► Elevated CO 2 enhanced the growth and yield of palak. ► Ambient and elevated ozone reduced the growth and yield of the test plant. ► Elevated CO 2 reduced negative effects of elevated O 3 by reducing oxidative stress. ► Higher amelioration was recorded at elevated CO 2 + O 3 compared to ambient CO 2 + O 3 . -- Predicted levels of CO 2 have greater ameliorative potential against negative effects of elevated ozone compared to present day CO 2 against ambient ozone

  2. Demonstration of de novo synthesis of enzymes by density labelling with stable isotopes

    International Nuclear Information System (INIS)

    Huebner, G.; Hirschberg, K.

    1977-01-01

    The technique of in vivo density labelling of proteins with H 2 18 O and 2 H 2 O has been used to investigate hormonal regulation and de