WorldWideScience

Sample records for acid oxidase fraction

  1. Screening of Bothrops snake venoms for L-amino acid oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Pessati, M.L.; Fontana, J.D.; Guimaraes, M.F. [Federal Univ. of Parana, Curitiba (Brazil)

    1995-12-31

    Toxins, enzymes, and biologically active peptides are the main components of snake venoms from the genus Bothrops. Following the venom inoculation, the local effects are hemorrhage, edema, and myonecrosis. Nineteen different species of Brazilian Bothrops were screened for protein content and L-amino acid oxidase activity. B. cotiara, formerly found in the South of Brazil, is now threatened with extinction. Its venom contains a highly hemorrhagic fraction and, as expected from the deep yellow color of the corresponding lyophilized powder, a high L-amino acid oxidase (LAO) activity was also characterized. Flavin adenine dinucleotide (FAD) is its associate coenzyme. B. cotiara venom LAO catalyzed the oxidative deamination of several L-amino acids, and the best substrates were methionine, leucine, tryptophan, and phenylalanine, hence, its potential application for the use in biosensors for aspartame determination and for the removal of amino acids from plasma. High levels for LAO were also found in other species than B. cotiara. In addition, the technique of isoelectric focusing (IEF) was employed as a powerful tool to study the iso- or multi-enzyme distribution for LAO activity in the B. cotiara snake venom.

  2. Production of a new D-amino acid oxidase from the fungus Fusarium oxysporum.

    Science.gov (United States)

    Gabler, M; Fischer, L

    1999-08-01

    The fungus Fusarium oxysporum produced a D-amino acid oxidase (EC 1. 4.3.3) in a medium containing glucose as the carbon and energy source and ammonium sulfate as the nitrogen source. The specific D-amino acid oxidase activity was increased up to 12.5-fold with various D-amino acids or their corresponding derivatives as inducers. The best inducers were D-alanine (2.7 microkat/g of dry biomass) and D-3-aminobutyric acid (2.6 microkat/g of dry biomass). The addition of zinc ions was necessary to permit the induction of peroxisomal D-amino acid oxidase. Bioreactor cultivations were performed on a 50-liter scale, yielding a volumetric D-amino acid oxidase activity of 17 microkat liter(-1) with D-alanine as an inducer. Under oxygen limitation, the volumetric activity was increased threefold to 54 microkat liter(-1) (3,240 U liter(-1)).

  3. In vitro antioxidant, lipoxygenase and xanthine oxidase inhibitory activities of fractions from Cienfuegosia digitata Cav., Sida alba L. and Sida acuta Burn f. (Malvaceae).

    Science.gov (United States)

    Konaté, K; Souza, A; Coulibaly, A Y; Meda, N T R; Kiendrebeogo, M; Lamien-Meda, A; Millogo-Rasolodimby, J; Lamidi, M; Nacoulma, O G

    2010-11-15

    In this study polyphenol content, antioxidant activity, lipoxygenase (LOX) and Xanthine Oxidase (XO) inhibitory effects of n-hexane, dichloromethane, ethyl acetate and n-butanol fractions of aqueous acetone extracts from S. alba L., S. acuta Burn f and Cienfuegosia digitata Cav. were investigated. The total phenolics, flavonoids, flavonols and total tannins were determined by spectrophotometric methods using Folin-ciocalteu, AlCl3 reagents and tannic acid, respectively. The antioxidant potential was evaluated using three methods: inhibition of free radical 2,2-diphenyl-1-picrylhydramzyl (DPPH), ABTS radical cation decolorization assay and Iron (III) to iron (II) reduction activity (FRAP). For enzymatic activity, lipoxygenase and xanthine oxidase inhibitory activities were used. This study shows a relationship between polyphenol contents, antioxidant and enzymatic activities. Present results showed that ethyl acetate and dichloromethane fractions elicit the highest polyphenol content, antioxidant and enzymatic activities.

  4. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    International Nuclear Information System (INIS)

    Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N.; Andrade Junior, H.F.

    1999-01-01

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a 60 Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author)

  5. Production of α-keto acids Part I. Immobilized cells ofTrigonopsis variabilis containing D-amino acid oxidase.

    Science.gov (United States)

    Brodelius, P; Nilsson, K; Mosbach, K

    1981-12-01

    Whole cells ofTrigonopsis variabilis were immobilized by entrapment in Ca(2+)-alginate and used for the production of α-keto acids from the corresponding D-amino acids. The D-amino acid oxidase within the immobilized cells has a broad substrate specificity. Hydrogen peroxide formed in the enzymatic reaction was efficiently hydrolyzed by manganese oxide co-immobilized with the cells. The amino acid oxidase activity was assayed with a new method based on reversed-phase HPLC. Oxygen requirements, bead size, concentration of cells in the beads, flow rate, and other factors were investigated in a " trickle-bed " reactor.

  6. In vitro oxidation of indoleacetic acid by soluble auxin-oxidases and peroxidases from maize roots

    International Nuclear Information System (INIS)

    Beffa, R.; Martin, H.V.; Pilet, P.E.

    1990-01-01

    Soluble auxin-oxidases were extracted from Zea mays L. cv LG11 apical root segments and partially separated from peroxidases (EC 1.11.1.7) by size-exclusion chromatography. Auxin-oxidases were resolved into one main peak corresponding to a molecular mass of 32.5 kilodaltons and a minor peak at 54.5 kilodaltons. Peroxidases were separated into at least four peaks, with molecular masses from 32.5 to 78 kilodaltons. In vitro activity of indoleacetic acid-oxidases was dependent on the presence of MnCl 2 and p-coumaric acid. Compound(s) present in the crude extract and several synthetic auxin transport inhibitors (including 2,3,5-triiodobenzoic acid and N-1-naphthylphthalamic acid) inhibited auxin-oxidase activity, but had no effect on peroxidases. The products resulting from the in vitro enzymatic oxidation of [ 3 H]indoleacetic acid were separated by HPLC and the major metabolite was found to cochromatograph with indol-3yl-methanol

  7. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia; Andrade Junior, H.F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Inst. de Medicina Tropical

    1999-11-01

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a {sup 60} Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author) 13 refs., 3 figs.

  8. Electrochemical L-Lactic Acid Sensor Based on Immobilized ZnO Nanorods with Lactate Oxidase

    Directory of Open Access Journals (Sweden)

    Kimleang Khun

    2012-02-01

    Full Text Available In this work, fabrication of gold coated glass substrate, growth of ZnO nanorods and potentiometric response of lactic acid are explained. The biosensor was developed by immobilizing the lactate oxidase on the ZnO nanorods in combination with glutaraldehyde as a cross linker for lactate oxidase enzyme. The potentiometric technique was applied for the measuring the output (EMF response of L-lactic acid biosensor. We noticed that the present biosensor has wide linear detection range of concentration from 1 × 10−4–1 × 100 mM with acceptable sensitivity about 41.33 ± 1.58 mV/decade. In addition, the proposed biosensor showed fast response time less than 10 s, a good selectivity towards L-lactic acid in presence of common interfering substances such as ascorbic acid, urea, glucose, galactose, magnesium ions and calcium ions. The present biosensor based on immobilized ZnO nanorods with lactate oxidase sustained its stability for more than three weeks.

  9. Electrochemical L-lactic acid sensor based on immobilized ZnO nanorods with lactate oxidase.

    Science.gov (United States)

    Ibupoto, Zafar Hussain; Shah, Syed Muhammad Usman Ali; Khun, Kimleang; Willander, Magnus

    2012-01-01

    In this work, fabrication of gold coated glass substrate, growth of ZnO nanorods and potentiometric response of lactic acid are explained. The biosensor was developed by immobilizing the lactate oxidase on the ZnO nanorods in combination with glutaraldehyde as a cross linker for lactate oxidase enzyme. The potentiometric technique was applied for the measuring the output (EMF) response of l-lactic acid biosensor. We noticed that the present biosensor has wide linear detection range of concentration from 1 × 10(-4)-1 × 10(0) mM with acceptable sensitivity about 41.33 ± 1.58 mV/decade. In addition, the proposed biosensor showed fast response time less than 10 s, a good selectivity towards l-lactic acid in presence of common interfering substances such as ascorbic acid, urea, glucose, galactose, magnesium ions and calcium ions. The present biosensor based on immobilized ZnO nanorods with lactate oxidase sustained its stability for more than three weeks.

  10. The cytochemical demonstration of catalase and D-amino acid oxidase in the microbodies of teleost kidney cells

    NARCIS (Netherlands)

    Veenhuis, M.; Wendelaar Bonga, S.D.

    1977-01-01

    The distribution of catalase and D-amino acid oxidase, marker enzymes for peroxisomes, was determined cytochemically in the kidney tubules of an euryhaline teleost, the three-spined stickleback. Catalase activity was localized with the diaminobenzidine technique. The presence of D-amino acid oxidase

  11. Purification and partial amino-acid sequence of gibberellin 20-oxidase from Cucurbita maxima L. endosperm.

    Science.gov (United States)

    Lange, T

    1994-01-01

    Gibberellin (GA) 20-oxidase was purified to apparent homogeneity from Cucurbita maxima endosperm by fractionated ammonium-sulphate precipitation, gel-filtration chromatography and anion-exchange and hydrophobic-interaction high-performance liquid chromatography (HPLC). Average purification after the last step was 55-fold with 3.9% of the activity recovered. The purest single fraction was enriched 101-fold with 0.2% overall recovery. Apparent relative molecular mass of the enzyme was 45 kDa, as determined by gel-filtration HPLC and sodium dodecyl sulphate-polyacrylamide gel electrophoresis, indicating that GA 20-oxidase is probably a monomeric enzyme. The purified enzyme degraded on two-dimensional gel electrophoresis, giving two protein spots: a major one corresponding to a molecular mass of 30 kDa and a minor one at 45 kDa. The isoelectric point for both was 5.4. The amino-acid sequences of the amino-terminus of the purified enzyme and of two peptides from a tryptic digest were determined. The purified enzyme catalysed the sequential conversion of [14C]GA12 to [14C]GA15, [14C]GA24 and [14C]GA25, showing that carbon atom 20 was oxidised to the corresponding alcohol, aldehyde and carboxylic acid in three consecutive reactions. [14C]Gibberellin A53 was similarly converted to [14C]GA44, [14C]GA19, [14C]GA17 and small amounts of a fourth product, which was preliminarily identified as [14C]GA20, a C19-gibberellin. All GAs except [14C]GA20 were identified by combined gas chromatography-mass spectrometry. The cofactor requirements in the absence of dithiothreitol were essentially as in its presence (Lange et al., Planta 195, 98-107, 1994), except that ascorbate was essential for enzyme activity and the optimal concentration of catalase was lower.

  12. Process technology for the application of d-amino acid oxidases in pharmaceutical intermediate manufacturing

    DEFF Research Database (Denmark)

    Tindal, Stuart; Carr, Reuben; Archer, Ian V. J.

    2011-01-01

    Recent advances in biocatalysis have seen increased interest in the use of D-amino acid oxidase to synthesize optically pure amino acids. However, the creation of a genuine oxidase based platform technology will require suitable process technology as well as an understanding of the challenges...... and opportunities of a wider portfolio of synthetic targets. In this article we address some of the recent progress in process technology to enable the future development of a generic platform technology....

  13. D-amino acid oxidase activator gene (DAOA) variation affects cerebrospinal fluid homovanillic acid concentrations in healthy Caucasians

    DEFF Research Database (Denmark)

    Andreou, Dimitrios; Saetre, Peter; Werge, Thomas

    2012-01-01

    The D-amino acid oxidase activator (DAOA) protein regulates the function of D-amino oxidase (DAO), an enzyme that catalyzes the oxidative deamination of D-3,4-dihydroxyphenylalanine (D-DOPA) and D-serine. D-DOPA is converted to L-3,4-DOPA, a precursor of dopamine, whereas D-serine participates...... in glutamatergic transmission. We hypothesized that DAOA polymorphisms are associated with dopamine, serotonin and noradrenaline turnover in the human brain. Four single-nucleotide polymorphisms, previously reported to be associated with schizophrenia, were genotyped. Cerebrospinal fluid (CSF) samples were drawn...... by lumbar puncture, and the concentrations of the major dopamine metabolite homovanillic acid (HVA), the major serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the major noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured. Two of the investigated polymorphisms, rs...

  14. Assays of D-Amino Acid Oxidase Activity

    Directory of Open Access Journals (Sweden)

    Elena Rosini

    2018-01-01

    Full Text Available D-amino acid oxidase (DAAO is a well-known flavoenzyme that catalyzes the oxidative FAD-dependent deamination of D-amino acids. As a result of the absolute stereoselectivity and broad substrate specificity, microbial DAAOs have been employed as industrial biocatalysts in the production of semi-synthetic cephalosporins and enantiomerically pure amino acids. Moreover, in mammals, DAAO is present in specific brain areas and degrades D-serine, an endogenous coagonist of the N-methyl-D-aspartate receptors (NMDARs. Dysregulation of D-serine metabolism due to an altered DAAO functionality is related to pathological NMDARs dysfunctions such as in amyotrophic lateral sclerosis and schizophrenia. In this protocol paper, we describe a variety of direct assays based on the determination of molecular oxygen consumption, reduction of alternative electron acceptors, or α-keto acid production, of coupled assays to detect the hydrogen peroxide or the ammonium production, and an indirect assay of the α-keto acid production based on a chemical derivatization. These analytical assays allow the determination of DAAO activity both on recombinant enzyme preparations, in cells, and in tissue samples.

  15. Feasibility of converting lactic acid to ethanol in food waste fermentation by immobilized lactate oxidase

    International Nuclear Information System (INIS)

    Ma, Hong-zhi; Xing, Yi; Yu, Miao; Wang, Qunhui

    2014-01-01

    Highlights: • Residue lactic acid in food waste could be converted to pyruvic acid. • Calcium alginate immobilized the lactate oxidase with high pH and thermal stability. • Immobilized enzyme could convert 70% lactic acid to pyruvic acid. • Ethanol yield could be increased by 20% with lactate oxidase added. - Abstract: Adoption of lactic acid bacteria (LAB) into ethanol fermentation from food waste can replace the sterilization process. However, LAB inoculation will convert part of the substrate into lactic acid (LA), not ethanol. This study adopted lactate oxidase to convert the produced LA to pyruvate, and then ethanol fermentation was carried out. The immobilization enzyme was utilized, and corresponding optimum conditions were determined. Results showed that calcium alginate could successfully immobilize the enzyme and improve pH and thermal stability. The optimum pH and temperature were 6.2 and 55 °C, respectively. The utilization of immobilized enzyme with catalytic time of 5 h could convert 70% LA to pyruvate, and the addition of enzyme increased the ethanol yield by 20% more than that of the control. The process could be applied in food waste storage and can help in reducing carbon source consumption

  16. Glucose oxidase variants with improved properities

    OpenAIRE

    Fischer, Rainer; Ostafe, Raluca; Prodanovic, Radivoje

    2014-01-01

    Source: WO14173822A3 [EN] The technology provided herein relates to novel variants of microbial glucose oxidase with improved properties, more specifically to polypeptides having glucose oxidase activity as their major enzymatic activity; to nucleic acid molecules encoding said glucose oxidases; vectors and host cells containing the nucleic acids and methods for producing the glucose oxidase; compositions comprising said glucose oxidase; methods for the preparation and production of such enzy...

  17. Effect of Soy Sauce on Serum Uric Acid Levels in Hyperuricemic Rats and Identification of Flazin as a Potent Xanthine Oxidase Inhibitor.

    Science.gov (United States)

    Li, Huipin; Zhao, Mouming; Su, Guowan; Lin, Lianzhu; Wang, Yong

    2016-06-15

    This is the first report on the ability of soy sauce to effectively reduce the serum uric acid levels and xanthine oxidase (XOD) activities of hyperuricemic rats. Soy sauce was partitioned sequentially into ethyl acetate and water fractions. The ethyl acetate fraction with strong XOD inhibition effect was purified further. On the basis of xanthine oxidase inhibitory (XOI) activity-guided purification, nine compounds including 3,4-dihydroxy ethyl cinnamate, diisobutyl terephthalate, harman, daidzein, flazin, catechol, thymine, genistein, and uracil were obtained. It was the first time that 3,4-dihydroxy ethyl cinnamate and diisobutyl terephthalate had been identified from soy sauce. Flazin with hydroxymethyl furan ketone group at C-1 and carboxyl at C-3 exhibited the strongest XOI activity (IC50 = 0.51 ± 0.05 mM). According to fluorescence quenching and molecular docking experiments, flazin could enter into the catalytic center of XOD to interact with Lys1045, Gln1194, and Arg912 mainly by hydrophobic forces and hydrogen bonds. Flazin, catechol, and genistein not only were potent XOD inhibitors but also held certain antioxidant activities. According to ADME (absorption, distribution, metabolism, and excretion) simulation in silico, flazin had good oral bioavailability in vivo.

  18. Activation of a peroxisomal Pichia pastoris d-amino acid oxidase, which uses d-alanine as a preferred substrate, depends on pyruvate carboxylase

    NARCIS (Netherlands)

    Klompmaker, Sandra H.; Kilic, Aysun; Baerends, Richard J.; Veenhuis, Marten; van der Klei, Ida J.; Goffeau, André

    d-Amino acid oxidase (DAO) is an important flavo-enzyme that catalyzes the oxidative deamination of d-amino acids into the corresponding alpha-keto acid, ammonia and H(2)O(2). We identified two amino acid oxidases in the methylotrophic yeast Pichia pastoris: Dao1p, which preferentially uses

  19. Localization of ascorbic acid, ascorbic acid oxidase, and glutathione in roots of Cucurbita maxima L.

    Science.gov (United States)

    Liso, Rosalia; De Tullio, Mario C; Ciraci, Samantha; Balestrini, Raffaella; La Rocca, Nicoletta; Bruno, Leonardo; Chiappetta, Adriana; Bitonti, Maria Beatrice; Bonfante, Paola; Arrigoni, Oreste

    2004-12-01

    To understand the function of ascorbic acid (ASC) in root development, the distribution of ASC, ASC oxidase, and glutathione (GSH) were investigated in cells and tissues of the root apex of Cucubita maxima. ASC was regularly distributed in the cytosol of almost all root cells, with the exception of quiescent centre (QC) cells. ASC also occurred at the surface of the nuclear membrane and correspondingly in the nucleoli. No ASC could be observed in vacuoles. ASC oxidase was detected by immunolocalization mainly in cell walls and vacuoles. This enzyme was particularly abundant in the QC and in differentiating vascular tissues and was absent in lateral root primordia. Administration of the ASC precursor L-galactono-gamma-lactone markedly increased ASC content in all root cells, including the QC. Root treatment with the ASC oxidized product, dehydroascorbic acid (DHA), also increased ASC content, but caused ASC accumulation only in peripheral tissues, where DHA was apparently reduced at the expense of GSH. The different pattern of distribution of ASC in different tissues and cell compartments reflects its possible role in cell metabolism and root morphogenesis.

  20. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with 60Co gamma rays, in Leishmania spp

    International Nuclear Information System (INIS)

    Cardoso, Andre Gustavo Tempone

    1999-01-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 μg/ml (EC 50 ), L.(V.) panamensis (0.78 |μg/ml) and L.(L.) chagasi (0.63 (μg/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC 50 of 11|μg/ml. Irradiation of LAO with 6 0C o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC 50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  1. Functional analysis of fructosyl-amino acid oxidases of Aspergillus oryzae.

    Science.gov (United States)

    Akazawa, Shin-Ichi; Karino, Tetsuya; Yoshida, Nobuyuki; Katsuragi, Tohoru; Tani, Yoshiki

    2004-10-01

    Three active fractions of fructosyl-amino acid oxidase (FAOD-Ao1, -Ao2a, and -Ao2b) were isolated from Aspergillus oryzae strain RIB40. N-terminal and internal amino acid sequences of FAOD-Ao2a corresponded to those of FAOD-Ao2b, suggesting that these two isozymes were derived from the same protein. FAOD-Ao1 and -Ao2 were different in substrate specificity and subunit assembly; FAOD-Ao2 was active toward N(epsilon)-fructosyl N(alpha)-Z-lysine and fructosyl valine (Fru-Val), whereas FAOD-Ao1 was not active toward Fru-Val. The genes encoding the FAOD isozymes (i.e., FAOAo1 and FAOAo2) were cloned by PCR with an FAOD-specific primer set. The deduced amino acid sequences revealed that FAOD-Ao1 was 50% identical to FAOD-Ao2, and each isozyme had a peroxisome-targeting signal-1, indicating their localization in peroxisomes. The genes was expressed in Escherichia coli and rFaoAo2 showed the same characteristics as FAOD-Ao2, whereas rFaoAo1 was not active. FAOAo2 disruptant was obtained by using ptrA as a selective marker. Wild-type strain grew on the medium containing Fru-Val as the sole carbon and nitrogen sources, but strain Delta faoAo2 did not grow. Addition of glucose or (NH(4))(2)SO(4) to the Fru-Val medium did not affect the assimilation of Fru-Val by wild-type, indicating glucose and ammonium repressions did not occur in the expression of the FAOAo2 gene. Furthermore, conidia of the wild-type strain did not germinate on the medium containing Fru-Val and NaNO(2) as the sole carbon and nitrogen sources, respectively, suggesting that Fru-Val may also repress gene expression of nitrite reductase. These results indicated that FAOD is needed for utilization of fructosyl-amino acids as nitrogen sources in A. oryzae.

  2. Salicylic Acid Regulation of Respiration in Higher Plants: Alternative Oxidase Expression.

    Science.gov (United States)

    Rhoads, DM; McIntosh, L

    1992-01-01

    Alternative respiratory pathway capacity increases during the development of the thermogenic appendix of a voodoo lily inflorescence. The levels of the alternative oxidase proteins increased dramatically between D-4 (4 days prior to the day of anthesis) and D-3 and continued to increase until the day of anthesis (D-day). The level of salicylic acid (SA) in the appendix is very low early on D-1, but increases to a high level in the evening of D-1. Thermogenesis occurs after a few hours of light on D-day. Therefore, the initial accumulation of the alternative oxidase proteins precedes the increase in SA by 3 days, indicating that other regulators may be involved. A 1.6-kb transcript encoding the alternative oxidase precursor protein accumulated to a high level in the appendix tissue by D-1. Application of SA to immature appendix tissue caused an increase in alternative pathway capacity and a dramatic accumulation of the alternative oxidase proteins and the 1.6-kb transcript. Time course experiments showed that the increase in capacity, protein levels, and transcript level corresponded precisely. The response to SA was blocked by cycloheximide or actinomycin D, indicating that de novo transcription and translation are required. However, nuclear, in vitro transcription assays indicated that the accumulation of the 1.6-kb transcript did not result from a simple increase in the rate of transcription of aox1. PMID:12297672

  3. Barley polyamine oxidase: Characterisation and analysis of the cofactor and the N-terminal amino acid sequence

    DEFF Research Database (Denmark)

    Radova, A.; Sebela, M.; Galuszka, P.

    2001-01-01

    This paper reports the first purification method developed for the isolation of an homogeneous polyamine oxidase (PAO) from etiolated barley seedlings. The crude enzyme preparation was obtained after initial precipitation of the extract with protamine sulphate and ammonium sulphate. The enzyme...... was further confirmed by measuring the fluorescence spectra, Barley PAO is an acidic protein (pI 5.4) containing 3% of neutral sugars: its molecular mass determined by SDS-PAGE was 56 kDa, whilst gel permeation chromatography revealed the higher value of 76 kDa. The N-terminal amino acid sequence of barley...... PAO shows a high degree of similarity to that of maize PAO and to several other flavoprotein oxidases. The polyamines spermine and spermidine were the only two substrates of the enzyme with K-m values 4 x 10(-5) and 3 x 10(-5) M and pH optima of 5.0 and 6.0, respectively. Barley polyamine oxidase...

  4. Antioxidant, xanthine oxidase and lipoxygenase inhibitory activities and phenolics of Bauhinia rufescens Lam. (Caesalpiniaceae).

    Science.gov (United States)

    Compaoré, M; Lamien, C E; Lamien-Meda, A; Vlase, L; Kiendrebeogo, M; Ionescu, C; Nacoulma, O G

    2012-01-01

    An aqueous acetone extract of the stem with the leaves of Bauhinia rufescens and its fractions were analysed for their antioxidant and enzyme-inhibitory activities, as well as their phytochemical composition. For measurement of the antioxidant activities, the 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzoline-6-sulphonate) and the ferric-reducing methods were used. The results indicated that the aqueous acetone, its ethyl acetate and n-butanol fractions possessed considerable antioxidant activity. Further, the xanthine oxidase and lipoxygenase inhibitory assays showed that the n-butanol fraction possessed compounds that can inhibit both these enzymes. In the phytochemical analysis, the ethyl acetate and the n-butanol fractions of the aqueous acetone extract were screened by HPLC-MS for their phenolic content. The results indicated the presence of hyperoside, isoquercitrin, rutin quercetin, quercitrin, p-coumaric and ferulic acids in the non-hydrolysed fractions. In the hydrolysed fractions, kaempferol, p-coumaric and ferulic acids were identified.

  5. Comparative studies on mitochondria isolated from neuron-enriched and glia-enriched fractions of rabbit and beef brain.

    Science.gov (United States)

    Hamberger, A; Blomstrand, C; Lehninger, A L

    1970-05-01

    Fractions enriched in neuronal and glial cells were obtained from dispersions of whole beef brain and rabbit cerebral cortex by large-scale density gradient centrifugation procedures. The fractions were characterized by appropriate microscopic observation. Mitochondria were then isolated from these fractions by differential centrifugation of their homogenates. The two different types of mitochondria were characterized with respect to certain enzyme activities, respiratory rate, rate of protein synthesis, and their buoyant density in sucrose gradients. The mitochondria from the neuron-enriched fraction were distinguished by a higher rate of incorporation of amino acids into protein, higher cytochrome oxidase activity, and a higher buoyant density in sucrose density gradients. Mitochondria from the glia-enriched fraction showed relatively high monoamine oxidase and Na(+)- and K(+)-stimulated ATPase activities. The rates of oxidation of various substrates and the acceptor control ratios did not differ appreciably between the two types of mitochondria. The difference in the buoyant density of mitochondria isolated from the neuron-enriched and glia-enriched cell fractions was utilized in attempts to separate neuronal and glial mitochondria from the mixed mitochondria obtained from whole brain homogenates in shallow sucrose gradients. The appearance of two peaks of cytochrome oxidase, monoamine oxidase, and protein concentration in such gradients shows the potential feasibility of such an approach.

  6. Isolation of oxalic acid tolerating fungi and decipherization of its potential to control Sclerotinia sclerotiorum through oxalate oxidase like protein.

    Science.gov (United States)

    Yadav, Shivani; Srivastava, Alok K; Singh, Dhanajay P; Arora, Dilip K

    2012-11-01

    Oxalic acid plays major role in the pathogenesis by Sclerotinia sclerotiorum; it lowers the pH of nearby environment and creates the favorable condition for the infection. In this study we examined the degradation of oxalic acid through oxalate oxidase and biocontrol of Sclerotinia sclerotiorum. A survey was conducted to collect the rhizospheric soil samples from Indo-Gangetic Plains of India to isolate the efficient fungal strains able to tolerate oxalic acid. A total of 120 fungal strains were isolated from root adhering soils of different vegetable crops. Out of 120 strains a total of 80 isolates were able to grow at 10 mM of oxalic acid whereas only 15 isolates were grow at 50 mM of oxalic acid concentration. Then we examined the antagonistic activity of the 15 isolates against Sclerotinia sclerotiorum. These strains potentially inhibit the growth of the test pathogen. A total of three potential strains and two standard cultures of fungi were tested for the oxalate oxidase activity. Strains S7 showed the maximum degradation of oxalic acid (23 %) after 60 min of incubation with fungal extract having oxalate oxidase activity. Microscopic observation and ITS (internally transcribed spacers) sequencing categorized the potential fungal strains into the Aspergillus, Fusarium and Trichoderma. Trichoderma sp. are well studied biocontrol agent and interestingly we also found the oxalate oxidase type activity in these strains which further strengthens the potentiality of these biocontrol agents.

  7. Enzymatic production of α-ketoglutaric acid from l-glutamic acid via l-glutamate oxidase.

    Science.gov (United States)

    Niu, Panqing; Dong, Xiaoxiang; Wang, Yuancai; Liu, Liming

    2014-06-10

    In this study, a novel strategy for α-ketoglutaric acid (α-KG) production from l-glutamic acid using recombinant l-glutamate oxidase (LGOX) was developed. First, by analyzing the molecular structure characteristics of l-glutamic acid and α-KG, LGOX was found to be the best catalyst for oxidizing the amino group of l-glutamic acid to a ketonic group without the need for exogenous cofactor. Then the LGOX gene was expressed in Escherichia coli BL21 (DE3) in a soluble and active form, and the recombinant LGOX activity reached to a maximum value of 0.59U/mL at pH 6.5, 30°C. Finally, the maximum α-KG concentration reached 104.7g/L from 110g/L l-glutamic acid in 24h, under the following optimum conditions: 1.5U/mL LGOX, 250U/mL catalase, 3mM MnCl2, 30°C, and pH 6.5. Copyright © 2014. Published by Elsevier B.V.

  8. l-Amino acid oxidase isolated from Calloselasma rhodostoma snake venom induces cytotoxicity and apoptosis in JAK2V617F-positive cell lines

    Directory of Open Access Journals (Sweden)

    Cristiane Tavares

    2016-06-01

    Full Text Available ABSTRACT BACKGROUND: Myeloproliferative neoplasms are Philadelphia chromosome-negative diseases characterized by hyperproliferation of mature myeloid cells, associated or not with the Janus kinase 2 tyrosine kinase mutation, JAK2V617F. As there is no curative therapy, researchers have been investigating new drugs to treat myeloproliferative neoplasms, including l-amino acid oxidase from Calloselasma rhodostoma snake venom (CR-LAAO, which is a toxin capable of eliciting apoptosis in several tumor cell lines. OBJECTIVE: To evaluate the effects of l-amino acid oxidase from C. rhodostoma snake venom in the apoptotic machinery of JAK2-mutated cell lines. METHODS: The HEL 92.1.7 and SET-2 cell lines were cultured with l-amino acid oxidase and catalase for 12 h at 37 °C in 5% carbon dioxide. The cell viability was assessed by the multi-table tournament method, the level of apoptosis was measured by flow cytometry, and the expression of cysteine-dependent aspartate-specific proteases and cleaved Poly(ADP-ribose polymerase were analyzed by Western blotting. RESULTS: l-Amino acid oxidase from C. rhodostoma snake venom was cytotoxic to HEL 92.1.7 and SET-2 cells (50% inhibitory concentration = 0.15 µg/mL and 1.5 µg/mL, respectively and induced apoptosis in a concentration-dependent manner. Cell treatment with catalase mitigated the l-amino acid oxidase toxicity, indicating that hydrogen peroxide is a key component of its cytotoxic effect.The activated caspases 3 and 8 expression and cleaved PARP in HEL 92.1.7 and SET-2 cells confirmed the apoptosis activation by CR-LAAO. CONCLUSIONS: l-Amino acid oxidase from C. rhodostoma snake venom is a potential antineoplastic agent against HEL 92.1.7 and SET-2 JAK2V617F-positive cells as it activates the extrinsic apoptosis pathway.

  9. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    Directory of Open Access Journals (Sweden)

    M. B. Akın

    2015-05-01

    Full Text Available In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w. The cultures were grown (37 °C, 12 h in UHT skimmed milk. The fermented milk was added to the ice-cream mix up to a level of 10 % w/w. Increasing the concentration of ascorbic acid stimulated the growth of Lactobacillus acidophilus LA-5 (L. acidophilus and Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12. On contrary, increasing the concentration of glucose oxidase negatively affected the growth of L. acidophilus and Bifidobacterium BB-12. However, both, ascorbic acid and glucose oxidase concentration had no effect on physical and sensory properties of ice cream. The results suggested that the addition of ascorbic acid stimulated the growth of L. acidophilus and Bifidobacterium BB-12 and could be recommended for ice cream production.

  10. Myeloperoxidase amplified high glucose-induced endothelial dysfunction in vasculature: Role of NADPH oxidase and hypochlorous acid.

    Science.gov (United States)

    Tian, Rong; Ding, Yun; Peng, Yi-Yuan; Lu, Naihao

    2017-03-11

    Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H 2 O 2 ), have emerged as important molecules in the pathogenesis of diabetic endothelial dysfunction. Additionally, neutrophils-derived myeloperoxidase (MPO) and MPO-catalyzed hypochlorous acid (HOCl) play important roles in the vascular injury. However, it is unknown whether MPO can use vascular-derived ROS to induce diabetic endothelial dysfunction. In the present study, we demonstrated that NADPH oxidase was the main source of ROS formation in high glucose-cultured human umbilical vein endothelial cells (HUVECs), and played a critical role in high glucose-induced endothelial dysfunction such as cell apoptosis, loss of cell viability and reduction of nitric oxide (NO). However, the addition of MPO could amplify the high glucose-induced endothelial dysfunction which was inhibited by the presence of apocynin (NADPH oxidase inhibitor), catalase (H 2 O 2 scavenger), or methionine (HOCl scavenger), demonstrating the contribution of NADPH oxidase-H 2 O 2 -MPO-HOCl pathway in the MPO/high glucose-induced vascular injury. In high glucose-incubated rat aortas, MPO also exacerbated the NADPH oxidase-induced impairment of endothelium-dependent relaxation. Consistent with these in vitro data, in diabetic rat aortas, both MPO expresion and NADPH oxidase activity were increased while the endothelial function was simultaneously impaired. The results suggested that vascular-bound MPO could amplify high glucose-induced vascular injury in diabetes. MPO-NADPH oxidase-HOCl may represent an important pathogenic pathway in diabetic vascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Activation of Recombinantly Expressed l-Amino Acid Oxidase from Rhizoctonia solani by Sodium Dodecyl Sulfate

    Directory of Open Access Journals (Sweden)

    Katharina Hahn

    2017-12-01

    Full Text Available l-Amino acid oxidases (l-AAO catalyze the oxidative deamination of l-amino acids to the corresponding α-keto acids. The non-covalently bound cofactor FAD is reoxidized by oxygen under formation of hydrogen peroxide. We expressed an active l-AAO from the fungus Rhizoctonia solani as a fusion protein in E. coli. Treatment with small amounts of the detergent sodium dodecyl sulfate (SDS stimulated the activity of the enzyme strongly. Here, we investigated whether other detergents and amphiphilic molecules activate 9His-rsLAAO1. We found that 9His-rsLAAO1 was also activated by sodium tetradecyl sulfate. Other detergents and fatty acids were not effective. Moreover, effects of SDS on the oligomerization state and the protein structure were analyzed. Native and SDS-activated 9His-rsLAAO1 behaved as dimers by size-exclusion chromatography. SDS treatment induced an increase in hydrodynamic radius as observed by size-exclusion chromatography and dynamic light scattering. The activated enzyme showed accelerated thermal inactivation and an exposure of additional protease sites. Changes in tryptophan fluorescence point to a more hydrophilic environment. Moreover, FAD fluorescence increased and a lower concentration of sulfites was sufficient to form adducts with FAD. Taken together, these data point towards a more open conformation of SDS-activated l-amino acid oxidase facilitating access to the active site.

  12. Optimization of glucose oxidase production by Aspergillus niger

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... manganese, cobalt, thioglycolic acid, and gluconic acid according to (Liu et al., .... In this experiment duplicate media of glucose 10% were adjusted at different ... Glucose oxidase as a pharmaceutical anti oxidant Drug. Devt. ... Plush KS, Hellmuth K, Rinas U (1996). kinetics of glucose oxidase excretion by ...

  13. Evaluation of oxalate decarboxylase and oxalate oxidase for industrial applications.

    Science.gov (United States)

    Cassland, Pierre; Sjöde, Anders; Winestrand, Sandra; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2010-05-01

    Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation. Oxalate decarboxylase degraded oxalic acid faster than oxalate oxidase in eight of the filtrates, while oxalate oxidase performed better in one filtrate. One of the filtrates inhibited both enzymes. The potential inhibitory effect of selected compounds on the enzymatic activity was tested. Oxalate decarboxylase was more sensitive than oxalate oxidase to hydrogen peroxide. Oxalate decarboxylase was not as sensitive to chlorate and chlorite as oxalate oxidase. Up to 4 mM chlorate ions, the highest concentration tested, had no inhibitory effect on oxalate decarboxylase. Analysis of the filtrates suggests that high concentrations of chlorate present in some of the filtrates were responsible for the higher sensitivity of oxalate oxidase in these filtrates. Oxalate decarboxylase was thus a better choice than oxalate oxidase for treatment of filtrates from chlorine dioxide bleaching.

  14. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    International Nuclear Information System (INIS)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-01-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO_2 and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO_2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  15. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  16. Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures

    International Nuclear Information System (INIS)

    Earnshaw, B.A.

    1986-01-01

    Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of 14 C-2, 4-D. The embryo fraction had a lower concentration of 14 C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected

  17. Interference effects from coexisting fatty acids on elaidic acid separation by fractionating crystallization: A model study

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Bjerring, Thomas

    2010-01-01

    A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating...

  18. Effect of high pressure on peanut allergens in the presence of polyphenol oxidase and caffeic acid

    Science.gov (United States)

    High pressure (HP) enhances enzymatic reactions. Because polyphenol oxidase (PPO) is an enzyme, and reduces IgE binding of peanut allergens in presence of caffeic acid (CA), we postulated that a further reduction in IgE binding can be achieved, using HP together with PPO and CA. Peanut extracts cont...

  19. Ligand complex structures of l-amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813 and its conformational change.

    Science.gov (United States)

    Im, Dohyun; Matsui, Daisuke; Arakawa, Takatoshi; Isobe, Kimiyasu; Asano, Yasuhisa; Fushinobu, Shinya

    2018-03-01

    l-Amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813 (l-AAO/MOG) catalyzes both the oxidative deamination and oxidative decarboxylation of the α-group of l-Lys to produce a keto acid and amide, respectively. l-AAO/MOG exhibits limited specificity for l-amino acid substrates with a basic side chain. We previously determined its ligand-free crystal structure and identified a key residue for maintaining the dual activities. Here, we determined the structures of l-AAO/MOG complexed with l-Lys, l-ornithine, and l-Arg and revealed its substrate recognition. Asp238 is located at the ceiling of a long hydrophobic pocket and forms a strong interaction with the terminal, positively charged group of the substrates. A mutational analysis on the D238A mutant indicated that the interaction is critical for substrate binding but not for catalytic control between the oxidase/monooxygenase activities. The catalytic activities of the D238E mutant unexpectedly increased, while the D238F mutant exhibited altered substrate specificity to long hydrophobic substrates. In the ligand-free structure, there are two channels connecting the active site and solvent, and a short region located at the dimer interface is disordered. In the l-Lys complex structure, a loop region is displaced to plug the channels. Moreover, the disordered region in the ligand-free structure forms a short helix in the substrate complex structures and creates the second binding site for the substrate. It is assumed that the amino acid substrate enters the active site of l-AAO/MOG through this route. The atomic coordinates and structure factors (codes 5YB6, 5YB7, and 5YB8) have been deposited in the Protein Data Bank (http://wwpdb.org/). 1.4.3.2 (l-amino acid oxidase), 1.13.12.2 (lysine 2-monooxygenase).

  20. Amine oxidases as important agents of pathological processes of rhabdomyolysis in rats.

    Science.gov (United States)

    Gudkova, O O; Latyshko, N V; Shandrenko, S G

    2016-01-01

    In this study we have tested an idea on the important role of amine oxidases (semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase) as an additional source of oxidative/carbonyl stress under glycerol-induced rhabdomyolysis, since the enhanced formation of reactive oxygen species and reactive carbonyl species in a variety of tissues is linked to various diseases. In our experiments we used the sensitive fluorescent method devised for estimation of amine oxidases activity in the rat kidney and thymus as targeted organs under rhabdomyolysis. We have found in vivo the multiple rises in activity of semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase (2-4.5 times) in the corresponding cell fractions, whole cells or their lysates at the 3-6th day after glycerol injection. Aberrant antioxidant activities depended on rhabdomyolysis stage and had organ specificity. Additional treatment of animals with metal chelator ‘Unithiol’ adjusted only the activity of antioxidant enzymes but not amine oxidases in both organs. Furthermore the in vitro experiment showed that Fenton reaction (hydrogen peroxide in the presence of iron) products alone had no effect on semicarbazide-sensitive amine oxidase activity in rat liver cell fraction whereas supplementation with methylglyoxal resulted in its significant 2.5-fold enhancement. Combined action of the both agents had additive effect on semicarbazide-sensitive amine oxidase activity. We can assume that biogenic amine and polyamine catabolism by amine oxidases is upregulated by oxidative and carbonyl stress factors directly under rhabdomyolysis progression, and the increase in catabolic products concentration contributes to tissue damage in glycerol-induced acute renal failure and apoptosis stimulation in thymus.

  1. Nitro-oleic acid ameliorates oxygen and glucose deprivation/re-oxygenation triggered oxidative stress in renal tubular cells via activation of Nrf2 and suppression of NADPH oxidase.

    Science.gov (United States)

    Nie, Huibin; Xue, Xia; Liu, Gang; Guan, Guangju; Liu, Haiying; Sun, Lina; Zhao, Long; Wang, Xueling; Chen, Zhixin

    2016-01-01

    Nitroalkene derivative of oleic acid (OA-NO 2 ), due to its ability to mediate revisable Michael addition, has been demonstrated to have various biological properties and become a therapeutic agent in various diseases. Though its antioxidant properties have been reported in different models of acute kidney injury (AKI), the mechanism by which OA-NO 2 attenuates intracellular oxidative stress is not well investigated. Here, we elucidated the anti-oxidative mechanism of OA-NO 2 in an in vitro model of renal ischemia/reperfusion (I/R) injury. Human tubular epithelial cells were subjected to oxygen and glucose deprivation/re-oxygenation (OGD/R) injury. Pretreatment with OA-NO 2 (1.25 μM, 45 min) attenuated OGD/R triggered reactive oxygen species (ROS) generation and subsequent mitochondrial membrane potential disruption. This action was mediated via up-regulating endogenous antioxidant defense components including superoxide dismutase (SOD1), heme oxygenase 1 (HO-1), and γ-glutamyl cysteine ligase modulatory subunits (GCLM). Moreover, subcellular fractionation analyses demonstrated that OA-NO 2 promoted nuclear translocation of nuclear factor-E2- related factor-2 (Nrf2) and Nrf2 siRNA partially abrogated these protective effects. In addition, OA-NO 2 inhibited NADPH oxidase activation and NADPH oxidase 4 (NOX4), NADPH oxidase 2 (NOX2) and p22 phox up-regulation after OGD/R injury, which was not relevant to Nrf2. These results contribute to clarify that the mechanism of OA-NO 2 reno-protection involves both inhibition of NADPH oxidase activity and induction of SOD1, Nrf2-dependent HO-1, and GCLM.

  2. Oleic, Linoleic and Linolenic Acids Increase ROS Production by Fibroblasts via NADPH Oxidase Activation

    Science.gov (United States)

    Hatanaka, Elaine; Dermargos, Alexandre; Hirata, Aparecida Emiko; Vinolo, Marco Aurélio Ramirez; Carpinelli, Angelo Rafael; Newsholme, Philip; Armelin, Hugo Aguirre; Curi, Rui

    2013-01-01

    The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts. PMID:23579616

  3. Oleic, linoleic and linolenic acids increase ros production by fibroblasts via NADPH oxidase activation.

    Directory of Open Access Journals (Sweden)

    Elaine Hatanaka

    Full Text Available The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47 (phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47 (phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts.

  4. Antibacterial properties of the mammalian L-amino acid oxidase IL4I1.

    Directory of Open Access Journals (Sweden)

    Marie-Line Puiffe

    Full Text Available L-amino acid oxidases (LAAO are flavoproteins that catalyze the oxidative deamination of L-amino acids to a keto-acid along with the production of H₂O₂ and ammonia. Interleukin 4 induced gene 1 (IL4I1 is a secreted LAAO expressed by macrophages and dendritic cells stimulated by microbial derived products or interferons, which is endowed with immunoregulatory properties. It is the first LAAO described in mammalian innate immune cells. In this work, we show that this enzyme blocks the in vitro and in vivo growth of Gram negative and Gram positive bacteria. This antibiotic effect is primarily mediated by H₂O₂ production but is amplified by basification of the medium due to the accumulation of ammonia. The depletion of phenylalanine (the primary amino acid catabolized by IL4I1 may also participate in the in vivo inhibition of staphylococci growth. Thus, IL4I1 plays a distinct role compared to other antibacterial enzymes produced by mononuclear phagocytes.

  5. A novel L-amino acid oxidase from Trichoderma harzianum ETS 323 associated with antagonism of Rhizoctonia solani.

    Science.gov (United States)

    Yang, Chia-Ann; Cheng, Chi-Hua; Lo, Chaur-Tsuen; Liu, Shu-Ying; Lee, Jeng-Woei; Peng, Kou-Cheng

    2011-05-11

    Trichoderma spp. are used as biocontrol agents against phytopathogens such as Rhizoctonia solani, but their biocontrol mechanisms are poorly understood. A novel L-amino oxidase (Th-LAAO) was identified from the extracellular proteins of Trichoderma harzianum ETS 323. Here, we show a FAD-binding glycoprotein with the best substrate specificity constant for L-phenylalanine. Although the amino acid sequence of Th-LAAO revealed limited homology (16-24%) to other LAAO members, a highly conserved FAD-binding motif was identified in the N-terminus. Th-LAAO was shown to be a homodimeric protein, but the monomeric form was predominant when grown in the presence of deactivated Rhizoctonia solani. Furthermore, in vitro assays demonstrated that Th-LAAO had an antagonistic effect against Rhizoctonia solani and a stimulatory one on hyphal density and sporulation in T. harzianum ETS 323. These findings further our understanding of T. harzianum as a biocontrol agent and provide insight into the biological function of l-amino acid oxidase.

  6. Cytochemical localization of catalase and several hydrogen peroxide-producing oxidases in the nucleoids and matrix of rat liver peroxisomes

    NARCIS (Netherlands)

    Veenhuis, M.; Wendelaar Bonga, S.E.

    1979-01-01

    The distribution of catalase, amino acid oxidase, α-hydroxy acid oxidase, urate oxidase and alcohol oxidase was studied cytochemically in rat hepatocytes. The presence of catalase was demonstrated with the conventional diaminobenzidine technique. Oxidase activities were visualized with methods based

  7. The incorporation of labelled amino acids into the subcellular fractions of the rabbit brain

    International Nuclear Information System (INIS)

    Ogrodnik, W.

    1980-01-01

    Radioactive amino acids were injected into the fourth ventriculum of adult rabbits. After 3, 6 and 13 hours the animals were killed and tissue subcellular fractions were prepared from their brains. Nucleic acids were extracted and quantitatively determined from nucleic, myelin, mitochondrial, microsomal and cytoplasmic fractions. The radioactivity was determined in the protein and nucleic acid fractions. It was found out that the incorporation of radioactive amino acids increased in relation to time. In the analyzed subcellular fractions a very rapid incorporation of glutamic acid and leucine into cytoplasmic proteins was observed. The chromatographic analysis of the nucleic acids showed that radioactivity in the nucleic acid fractions depended on a radioactive protein contamination. Radioactive aminoacyl-tRNA was not found in the nucleic acid fractions, extracted from different subcellular fractions. (author)

  8. Isolation, crystallization and preliminary X-ray diffraction analysis of l-amino-acid oxidase from Vipera ammodytes ammodytes venom

    International Nuclear Information System (INIS)

    Georgieva, Dessislava; Kardas, Anna; Buck, Friedrich; Perbandt, Markus; Betzel, Christian

    2008-01-01

    A novel l-amino-acid oxidase was isolated from V. ammodytes ammodytes venom and crystallized. The solution conditions under which the protein sample was monodisperse were optimized using dynamic light scattering prior to crystallization. Preliminary diffraction data were collected to 2.6 Å resolution. l-Amino-acid oxidase from the venom of Vipera ammodytes ammodytes, the most venomous snake in Europe, was isolated and crystallized using the sitting-drop vapour-diffusion method. The solution conditions under which the protein sample was monodisperse were optimized using dynamic light scattering prior to crystallization. The crystals belonged to space group C2, with unit-cell parameters a = 198.37, b = 96.38, c = 109.11 Å, β = 92.56°. Initial diffraction data were collected to 2.6 Å resolution. The calculated Matthews coefficient is approximately 2.6 Å 3 Da −1 assuming the presence of four molecules in the asymmetric unit

  9. Oxidases as Breast Cancer Oncogens

    National Research Council Canada - National Science Library

    Yeldandi, Anjana

    2000-01-01

    ...) in a non-tumorigenic human mammary epithelial cell line to ascertain whether oxidase overexpressing cells undergo transformation when exposed to substrate xanthine for XOX and uric acid for UOX...

  10. Genipin Cross-Linked Glucose Oxidase and Catalase Multi-enzyme for Gluconic Acid Synthesis.

    Science.gov (United States)

    Cui, Caixia; Chen, Haibin; Chen, Biqiang; Tan, Tianwei

    2017-02-01

    In this work, glucose oxidase (GOD) and catalase (CAT) were used simultaneously to produce gluconic acid from glucose. In order to reduce the distance between the two enzymes, and therefore improve efficiency, GOD and CAT were cross-linked together using genipin. Improvements in gluconic acid production were due to quick removal of harmful intermediate hydrogen peroxide by CAT. GOD activity was significantly affected by the proportion of CAT in the system, with GOD activity in the cross-linked multi-enzyme (CLME) being 10 times higher than that in an un-cross-linked GOD/CAT mixture. The glucose conversion rate after 15 h using 15 % glucose was also 10 % higher using the CLME than was measured using a GOD/CAT mixture.

  11. A quantitative histochemical study of D-amino acid oxidase activity in rat liver in relationship with feeding conditions

    NARCIS (Netherlands)

    Patel, H. R.; Frederiks, W. M.; Marx, F.; Best, A. J.; van Noorden, C. J.

    1991-01-01

    The histochemical method for the demonstration of D-amino acid oxidase activity in rat liver, based on the use of cerium ions and the diaminobenzidine-cobalt-hydrogen peroxide procedure, was improved by the application of unfixed cryostat sections and a semipermeable membrane interposed between

  12. Chemoenzymatic combination of glucose oxidase with titanium silicalite -1

    DEFF Research Database (Denmark)

    Vennestrøm, Peter Nicolai Ravnborg; Taarning, Esben; Christensen, Claus H.

    2010-01-01

    Zeozymes: A proof-of-concept is presented for the chemoenzymatic combination of titanium silicalite-1 zeolite with glucose oxidase. In this combination, glucose is oxidized to gluconic acid and the H2O2 byproduct formed in situ is used for the simultaneous oxidation of chemical substrates. Both...... a soluble glucose oxidase and a truly integrated heterogeneous combination whereby the oxidase enzyme is anchored onto the zeolite surface are reported....

  13. New derivatives of 3,4-dihydroisoquinoline-3-carboxylic acid with free-radical scavenging, D-amino acid oxidase, acetylcholinesterase and butyrylcholinesterase inhibitory activity.

    Science.gov (United States)

    Solecka, Jolanta; Guśpiel, Adam; Postek, Magdalena; Ziemska, Joanna; Kawęcki, Robert; Lęczycka, Katarzyna; Osior, Agnieszka; Pietrzak, Bartłomiej; Pypowski, Krzysztof; Wyrzykowska, Agata

    2014-09-30

    A series of 3,4-dihydroisoquinoline-3-carboxylic acid derivatives were synthesised and tested for their free-radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS·+), superoxide anion radical (O2·-) and nitric oxide radical (·NO) assays. We also studied d-amino acid oxidase (DAAO), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity. Almost each of newly synthesised compounds exhibited radical scavenging capabilities. Moreover, several compounds showed moderate inhibitory activities against DAAO, AChE and BuChE. Compounds with significant free-radical scavenging activity may be potential candidates for therapeutics used in oxidative-stress-related diseases.

  14. Variations of L- and D-amino acid levels in the brain of wild-type and mutant mice lacking D-amino acid oxidase activity.

    Science.gov (United States)

    Du, Siqi; Wang, Yadi; Weatherly, Choyce A; Holden, Kylie; Armstrong, Daniel W

    2018-05-01

    D-amino acids are now recognized to be widely present in organisms and play essential roles in biological processes. Some D-amino acids are metabolized by D-amino acid oxidase (DAO), while D-Asp and D-Glu are metabolized by D-aspartate oxidase (DDO). In this study, levels of 22 amino acids and the enantiomeric compositions of the 19 chiral proteogenic entities have been determined in the whole brain of wild-type ddY mice (ddY/DAO +/+ ), mutant mice lacking DAO activity (ddY/DAO -/- ), and the heterozygous mice (ddY/DAO +/- ) using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). No significant differences were observed for L-amino acid levels among the three strains except for L-Trp which was markedly elevated in the DAO +/- and DAO -/- mice. The question arises as to whether this is an unknown effect of DAO inactivity. The three highest levels of L-amino acids were L-Glu, L-Asp, and L-Gln in all the three strains. The lowest L-amino acid level was L-Cys in ddY/DAO +/- and ddY/DAO -/- mice, while L-Trp showed the lowest level in ddY/DAO +/+ mice. The highest concentration of D-amino acid was found to be D-Ser, which also had the highest % D value (~ 25%). D-Glu had the lowest % D value (~ 0.01%) in all the three strains. Significant differences of D-Leu, D-Ala, D-Ser, D-Arg, and D-Ile were observed in ddY/DAO +/- and ddY/DAO -/- mice compared to ddY/DAO +/+ mice. This work provides the most complete baseline analysis of L- and D-amino acids in the brains of ddY/DAO +/+ , ddY/DAO +/- , and ddY/DAO -/- mice yet reported. It also provides the most effective and efficient analytical approach for measuring these analytes in biological samples. This study provides fundamental information on the role of DAO in the brain and may be relevant for future development involving novel drugs for DAO regulation.

  15. The Arabidopsis aldehyde oxidase 3 (AA03) gene product catalyzes the final step in abscisic acid biosynthesis in leaves

    NARCIS (Netherlands)

    Seo, M.; Peeters, A.J.M.; Koiwai, H.; Oritani, T.; Marion-Poll, A.; Zeevaart, J.A.D.; Koornneef, M.; Kamiya, Y.; Koshiba, T.

    2000-01-01

    Abscisic acid (ABA) is a plant hormone involved in seed development and germination and in responses to various environmental stresses. The last step of ABA biosynthesis involves oxidation of abscisic aldehyde, and aldehyde oxidase (EC 1.2.3.1) is thought to catalyze this reaction. An aldehyde

  16. MipLAAO, a new L-amino acid oxidase from the redtail coral snake Micrurus mipartitus

    Directory of Open Access Journals (Sweden)

    Paola Rey-Suárez

    2018-06-01

    Full Text Available L-amino acid oxidases (LAAOs are ubiquitous enzymes in nature. Bioactivities described for these enzymes include apoptosis induction, edema formation, induction or inhibition of platelet aggregation, as well as antiviral, antiparasite, and antibacterial actions. With over 80 species, Micrurus snakes are the representatives of the Elapidae family in the New World. Although LAAOs in Micrurus venoms have been predicted by venom gland transcriptomic studies and detected in proteomic studies, no enzymes of this kind have been previously purified from their venoms. Earlier proteomic studies revealed that the venom of M. mipartitus from Colombia contains ∼4% of LAAO. This enzyme, here named MipLAAO, was isolated and biochemically and functionally characterized. The enzyme is found in monomeric form, with an isotope-averaged molecular mass of 59,100.6 Da, as determined by MALDI-TOF. Its oxidase activity shows substrate preference for hydrophobic amino acids, being optimal at pH 8.0. By nucleotide sequencing of venom gland cDNA of mRNA transcripts obtained from a single snake, six isoforms of MipLAAO with minor variations among them were retrieved. The deduced sequences present a mature chain of 483 amino acids, with a predicted pI of 8.9, and theoretical masses between 55,010.9 and 55,121.0 Da. The difference with experimentally observed mass is likely due to glycosylation, in agreement with the finding of three putative N-glycosylation sites in its amino acid sequence. A phylogenetic analysis of MmipLAAO placed this new enzyme within the clade of homologous proteins from elapid snakes, characterized by the conserved Serine at position 223, in contrast to LAAOs from viperids. MmipLAAO showed a potent bactericidal effect on S. aureus (MIC: 2 µg/mL, but not on E. coli. The former activity could be of interest to future studies assessing its potential as antimicrobial agent.

  17. Cytochemical Localization of Glucose Oxidase in Peroxisomes of Aspergillus niger

    NARCIS (Netherlands)

    Veenhuis, Marten; Dijken, Johannes Pieter van

    1980-01-01

    The subcellular localization of glucose oxidase (E.C. 1.1.3.4) in mycelia of Aspergillus niger has been investigated using cytochemical staining techniques. Mycelia from fermenter cultures, which produced gluconic acid from glucose, contained elevated levels of glucose oxidase and catalase. Both

  18. Fabricating an Amperometric Cholesterol Biosensor by a Covalent Linkage between Poly(3-thiopheneacetic acid and Cholesterol Oxidase

    Directory of Open Access Journals (Sweden)

    Kuo-Chuan Ho

    2009-03-01

    Full Text Available In this study, use of the covalent enzyme immobilization method was proposed to attach cholesterol oxidase (ChO on a conducting polymer, poly(3-thiopheneacetic acid, [poly(3-TPAA]. Three red-orange poly(3-TPAA films, named electrodes A, B and C, were electropolymerized on a platinum electrode by applying a constant current of 1.5 mA, for 5, 20 and 100 s, respectively. Further, 1-ethyl-3-(3-dimethylamiopropylcarbodiimide hydrochloride (EDC‧HCl and N-hydroxysuccinimide (NHS were used to activate the free carboxylic groups of the conducting polymer. Afterwards, the amino groups of the cholesterol oxidase were linked on the activated groups to form peptide bonds. The best sensitivity obtained for electrode B is 4.49 mA M-1 cm-2,with a linear concentration ranging from 0 to 8 mM, which is suitable for the analysis of cholesterol in humans. The response time (t95 is between 70 and 90 s and the limit of detection is 0.42 mM, based on the signal to noise ratio equal to 3. The interference of species such as ascorbic acid and uric acid increased to 5.2 and 10.3% of the original current response, respectively, based on the current response of cholesterol (100%. With respect to the long-term stability, the sensing response retains 88% of the original current after 13 days.

  19. Fabricating an Amperometric Cholesterol Biosensor by a Covalent Linkage between Poly(3-thiopheneacetic acid) and Cholesterol Oxidase.

    Science.gov (United States)

    Nien, Po-Chin; Chen, Po-Yen; Ho, Kuo-Chuan

    2009-01-01

    In this study, use of the covalent enzyme immobilization method was proposed to attach cholesterol oxidase (ChO) on a conducting polymer, poly(3-thiopheneacetic acid), [poly(3-TPAA)]. Three red-orange poly(3-TPAA) films, named electrodes A, B and C, were electropolymerized on a platinum electrode by applying a constant current of 1.5 mA, for 5, 20 and 100 s, respectively. Further, 1-ethyl-3-(3-dimethylamiopropyl)carbodiimide hydrochloride (EDC · HCl) and N-hydroxysuccinimide (NHS) were used to activate the free carboxylic groups of the conducting polymer. Afterwards, the amino groups of the cholesterol oxidase were linked on the activated groups to form peptide bonds. The best sensitivity obtained for electrode B is 4.49 mA M(-1) cm(-2), with a linear concentration ranging from 0 to 8 mM, which is suitable for the analysis of cholesterol in humans. The response time (t(95)) is between 70 and 90 s and the limit of detection is 0.42 mM, based on the signal to noise ratio equal to 3. The interference of species such as ascorbic acid and uric acid increased to 5.2 and 10.3% of the original current response, respectively, based on the current response of cholesterol (100%). With respect to the long-term stability, the sensing response retains 88% of the original current after 13 days.

  20. In Situ Enzymatically Generated Photoswitchable Oxidase Mimetics and Their Application for Colorimetric Detection of Glucose Oxidase.

    Science.gov (United States)

    Cao, Gen-Xia; Wu, Xiu-Ming; Dong, Yu-Ming; Li, Zai-Jun; Wang, Guang-Li

    2016-07-09

    In this study, a simple and amplified colorimetric assay is developed for the detection of the enzymatic activity of glucose oxidase (GOx) based on in situ formation of a photoswitchable oxidase mimetic of PO₄(3-)-capped CdS quantum dots (QDs). GOx catalyzes the oxidation of 1-thio-β-d-glucose to give 1-thio-β-d-gluconic acid which spontaneously hydrolyzes to β-d-gluconic acid and H₂S; the generated H₂S instantly reacts with Cd(2+) in the presence of Na₃PO₄ to give PO₄(3-)-stabilized CdS QDs in situ. Under visible-light (λ ≥ 400 nm) stimulation, the PO₄(3-)-capped CdS QDs are a new style of oxidase mimic derived by producing some active species, such as h⁺, (•)OH, O₂(•-) and a little H₂O₂, which can oxidize the typical substrate (3,3,5,5-tetramethylbenzydine (TMB)) with a color change. Based on the GOx-triggered growth of the oxidase mimetics of PO₄(3-)-capped CdS QDs in situ, we developed a simple and amplified colorimetric assay to probe the enzymatic activity of GOx. The proposed method allowed the detection of the enzymatic activity of GOx over the range from 25 μg/L to 50 mg/L with a low detection limit of 6.6 μg/L. We believe the PO₄(3-)-capped CdS QDs generated in situ with photo-stimulated enzyme-mimicking activity may find wide potential applications in biosensors.

  1. Snake venom L-amino acid oxidases: an overview on their antitumor effects

    Science.gov (United States)

    2014-01-01

    The L-amino acid oxidases (LAAOs) constitute a major component of snake venoms and have been widely studied due to their widespread presence and various effects, such as apoptosis induction, cytotoxicity, induction and/or inhibition of platelet aggregation, hemorrhage, hemolysis, edema, as well as antimicrobial, antiparasitic and anti-HIV activities. The isolated and characterized snake venom LAAOs have become important research targets due to their potential biotechnological applications in pursuit for new drugs of interest in the scientific and medical fields. The current study discusses the antitumor effects of snake venom LAAOs described in the literature to date, highlighting the mechanisms of apoptosis induction proposed for this class of proteins. PMID:24940304

  2. Biochemical Conservation and Evolution of Germacrene A Oxidase in Asteraceae*

    Science.gov (United States)

    Nguyen, Don Trinh; Göpfert, Jens Christian; Ikezawa, Nobuhiro; MacNevin, Gillian; Kathiresan, Meena; Conrad, Jürgen; Spring, Otmar; Ro, Dae-Kyun

    2010-01-01

    Sesquiterpene lactones are characteristic natural products in Asteraceae, which constitutes ∼8% of all plant species. Despite their physiological and pharmaceutical importance, the biochemistry and evolution of sesquiterpene lactones remain unexplored. Here we show that germacrene A oxidase (GAO), evolutionarily conserved in all major subfamilies of Asteraceae, catalyzes three consecutive oxidations of germacrene A to yield germacrene A acid. Furthermore, it is also capable of oxidizing non-natural substrate amorphadiene. Co-expression of lettuce GAO with germacrene synthase in engineered yeast synthesized aberrant products, costic acids and ilicic acid, in an acidic condition. However, cultivation in a neutral condition allowed the de novo synthesis of a single novel compound that was identified as germacrene A acid by gas and liquid chromatography and NMR analyses. To trace the evolutionary lineage of GAO in Asteraceae, homologous genes were further isolated from the representative species of three major subfamilies of Asteraceae (sunflower, chicory, and costus from Asteroideae, Cichorioideae, and Carduoideae, respectively) and also from the phylogenetically basal species, Barnadesia spinosa, from Barnadesioideae. The recombinant GAOs from these genes clearly showed germacrene A oxidase activities, suggesting that GAO activity is widely conserved in Asteraceae including the basal lineage. All GAOs could catalyze the three-step oxidation of non-natural substrate amorphadiene to artemisinic acid, whereas amorphadiene oxidase diverged from GAO displayed negligible activity for germacrene A oxidation. The observed amorphadiene oxidase activity in GAOs suggests that the catalytic plasticity is embedded in ancestral GAO enzymes that may contribute to the chemical and catalytic diversity in nature. PMID:20351109

  3. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    Science.gov (United States)

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  4. Antiglycation, radical scavenging, and semicarbazide-sensitive amine oxidase inhibitory activities of acetohydroxamic acid in vitro

    Directory of Open Access Journals (Sweden)

    Liu YH

    2017-07-01

    Full Text Available Yuh-Hwa Liu,1,2,* Yeh-Lin Lu,3,* Der-Zen Liu,4 Wen-Chi Hou5 1Division of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 2Department of General Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3Department of Pharmacy, Taipei Medical University, Taipei, Taiwan; 4Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei, Taiwan; 5Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan *These authors contributed equally to this work Abstract: Advanced glycation endproducts (AGEs can promote intracellular reactive oxygen species production, and the levels of AGEs are highly correlated with cardiovascular disease and diabetes complications. Acetohydroxamic acid (acetH is a bacterial urease inhibitor drug used to treat kidney stones and infections in the urinary tract, and hydroxyurea (HU is a drug used for antineoplasm and sickle cell diseases. Both acetH and HU are hydroxamic acid derivatives. It was found that acetH and HU at 2.5 or 5 mM showed anti-AGE formation by lowering the AGEs’ fluorescent intensities and Nε-(carboxymethyllysine formation in bovine serum albumin/galactose models, and both showed better and significant differences (P<0.05 compared to the positive control of aminoguanidine. Regarding radical scavenging activities, the half-inhibition concentrations (IC50 of acetH against α,α-diphenyl-β-picrylhydrazyl radical and hydroxyl radical were 34.86 and 104.42 µM, respectively. The IC50 of acetH against semicarbazide-sensitive amine oxidase was 10.56 µM, and acetH showed noncompetitive inhibition respective to the substrates (benzylamine. The antiglycation, antioxidant, and semicarbazide-sensitive amine oxidase inhibitory activities of acetH prove that it has the potential for treating cardiovascular disease and diabetes complications and it needs further investigation in animal models. Keywords: acetH, AGEs, Nε

  5. Gold electrode modified with a self-assembled glucose oxidase and 2,6-pyridinedicarboxylic acid as novel glucose bioanode for biofuel cells

    NARCIS (Netherlands)

    Ammam, Malika; Fransaer, Jan

    2014-01-01

    In this study, we have constructed a gold electrode modified with (3-aminopropyl)trimethoxysilane/2,6-pyridinedicarboxylic acid/glucose oxidase (abbreviated as, Au/ATS/PDA/GOx) by sequential chemical adsorption. Au/ATS/PDA/GOx electrode was characterized by Fourier Transform Infrared Spectroscopy

  6. Aristolochic acid and its derivatives as inhibitors of snake venom L-amino acid oxidase.

    Science.gov (United States)

    Bhattacharjee, Payel; Bera, Indrani; Chakraborty, Subhamoy; Ghoshal, Nanda; Bhattacharyya, Debasish

    2017-11-01

    Snake venom L-amino acid oxidase (LAAO) exerts toxicity by inducing hemorrhage, pneumorrhagia, pulmonary edema, cardiac edema, liver cell necrosis etc. Being well conserved, inhibitors of the enzyme may be synthesized using the template of the substrate, substrate binding site and features of the catalytic site of the enzyme. Previous findings showed that aristolochic acid (AA), a major constituent of Aristolochia indica, inhibits Russell's viper venom LAAO enzyme activity since, AA interacts with DNA and causes genotoxicity, derivatives of this compound were synthesized by replacing the nitro group to reduce toxicity while retaining the inhibitory potency. The interactions of AA and its derivatives with LAAO were followed by inhibition kinetics and surface plasmon resonance. Similar interactions with DNA were followed by absorption spectroscopy and atomic force microscopy. LAAO-induced cytotoxicity was evaluated by generation of reactive oxygen species (ROS), cell viability assays, confocal and epifluorescence microscopy. The hydroxyl (AA-OH) and chloro (AA-Cl) derivatives acted as inhibitors of LAAO but did not interact with DNA. The derivatives significantly reduced LAAO-induced ROS generation and cytotoxicity in human embryonic kidney (HEK 293) and hepatoma (HepG2) cell lines. Confocal images indicated that AA, AA-OH and AA-Cl interfered with the binding of LAAO to the cell membrane. AA-OH and AA-Cl significantly inhibited LAAO activity and reduced LAAO-induced cytotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Ethylene biosynthesis by 1-aminocyclopropane-1-carboxylic acid oxidase: a DFT study.

    Science.gov (United States)

    Bassan, Arianna; Borowski, Tomasz; Schofield, Christopher J; Siegbahn, Per E M

    2006-11-24

    The reaction catalyzed by the plant enzyme 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO) was investigated by using hybrid density functional theory. ACCO belongs to the non-heme iron(II) enzyme superfamily and carries out the bicarbonate-dependent two-electron oxidation of its substrate ACC (1-aminocyclopropane-1-carboxylic acid) concomitant with the reduction of dioxygen and oxidation of a reducing agent probably ascorbate. The reaction gives ethylene, CO(2), cyanide and two water molecules. A model including the mononuclear iron complex with ACC in the first coordination sphere was used to study the details of O-O bond cleavage and cyclopropane ring opening. Calculations imply that this unusual and complex reaction is triggered by a hydrogen atom abstraction step generating a radical on the amino nitrogen of ACC. Subsequently, cyclopropane ring opening followed by O-O bond heterolysis leads to a very reactive iron(IV)-oxo intermediate, which decomposes to ethylene and cyanoformate with very low energy barriers. The reaction is assisted by bicarbonate located in the second coordination sphere of the metal.

  8. Presteady-state and steady-state kinetic properties of human cytochrome c oxidase. Identification of rate-limiting steps in mammalian cytochrome c oxidase

    NARCIS (Netherlands)

    van Kuilenburg, A. B.; Gorren, A. C.; Dekker, H. L.; Nieboer, P.; van Gelder, B. F.; Muijsers, A. O.

    1992-01-01

    Human cytochrome c oxidase was purified in a fully active form from heart and skeletal muscle. The enzyme was selectively solubilised with octylglucoside and KCl from submitochondrial particles followed by ammonium sulphate fractionation. The presteady-state and steady-state kinetic properties of

  9. Development of 2-(Substituted Benzylamino)-4-Methyl-1, 3-Thiazole-5-Carboxylic Acid Derivatives as Xanthine Oxidase Inhibitors and Free Radical Scavengers.

    Science.gov (United States)

    Ali, Md Rahmat; Kumar, Suresh; Afzal, Obaid; Shalmali, Nishtha; Sharma, Manju; Bawa, Sandhya

    2016-04-01

    A series of 2-(substituted benzylamino)-4-methylthiazole-5-carboxylic acid was designed and synthesized as structural analogue of febuxostat. A methylene amine spacer was incorporated between the phenyl ring and thiazole ring in contrast to febuxostat in which the phenyl ring was directly linked with the thiazole moiety. The purpose of incorporating methylene amine was to provide a heteroatom which is expected to favour hydrogen bonding within the active site residues of the enzyme xanthine oxidase. The structure of all the compounds was established by the combined use of FT-IR, NMR and MS spectral data. All the compounds were screened in vitro for their ability to inhibit the enzyme xanthine oxidase as per the reported procedure along with DPPH free radical scavenging assay. Compounds 5j, 5k and 5l demonstrated satisfactory potent xanthine oxidase inhibitory activities with IC50 values, 3.6, 8.1 and 9.9 μm, respectively, whereas compounds 5k, 5n and 5p demonstrated moderate antioxidant activities having IC50 15.3, 17.6 and 19.6 μm, respectively, along with xanthine oxidase inhibitory activity. Compound 5k showed moderate xanthine oxidase inhibitory activity as compared with febuxostat along with antioxidant activity. All the compounds were also studied for their binding affinity in active site of enzyme (PDB ID-1N5X). © 2015 John Wiley & Sons A/S.

  10. Comparison of bolus versus fractionated oral applications of [13C]-linoleic acid in humans.

    Science.gov (United States)

    Demmelmair, H; Iser, B; Rauh-Pfeiffer, A; Koletzko, B

    1999-07-01

    The endogenous conversion of linoleic acid into long-chain polyunsaturated fatty acids is of potential importance for meeting substrate requirements, particularly in young infants. After application of [13C]-linoleic acid, we estimated its conversion to dihomo-gamma-linolenic and arachidonic acids from only two blood samples. Oral tracer doses were given to five healthy adults as a single bolus. In four subjects the tracer was given in nine equal portions over 3 days. Concentration and 13C content of fatty acids from serum phospholipids were analysed by gas chromatography combustion isotope ratio-mass spectrometry. Areas under the tracer-concentration curves were calculated, and fractional transfer and turnover rates estimated from compartmental models. The median fractional turnover of linoleic acid was 93.7% per day (interquartile range 25.3) in the bolus group and 80. 0% per day (6.3) in the fraction group (NS). Fractional conversion of linoleic to dihomo-gamma-linolenic acid was 1.5% (0.9) vs. 2.1% (0.7) (bolus vs. fraction, P /= 0.94, P < 0.05) with the ratio of areas under the curve. Using areas under the curve overestimates the conversion, because different residence times are not considered. Estimation of conversion intensity appears possible with only one blood sample obtained after tracer application.

  11. Acid fractionation for low level liquid waste cleanup and recycle

    International Nuclear Information System (INIS)

    Gombert, D. II; McIntyre, C.V.; Mizia, R.E.; Schindler, R.E.

    1990-01-01

    At the Idaho Chemical Processing Plant, low level liquid wastes containing small amounts of radionuclides are concentrated via a thermosyphon evaporator for calcination with high level waste, and the evaporator condensates are discharged with other plant wastewater to a percolation pond. Although all existing discharge guidelines are currently met, work has been done to reduce all waste water discharges to an absolute minimum. In this regard, a 15-tray acid fractionation column will be used to distill the mildly acidic evaporator condensates into concentrated nitric acid for recycle in the plant. The innocuous overheads from the fractionator having a pH greater than 2, are superheated and HEPA filtered for atmospheric discharge. Nonvolatile radionuclides are below detection limits. Recycle of the acid not only displaces fresh reagent, but reduces nitrate burden to the environment, and completely eliminates routine discharge of low level liquid wastes to the environment

  12. Functional groups and reactivity of size-fractionated Aldrich humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Tadao, E-mail: tanaka.tadao26@jaea.go.jp [Nuclear Safety Research Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Naka, Ibaraki, 319-1195 (Japan)

    2012-03-20

    The complexation affinity of the Aldrich Chemicals humic acid with {sup 60}Co was examined with respect to molecular size of humic acid. Correlations between the affinity and the structures of humic acid were studied. At low humic acid concentration range, {sup 60}Co was interacted with the humic acid of size fraction over 100k Da (HA(100<)). With increasing humic acid concentration, the {sup 60}Co was preferentially interacted with the 30k-100k Da of humic acid (HA(30-100)). Fractionated HA(100<) and HA(30-100) were characterized from their FTIR (Fourier Transform Infra-Red), {sup 13}C NMR spectral analyses and acid-base titration curves. The HA(10<) having aliphatic branched structure, smaller amount of COOH group and large proton exchangeable capacity, seem to show low covalent bonding nature and high ion exchangeability in the complexation. In addition, steric hindrance may affect on the complexation, by winding up like random coils from the branched structure. The HA(30-100) is dominated with the aromatic COOH group and OH group and it may preferentially coordinate to {sup 60}Co by covalent binding. These presumptions were supported by XPS analysis, in which the biding energy of cobalt-humates was discussed.

  13. Engineering glucose oxidase to minimize the influence of oxygen on sensor response

    International Nuclear Information System (INIS)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2014-01-01

    Glucose oxidase (GOx) is an important industrial enzyme and is recognized as the gold standard for monitoring blood glucose. However, due to its inherent oxidase property, the presence of oxygen affects electrochemical measurements of venous blood glucose employing artificial electron mediators. We therefore attempted to engineer Penicillium amagasakiense-derived GOx into a dehydrogenase by focusing on the amino acid residues predicted to interact with oxygen. Our rational amino acid substitution approach resulted in the construction of the Ser114Ala/Phe355Leu mutant, which has an 11-fold decrease in oxidase activity and 2.8-fold increase in dehydrogenase activity compared with wild-type GOx. As a result, the dehydrogenase/oxidase activity ratio of the engineered enzyme was 32-fold greater than that of the wild-type enzyme. The enzyme sensor constructed with Ser114Ala/Phe355Leu was considerably less affected by oxygen than the wild-type GOx-based sensor at lower glucose concentrations

  14. Copper isotope fractionation in acid mine drainage

    Science.gov (United States)

    Kimball, B.E.; Mathur, R.; Dohnalkova, A.C.; Wall, A.J.; Runkel, R.L.; Brantley, S.L.

    2009-01-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The ??65Cu values (based on 65Cu/63Cu) of enargite (??65Cu = -0.01 ?? 0.10???; 2??) and chalcopyrite (??65Cu = 0.16 ?? 0.10???) are within the range of reported values for terrestrial primary Cu sulfides (-1??? waters (1.38??? ??? ??65Cu ??? 1.69???). The average isotopic fractionation (??aq-min = ??65Cuaq - ??65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ?? 0.14??? and 1.60 ?? 0.14??? for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ?? 0.14???) and enargite (0.98 ?? 0.14???) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (??aq-mino = - 0.57 ?? 0.14 ???, where mino refers to the starting mineral) and no apparent fractionation for enargite (??aq-mino = 0.14 ?? 0.14 ???). Abiotic fractionation is attributed to preferential oxidation of 65Cu+ at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cuaq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of ??65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures resulting from Cu sulfide dissolution should be useful for acid mine drainage

  15. Rac1-NADPH oxidase signaling promotes CD36 activation under glucotoxic conditions in pancreatic beta cells.

    Science.gov (United States)

    Elumalai, Suma; Karunakaran, Udayakumar; Lee, In Kyu; Moon, Jun Sung; Won, Kyu Chang

    2017-04-01

    We recently reported that cluster determinant 36 (CD36), a fatty acid transporter, plays a pivotal role in glucotoxicity-induced β-cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression. Emerging evidence suggests that the small GTPase Rac1 is involved in the pathogenesis of beta cell dysfunction in type 2 diabetes (T2D). The primary objective of the current study was to determine the role of Rac1 in CD36 activation and its impact on β-cell dysfunction in diabetes mellitus. To address this question, we subjected INS-1 cells and human beta cells (1.1B4) to high glucose conditions (30mM) in the presence or absence of Rac1 inhibition either by NSC23766 (Rac1 GTPase inhibitor) or small interfering RNA. High glucose exposure in INS-1 and human beta cells (1.1b4) resulted in the activation of Rac1 and induced cell apoptosis. Rac1 activation mediates NADPH oxidase (NOX) activation leading to elevated ROS production in both cells. Activation of the Rac1-NOX complex by high glucose levels enhanced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. The inhibition of Rac1 by NSC23766 inhibited NADPH oxidase activity and ROS generation induced by high glucose concentrations in INS-1 & human 1.1b4 beta cells. Inhibition of Rac1-NOX complex activation by NSC23766 significantly reduced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. In addition, Rac1 inhibition by NSC23766 significantly reduced high glucose-induced mitochondrial dysfunction. Furthermore, NADPH oxidase inhibition by VAS2870 also attenuated high glucose-induced ROS generation and cell apoptosis. These results suggest that Rac1-NADPH oxidase dependent CD36 expression contributes to high glucose-induced beta cell dysfunction and cell death. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Quinolinic Carboxylic Acid Derivatives as Potential Multi-target Compounds for Neurodegeneration: Monoamine Oxidase and Cholinesterase Inhibition.

    Science.gov (United States)

    Khan, Nehal A; Khan, Imtiaz; Abid, Syed M A; Zaib, Sumera; Ibrar, Aliya; Andleeb, Hina; Hameed, Shahid; Iqbal, Jamshed

    2018-01-01

    Parkinson's disease (PD), a debilitating and progressive disorder, is among the most challenging and devastating neurodegenerative diseases predominantly affecting the people over 60 years of age. To confront PD, an advanced and operational strategy is to design single chemical functionality able to control more than one target instantaneously. In this endeavor, for the exploration of new and efficient inhibitors of Parkinson's disease, we synthesized a series of quinoline carboxylic acids (3a-j) and evaluated their in vitro monoamine oxidase and cholinesterase inhibitory activities. The molecular docking and in silico studies of the most potent inhibitors were performed to identify the probable binding modes in the active site of the monoamine oxidase enzymes. Moreover, molecular properties were calculated to evaluate the druglikeness of the compounds. The biological evaluation results revealed that the tested compounds were highly potent against monoamine oxidase (A & B), 3c targeted both the isoforms of MAO with IC50 values of 0.51 ± 0.12 and 0.51 ± 0.03 µM, respectively. The tested compounds also demonstrated high and completely selective inhibitory action against acetylcholinesterase (AChE) with IC50 values ranging from 4.36 to 89.24 µM. Among the examined derivatives, 3i was recognized as the most potent inhibitor of AChE with an IC50 value of 4.36 ± 0.12 ±µM. The compounds appear to be promising inhibitors and could be used for the future development of drugs targeting neurodegenerative disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Involvement of NADH Oxidase in Biofilm Formation in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available Biofilms play important roles in microbial communities and are related to infectious diseases. Here, we report direct evidence that a bacterial nox gene encoding NADH oxidase is involved in biofilm formation. A dramatic reduction in biofilm formation was observed in a Streptococcus sanguinis nox mutant under anaerobic conditions without any decrease in growth. The membrane fluidity of the mutant bacterial cells was found to be decreased and the fatty acid composition altered, with increased palmitic acid and decreased stearic acid and vaccenic acid. Extracellular DNA of the mutant was reduced in abundance and bacterial competence was suppressed. Gene expression analysis in the mutant identified two genes with altered expression, gtfP and Idh, which were found to be related to biofilm formation through examination of their deletion mutants. NADH oxidase-related metabolic pathways were analyzed, further clarifying the function of this enzyme in biofilm formation.

  18. Significance of membrane bioreactor design on the biocatalytic performance of glucose oxidase and catalase: Free vs. immobilized enzyme systems

    DEFF Research Database (Denmark)

    Morthensen, Sofie Thage; Meyer, Anne S.; Jørgensen, Henning

    2017-01-01

    Membrane separation of xylose and glucose can be accomplished via oxidation of glucose to gluconic acid by enzymatic glucose oxidase catalysis. Oxygen for this reaction can be supplied via decomposition of hydrogen peroxide by enzymatic catalase catalysis. In order to maximize the biocatalytic...... productivity of glucose oxidase and catalase (gluconic acid yield per total amount of enzyme) the following system set-ups were compared: immobilization of glucose oxidase alone; co-immobilization of glucose oxidase and catalase; glucose oxidase and catalase free in the membrane bioreactor. Fouling......-induced enzyme immobilization in the porous support of an ultrafiltration membrane was used as strategy for entrapment of glucose oxidase and catalase. The biocatalytic productivity of the membrane reactor was found to be highly related to the oxygen availability, which in turn depended on the reactor...

  19. Gene cloning and characterization of NADH oxidase from ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... potent inhibitors of NADH oxidases, silver nitrate and potassium cyanide did not show any significant ... anaerobes, a class of organisms that have not been ... DNA and amino acid sequence analyses were performed using.

  20. Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1.

    Directory of Open Access Journals (Sweden)

    Silvia Schumann

    Full Text Available Mouse aldehyde oxidase (mAOX1 forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Escherichia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.

  1. Metavanadate causes cellular accumulation of copper and decreased lysyl oxidase activity

    International Nuclear Information System (INIS)

    Cui, Changtai T.; Uriu-Adams, Janet Y.; Tchaparian, Eskouhie H.; Keen, Carl L.; Rucker, Robert B.

    2004-01-01

    Selected indices of copper metabolism in weanling rats and fibroblast cultures were progressively altered in response to increased levels of sodium metavanadate. In diets, vanadium was added in amounts ranging from 0 to 80 μg V/g of diet, that is, 0-1.6 μmol V/g of diet. In fibroblast cultures, vanadium ranged from 0 to 400 nmol V/ml. The inhibition of P-ATPase-7A activity by metavanadate, important to copper egress from cells, was a primary focus. In skin, and tendon, the copper concentration was increased in response to increased dietary levels of metavanadate, whereas lysyl oxidase activity, a secreted cuproprotein, was reduced. The reduction in lysyl oxidase activity was also accompanied by reduced redox cycling potential of isolated fractions of lysyl oxidase, presumably due to reduced lysyltyrosyl quinone (LTQ) formation at the active site of lysyl oxidase. In contrast, liver copper concentrations and plasma ceruloplasmin activity were not affected by metavanadate exposure. However, semicarbazide-sensitive benzylamine oxidase (SCBO) activity, which was taken as an indirect measure of vascular adhesive protein-1 (VAP-1), was increased. In cultured fibroblasts, cellular copper was also increased and lysyl oxidase decreased in response to metavanadate. Moreover, the steady-state levels of atp7a and lysyl oxidase mRNAs were not affected by addition of metavanadate to culture medium up to 200 nmol/ml. Taken together, these data suggest that pathways involving copper egress and lysyl oxidase activation are particularly sensitive to metavanadate exposure through processes that are predominately posttranslational

  2. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with {sup 60}Co gamma rays, in Leishmania spp; Acao do veneno de Bothrops moojeni e sua fracao L-aminoacido oxidase, submetida ao tratamento com raios gama de {sup 60}Co, em Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Andre Gustavo Tempone

    1999-07-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 {mu}g/ml (EC{sub 50}), L.(V.) panamensis (0.78 |{mu}g/ml) and L.(L.) chagasi (0.63 ({mu}g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC{sub 50} of 11|{mu}g/ml. Irradiation of LAO with 6{sup 0C}o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC{sub 50} of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  3. Monoamine Oxidase Inhibitory Activity of Ferulic Acid Amides: Curcumin-Based Design and Synthesis.

    Science.gov (United States)

    Badavath, Vishnu N; Baysal, İpek; Uçar, Gülberk; Mondal, Susanta K; Sinha, Barij N; Jayaprakash, Venkatesan

    2016-01-01

    Ferulic acid has structural similarity with curcumin which is being reported for its monoamine oxidase (MAO) inhibitory activity. Based on this similarity, we designed a series of ferulic acid amides 6a-m and tested for their inhibitory activity on human MAO (hMAO) isoforms. All the compounds were found to inhibit the hMAO isoforms either selectively or non-selectively. Nine compounds (6a, 6b, 6g-m) were found to inhibit hMAO-B selectively, whereas the other four (6c-f) were found to be non-selective. There is a gradual shift from hMAO-B selectivity (6a,b) to non-selectivity (6c-f) as there is an increase in chain length at the amino terminus. In case of compounds having an aromatic nucleus at the amino terminus, increasing the carbon number between N and the aromatic ring increases the potency as well as selectivity toward hMAO-B. Compounds 6f, 6j, and 6k were subjected to membrane permeability and metabolic stability studies by in vitro assay methods. They were found to have a better pharmacokinetic profile than curcumin, ferulic acid, and selegiline. In order to understand the structural features responsible for the potency and selectivity of 6k, we carried out a molecular docking simulation study. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Periodic variation in bile acids controls circadian changes in uric acid via regulation of xanthine oxidase by the orphan nuclear receptor PPARα.

    Science.gov (United States)

    Kanemitsu, Takumi; Tsurudome, Yuya; Kusunose, Naoki; Oda, Masayuki; Matsunaga, Naoya; Koyanagi, Satoru; Ohdo, Shigehiro

    2017-12-29

    Xanthine oxidase (XOD), also known as xanthine dehydrogenase, is a rate-limiting enzyme in purine nucleotide degradation, which produces uric acid. Uric acid concentrations in the blood and liver exhibit circadian oscillations in both humans and rodents; however, the underlying mechanisms remain unclear. Here, we demonstrate that XOD expression and enzymatic activity exhibit circadian oscillations in the mouse liver. We found that the orphan nuclear receptor peroxisome proliferator-activated receptor-α (PPARα) transcriptionally activated the mouse XOD gene and that bile acids suppressed XOD transactivation. The synthesis of bile acids is known to be under the control of the circadian clock, and we observed that the time-dependent accumulation of bile acids in hepatic cells interfered with the recruitment of the co-transcriptional activator p300 to PPARα, thereby repressing XOD expression. This time-dependent suppression of PPARα-mediated transactivation by bile acids caused an oscillation in the hepatic expression of XOD, which, in turn, led to circadian alterations in uric acid production. Finally, we also demonstrated that the anti-hyperuricemic effect of the XOD inhibitor febuxostat was enhanced by administering it at the time of day before hepatic XOD activity increased. These results suggest an underlying mechanism for the circadian alterations in uric acid production and also underscore the importance of selecting an appropriate time of day for administering XOD inhibitors. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Fatty acid content and lipid fractions in herbs

    DEFF Research Database (Denmark)

    Petersen, Majbritt Bonefeld; Søegaard, Karen; Jensen, Søren Krogh

    2012-01-01

    Experiments have shown a higher transfer efficiency of n-3 and n-6 fatty acids (FA) to milk when feeding herbs compared to feeding grass-clover. With the aim to gain more knowledge for this, the FA profile of ten single plant species and the incorporation of FA in lipid fractions were analysed...

  6. Antihistaminic and antieicosanoid effects of oleanolic and ursolic acid fraction from Helichrysum picardii.

    Science.gov (United States)

    Santos Rosa, C; García Gimenez, M D; Saenz Rodriguez, M T; De la Puerta Vazquez, R

    2007-06-01

    Helichrysum picardii Boiss. & Reuter is a Mediterranean vegetal species from the Asteraceae family. From the methanolic extract of the aerial flowering parts of this plant, a fraction of two pentacyclic triterpenes has been isolated. Gas chromatography revealed that the triterpene isomers ursolic and oleanolic acids comprised 69% and 29% respectively of the composition of this fraction. The triterpene isomeric fraction was tested in two phagocyte cell systems. It inhibited compound 48/80-induced histamine release from rat peritoneal mast cells in an approximately percentage of 45% at 100 microM and myeloperoxidase secretion from A23187-ionophore-stimulated rat peritoneal leukocytes in a significant manner at doses of 50 and 100 miroM. Furthermore, the triterpene isomers very significantly and dose-dependently inhibited generation of the cyclo-oxygenase metabolite prostaglandin E2 (41% inhibition at 50 miroM) and the 5-lipoxygenase metabolite leukotriene B4 (79% inhibition at 50 microM) from activated rat leukocytes. This anti-eicosanoid activity of the triterpene fraction was more potent than that produced by the pure triterpene oleanolic acid used for comparision, indicating a stronger action of the ursolic acid, the major compound of the isolated triterpene fraction. From these data, it can be suggested that the triterpene isomers oleanolic and ursolic acids present in the medicinal plant Helichrysum picardii contribute to the anti-inflammatory profile of this vegetal species.

  7. Genomic sequencing of uric acid metabolizing and clearing genes in relationship to xanthine oxidase inhibitor dose.

    Science.gov (United States)

    Carroll, Matthew B; Smith, Derek M; Shaak, Thomas L

    2017-03-01

    It remains unclear why the dose of xanthine oxidase inhibitors (XOI) allopurinol or febuxostat varies among patients though they reach similar serum uric acid (SUA) goal. We pursued genomic sequencing of XOI metabolism and clearance genes to identify single-nucleotide polymorphisms (SNPs) relate to differences in XOI dose. Subjects with a diagnosis of Gout based on the 1977 American College of Rheumatology Classification Criteria for the disorder, who were on stable doses of a XOI, and who were at their goal SUA level, were enrolled. The primary outcome was relationship between SNPs in any of these genes to XOI dose. The secondary outcome was relationship between SNPs and change in pre- and post-treatment SUA. We enrolled 100 subjects. The average patient age was 68.6 ± 10.6 years old. Over 80% were men and 77% were Caucasian. One SNP was associated with a higher XOI dose: rs75995567 (p = 0.031). Two SNPs were associated with 300 mg daily of allopurinol: rs11678615 (p = 0.022) and rs3731722 on Aldehyde Oxidase (AO) (His1297Arg) (p = 0.001). Two SNPs were associated with a lower dose of allopurinol: rs1884725 (p = 0.033) and rs34650714 (p = 0.006). For the secondary outcome, rs13415401 was the only SNP related to a smaller mean SUA change. Ten SNPs were identified with a larger change in SUA. Though multiple SNPs were identified in the primary and secondary outcomes of this study, rs3731722 is known to alter catalytic function for some aldehyde oxidase substrates.

  8. Mapping the primary structure of copper/topaquinone-containing methylamine oxidase from Aspergillus niger.

    Science.gov (United States)

    Lenobel, R; Sebela, M; Frébort, I

    2005-01-01

    The amino acid sequence of methylamine oxidase (MeAO) from the fungus Aspergillus niger was analyzed using mass spectrometry (MS). First, MeAO was characterized by an accurate molar mass of 72.4 kDa of the monomer measured using MALDI-TOF-MS and by a pI value of 5.8 determined by isoelectric focusing. MALDI-TOF-MS revealed a clear peptide mass fingerprint after tryptic digestion, which did not provide any relevant hit when searched against a nonredundant protein database and was different from that of A. niger amine oxidase AO-I. Tandem mass spectrometry with electrospray ionization coupled to liquid chromatography allowed unambiguous reading of six peptide sequences (11-19 amino acids) and seven sequence tags (4-15 amino acids), which were used for MS BLAST homology searching. MeAO was found to be largely homologous to a hypothetical protein AN7641.2 (EMBL/GenBank protein-accession code EAA61827) from Aspergillus nidulans FGSC A4 with a theoretical molar mass of 76.46 kDa and pI 6.14, which belongs to the superfamily of copper amine oxidases. The protein AN7641.2 is only little homologous to the amine oxidase AO-I (32% identity, 49 % similarity).

  9. Fractionated dose cholecystography: a comparison between iopanoic acid and sodium ipodate

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, R.G.; Lawson, M.J.; Davies, G.T.; Tucker, W.G.; Mileski, O.; Read, T.R.; Grant, A.K. (Queen Elizabeth Hospital, Adelaide (Australia))

    1980-11-01

    Two randomised groups of 100 subjects each, undergoing oral cholecystography, were given either a 6 g fractionated dose of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) to determine the relative merits of this dose schedule. Exclusions to the study were pregnancy and iodine sensitivity. Calculi or abnormal gall-bladder opacification were present in 45% of subjects. Both agents were equally effective in demonstrating abnormalities, although bile duct visualisation was better using iopanoic acid (P<0.05). Of 46 subjects with abnormal cholecystograms subsequently undergoing surgery, all had the diagnosis confirmed. Side effects occurred in 63% of all subjects, being twice as common in those taking iopanoic acid (P<0.01). Sodium ipodate in a large fractionated dose is favoured because of the lower occurrence of side effects without loss of diagnostic accuracy.

  10. Fractionated dose cholecystography: a comparison between iopanoic acid and sodium ipodate

    International Nuclear Information System (INIS)

    Reiner, R.G.; Lawson, M.J.; Davies, G.T.; Tucker, W.G.; Mileski, O.; Read, T.R.; Grant, A.K.

    1980-01-01

    Two randomised groups of 100 subjects each, undergoing oral cholecystography, were given either a 6 g fractionated dose of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) to determine the relative merits of this dose schedule. Exclusions to the study were pregnancy and iodine sensitivity. Calculi or abnormal gall-bladder opacification were present in 45% of subjects. Both agents were equally effective in demonstrating abnormalities, although bile duct visualisation was better using iopanoic acid (P<0.05). Of 46 subjects with abnormal cholecystograms subsequently undergoing surgery, all had the diagnosis confirmed. Side effects occurred in 63% of all subjects, being twice as common in those taking iopanoic acid (P<0.01). Sodium ipodate in a large fractionated dose is favoured because of the lower occurrence of side effects without loss of diagnostic accuracy. (author)

  11. Three-dimensional fluorescence analysis of chernozem humic acids and their electrophoretic fractions

    Science.gov (United States)

    Trubetskoi, O. A.; Trubetskaya, O. E.

    2017-09-01

    Polyacrylamide gel electrophoresis in combination with size-exclusion chromatography (SEC-PAGE) has been used to obtain stable electrophoretic fractions of different molecular size (MS) from chernozem humic acids (HAs). Three-dimensional fluorescence charts of chernozem HAs and their fractions have been obtained for the first time, and all fluorescence excitation-emission maxima have been identified in the excitation wavelength range of 250-500 nm. It has been found that fractionation by the SEC-PAGE method results in a nonuniform distribution of protein- and humin-like fluorescence of the original HA preparation among the electrophoretic fractions. The electrophoretic fractions of the highest and medium MSs have only the main protein-like fluorescence maximum and traces of humin-like fluorescence. In the electrophoretic fraction of the lowest MS, the intensity of protein-like fluorescence is low, but the major part of humin-like fluorescence is localized there. Relationships between the intensity of protein-like fluorescence and the weight distribution of amino acids have been revealed, as well as between the degree of aromaticity and the intensity of humin-like fluorescence in electrophoretic fractions of different MSs. The obtained relationships can be useful in the interpretation of the spatial structural organization and ecological functions of soil HAs.

  12. Changes in D-aspartic acid and D-glutamic acid levels in the tissues and physiological fluids of mice with various D-aspartate oxidase activities.

    Science.gov (United States)

    Han, Hai; Miyoshi, Yurika; Koga, Reiko; Mita, Masashi; Konno, Ryuichi; Hamase, Kenji

    2015-12-10

    D-Aspartic acid (D-Asp) and D-glutamic acid (D-Glu) are currently paid attention as modulators of neuronal transmission and hormonal secretion. These two D-amino acids are metabolized only by D-aspartate oxidase (DDO) in mammals. Therefore, in order to design and develop new drugs controlling the D-Asp and D-Glu amounts via regulation of the DDO activities, changes in these acidic D-amino acid amounts in various tissues are expected to be clarified in model animals having various DDO activities. In the present study, the amounts of Asp and Glu enantiomers in 6 brain tissues, 11 peripheral tissues and 2 physiological fluids of DDO(+/+), DDO(+/-) and DDO(-/-) mice were determined using a sensitive and selective two-dimensional HPLC system. As a result, the amounts of D-Asp were drastically increased with the decrease in the DDO activity in all the tested tissues and physiological fluids. On the other hand, the amounts of D-Glu were almost the same among the 3 strains of mice. The present results are useful for designing new drug candidates, such as DDO inhibitors, and further studies are expected. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Acid-base and copper-binding properties of three organic matter fractions isolated from a forest floor soil solution

    Science.gov (United States)

    van Schaik, Joris W. J.; Kleja, Dan B.; Gustafsson, Jon Petter

    2010-02-01

    Vast amounts of knowledge about the proton- and metal-binding properties of dissolved organic matter (DOM) in natural waters have been obtained in studies on isolated humic and fulvic (hydrophobic) acids. Although macromolecular hydrophilic acids normally make up about one-third of DOM, their proton- and metal-binding properties are poorly known. Here, we investigated the acid-base and Cu-binding properties of the hydrophobic (fulvic) acid fraction and two hydrophilic fractions isolated from a soil solution. Proton titrations revealed a higher total charge for the hydrophilic acid fractions than for the hydrophobic acid fraction. The most hydrophilic fraction appeared to be dominated by weak acid sites, as evidenced by increased slope of the curve of surface charge versus pH at pH values above 6. The titration curves were poorly predicted by both Stockholm Humic Model (SHM) and NICA-Donnan model calculations using generic parameter values, but could be modelled accurately after optimisation of the proton-binding parameters (pH ⩽ 9). Cu-binding isotherms for the three fractions were determined at pH values of 4, 6 and 9. With the optimised proton-binding parameters, the SHM model predictions for Cu binding improved, whereas the NICA-Donnan predictions deteriorated. After optimisation of Cu-binding parameters, both models described the experimental data satisfactorily. Iron(III) and aluminium competed strongly with Cu for binding sites at both pH 4 and pH 6. The SHM model predicted this competition reasonably well, but the NICA-Donnan model underestimated the effects significantly at pH 6. Overall, the Cu-binding behaviour of the two hydrophilic acid fractions was very similar to that of the hydrophobic acid fraction, despite the differences observed in proton-binding characteristics. These results show that for modelling purposes, it is essential to include the hydrophilic acid fraction in the pool of 'active' humic substances.

  14. Molybdenum isotope fractionation during acid leaching of a granitic uranium ore

    Science.gov (United States)

    Migeon, Valérie; Bourdon, Bernard; Pili, Eric; Fitoussi, Caroline

    2018-06-01

    As an attempt to prevent illicit trafficking of nuclear materials, it is critical to identify the origin and transformation of uranium materials from the nuclear fuel cycle based on chemical and isotope tracers. The potential of molybdenum (Mo) isotopes as tracers is considered in this study. We focused on leaching, the first industrial process used to release uranium from ores, which is also known to extract Mo depending on chemical conditions. Batch experiments were performed in the laboratory with pH ranging from 0.3 to 5.5 in sulfuric acid. In order to span a large range in uranium and molybdenum yields, oxidizers such as nitric acid, hydrogen peroxide and manganese dioxide were also added. An enrichment in heavy Mo isotopes is produced in the solution during leaching of a granitic uranium ore, when Mo recovery is not quantitative. At least two Mo reservoirs were identified in the ore: ∼40% as Mo oxides soluble in water or sulfuric acid, and ∼40% of Mo hosted in sulfides soluble in nitric acid or hydrogen peroxide. At pH > 1.8, adsorption and/or precipitation processes induce a decrease in Mo yields with time correlated with large Mo isotope fractionations. Quantitative models were used to evaluate the relative importance of the processes involved in Mo isotope fractionation: dissolution, adsorption, desorption, precipitation, polymerization and depolymerization. Model best fits are obtained when combining the effects of dissolution/precipitation, and adsorption/desorption onto secondary minerals. These processes are inferred to produce an equilibrium isotope fractionation, with an enrichment in heavy Mo isotopes in the liquid phase and in light isotopes in the solid phase. Quantification of Mo isotope fractionation resulting from uranium leaching is thus a promising tool to trace the origin and transformation of nuclear materials. Our observations of Mo leaching are also consistent with observations of natural Mo isotope fractionation taking place during

  15. H-binding of size- and polarity-fractionated soil and lignite humic acids after removal of metal and ash components

    Science.gov (United States)

    Drosos, Marios; Leenheer, Jerry A.; Avgeropoulos, Apostolos; Deligiannakis, Yiannis

    2014-01-01

    A fractionation technique, combining dialysis removal of metal and ash components with hydrofluoric acid and pH 10 citrate buffer followed by chromatography of dialysis permeate on XAD-8 resin at decreasing pH values, has been applied to lignite humic acid (lignite-HA) and soil humic acid (soil-HA). H-binding data and non ideal competitive adsorption-Donnan model parameters were obtained for the HA fractions by theoretical analysis of H-binding data which reveal a significant increase of the carboxyl and the phenolic charge for the lignite-HA fractions vs. the parental lignite humic acid (LParentalHA). The fractionated lignite-HA material consisted mainly of permeate fractions, some of which were fulvic acid-like. The fractionated soil-HA material consisted mainly of large macromolecular structures that did not permeate the dialysis membrane during deashing. Chargeable groups had comparable concentrations in soil-HA fractions and parental soil humic acid (SParentalHA), indicating minimal interference of ash components with carboxyl and phenolic (and/or enolic) groups. Fractionation of HA, combined with theoretical analysis of H-binding, can distinguish the supramolecular vs. macromolecular nature of fractions within the same parental HA.

  16. Thermal stability of L-ascorbic acid and ascorbic acid oxidase in broccoli (Brassica oleracea var. italica).

    Science.gov (United States)

    Munyaka, Ann Wambui; Makule, Edna Edward; Oey, Indrawati; Van Loey, Ann; Hendrickx, Marc

    2010-05-01

    The thermal stability of vitamin C (including l-ascorbic acid [l-AA] and dehydroascorbic acid [DHAA]) in crushed broccoli was evaluated in the temperature range of 30 to 90 degrees C whereas that of ascorbic acid oxidase (AAO) was evaluated in the temperature range of 20 to 95 degrees C. Thermal treatments (for 15 min) of crushed broccoli at 30 to 60 degrees C resulted in conversion of l-AA to DHAA whereas treatments at 70 to 90 degrees C retained vitamin C as l-AA. These observations indicated that enzymes (for example, AAO) could play a major role in the initial phase (that is, oxidation of l-AA to DHAA) of vitamin C degradation in broccoli. Consequently, a study to evaluate the temperature-time conditions that could result in AAO inactivation in broccoli was carried out. In this study, higher AAO activity was observed in broccoli florets than stalks. During thermal treatments for 10 min, AAO in broccoli florets and stalks was stable until around 50 degrees C. A 10-min thermal treatment at 80 degrees C almost completely inactivated AAO in broccoli. AAO inactivation followed 1st order kinetics in the temperature range of 55 to 65 degrees C. Based on this study, a thermal treatment above 70 degrees C is recommended for crushed vegetable products to prevent oxidation of l-AA to DHAA, the onset of vitamin C degradation. The results reported in this study are applicable for both domestic and industrial processing of vegetables into products such as juices, soups, and purees. In this report, we have demonstrated that processing crushed broccoli in a temperature range of 30 to 60 degrees C could result in the conversion of l-ascorbic acid to dehydroascorbic (DHAA), a very important reaction in regard to vitamin C degradation because DHAA could be easily converted to other compounds that do not have the biological activity of vitamin C.

  17. fractionation of lead-acid battery soil amended with biochar 36

    African Journals Online (AJOL)

    USER

    Biochar has a high surface area, highly porous, variable – charge organic material that has the potential to ... Keywords: Biochar, Lead–acid Battery, Fractionation and Heavy metals. INTRODUCTION .... toxicity of heavy metal ions in the soils.

  18. Purification and Characterization of Polyphenol Oxidase, Peroxidase and Lipoxygenase from Freshly Cut Lettuce (L. sativa

    Directory of Open Access Journals (Sweden)

    Vural Gökmen

    2011-01-01

    Full Text Available Enzymatic reactions taking place in minimally processed vegetables are considered as a major problem, because they adversely affect sensorial and nutritional quality. Polyphenol oxidase (PPO, peroxidase (POD and lipoxygenase (LOX from lettuce were purified on a column packed with positively charged diethylaminoethyl (DEAE cellulose by applying pH gradient elution from pH=4.0 to 9.0. The main purified fractions (PPO1 and PPO4, POD1 and POD2, LOX1 and LOX2 were characterized for enzyme concentration-reaction rate relationship, thermal stability, pH activity and kinetic parameters. Kinetic properties of each isoform were considerably different. Cysteine was found as the most effective inhibitor of both fractions of PPO. Kinetic parameters of lettuce POD were presented using guaiacol at various H2O2 concentrations. β-carotene directly influences lettuce LOX in the reaction medium available for the catalytic conversion of linoleic acid into hydroperoxides. Ascorbic and oxalic acids appear as effective PPO inhibitors, protecting phenolic compounds against oxidation in lettuce. Understanding the characteristics of deteriorative enzymes becomes important to maintain suitable conditions for fresh-like quality of lettuce. The results can be useful to keep the nutritional quality of minimally processed lettuce during shelf-life.

  19. Bienzymatic Acetylcholinesterase and Choline Oxidase Immobilized Biosensor Based on a Phenyl Carboxylic Acid-Grafted Multiwalled Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    So-Ra Lee

    2014-01-01

    Full Text Available Bienzymatic acetylcholinesterase (AChE and choline oxidase (ChOx immobilized biosensor based on a phenyl carboxylic acid-grafted multiwalled carbon nanotube (MWNT modified glass carbon electrode (GCE and carbon-screen printed electrode (SPE was fabricated for acetylcholine detection in human blood samples. Phenyl carboxylic acid-modified MWNT supports were prepared by electrochemical polymerization of 4-carboxyphenyl diazonium salts, which were synthesized by an amine group and sodium nitrite, on the surface of the MWNT-modified GCE and SPE in 0.1 M PBS. The successful fabrication of the AChE-ChOx-immobilized biosensor was confirmed via scanning electron microscopy (SEM, X-ray photoelectron spectroscopy (XPS, electrochemical impedance spectroscopy (EIS, and cyclic voltammetry (CV. The sensing range of the biosensor based on a GCE and SPE was 1.0~10 μM and 10~100 μM, respectively. The interfering effect of 0.1 M L-ascorbic acid, 0.1 M L-cysteine, and 0.1 M uric acid to 0.1 M acetylcholine was 3.00%, 9.00%, and 3.00%, respectively. Acetylcholine in a human blood sample was detected by the AChE-ChOx-immobilized biosensor.

  20. Cloning and characterization of the gene for L-amino acid oxidase in hybrid tilapia.

    Science.gov (United States)

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-12-01

    Tilapia is the common name for a group of cichlid fishes. Identification of DNA markers significantly associated with important traits in candidate genes may speed up genetic improvement. L-Amino acid oxidase (LAO) plays a crucial role in the innate immune defences of animals. Previously, whether LAO variants were associated with economic traits had not been studied in fish. We characterized the cDNA sequence of the LAO gene of hybrid tilapia (Oreochromis spp.). Its ORF was 1536 bp, encoding a flavoenzyme of 511 amino acids. This gene consisted of seven exons and six introns. Its expression was detected in the intestine, blood, kidney, skin, liver. It was highly expressed in the intestine. After a challenge with a bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the liver, intestine and spleen (P tilapia. The investigation of relationship between polymorphism of LAO gene and disease resistance and growth in tilapia showed that one SNP was associated significantly with body length. Further experiments on whether SNPs in the LAO gene are associated with growth in tilapia and other populations could be useful in understanding more functions of the LAO gene.

  1. Activation of NADPH oxidase mediates increased endoplasmic reticulum stress and left ventricular remodeling after myocardial infarction in rabbits.

    Science.gov (United States)

    Li, Bao; Tian, Jing; Sun, Yi; Xu, Tao-Rui; Chi, Rui-Fang; Zhang, Xiao-Li; Hu, Xin-Ling; Zhang, Yue-An; Qin, Fu-Zhong; Zhang, Wei-Fang

    2015-05-01

    Nicotinamide adenine dinucleotide 3-phosphate (NADPH) oxidase activity and endoplasmic reticulum (ER) stress are increased after myocardial infarction (MI). In this study, we proposed to test whether activation of the NADPH oxidase in the remote non-infarcted myocardium mediates ER stress and left ventricular (LV) remodeling after MI. Rabbits with MI or sham operation were randomly assigned to orally receive an NADPH oxidase inhibitor apocynin or placebo for 30 days. The agents were administered beginning at 1 week after surgery. MI rabbits exhibited decreases in LV fractional shortening, LV ejection fraction and the first derivative of the LV pressure rise, which were abolished by apocynin treatment. NADPH oxidase Nox2 protein and mRNA expressions were increased in the remote non-infarcted myocardium after MI. Immunolabeling further revealed that Nox2 was increased in cardiac myocytes in the remote myocardium. The apocynin treatment prevented increases in the Nox2 expression, NADPH oxidase activity, oxidative stress, myocyte apoptosis and GRP78, CHOP and cleaved caspase 12 protein expression in the remote myocardium. The apocynin treatment also attenuated increases in myocyte diameter and cardiac fibrosis. In cultured H9C2 cardiomyocytes exposed to angiotensin II, an important stimulus for post-MI remodeling, Nox2 knockdown with siRNA significantly inhibited angiotensin II-induced NADPH oxidase activation, reactive oxygen species and GRP78 and CHOP protein expression. We conclude that NADPH oxidase inhibition attenuates increased ER stress in the remote non-infarcted myocardium and LV remodeling late after MI in rabbits. These findings suggest that the activation of NADPH oxidase in the remote non-infarcted myocardium mediates increased ER stress, contributing to myocyte apoptosis and LV remodeling after MI. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Influence of multi-step washing using Na2EDTA, oxalic acid and phosphoric acid on metal fractionation and spectroscopy characteristics from contaminated soil.

    Science.gov (United States)

    Wei, Meng; Chen, Jiajun

    2016-11-01

    A multi-step soil washing test using a typical chelating agent (Na 2 EDTA), organic acid (oxalic acid), and inorganic weak acid (phosphoric acid) was conducted to remediate soil contaminated with heavy metals near an arsenic mining area. The aim of the test was to improve the heavy metal removal efficiency and investigate its influence on metal fractionation and the spectroscopy characteristics of contaminated soil. The results indicated that the orders of the multi-step washing were critical for the removal efficiencies of the metal fractions, bioavailability, and potential mobility due to the different dissolution levels of mineral fractions and the inter-transformation of metal fractions by XRD and FT-IR spectral analyses. The optimal soil washing options were identified as the Na 2 EDTA-phosphoric-oxalic acid (EPO) and phosphoric-oxalic acid-Na 2 EDTA (POE) sequences because of their high removal efficiencies (approximately 45 % for arsenic and 88 % for cadmium) and the minimal harmful effects that were determined by the mobility and bioavailability of the remaining heavy metals based on the metal stability (I R ) and modified redistribution index ([Formula: see text]).

  3. FRACTIONATION OF FATTY ACID OMEGA 3, 6 AND 9 FROM SNAIL (Achatina fulica USING COLOUM CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Winarto Haryadi

    2010-06-01

    Full Text Available The extraction of fat from snail has been carried out by Soxhlet extractor with petroleum ether solvent. Fatty product from extraction was transesterificated in BF3/methanol solvent for an hour by reflux procedure, then extracted by n-hexane to produce methyl ester fatty acid. Free water fatty acid methyl ester was analyzed by Gas Chromatography-Mass spectrometer (GC-MS. Fatty acid ester was separated from its fractions use column chromatography in n-hexane, n-hexane:dietil eter (2:1 v/v, dietil eter, aseton, ethanol and methanol. This fractions wer also analized by GC-MS. From GC-MS data sheet can be obtained 5 fractions which details are; fraction 1 contains omega 3: 27.54 %, omega 6: 15.40 % and omega 9: 6.77 %. Fraction 2 contains omega 3: 3.08 %, omega 6: 15.62 % and omega 9: 10.72 %. Fraction 3 contains omega 6: 3.57 %, omega 9: 7.02 % and none omega 3 inside it. Omega 3, 6 and 9 can't be identification in fraction 4 and 5.   Keywords: extraction, transesterification, column chromatography, GC-MS

  4. Increased xanthine oxidase during labour--implications for oxidative stress.

    Science.gov (United States)

    Many, A; Roberts, J M

    1997-11-01

    Xanthine dehydrogenase/oxidase (XDH/XO) produces uric acid. When in the oxidase form, this production is coupled with the generation of free radicals. Hypoxia-reperfusion enhances conversion of XDH to XO. Since the placenta is exposed to short periods of hypoxia reperfusion during labour, 17 placentae of pregnancy terminated by elective caesarean section and five placentae of pregnancies terminated by caesarean section during labour were examined for XDH/XO activity. It was found that XO activity was higher in the placentae of labouring women (P = 0.003), which suggests that labour enhances conversion of XDH to XO, facilitating free radical production.

  5. Nonlinear binding of phenanthrene to the extracted fulvic acid fraction in soil in comparison with other organic matter fractions and to the whole soil sample

    International Nuclear Information System (INIS)

    Liu Wenxin; Xu, Shanshan; Xing, Baoshan; Pan, Bo; Tao, Shu

    2010-01-01

    Fractions of soil organic matter in a natural soil were extracted and sorption (or binding) characteristics of phenanthrene on each fraction and to the whole sample were investigated. The organic carbon normalized single point sorption (or binding) coefficient followed lipid > humin (HM) > humic acid (HA) > fulvic acid (FA) > whole soil sample, while the nonlinear exponent exhibited lipid > FA > HA > whole soil sample > HM. FA showed nonlinear binding of phenanthrene as it often does with other fractions. HM and HA contributed the majority of organic carbon in the soil. The calculated sorption coefficients of the whole soil were about two times greater than the measured values at different equilibrium phenanthrene concentrations. As for phenanthrene, the sorption capacity and nonlinearity of the physically mixed HA-HM mixtures were stronger as compared to the chemically reconstituted HA-HM composite. This was attributed to (besides the conditioning effect of the organic solvents) interactions between HA and HM and acid-base additions during fractionation. - Nonlinear binding of phenanthrene to fulvic acid extracted from soil organic matter was found.

  6. Construction of mutant glucose oxidases with increased dye-mediated dehydrogenase activity.

    Science.gov (United States)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-11-02

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  7. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Science.gov (United States)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-01-01

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor. PMID:23203056

  8. A Global Assessment of Circulating Prolysyl Oxidase in Nonischemic Patients With Garden-variety Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Muñoz Calvo, Benjamín; Villa Martínez, Ana; López Orgil, Susana; López Andrés, Natalia; Román García, Feliciano; Víctor Palomares, Virginia; de la Calle de la Villa, Esther; Nadador Patiño, Verónica; Arribas-Gómez, Ignacio

    2018-05-25

    Lysyl oxidase is overexpressed in the myocardium of patients with hypertensive cardiomyopathy. We aimed to explore whether patients with hypertensive-metabolic heart failure with preserved ejection fraction (HM-HFpEF) also have increased concentrations of circulating prolysyl oxidase (cpLOX) and its possible consequences. We quantified cpLOX concentrations in 85 nonischemic patients with stage C, HM-HFpEF, and compared them with those of 51 healthy controls. We also assessed the correlations of cpLOX with myocardial stiffness parameters, collagen turnover products and fibrogenic cytokines, as well as the predictive value of plasma proenzyme levels at 1-year of follow-up. We detected raised cpLOX values and found that they correlated with calculated E/E' ratios and stiffness constants. The subgroup of patients with type I diastolic dysfunction showed a single negative correlation between cpLOX and B-type natriuretic peptide whereas patients with a restrictive diastolic pattern showed a strong correlation between cpLOX and galectin-3. Kaplan-Meier analysis revealed that cpLOX > 52.20 ng/mL slightly increased the risk of a fatal outcome (log-rank = 4.45; P = .034). When Cox regression was used, cpLOX was found to be a significant independent predictor of cardiovascular death or hospitalization due to the decompensation of HM-HFpEF (HR, 1.360; 95%CI, 1.126-1.638; P = .046). Patients with symptomatic HM-HFpEF show high cpLOX serum levels associated with restrictive diastolic filling indices. These levels represent a moderate risk factor for poor clinical outcome. Throughout the natural history of HM-HFpEF, we observed that cpLOX concentrations were initially negatively correlated with B-type natriuretic peptide but positively correlated with galectin-3 as advanced diastolic dysfunction developed. Copyright © 2018. Published by Elsevier España, S.L.U.

  9. Involvement of abscisic acid in regulating antioxidative defense systems and IAA-oxidase activity and improving adventitious rooting in mung bean [Vigna radiata (L.) Wilczek] seedlings under cadmium stress.

    Science.gov (United States)

    Li, Shi-Weng; Leng, Yan; Feng, Lin; Zeng, Xiao-Ying

    2014-01-01

    In vitro experiments were conducted to investigate the effects of abscisic acid (ABA) and Cd on antioxidative defense systems and indole-3-acetic acid (IAA) oxidase during adventitious rooting in mung bean [Vigna radiata (L.) Wilczek] seedlings. The exogenous ABA significantly enhanced the number and fresh weight of the adventitious roots. CdCl2 strongly inhibited adventitious rooting. Pretreatment with 10 μM ABA clearly alleviated the inhibitory effect of Cd on rooting. ABA significantly reduced superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT) activities, as well as the levels of glutathione (GSH) and ascorbic acid (ASA) during adventitious rooting. ABA strongly increased IAA-oxidase activity during the induction (0-12 h) and expression (after 48 h) phases and increased the phenols levels. Cd treatment significantly reduced the activities of SOD, APX, POD, and IAA oxidase, as well as GSH level. Cd strongly increased ASA levels. ABA pretreatment counteracted Cd-induced alterations of certain antioxidants and antioxidative enzymes, e.g., remarkably rescued APX and POD activities, reduced the elevated SOD and CAT activities and ASA levels, and recovered the reduced GSH levels, caused by Cd stress. Thus, the physiological effects of the combination of ABA and Cd treatments were opposite of those obtained with Cd treatment alone, suggesting that ABA involved in the regulation of antioxidative defense systems and the alleviation of wounding- and Cd-induced oxidative stress.

  10. Immobilization of xanthine oxidase on a polyaniline silicone support.

    Science.gov (United States)

    Nadruz, W; Marques, E T; Azevedo, W M; Lima-Filho, J L; Carvalho, L B

    1996-03-01

    A polyaniline silicone support to immobilize xanthine oxidase is proposed as a reactor coil to monitor the action of xanthine oxidase on hypoxanthine, xanthine and 6-mercaptopurine. A purified xanthine oxidase immobilized on this support lost 80% of the initial activity after 12 min of use. Co-immobilization of superoxide dismutase and catalase increased the stability of immobilized xanthine oxidase so that the derivative maintained 79% of its initial activity after 4.6 h of continuous use in which 1.5 mumol purine bases were converted by the immobilized enzyme system. There is no evidence of either polyaniline or protein leaching from the coil during 3 h of continuous use. When solutions (10 ml) of hypoxanthine, xanthine and 6-mercaptopurine were circulated individually through the xanthine oxidase-superoxide dismutase-catalase-polyaniline coil (1 mm internal diameter and 3 m in length, 3 ml internal volume) activities of 8.12, 11.17 and 1.09 nmol min-1 coil-1, respectively, were obtained. The advantages of the reactor configuration and the redox properties of the polymer, particularly with respect to immobilized oxidoreductases, make this methodology attractive for similar enzyme systems. This immobilized enzyme system using polyaniline-silicone as support converted 6-mercaptopurine to 6-thiouric acid with equal efficiency as resins based on polyacrylamide and polyamide 11.

  11. Molecular Modeling of Peroxidase and Polyphenol Oxidase: Substrate Specificity and Active Site Comparison

    Directory of Open Access Journals (Sweden)

    Lalida Shank

    2010-09-01

    Full Text Available Peroxidases (POD and polyphenol oxidase (PPO are enzymes that are well known to be involved in the enzymatic browning reaction of fruits and vegetables with different catalytic mechanisms. Both enzymes have some common substrates, but each also has its specific substrates. In our computational study, the amino acid sequence of grape peroxidase (ABX was used for the construction of models employing homology modeling method based on the X-ray structure of cytosolic ascorbate peroxidase from pea (PDB ID:1APX, whereas the model of grape polyphenol oxidase was obtained directly from the available X-ray structure (PDB ID:2P3X. Molecular docking of common substrates of these two enzymes was subsequently studied. It was found that epicatechin and catechin exhibited high affinity with both enzymes, even though POD and PPO have different binding pockets regarding the size and the key amino acids involved in binding. Predicted binding modes of substrates with both enzymes were also compared. The calculated docking interaction energy of trihydroxybenzoic acid related compounds shows high affinity, suggesting specificity and potential use as common inhibitor to grape ascorbate peroxidase and polyphenol oxidase.

  12. Development of Galactose Biosensor Based on Functionalized ZnO Nanorods with Galactose Oxidase

    Directory of Open Access Journals (Sweden)

    K. Khun

    2012-01-01

    Full Text Available The fabrication of galactose biosensor based on functionalised ZnO nanorods is described. The galactose biosensor was developed by immobilizing galactose oxidase on ZnO nanorods in conjunction with glutaraldehyde as a cross-linker molecule. The IRAS study provided evidence for the interaction of galactose oxidase with the surface of ZnO nanorods. The electromotive force (EMF response of the galactose biosensor was measured by potentiometric method. We observed that the proposed biosensor has a linear detection range over a concentration range from 10 mM to 200 mM with good sensitivity of 89.10±1.23 mV/decade. In addition, the proposed biosensor has shown fast time response of less than 10 s and a good selectivity towards galactose in the presence of common interferents such as ascorbic acid, uric acid, glucose, and magnesium ions. The galactose biosensor based on galactose oxidase immobilized ZnO nanorods has a shelf life more than four weeks.

  13. The Role of Aldehyde Oxidase and Xanthine Oxidase in the Biotransformation of a Novel Negative Allosteric Modulator of Metabotropic Glutamate Receptor Subtype 5

    Science.gov (United States)

    Morrison, Ryan D.; Blobaum, Anna L.; Byers, Frank W.; Santomango, Tammy S.; Bridges, Thomas M.; Stec, Donald; Brewer, Katrina A.; Sanchez-Ponce, Raymundo; Corlew, Melany M.; Rush, Roger; Felts, Andrew S.; Manka, Jason; Bates, Brittney S.; Venable, Daryl F.; Rodriguez, Alice L.; Jones, Carrie K.; Niswender, Colleen M.; Conn, P. Jeffrey; Lindsley, Craig W.; Emmitte, Kyle A.

    2012-01-01

    Negative allosteric modulation (NAM) of metabotropic glutamate receptor subtype 5 (mGlu5) represents a therapeutic strategy for the treatment of childhood developmental disorders, such as fragile X syndrome and autism. VU0409106 emerged as a lead compound within a biaryl ether series, displaying potent and selective inhibition of mGlu5. Despite its high clearance and short half-life, VU0409106 demonstrated efficacy in rodent models of anxiety after extravascular administration. However, lack of a consistent correlation in rat between in vitro hepatic clearance and in vivo plasma clearance for the biaryl ether series prompted an investigation into the biotransformation of VU0409106 using hepatic subcellular fractions. An in vitro appraisal in rat, monkey, and human liver S9 fractions indicated that the principal pathway was NADPH-independent oxidation to metabolite M1 (+16 Da). Both raloxifene (aldehyde oxidase inhibitor) and allopurinol (xanthine oxidase inhibitor) attenuated the formation of M1, thus implicating the contribution of both molybdenum hydroxylases in the biotransformation of VU0409106. The use of 18O-labeled water in the S9 experiments confirmed the hydroxylase mechanism proposed, because 18O was incorporated into M1 (+18 Da) as well as in a secondary metabolite (M2; +36 Da), the formation of which was exclusively xanthine oxidase-mediated. This unusual dual and sequential hydroxylase metabolism was confirmed in liver S9 and hepatocytes of multiple species and correlated with in vivo data because M1 and M2 were the principal metabolites detected in rats administered VU0409106. An in vitro-in vivo correlation of predicted hepatic and plasma clearance was subsequently established for VU0409106 in rats and nonhuman primates. PMID:22711749

  14. Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

    Directory of Open Access Journals (Sweden)

    Lan Yao

    2018-02-01

    Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

  15. $^{111m}$Cd- and $^{199m}$Hg-derivatives of blue oxidases

    CERN Multimedia

    2002-01-01

    The rack-induced bonding concept (H.B.Gray & B.G.~Malmstroem, Comments Inorg. Chem, 2, 203, 1983) postulates that the bound metal ion in metalloproteins is forced to adopt a coordination geometry determined by the rigid peptide conformation of the protein. Alternatively, the metal ion could create its own favoured coordination geometry in a soft peptide conformation. In order to decide who is slave or master the changes of coordination and rigidity of metal sites in blue copper proteins due to metal and ligand exchange were studied by $^{111m}$Cd and $^{199m}$Hg $\\gamma$-$\\gamma$-perturbed angular correlation (PAC). To get a better understanding of the so called " Type 1 Copper Site " of the blue oxidases laccase (LAC) and ascorbate oxidase (AO) we concentrated our investigations on the small blue copper proteins azurin and plastocyanin. \\\\ \\\\In azurin~(Az), the metal ligand methionine 121~(M121) was replaced by several amino acids, e.g. asparagine~(N), glutamic acid~(E), via site directed mutagenesis. Di...

  16. Identification of crucial amino acids in mouse aldehyde oxidase 3 that determine substrate specificity.

    Directory of Open Access Journals (Sweden)

    Martin Mahro

    Full Text Available In order to elucidate factors that determine substrate specificity and activity of mammalian molybdo-flavoproteins we performed site directed mutagenesis of mouse aldehyde oxidase 3 (mAOX3. The sequence alignment of different aldehyde oxidase (AOX isoforms identified variations in the active site of mAOX3 in comparison to other AOX proteins and xanthine oxidoreductases (XOR. Based on the structural alignment of mAOX3 and bovine XOR, differences in amino acid residues involved in substrate binding in XORs in comparison to AOXs were identified. We exchanged several residues in the active site to the ones found in other AOX homologues in mouse or to residues present in bovine XOR in order to examine their influence on substrate selectivity and catalytic activity. Additionally we analyzed the influence of the [2Fe-2S] domains of mAOX3 on its kinetic properties and cofactor saturation. We applied UV-VIS and EPR monitored redox-titrations to determine the redox potentials of wild type mAOX3 and mAOX3 variants containing the iron-sulfur centers of mAOX1. In addition, a combination of molecular docking and molecular dynamic simulations (MD was used to investigate factors that modulate the substrate specificity and activity of wild type and AOX variants. The successful conversion of an AOX enzyme to an XOR enzyme was achieved exchanging eight residues in the active site of mAOX3. It was observed that the absence of the K889H exchange substantially decreased the activity of the enzyme towards all substrates analyzed, revealing that this residue has an important role in catalysis.

  17. Fractionation for further conversion: from raw corn stover to lactic acid

    Science.gov (United States)

    He, Ting; Jiang, Zhicheng; Wu, Ping; Yi, Jian; Li, Jianmei; Hu, Changwei

    2016-12-01

    Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050 M oxalic acid is used to simultaneously fractionate 88.0 wt% of hemicellulose and 89.2 wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with β-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with β-5 and β-β linkages of lignin. Oxalic acid effectively catalyzes the hydrolysis of hemicellulose and breaks the intermolecular linkages between hemicellulose and lignin, therefore further promotes the release of lignin. The dissolved hemicelluloses derivatives are reprocessed to produce lactic acid obtaining a high yield of 79.6 wt% with 90% selectivity by the catalysis of MgO. The remained cellulose and recovered lignin can be used further as feedstock to produce chemicals.

  18. Fractionation for further conversion: from raw corn stover to lactic acid

    Science.gov (United States)

    He, Ting; Jiang, Zhicheng; Wu, Ping; Yi, Jian; Li, Jianmei; Hu, Changwei

    2016-01-01

    Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050 M oxalic acid is used to simultaneously fractionate 88.0 wt% of hemicellulose and 89.2 wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with β-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with β-5 and β-β linkages of lignin. Oxalic acid effectively catalyzes the hydrolysis of hemicellulose and breaks the intermolecular linkages between hemicellulose and lignin, therefore further promotes the release of lignin. The dissolved hemicelluloses derivatives are reprocessed to produce lactic acid obtaining a high yield of 79.6 wt% with 90% selectivity by the catalysis of MgO. The remained cellulose and recovered lignin can be used further as feedstock to produce chemicals. PMID:27917955

  19. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Koji Sode

    2012-11-01

    Full Text Available Mutagenesis studies on glucose oxidases (GOxs were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe and Aspergillus niger GOx (PDB ID; 1cf3. We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  20. Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions

    Science.gov (United States)

    Allison, S. D.; Jastrow, J. D.

    2004-12-01

    Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

  1. Pt.3. Carbon-13 fractionation in the decomposition of formic acid initiated by phosphoric anhydride. 13C fractionation in the decomposition of HCOOH initiated by P2O5

    International Nuclear Information System (INIS)

    Zielinski, M.; Zielinska, A.

    1998-01-01

    13 C isotope effects in the decarbonylation of formic acid of natural isotopic composition initiated by phosphorus pentoxide have been studied in a large temperature range (-5 o C) - (+90 o C). The 13 C fractionation in the carbon monooxide production at -5 o C increased from a low value of 1.2% characteristic of the first fractions of consecutively controlled portions of carbon monooxide to higher values of 13 C KIE observed in the decarbonylation of pure formic acid at corresponding temperatures. The temperature and time dependences of the measured 13 C fractionation are functions of the relative number of milimoles of formic acid and the dehydrating phosphoric anhydride, P 2 O 5 . The addition of metaphosphoric acid reagent to unreacted formic acid containing H 3 PO 4 significantly increased the 13 C fractionation in subsequent decarbonylations at 70.4 o C but to a slightly less degree than expected ( 13 C KIE = 1.0503 instead 1.0535). The addition of metaphosphoric acid reagent to formic acid saturated with NaCl results in the experimental 13 C fractionation of the value of 1.0534 very close to the theoretical one. An explanation of the low values of 13 C KIE in the initial stages of HCOOH/P 2 O 5 decarbonylations has been presented. (author)

  2. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Science.gov (United States)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-11-01

    Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  3. Immunological and molecular comparison of polyphenol oxidase in Rosaceae fruit trees.

    Science.gov (United States)

    Haruta, M; Murata, M; Kadokura, H; Homma, S

    1999-03-01

    An antibody raised against apple polyphenol oxidase (PPO) cross-reacted with PPOs from Japanese pear (Pyrus pyrifolia), pear (Pyrus communis), peach (Prunus persica), Chinese quince (Pseudocydonia sinensis) and Japanese loquat (Eriobotrya japonica). Core fragments (681 bp) of the corresponding PPO genes were amplified and characterized. The deduced protein sequences showed identities of 85.3 to 97.5%. Chlorogenic acid oxidase activity of these PPOs showed higher activities when assayed at pH 4 than at pH 6. These results indicate that PPOs in Rosaceae plants are structurally and enzymatically similar.

  4. Add-on treatment of benzoate for schizophrenia: a randomized, double-blind, placebo-controlled trial of D-amino acid oxidase inhibitor.

    Science.gov (United States)

    Lane, Hsien-Yuan; Lin, Ching-Hua; Green, Michael F; Hellemann, Gerhard; Huang, Chih-Chia; Chen, Po-Wei; Tun, Rene; Chang, Yue-Cung; Tsai, Guochuan E

    2013-12-01

    In addition to dopaminergic hyperactivity, hypofunction of the N-methyl-d-aspartate receptor (NMDAR) has an important role in the pathophysiology of schizophrenia. Enhancing NMDAR-mediated neurotransmission is considered a novel treatment approach. To date, several trials on adjuvant NMDA-enhancing agents have revealed beneficial, but limited, efficacy for positive and negative symptoms and cognition. Another method to enhance NMDA function is to raise the levels of d-amino acids by blocking their metabolism. Sodium benzoate is a d-amino acid oxidase inhibitor. To examine the clinical and cognitive efficacy and safety of add-on treatment of sodium benzoate for schizophrenia. A randomized, double-blind, placebo-controlled trial in 2 major medical centers in Taiwan composed of 52 patients with chronic schizophrenia who had been stabilized with antipsychotic medications for 3 months or longer. Six weeks of add-on treatment of 1 g/d of sodium benzoate or placebo. The primary outcome measure was the Positive and Negative Syndrome Scale (PANSS) total score. Clinical efficacy and adverse effects were assessed biweekly. Cognitive functions were measured before and after the add-on treatment. Benzoate produced a 21% improvement in PANSS total score and large effect sizes (range, 1.16-1.69) in the PANSS total and subscales, Scales for the Assessment of Negative Symptoms-20 items, Global Assessment of Function, Quality of Life Scale and Clinical Global Impression and improvement in the neurocognition subtests as recommended by the National Institute of Mental Health's Measurement and Treatment Research to Improve Cognition in Schizophrenia initiative, including the domains of processing speed and visual learning. Benzoate was well tolerated without significant adverse effects. Benzoate adjunctive therapy significantly improved a variety of symptom domains and neurocognition in patients with chronic schizophrenia. The preliminary results show promise for d-amino acid oxidase

  5. Synergistic effect of Aspergillus tubingensis CTM 507 glucose oxidase in presence of ascorbic acid and alpha amylase on dough properties, baking quality and shelf life of bread

    OpenAIRE

    Kriaa, Mouna; Ouhibi, Rabeb; Graba, Héla; Besbes, Souhail; Jardak, Mohamed; Kammoun, Radhouane

    2015-01-01

    The impact of Aspergillus tubingensis glucose oxidase (GOD) in combination with α-amylase and ascorbic acid on dough properties, qualities and shelf life of bread was investigated. Regression models of alveograph and texture parameters of dough and bread were adjusted. Indeed, the mixture of GOD (44 %) and ascorbic acid (56 %) on flour containing basal improver showed its potential as a corrective action to get better functional and rheological properties of dough and bread texture. Furthermo...

  6. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation. © 2015 SETAC.

  7. A structural and functional model for the 1-aminocyclopropane-1-carboxylic acid oxidase.

    Science.gov (United States)

    Sallmann, Madleen; Oldenburg, Fabio; Braun, Beatrice; Réglier, Marius; Simaan, A Jalila; Limberg, Christian

    2015-10-12

    The hitherto most realistic low-molecular-weight analogue for the 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO) is reported. The ACCOs 2-His-1-carboxylate iron(II) active site was mimicked by a TpFe moiety, to which the natural substrate ACC could be bound. The resulting complex [Tp(Me,Ph) FeACC] (1), according to X-ray diffraction analysis performed for the nickel analogue, represents an excellent structural model, featuring ACC coordinated in a bidentate fashion-as proposed for the enzymatic substrate complex-as well as a vacant coordination site that forms the basis for the first successful replication also of the ACCO function: 1 is the first known ACC complex that reacts with O2 to produce ethylene. As a FeOOH species had been suggested as intermediate in the catalytic cycle, H2 O2 was tested as the oxidant, too, and indeed evolution of ethylene proceeded even more rapidly to give 65 % yield. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Spatio-temporal detection of the Thiomonas population and the Thiomonas arsenite oxidase involved in natural arsenite attenuation processes in the Carnoulès Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Agnès eHovasse

    2016-02-01

    Full Text Available The acid mine drainage (AMD impacted creek of the Carnoulès mine (Southern France is characterized by acid waters with a high heavy metal content. The microbial community inhabiting this AMD was extensively studied using isolation, metagenomic and metaproteomic methods, and the results showed that a natural arsenic (and iron attenuation process involving the arsenite oxidase activity of several Thiomonas strains occurs at this site. A sensitive quantitative Selected Reaction Monitoring (SRM-based proteomic approach was developed for detecting and quantifying the two subunits of the arsenite oxidase and RpoA of two different Thiomonas groups. Using this approach combined with 16S rRNA gene sequence analysis based on pyrosequencing and FISH, it was established here for the first time that these Thiomonas strains are ubiquitously present in minor proportions in this AMD and that they express the key enzymes involved in natural remediation processes at various locations and time points. In addition to these findings, this study also confirms that targeted proteomics applied at the community level can be used to detect weakly abundant proteins in situ.

  9. Effects of olive oil and its fractions on oxidative stress and the liver's fatty acid composition in 2,4-Dichlorophenoxyacetic acid-treated rats

    Directory of Open Access Journals (Sweden)

    Ellouz Meriem

    2010-10-01

    Full Text Available Abstract Background Olive oil's beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil and its fractions on 2,4-D- induced oxidative damage in the liver of rats. Methods Male Wistar rats were randomly divided into eight groups of ten each: (C a control group, (D group that received 2,4-D (5 mg/kg b.w., (D/EVOO group treated with 2,4-D plus extra virgin olive oil, (D/OOHF group that received 2,4-D plus hydrophilic fraction, (D/OOLF group treated with 2,4-D plus lipophilic fraction, (EVOO group that received only extra virgin olive oil, (OOHF group given hydrophilic fraction and (OOLF group treated with lipophilic fraction. These components were daily administered by gavage for 4 weeks. Results A significant liver damage was observed in rats treated with 2,4-D via increased serum levels of transaminases and alkaline phosphatase, hepatic lipid peroxidation and decreased hepatic antioxidant enzyme activities, namely, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. The liver's fatty acid composition was also significantly modified with 2,4-D exposure. However, extra virgin olive oil and hydrophilic fraction intake during 2,4-D treatment induced a significant increase in the antioxidant enzyme activities and a decrease in the conjugated dienes (CD and thiobarbituric acid-reactive substances (TBARs levels in the liver. The lipophilic fraction supplemented to 2,4-D- treated rats did not show any improvement in the liver oxidative status while a marked improvement was detected in the hepatic fatty acid composition of rats supplemented with olive oil and the two fractions. Conclusion We concluded that the protective effect of olive oil against oxidative damage induced by 2,4-D is mainly related to the antioxidant potential of its hydrophilic fraction.

  10. Dysbindin and d-amino-acid-oxidase gene polymorphisms associated with positive and negative symptoms in schizophrenia

    DEFF Research Database (Denmark)

    Wirgenes, Katrine V; Djurovic, Srdjan; Agartz, Ingrid

    2009-01-01

    -amino-acid-oxidase (DAO) gene, both involved in glutamate receptor function, reported associations with negative symptoms and with anxiety and depression, respectively, when measured with the Positive and Negative Syndrome Scale (PANSS). METHODS: In the present study, the suggested association between dysbindin and DAO...... single nucleotide polymorphisms (SNPs) and PANSS scores was analyzed in 155 Norwegian schizophrenia patients. RESULTS: There was a significant association between the dysbindin SNP rs3213207 and severity of both negative symptoms and total symptom load, as well as between the DAO SNP rs2070587 and total...... symptom score and severity of anxiety and depression. CONCLUSION: The present association of dysbindin SNPs with negative symptoms and DAO SNPs with anxiety and depression is a replication of earlier findings and strengthens the hypothesis of a genetic association. It further indicates involvement...

  11. Intracellular lysyl oxidase: Effect of a specific inhibitor on nuclear mass in proliferating cells

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Fawzy A. [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Torres, Marie [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Wang, Hao [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Graham, Lila, E-mail: lilagraham@cs.com [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States)

    2010-06-11

    LOX, the principal enzyme involved in crosslinking of collagen, was the first of several lysyl oxidase isotypes to be characterized. Its active form was believed to be exclusively extracellular. Active LOX was later reported to be present in cell nuclei; its function there is unknown. LOX expression opposes the effect of mutationally activated Ras, which is present in about 30% of human cancers. The mechanism of LOX in countering the action of Ras is also unknown. In the present work, assessment of nuclear protein for possible effects of lysyl oxidase activity led to the discovery that proliferating cells dramatically increase their nuclear protein content when exposed to BAPN ({beta}-aminopropionitrile), a highly specific lysyl oxidase inhibitor that reportedly blocks LOX inhibition of Ras-induced oocyte maturation. In three cell types (PC12 cells, A7r5 smooth muscle cells, and NIH 3T3 fibroblasts), BAPN caused a 1.8-, 1.7-, and 2.1-fold increase in total nuclear protein per cell, respectively, affecting all major components in both nuclear matrix and chromatin fractions. Since nuclear size is correlated with proliferative status, enzyme activity restricting nuclear growth may be involved in the lysyl oxidase tumor suppressive effect. Evidence is also presented for the presence of apparent lysyl oxidase isotype(s) containing a highly conserved LOX active site sequence in the nuclei of PC12 cells, which do not manufacture extracellular lysyl oxidase substrates. Results reported here support the hypothesis that nuclear lysyl oxidase regulates nuclear growth, and thereby modulates cell proliferation.

  12. Fractionation for further conversion: from raw corn stover to lactic acid

    OpenAIRE

    Ting He; Zhicheng Jiang; Ping Wu; Jian Yi; Jianmei Li; Changwei Hu

    2016-01-01

    Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050?M oxalic acid is used to simultaneously fractionate 88.0?wt% of hemicellulose and 89.2?wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with ?-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with ...

  13. Hydroxylamine hydrochloride-acetic acid-soluble and -insoluble fractions of pelagic sediment: Readsorption revisited

    Science.gov (United States)

    Piper, D.Z.; Wandless, G.A.

    1992-01-01

    The extraction of the rare earth elements (REE) from deep-ocean pelagic sediment, using hydroxylamine hydrochloride-acetic acid, leads to the separation of approximately 70% of the bulk REE content into the soluble fraction and 30% into the insoluble fraction. The REE pattern of the soluble fraction, i.e., the content of REE normalized to average shale on an element-by-element basis and plotted against atomic number, resembles the pattern for seawater, whereas the pattern, as well as the absolute concentrations, in the insoluble fraction resembles the North American shale composite. These results preclude significant readsorption of the REE by the insoluble phases during the leaching procedure.

  14. Identification of the free phenolic profile of Adlay bran by UPLC-QTOF-MS/MS and inhibitory mechanisms of phenolic acids against xanthine oxidase.

    Science.gov (United States)

    Lin, Lianzhu; Yang, Qingyun; Zhao, Kun; Zhao, Mouming

    2018-07-01

    Adlay bran free phenolic extract has been previously demonstrated to possess potent xanthine oxidase (XOD) inhibitory activity. The aims of this study were to characterize the free phenolic profile of adlay bran and investigate the structure-activity relationship, underlying mechanism and interaction of phenolic acids as XOD inhibitors. A total of twenty phenolics including ten phenolic acids, two coumarins, two phenolic aldedhyes and six flavonoids were identified in a phenolic compound-guided separation by UPLC-QTOF-MS/MS. Adlay bran free phenolic extract possessed strong XOD inhibitory activity related to hydroxycinnamic acids with methoxyl groups. The hydrogen bonding and hydrophobic interactions were the main forces in the binding of adlay phenolics to XOD. Sinapic acid, identified in adlay bran for the first time, possessed strong XOD inhibitory activity in a mixed non-competitive manner, and synergistic effects with other adlay phenolic acids at low concentrations, and would be a promising agent for preventing and treating hyperuricemia. Copyright © 2018. Published by Elsevier Ltd.

  15. Chemical mechanism of D-amino acid oxidase from Rhodotorula gracilis: pH dependence of kinetic parameters.

    Science.gov (United States)

    Ramón, F; Castillón, M; De La Mata, I; Acebal, C

    1998-01-01

    The variation of kinetic parameters of d-amino acid oxidase from Rhodotorula gracilis with pH was used to gain information about the chemical mechanism of the oxidation of D-amino acids catalysed by this flavoenzyme. d-Alanine was the substrate used. The pH dependence of Vmax and Vmax/Km for alanine as substrate showed that a group with a pK value of 6.26-7.95 (pK1) must be unprotonated and a group with a pK of 10.8-9.90 (pK2) must be protonated for activity. The lower pK value corresponded to a group on the enzyme involved in catalysis and whose protonation state was not important for binding. The higher pK value was assumed to be the amino group of the substrate. Profiles of pKi for D-aspartate as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 8.4 becomes unprotonated; this basic group was not detected in Vmax/Km profiles suggesting its involvement in binding of the beta-carboxylic group of the inhibitor. PMID:9461524

  16. Reconstitution of apoglucose oxidase with FAD conjugates for biosensoring of progesterone

    NARCIS (Netherlands)

    Posthuma-Trumpie, G.A.; Berg, van den W.A.M.; Wiel, van de D.F.M.; Schaaper, W.M.M.; Korf, J.; Berkel, van W.J.H.

    2007-01-01

    The reconstitution of Aspergillus niger apoglucose oxidase (apoGOx) with FAD conjugates for biosensoring of progesterone was investigated. ApoGOx prepared by partial unfolding of the protein under acidic conditions consisted of reconstitutable monomers (50 ± 10%), reconstitutable dimers (20 ± 10%)

  17. The free fractions of circulating docosahexaenoic acid and eicosapentenoic acid as optimal end-point of measure in bioavailability studies on n-3 fatty acids.

    Science.gov (United States)

    Scarsi, Claudia; Levesque, Ann; Lisi, Lucia; Navarra, Pierluigi

    2015-05-01

    The high complexity of n-3 fatty acids absorption process, along with the huge amount of endogenous fraction, makes bioavailability studies with these agents very challenging and deserving special consideration. In this paper we report the results of a bioequivalence study between a new formulation of EPA+DHA ethyl esters developed by IBSA Institut Biochimique and reference medicinal product present on the Italian market. Bioequivalence was demonstrated according to the criteria established by the EMA Guideline on the Investigation of Bioequivalence. We found that the free fractions represent a better and more sensitive end-point for bioequivalence investigations on n-3 fatty acids, since: (i) the overall and intra-subject variability of PK parameters was markedly lower compared to the same variability calculated on the total DHA and EPA fractions; (ii) the absorption process was completed within 4h, and the whole PK profile could be drawn within 12-15 h from drug administration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Characterization of Two VAO-Type Flavoprotein Oxidases from Myceliophthora thermophila

    Directory of Open Access Journals (Sweden)

    Alessandro R. Ferrari

    2018-01-01

    Full Text Available The VAO flavoprotein family consists mostly of oxidoreductases harboring a covalently linked flavin cofactor. The linkage can be either monocovalent at position 8 with a histidine or tyrosine or bicovalent at position 8 with a histidine and at position 6 with a cysteine. Bicovalently bound flavoproteins show a preference for bulkier substrates such as oligosaccharides or secondary metabolites. The genome of the thermophilic fungus Myceliophthora thermophila C1 was found to be rich in genes encoding putative covalent VAO-type flavoproteins. Enzymes from this fungus have the advantage of being rather thermostable and homologous overexpression in M. thermophila C1 is feasible. Recently we discovered a new and VAO-type carbohydrate oxidase from this fungus: xylooligosaccharide oxidase. In this study, two other putative VAO-type oxidases, protein sequence XP_003663615 (MtVAO615 and XP_003665713 (MtVAO713, were expressed in M. thermophila C1, purified and characterized. Enzyme MtVAO615 was found to contain a bicovalently bound FAD, while enzyme MtVAO713 contained a monocovalent histidyl-bound FAD. The crystal structures of both proteins were obtained which revealed atypical active site architectures. It could be experimentally verified that both proteins, when reduced, rapidly react with molecular oxygen, a hallmark of flavoprotein oxidases. A large panel of alcohols, including carbohydrates, steroids and secondary alcohols were tested as potential substrates. For enzyme MtVAO713 low oxidase activity was discovered towards ricinoleic acid.

  19. Polyacrylic acid-coated cerium oxide nanoparticles: An oxidase mimic applied for colorimetric assay to organophosphorus pesticides.

    Science.gov (United States)

    Zhang, Shi-Xiang; Xue, Shi-Fan; Deng, Jingjing; Zhang, Min; Shi, Guoyue; Zhou, Tianshu

    2016-11-15

    It is important and urgent to develop reliable and highly sensitive methods that can provide on-site and rapid detection of extensively used organophosphorus pesticides (OPs) for their neurotoxicity. In this study, we developed a novel colorimetric assay for the detection of OPs based on polyacrylic acid-coated cerium oxide nanoparticles (PAA-CeO2) as an oxidase mimic and OPs as inhibitors to suppress the activity of acetylcholinesterase (AChE). Firstly, highly dispersed PAA-CeO2 was prepared in aqueous solution, which could catalyze the oxidation of TMB to produce a color reaction from colorless to blue. And the enzyme of AChE was used to catalyze the substrate of acetylthiocholine (ATCh) to produce thiocholine (TCh). As a thiol-containing compound with reducibility, TCh can decrease the oxidation of TMB catalyzed by PAA-CeO2. Upon incubated with OPs, the enzymatic activity of AChE was inhibited to produce less TCh, resulting in more TMB catalytically oxidized by PAA-CeO2 to show an increasing blue color. The two representative OPs, dichlorvos and methyl-paraoxon, were tested using our proposed assay. The novel assay showed notable color change in a concentration-dependent manner, and as low as 8.62 ppb dichlorvos and 26.73 ppb methyl-paraoxon can be readily detected. Therefore, taking advantage of such oxidase-like activity of PAA-CeO2, our proposed colorimetric assay can potentially be a screening tool for the precise and rapid evaluation of the neurotoxicity of a wealth of OPs. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Xanthine oxidase and uric acid as independent predictors of albuminuria in patients with diabetes mellitus type 2.

    Science.gov (United States)

    Klisic, Aleksandra; Kocic, Gordana; Kavaric, Nebojsa; Jovanovic, Milovan; Stanisic, Verica; Ninic, Ana

    2018-05-01

    Xanthine oxidase (XO) is an important enzyme responsible for conversion of purine bases to uric acid and represents the major source of reactive oxygen species (ROS) production in circulation. Since pathophysiological mechanism of the relationship between XO activity and urinary albumin excretion (UAE) rate is not well elucidated, we aimed to investigate this association in patients with diabetes mellitus type 2 (DM2). In addition, we wanted to examine whether uric acid itself plays an independent role in albuminuria onset and progression, or it is only mediated through XO activity. A total of 83 patients with DM2 (of them 56.6% females) were included in this cross-sectional study. Anthropometric, biochemical parameters and blood pressure were obtained. Multivariate logistic regression analysis showed that uric acid and XO were the independent predictors for albuminuria onset in patients with DM2 [odds ratio (OR) 1.015, 95% CI (1.008-1.028), p = 0.026 and OR 1.015, 95% CI (1.006-1.026), p = 0.040, respectively]. Rise in uric acid for 1 µmol/L enhanced the probability for albuminuria by 1.5%. Also, elevation in XO activity for 1 U/L increased the probability for albuminuria for 1.5%. A total of 66.7% of variation in UAE could be explained with this Model. Both XO and uric acid are independently associated with albuminuria in diabetes. Better understanding of pathophysiological relationship between oxidative stress and albuminuria could lead to discoveries of best pharmacological treatment of XO- and/or uric acid-induced ROS, in order to prevent albuminuria onset and progression.

  1. Comparative study between dimethyl sulfoxide (dmso), allopurinol and urate oxidase administration in nephrotoxic rats induced with

    International Nuclear Information System (INIS)

    Heibashy, M.I.A.; El-Nahla, A.M.; Ibrahim, A.I.; Saleh, Sh.Y.A.

    2010-01-01

    This study was conducted to show whether DMSO, allopurinol and urate oxidase could offer ameliorating effects against abnormal alterations in kidney function tests in gentamicin (GM) induced nephrotoxic rats . Two experiments were carried out, the first one showed that daily injection of 80 mg GM/kg b. wt interapertonealy (I.P) for two weeks induced acute renal failure indicated by significant elevation in serum urea, creatinine, uric acid, potassium, inorganic phosphorus, TBARS and PTH and a significant decline in serum sodium, total and ionized calcium when compared with their corresponding values in saline injected rats. In the second experiment, comparisons were made between GM induced nephrotoxic rats and other nephrotoxic groups received daily pf I.P injection of DMSO (4 ml/kg b.wt), allopurinol (1.5 mg/100 g b.wt) and urate oxidase (10 mg/100 g b.wt) for 30 days after the incidence of nephrotoxicity. At all intervals, 10,20 and 30 days; serum urea, creatinine, uric acid, potassium, inorganic phosphorus, TBARS and PTH in DMSO, allopurinol and urate oxidase treated groups exhibited significant reduction than nephrotoxic untreated rats. During the same intervals, the levels of serum total and ionized calcium showed an opposite trend. serum sodium level did not show any significant difference between all treated groups except after 20 days , it was increased significantly in urate oxidase treated group and after 30 days in both allopurinol and urate oxidase treated groups. in term time intervals, a significant correction was recorded on the level of most measured parameters. in nephritic rats, the administration of DMSO, allopurinol or urate oxidase led to a significant amelioration effects in the kidney function tests and urate oxidase was the best protective.

  2. Omega-3 fatty acids and oxidative stability of ice cream supplemented with olein fraction of chia (Salvia hispanica L.) oil

    OpenAIRE

    Ullah, Rahman; Nadeem, Muhammad; Imran, Muhammad

    2017-01-01

    Background Chia (Salvia hispanica L.) has been regarded as good source of polyunsaturated omega-3 fatty acids with cardiac, hepatic, hypotensive, antiallergic and antidiabetic role. Concentration of omega-3 fatty acids in chia oil can be enhanced by fractionation. Olein/low melting fraction of chia oil has higher concentration of omega-3 fatty acids. Therefore, main objective of current investigation was determination of various concentration effect of olein fraction of chia oil on omega-3 fa...

  3. Enzymatic halogenation and oxidation using an alcohol oxidase-vanadium chloroperoxidase cascade

    NARCIS (Netherlands)

    But, Andrada; Noord, Van Aster; Poletto, Francesca; Sanders, Johan P.M.; Franssen, Maurice C.R.; Scott, Elinor L.

    2017-01-01

    The chemo-enzymatic cascade which combines alcohol oxidase from Hansenula polymorpha (AOXHp) with vanadium chloroperoxidase (VCPO), for the production of biobased nitriles from amino acids was investigated. In the first reaction H2O2 (and acetaldehyde) are generated from ethanol and oxygen by AOXHp.

  4. Differences in activity of cytochrome C oxidase in brain between sleep and wakefulness.

    Science.gov (United States)

    Nikonova, Elena V; Vijayasarathy, Camasamudram; Zhang, Lin; Cater, Jacqueline R; Galante, Raymond J; Ward, Stephen E; Avadhani, Narayan G; Pack, Allan I

    2005-01-01

    Increased mRNA level of subunit 1 cytochrome c oxidase (COXI) during wakefulness and after short-term sleep deprivation has been described in brain. We hypothesized that this might contribute to increased activity of cytochrome oxidase (COX) enzyme during wakefulness, as part of the mechanisms to provide sufficient amounts of adenosine triphosphate to meet increased neuronal energy demands. COX activity was measured in isolated mitochondria from different brain regions in groups of rats with 3 hours of spontaneous sleep, 3 hours of spontaneous wake, and 3 hours of sleep deprivation. The group with 3 hours of spontaneous wake was added to delineate the circadian component of changes in the enzyme activity. Northern blot analysis was performed to examine the mRNA levels of 2 subunits of the enzyme COXI and COXIV, encoded by mitochondrial and nuclear DNA, respectively. Laboratory of Biochemistry, Department of Animal Biology, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania. 2-month-old male Fischer rats (N = 21) implanted for polygraphic recording. For COX activity, there was a main effect by analysis of variance of experimental group (P sleep-deprived groups as compared to the sleep group. A main effect of brain region was also significant (P sleep. There is an increase in COX activity after both 3 hours of spontaneous wake and 3 hours of sleep deprivation as compared with 3 hours of spontaneous sleep in diverse brain regions, which could be, in part, explained by the increased levels of bigenomic transcripts of the enzyme. This likely contributes to increased adenosine triphosphate production during wakefulness. ADP, adenosine diphosphate; ATP, adenosine triphosphate; COXI, cytochrome c oxidase subunit 1 mRNA; COX, cytochrome c oxidase (protein); CREB, cyclic AMP response element binding protein; DNA, deoxyribonucleic acid; EDTA, ethylenediaminetetraacetic acid; EEG, electroencephalography; EMG, electromyography; GABP, GA binding

  5. Stability of glucose oxidase and catalase adsorbed on variously activated 13X zeolite.

    Science.gov (United States)

    Pifferi, P G; Vaccari, A; Ricci, G; Poli, G; Ruggeri, O

    1982-10-01

    The use of 13X zeolite (0.1-0.4-mm granules), treated with 2N and 0.01N HCI, 0.01M citric acid, 0.1M citric-phosphate buffer (pH 3.6), and in untreated form to adsorb glucose oxidase of fungal origin and microbial catalase was examined. Physicochemical analysis of the support demonstrated that its crystalline structure, greatly altered by the HCl and buffer, could be partially maintained with citric acid. The specific adsorption of the enzymes increased with decreasing pH and proved to be considerable for all the supports. The stability with storage at 25 degrees C is strictly correlated with the titrable acidity of the activated zeolite expressed as meq NaOH/g and with pH value of the activation solution. It proved to be lower than 55 h for both enzymes if adsorbed on zeolite treated with 2N HCl, and 15-fold and 30-fold higher for glucose oxidase and catalase adsorbed, respectively, on zeolite treated with the 0.1M citric-phosphate buffer and 0.01M citric acid. The specific adsorption of glucose oxidase and catalase was, respectively, 1840 U/g at pH 3.0 and 6910 U/g at pH 5.0. Their half-life at 25 degrees C with storage at pH 3.5 for the former and at pH 5.0 for the latter was 800 and 1560 h vs. 40 and 110 h for the corresponding free enzymes.

  6. Antioxidant, anti-inflammatory and anti-septic potential of phenolic acids and flavonoid fractions isolated from Lolium multiflorum.

    Science.gov (United States)

    Choi, Ki-Choon; Son, Young-Ok; Hwang, Jung-Min; Kim, Beom-Tae; Chae, Minseon; Lee, Jeong-Chae

    2017-12-01

    Interest has recently renewed in using Lolium multiflorum Lam. (Poaceae) (called Italian ryegrass; IRG) silage as an antioxidant and anti-inflammatory diet. This study investigated the antioxidant, anti-inflammatory and anti-septic potential of IRG silage and identified the primary components in IRG active fractions. Total 16 fractions were separated from the chloroform-soluble extract of IRG aerial part using Sephadex LH-20 column before HPLC analysis. Antioxidant and anti-inflammatory activities of the fractions at doses of 0-100 μg/mL were investigated using various cell-free and cell-mediated assay systems. To explore anti-septic effect of IRG fractions, female ICR and BALB/c mice orally received 40 mg/kg of phenolic acid and flavonoid-rich active fractions F 7 and F 8 every other day for 10 days, respectively, followed by LPS challenge. The active fractions showed greater antioxidant and anti-inflammatory potential compared with other fractions. IC 50 values of F 7 and F 8 to reduce LPS-stimulated NO and TNF-α production were around 15 and 30 μg/mL, respectively. Comparison of retention times with authentic compounds through HPLC analysis revealed the presence of caffeic acid, ferulic acid, myricetin and kaempferol in the fractions as primary components. These fractions inhibited LPS-stimulated MAPK and NF-κB activation. Supplementation with F 7 or F 8 improved the survival rates of mice to 70 and 60%, respectively, in LPS-injected mice and reduced near completely serum TNF-α and IL-6 levels. This study highlights antioxidant, anti-inflammatory and anti-septic activities of IRG active fractions, eventually suggesting their usefulness in preventing oxidative damage and inflammatory disorders.

  7. The Antioxidant Properties of Pectin Fractions Isolated from Vegetables Using a Simulated Gastric Fluid

    Directory of Open Access Journals (Sweden)

    Vasily V. Smirnov

    2017-01-01

    Full Text Available The antioxidant properties of vegetable pectin fractions against intraluminal reactive oxygen species were elucidated in vitro in conjunction with their structural features. The pectin fractions were isolated using a simulated gastric fluid (pH 1.5, pepsin 0.5 g/L, 37°C, 4 h from fresh white cabbage, carrot, onion, and sweet pepper. The fraction from onion was found to inhibit the production of superoxide radicals by inhibiting the xanthine oxidase. The high molecular weight of onion pectin and a large number of galactose residues in its side chains appeared to participate in interaction with xanthine oxidase. All the isolated pectic polysaccharides were found to be associated with protein (2–9% and phenolics (0.5–0.7% as contaminants; these contaminants were shown to be responsible for the antioxidant effect of vegetable pectin fractions against the hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals.

  8. Extra virgin olive oil rich in polyphenols modulates VEGF-induced angiogenic responses by preventing NADPH oxidase activity and expression.

    Science.gov (United States)

    Calabriso, Nadia; Massaro, Marika; Scoditti, Egeria; D'Amore, Simona; Gnoni, Antonio; Pellegrino, Mariangela; Storelli, Carlo; De Caterina, Raffaele; Palasciano, Giuseppe; Carluccio, Maria Annunziata

    2016-02-01

    Previous studies have shown the antiinflammatory, antioxidant and antiangiogenic properties by pure olive oil polyphenols; however, the effects of olive oil phenolic fraction on the inflammatory angiogenesis are unknown. In this study, we investigated the effects of the phenolic fraction (olive oil polyphenolic extract, OOPE) from extra virgin olive oil and related circulating metabolites on the VEGF-induced angiogenic responses and NADPH oxidase activity and expression in human cultured endothelial cells. We found that OOPE (1-10 μg/ml), at concentrations achievable nutritionally, significantly reduced, in a concentration-dependent manner, the VEGF-induced cell migration, invasiveness and tube-like structure formation through the inhibition of MMP-2 and MMP-9. OOPE significantly (Pextra virgin olive oil, with high polyphenol content, decreased VEGF-induced NADPH oxidase activity and Nox4 expression, as well as, MMP-9 expression, as compared with fasting control serum. Overall, native polyphenols and serum metabolites of extra virgin olive oil rich in polyphenols are able to lower the VEGF-induced angiogenic responses by preventing endothelial NADPH oxidase activity and decreasing the expression of selective NADPH oxidase subunits. Our results provide an alternative mechanism by which the consumption of olive oil rich in polyphenols may account for a reduction of oxidative stress inflammatory-related sequelae associated with chronic degenerative diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Anti-tumour potential of a gallic acid-containing phenolic fraction from Oenothera biennis.

    Science.gov (United States)

    Pellegrina, Chiara Dalla; Padovani, Giorgia; Mainente, Federica; Zoccatelli, Gianni; Bissoli, Gaetano; Mosconi, Silvia; Veneri, Gianluca; Peruffo, Angelo; Andrighetto, Giancarlo; Rizzi, Corrado; Chignola, Roberto

    2005-08-08

    A phenolic fraction purified form defatted seeds of Oenothera biennis promoted selective apoptosis of human and mouse bone marrow-derived cell lines following first-order kinetics through a caspase-dependent pathway. In non-leukemia tumour cell lines, such as human colon carcinoma CaCo(2) cells and mouse fibrosarcoma WEHI164 cells, this fraction inhibited (3)H-thymidine incorporation but not cell death or cell cycle arrest. Human peripheral blood mononuclear cells showed low sensitivity to treatment. Single bolus injection of the phenolic fraction could delay the growth of established myeloma tumours in syngeneic animals. HPLC and mass spectrometry analysis revealed that the fraction contains gallic acid. However, the biological activity of the fraction differs from the activity of this phenol and hence it should be attributed to other co-purified molecules which remain still unidentified.

  10. The activity of ascorbic acid and catechol oxidase, the rate of photosynthesis and respiration as related to plant organs, stage of development and copper supply

    Directory of Open Access Journals (Sweden)

    St. Łyszcz

    2015-06-01

    Full Text Available Some experiments were performed to investigate the physiological role of copper in oat and sunflower and to recognize some effects of copper deficiency. Oat and sunflower plants were grown in pots on a peat soil under copper deficiency conditions (–Cu or with the optimal copper supply (+Cu. In plants the following measurements were carried out: 1 the activity of ascorbic acid oxidase (AAO and of catechol oxidase (PPO in different plant organs and at different stages of plant development, 2 the activity and the rate of photosynthesis, 3 the activity of RuDP-carboxylase, 4 the intensity of plant respiration. The activity of AAO and of PPO, and also the rate and the activity of photosynthesis were significantly lower under conditions of copper deficiency. The activity of both discussed oxidases depended on: 1 the plant species, 2 plant organs, 3 stage of plant development. Copper deficiency caused decrease of the respiration intensity of sunflower leaves but it increased to some extent the respiration of oat tops. Obtained results are consistent with the earlier suggestion of the authors that the PPO activity in sunflower leaves could be a sensitive indicator of copper supply of the plants, farther experiments are in progress.

  11. Investigation of adsorptive fractionation of humic acid on graphene oxide using fluorescence EEM-PARAFAC.

    Science.gov (United States)

    Lee, Bo-Mi; Seo, Young-Soo; Hur, Jin

    2015-04-15

    In this study, the adsorptive fractionation of a humic acid (HA, Elliott soil humic acid) on graphene oxide (GO) was examined at pH 4 and 6 using absorption spectroscopy and fluorescence excitation-emission matrix (EEM)-parallel factor analysis (PARAFAC). The extent of the adsorption was greater at pH 4.0 than at pH 6.0. Aromatic molecules within the HA were preferentially adsorbed onto the GO surface, and the preferential adsorption was more pronounced at pH 6, which is above the zero point of charge of GO. A relative ratio of two PARAFAC humic-like components (ex/em maxima at 270/510 nm and at (250, 265)/440 nm) presented an increasing trend with larger sizes of ultrafiltered humic acid fractions, suggesting the potential for using fluorescence EEM-PARAFAC for tracking the changes in molecular sizes of aromatic HA molecules. The individual adsorption behaviors of the two humic-like components revealed that larger sized aromatic components within HA had a higher adsorption affinity and more nonlinear isotherms compared to smaller sized fractions. Our results demonstrated that adsorptive fractionation of HA occurred on the GO surface with respect to their aromaticity and the sizes, but the degree was highly dependent on solution pH as well as the amount of adsorbed HS (or available surface sites). The observed adsorption behaviors were reasonably explained by a combination of different mechanisms previously suggested. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Implications of terminal oxidase function in regulation of salicylic acid on soybean seedling photosynthetic performance under water stress.

    Science.gov (United States)

    Tang, Yanping; Sun, Xin; Wen, Tao; Liu, Mingjie; Yang, Mingyan; Chen, Xuefei

    2017-03-01

    The aim of this study is to investigate whether exogenous application of salicylic acid (SA) could modulate the photosynthetic capacity of soybean seedlings in water stress tolerance, and to clarify the potential functions of terminal oxidase (plastid terminal oxidase (PTOX) and alternative oxidase (AOX)) in SA' s regulation on photosynthesis. The effects of SA and water stress on gas exchange, pigment contents, chlorophyll fluorescence, enzymes (guaiacol peroxidase (POD; EC 1.11.1.7), superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11) and NADP-malate dehydrogenase (NADP-MDH; EC1.1.1.82)) activity and transcript levels of PTOX, AOX1, AOX2a, AOX2b were examined in a hydroponic cultivation system. Results indicate that water stress significantly decreased the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), pigment contents (Chla + b, Chla/b, Car), maximum quantum yield of PSⅡphotochemistry (Fv/Fm), efficiency of excitation capture of open PSⅡcenter (Fv'/Fm'), quantum efficiency of PSⅡphotochemistry (ΦPSⅡ), photochemical quenching (qP), and increased malondialdehyde (MDA) content and the activity of all the enzymes. SA pretreatment led to significant decreases in Ci and MDA content, and increases in Pn, Gs, E, pigment contents, Fv/Fm, Fv'/Fm', ΦPSⅡ, qP, and the activity of all the enzymes. SA treatment and water stress alone significantly up-regulated the expression of PTOX, AOX1 and AOX2b. SA pretreatment further increased the transcript levels of PTOX and AOX2b of soybean seedling under water stress. These results indicate that SA application alleviates the water stress-induced decrease in photosynthesis may mainly through maintaining a lower reactive oxygen species (ROS) level, a greater PSⅡefficiency, and an enhanced alternative respiration and chlororespiration. PTOX and AOX may play important roles in SA-mediated resistance to water stress. Copyright © 2016

  13. Biophysical and physicochemical methods differentiate highly ligand-efficient human D-amino acid oxidase inhibitors.

    Science.gov (United States)

    Lange, Jos H M; Venhorst, Jennifer; van Dongen, Maria J P; Frankena, Jurjen; Bassissi, Firas; de Bruin, Natasja M W J; den Besten, Cathaline; de Beer, Stephanie B A; Oostenbrink, Chris; Markova, Natalia; Kruse, Chris G

    2011-10-01

    Many early drug research efforts are too reductionist thereby not delivering key parameters such as kinetics and thermodynamics of target-ligand binding. A set of human D-Amino Acid Oxidase (DAAO) inhibitors 1-6 was applied to demonstrate the impact of key biophysical techniques and physicochemical methods in the differentiation of chemical entities that cannot be adequately distinguished on the basis of their normalized potency (ligand efficiency) values. The resulting biophysical and physicochemical data were related to relevant pharmacodynamic and pharmacokinetic properties. Surface Plasmon Resonance data indicated prolonged target-ligand residence times for 5 and 6 as compared to 1-4, based on the observed k(off) values. The Isothermal Titration Calorimetry-derived thermodynamic binding profiles of 1-6 to the DAAO enzyme revealed favorable contributions of both ΔH and ΔS to their ΔG values. Surprisingly, the thermodynamic binding profile of 3 elicited a substantially higher favorable contribution of ΔH to ΔG in comparison with the structurally closely related fused bicyclic acid 4. Molecular dynamics simulations and free energy calculations of 1, 3, and 4 led to novel insights into the thermodynamic properties of the binding process at an atomic level and in the different thermodynamic signatures of 3 and 4. The presented holistic approach is anticipated to facilitate the identification of compounds with best-in-class properties at an early research stage. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  14. Uric acid, an important screening tool to detect inborn errors of metabolism: a case series.

    Science.gov (United States)

    Jasinge, Eresha; Kularatnam, Grace Angeline Malarnangai; Dilanthi, Hewa Warawitage; Vidanapathirana, Dinesha Maduri; Jayasena, Kandana Liyanage Subhashinie Priyadarshika Kapilani Menike; Chandrasiri, Nambage Dona Priyani Dhammika; Indika, Neluwa Liyanage Ruwan; Ratnayake, Pyara Dilani; Gunasekara, Vindya Nandani; Fairbanks, Lynette Dianne; Stiburkova, Blanka

    2017-09-06

    Uric acid is the metabolic end product of purine metabolism in humans. Altered serum and urine uric acid level (both above and below the reference ranges) is an indispensable marker in detecting rare inborn errors of metabolism. We describe different case scenarios of 4 Sri Lankan patients related to abnormal uric acid levels in blood and urine. CASE 1: A one-and-half-year-old boy was investigated for haematuria and a calculus in the bladder. Xanthine crystals were seen in microscopic examination of urine sediment. Low uric acid concentrations in serum and low urinary fractional excretion of uric acid associated with high urinary excretion of xanthine and hypoxanthine were compatible with xanthine oxidase deficiency. CASE 2: An 8-month-old boy presented with intractable seizures, feeding difficulties, screaming episodes, microcephaly, facial dysmorphism and severe neuro developmental delay. Low uric acid level in serum, low fractional excretion of uric acid and radiological findings were consistent with possible molybdenum cofactor deficiency. Diagnosis was confirmed by elevated levels of xanthine, hypoxanthine and sulfocysteine levels in urine. CASE 3: A 3-year-10-month-old boy presented with global developmental delay, failure to thrive, dystonia and self-destructive behaviour. High uric acid levels in serum, increased fractional excretion of uric acid and absent hypoxanthine-guanine phosphoribosyltransferase enzyme level confirmed the diagnosis of Lesch-Nyhan syndrome. CASE 4: A 9-year-old boy was investigated for lower abdominal pain, gross haematuria and right renal calculus. Low uric acid level in serum and increased fractional excretion of uric acid pointed towards hereditary renal hypouricaemia which was confirmed by genetic studies. Abnormal uric acid level in blood and urine is a valuable tool in screening for clinical conditions related to derangement of the nucleic acid metabolic pathway.

  15. Interleukin-6 and Cyclooxygenase-2 downregulation by fatty-acid fractions of Ranunculus constantinopolitanus.

    Science.gov (United States)

    Fostok, Sabreen F; Ezzeddine, Rima A; Homaidan, Fadia R; Al-Saghir, Jamal A; Salloum, Ralph G; Saliba, Najat A; Talhouk, Rabih S

    2009-11-16

    Medicinal plants represent alternative means for the treatment of several chronic diseases, including inflammation. The genus Ranunculus, a representative of the Ranunculaceae family, has been reported to possess anti-inflammatory, analgesic, antiviral, antibacterial, antiparasitic and antifungal activities, possibly due to the presence of anemonin and other. Different studies have shown the occurrence of unusual fatty acids (FAs) in Ranunculaceae; however, their therapeutic role has not been investigated. The purpose of this study is to characterize potential anti-inflammatory bioactivities in Ranunculus constantinopolitanus D'Urv., traditionally used in Eastern Mediterranean folk medicine. The aerial part of R. constantinopolitanus was subjected to methanol (MeOH) extraction and solvent fractionation. The bioactive fraction (I.2) was further fractionated using column chromatography, and the biologically active subfraction (Y2+3) was identified using infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The effects of I.2 and Y2+3 on cell viability were studied in mouse mammary epithelial SCp2 cells using trypan blue exclusion method. To study the anti-inflammatory activities of I.2 and Y2+3, their ability to reduce interleukin (IL)-6 levels was assessed in endotoxin (ET)-stimulated SCp2 cells using enzyme-linked immunosorbent assay (ELISA). In addition, the ability of Y2+3 to reduce cyclooxygenase (COX)-2 expression was studied in IL-1-treated mouse intestinal epithelial Mode-K cells via western blotting. Data were analyzed by one-way analysis of variance (ANOVA), Student-Newman-Keuls (SNK), Tukey HSD, two-sample t-test and Dunnett t-tests for multiple comparisons. The chloroform fraction (I.2) derived from crude MeOH extract of the plant, in addition to Y2+3, a FA mix isolated from this fraction and containing palmitic acid, C18:2 and C18:1 isomers and stearic acid (1:5:8:1 ratio), reduced ET-induced IL-6

  16. Interleukin-6 and Cyclooxygenase-2 downregulation by fatty-acid fractions of Ranunculus constantinopolitanus

    Directory of Open Access Journals (Sweden)

    Al-Saghir Jamal A

    2009-11-01

    Full Text Available Abstract Background Medicinal plants represent alternative means for the treatment of several chronic diseases, including inflammation. The genus Ranunculus, a representative of the Ranunculaceae family, has been reported to possess anti-inflammatory, analgesic, antiviral, antibacterial, antiparasitic and antifungal activities, possibly due to the presence of anemonin and other. Different studies have shown the occurrence of unusual fatty acids (FAs in Ranunculaceae; however, their therapeutic role has not been investigated. The purpose of this study is to characterize potential anti-inflammatory bioactivities in Ranunculus constantinopolitanus D'Urv., traditionally used in Eastern Mediterranean folk medicine. Methods The aerial part of R. constantinopolitanus was subjected to methanol (MeOH extraction and solvent fractionation. The bioactive fraction (I.2 was further fractionated using column chromatography, and the biologically active subfraction (Y2+3 was identified using infrared (IR spectroscopy, nuclear magnetic resonance (NMR and gas chromatography-mass spectrometry (GC-MS. The effects of I.2 and Y2+3 on cell viability were studied in mouse mammary epithelial SCp2 cells using trypan blue exclusion method. To study the anti-inflammatory activities of I.2 and Y2+3, their ability to reduce interleukin (IL-6 levels was assessed in endotoxin (ET-stimulated SCp2 cells using enzyme-linked immunosorbent assay (ELISA. In addition, the ability of Y2+3 to reduce cyclooxygenase (COX-2 expression was studied in IL-1-treated mouse intestinal epithelial Mode-K cells via western blotting. Data were analyzed by one-way analysis of variance (ANOVA, Student-Newman-Keuls (SNK, Tukey HSD, two-sample t-test and Dunnett t-tests for multiple comparisons. Results The chloroform fraction (I.2 derived from crude MeOH extract of the plant, in addition to Y2+3, a FA mix isolated from this fraction and containing palmitic acid, C18:2 and C18:1 isomers and stearic acid

  17. Fructose suppresses uric acid excretion to the intestinal lumen as a result of the induction of oxidative stress by NADPH oxidase activation.

    Science.gov (United States)

    Kaneko, Chihiro; Ogura, Jiro; Sasaki, Shunichi; Okamoto, Keisuke; Kobayashi, Masaki; Kuwayama, Kaori; Narumi, Katsuya; Iseki, Ken

    2017-03-01

    A high intake of fructose increases the risk for hyperuricemia. It has been reported that long-term fructose consumption suppressed renal uric acid excretion and increased serum uric acid level. However, the effect of single administration of fructose on excretion of uric acid has not been clarified. We used male Wistar rats, which were orally administered fructose (5g/kg). Those rats were used in each experiment at 12h after administration. Single administration of fructose suppressed the function of ileal uric acid excretion and had no effect on the function of renal uric acid excretion. Breast cancer resistance protein (BCRP) predominantly contributes to intestinal excretion of uric acid as an active homodimer. Single administration of fructose decreased BCRP homodimer level in the ileum. Moreover, diphenyleneiodonium (DPI), an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox), recovered the suppression of the function of ileal uric acid excretion and the Bcrp homodimer level in the ileum of rats that received single administration of fructose. Single administration of fructose decreases in BCRP homodimer level, resulting in the suppression the function of ileal uric acid excretion. The suppression of the function of ileal uric acid excretion by single administration of fructose is caused by the activation of Nox. The results of our study provide a new insight into the mechanism of fructose-induced hyperuricemia. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Urate oxidase for the prevention and treatment of tumour lysis syndrome in children with cancer.

    Science.gov (United States)

    Cheuk, Daniel Kl; Chiang, Alan Ks; Chan, Godfrey Cf; Ha, Shau Yin

    2017-03-08

    Tumour lysis syndrome (TLS) is a serious complication of malignancies and can result in renal failure or death. Previous reviews did not find clear evidence of benefit of urate oxidase in children with cancer. This review is the second update of a previously published Cochrane review. To assess the effects and safety of urate oxidase for the prevention and treatment of TLS in children with malignancies. In March 2016 we searched CENTRAL, MEDLINE, Embase, and CINAHL. In addition, we searched the reference lists of all identified relevant papers, trials registers and other databases. We also screened conference proceedings and we contacted experts in the field and the manufacturer of rasburicase, Sanofi-aventis. Randomised controlled trials (RCT) and controlled clinical trials (CCT) of urate oxidase for the prevention or treatment of TLS in children under 18 years with any malignancy. Two review authors independently extracted trial data and assessed individual trial quality. We used risk ratios (RR) for dichotomous data and mean difference (MD) for continuous data. We included seven trials, involving 471 participants in the treatment groups and 603 participants in the control groups. No new studies were identified in the update. One RCT and five CCTs compared urate oxidase and allopurinol. Three trials tested Uricozyme, and three trials tested rasburicase for the prevention of TLS.The RCT did not evaluate the primary outcome (incidence of clinical TLS). It showed no clear evidence of a difference in mortality (both all-cause mortality (Fisher's exact test P = 0.23) and mortality due to TLS (no deaths in either group)), renal failure (Fisher's exact test P = 0.46), and adverse effects between the treatment and the control groups (Fisher's exact test P = 1.0). The frequency of normalisation of uric acid at four hours (10 out of 10 participants in the treatment group versus zero out of nine participants in the control group, Fisher's exact test P oxidase (RR 9.10, 95

  19. Auxin-activated NADH oxidase activity of soybean plasma membranes is distinct from the constitutive plasma membrane NADH oxidase and exhibits prion-like properties

    Science.gov (United States)

    Morre, D. James; Morre, Dorothy M.; Ternes, Philipp

    2003-01-01

    The hormone-stimulated and growth-related cell surface hydroquinone (NADH) oxidase activity of etiolated hypocotyls of soybeans oscillates with a period of about 24 min or 60 times per 24-h day. Plasma membranes of soybean hypocotyls contain two such NADH oxidase activities that have been resolved by purification on concanavalin A columns. One in the apparent molecular weight range of 14-17 kDa is stimulated by the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The other is larger and unaffected by 2,4-D. The 2,4-D-stimulated activity absolutely requires 2,4-D for activity and exhibits a period length of about 24 min. Also exhibiting 24-min oscillations is the rate of cell enlargement induced by the addition of 2,4-D or the natural auxin indole-3-acetic acid (IAA). Immediately following 2,4-D or IAA addition, a very complex pattern of oscillations is frequently observed. However, after several hours a dominant 24-min period emerges at the expense of the constitutive activity. A recruitment process analogous to that exhibited by prions is postulated to explain this behavior.

  20. Effect of alkaline and acidic fractions of industrial effluents on some lymphoid cells of the fish Rasbora daniconius

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth, T K; Balasubramanian, N K; John, P A

    1981-01-01

    The percentage frequency of the different types of lymphoid cell found in the head-kidney of Rasbora daniconius exposed for 24 h to lc/sub 50/ levels of the ammonia (alkali), phosphoric and sulphuric acid fractions of the effluent from a fertiliser factory was determined by the imprint method. 'T' tests showed that both the alkaline and the acidic fractions could significantly affect the composition of the lymphoid cell population. Different types of lymphoid cell reacted differently to the different fractions; some cell types increased in number while others decreased. Some cell types were not affected. This indicated some sort of specificity in the action of the fractions on the lymphoid cells.

  1. Two-stage acid saccharification of fractionated Gelidium amansii minimizing the sugar decomposition.

    Science.gov (United States)

    Jeong, Tae Su; Kim, Young Soo; Oh, Kyeong Keun

    2011-11-01

    Two-stage acid hydrolysis was conducted on easy reacting cellulose and resistant reacting cellulose of fractionated Gelidium amansii (f-GA). Acid hydrolysis of f-GA was performed at between 170 and 200 °C for a period of 0-5 min, and an acid concentration of 2-5% (w/v, H2SO4) to determine the optimal conditions for acid hydrolysis. In the first stage of the acid hydrolysis, an optimum glucose yield of 33.7% was obtained at a reaction temperature of 190 °C, an acid concentration of 3.0%, and a reaction time of 3 min. In the second stage, a glucose yield of 34.2%, on the basis the amount of residual cellulose from the f-GA, was obtained at a temperature of 190 °C, a sulfuric acid concentration of 4.0%, and a reaction time 3.7 min. Finally, 68.58% of the cellulose derived from f-GA was converted into glucose through two-stage acid saccharification under aforementioned conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Effect of disintegration wave grinding on fractional protein and amino acid composition of chickpea

    OpenAIRE

    G. O. Magomedov; M. K. Sadigova; S. I. Lukina; V. Y. Kustov

    2013-01-01

    The study of fractional changes and amino acid composition of proteins in the application of chickpea disintegration wave grinding. Comparative analysis of six varieties of chickpea before and after grinding.

  3. The conserved baculovirus protein p33 (Ac92) is a flavin adenine dinucleotide-linked sulfhydryl oxidase

    International Nuclear Information System (INIS)

    Long, C.M.; Rohrmann, G.F.; Merrill, G.F.

    2009-01-01

    Open reading frame 92 of the Autographa californica baculovirus (Ac92) is one of about 30 core genes present in all sequenced baculovirus genomes. Computer analyses predicted that the Ac92 encoded protein (called p33) and several of its baculovirus orthologs were related to a family of flavin adenine dinucleotide (FAD)-linked sulfhydryl oxidases. Alignment of these proteins indicated that, although they were highly diverse, a number of amino acids in common with the Erv1p/Alrp family of sulfhydryl oxidases are present. Some of these conserved amino acids are predicted to stack against the isoalloxazine and adenine components of FAD, whereas others are involved in electron transfer. To investigate this relationship, Ac92 was expressed in bacteria as a His-tagged fusion protein, purified, and characterized both spectrophotometrically and for its enzymatic activity. The purified protein was found to have the color (yellow) and absorption spectrum consistent with it being a FAD-containing protein. Furthermore, it was demonstrated to have sulfhydryl oxidase activity using dithiothreitol and thioredoxin as substrates.

  4. Fractionation of SWNT/nucleic acid complexes by agarose gel electrophoresis

    International Nuclear Information System (INIS)

    Vetcher, Alexandre A; Srinivasan, Srimeenakshi; Vetcher, Ivan A; Abramov, Semen M; Kozlov, Mikhail; Baughman, Ray H; Levene, Stephen D

    2006-01-01

    We show that aqueous dispersions of single-walled carbon nanotubes (SWNTs), prepared with the aid of nucleic acids (NAs) such as RNA or DNA, can be separated into fractions using agarose gel electrophoresis. In a DC electric field, SWNT/NA complexes migrate in the gel in the direction of positive potential to form well-defined bands. Raman spectroscopy as a function of band position shows that nanotubes having different spectroscopic properties possess different electrophoretic mobilities. The migration patterns for SWNT/RNA and SWNT/DNA complexes differ. Parallel elution of the SWNT/NA complexes from the gel during electrophoresis and subsequent characterization by AFM reveals differences in nanotube diameter, length and curvature. The results suggest that fractionation of nanotubes can be achieved by this procedure. We discuss factors affecting the mobility of the nanotube complexes and propose analytical applications of this technique

  5. Fractionation of SWNT/nucleic acid complexes by agarose gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Vetcher, Alexandre A [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Srinivasan, Srimeenakshi [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Vetcher, Ivan A [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Abramov, Semen M [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Kozlov, Mikhail [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Baughman, Ray H [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Levene, Stephen D [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States)

    2006-08-28

    We show that aqueous dispersions of single-walled carbon nanotubes (SWNTs), prepared with the aid of nucleic acids (NAs) such as RNA or DNA, can be separated into fractions using agarose gel electrophoresis. In a DC electric field, SWNT/NA complexes migrate in the gel in the direction of positive potential to form well-defined bands. Raman spectroscopy as a function of band position shows that nanotubes having different spectroscopic properties possess different electrophoretic mobilities. The migration patterns for SWNT/RNA and SWNT/DNA complexes differ. Parallel elution of the SWNT/NA complexes from the gel during electrophoresis and subsequent characterization by AFM reveals differences in nanotube diameter, length and curvature. The results suggest that fractionation of nanotubes can be achieved by this procedure. We discuss factors affecting the mobility of the nanotube complexes and propose analytical applications of this technique.

  6. Graphene-glucose oxidase bioanodes for enzymatic biofuel cells

    DEFF Research Database (Denmark)

    Tang, Jing; Werchmeister, Rebecka Maria Larsen; Engelbrekt, Christian

    2017-01-01

    as supporting material, polyethyleneimine (PEI) as linker and glucose oxidase (GOD) as the chosen enzyme. GOD can catalyze oxidation of glucose to gluconolactone, but needs a mediator to assist electron transfer between the enzyme and electrodes. The redox molecule ferrocene carboxylic acid (Fc...... and systematically investigated. The assembled EBFCs show good reproducibility. EBFCs provide maximum output power density 2.47 μW cm-2 at 35 ℃, indicating the optimized activity of EBFCs fed with glucose....

  7. The influence of naphthenic acids and their fractions onto cell membrane permeability

    Directory of Open Access Journals (Sweden)

    Pavlović Ksenija

    2015-01-01

    Full Text Available The influence of naphthenic acids (NAs mixture and their narrow fractions (called NA pH 4, pH 8 and pH 10 onto permeability of beetroot cell membrane is examined. The results showed that the effect depends on treatment duration, concentration and NAs structure. Longer treatment of plant cell membranes with sodium naphthenate (Na-naph resulted in the increase of membrane permeability (e.g. 4-hour treatment with Na-naph (C=100 μmol L-1 increased membrane permeability about 3 times, while prolongation of treatment to 24 hour resulted in the 18 times increasing of the effect. NAs in the concentration range from 0.1 to 10 μmol L-1 does not change membrane permeability, while membrane permeability is increasing linearly with concentration increasing from 10-100 μmol L-1. The strongest effect expressed fraction pH 8, where bi- and tricyclic carboxylic acids are the most abundant. These structures are predominant in the total NAs mixture as well. Thereby could be explained their closest, but a little bit weaker effect, comparing to NAs present in fraction pH 8. The effect of NAs onto beetroot cell membrane is between the effects of anionic (SDS and LS and non-ionic surfactants (Triton X-100. [Projekat Ministarstva nauke Republike Srbije, br. 172006. i br. TR31036

  8. Glucose biosensor based on a platinum electrode modified with rhodium nanoparticles and with glucose oxidase immobilized on gold nanoparticles

    International Nuclear Information System (INIS)

    Guo, Xishan; Jian, Jinming; Liang, Bo; Ye, Xuesong; Zhang, Yelei

    2014-01-01

    We have developed an enzymatic glucose biosensor that is based on a flat platinum electrode which was covered with electrophoretically deposited rhodium (Rh) nanoparticles and then sintered to form a large surface area. The biosensor was obtained by depositing glucose oxidase (GOx), Nafion, and gold nanoparticles (AuNPs) on the Rh electrode. The electrical potential and the fractions of Nafion and GOx were optimized. The resulting biosensor has a very high sensitivity (68.1 μA mM −1 cm −2 ) and good linearity in the range from 0.05 to 15 mM (r = 0.989). The limit of detection is as low as 0.03 mM (at an SNR of 3). The glucose biosensor also is quite selective and is not interfered by electroactive substances including ascorbic acid, uric acid and acetaminophen. The lifespan is up to 90 days. It was applied to the determination of glucose in blood serum, and the results compare very well with those obtained with a clinical analyzer. (author)

  9. Oxidase-based biocatalytic processes

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Woodley, John; Krühne, Ulrich

    interestingbiocatalystsbecause they use a mild oxidant (oxygen) as a substrateas opposed to their chemical counterparts which use strong oxidants such as permanganates. A class of oxidases calledmonoamine oxidases has been used as the central case study for the thesis. The rationale for choosing thissystemis that it has been...

  10. Effect of disintegration wave grinding on fractional protein and amino acid composition of chickpea

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov

    2013-01-01

    Full Text Available The study of fractional changes and amino acid composition of proteins in the application of chickpea disintegration wave grinding. Comparative analysis of six varieties of chickpea before and after grinding.

  11. Omega-3 fatty acids and oxidative stability of ice cream supplemented with olein fraction of chia (Salvia hispanica L.) oil.

    Science.gov (United States)

    Ullah, Rahman; Nadeem, Muhammad; Imran, Muhammad

    2017-02-07

    Chia (Salvia hispanica L.) has been regarded as good source of polyunsaturated omega-3 fatty acids with cardiac, hepatic, hypotensive, antiallergic and antidiabetic role. Concentration of omega-3 fatty acids in chia oil can be enhanced by fractionation. Olein/low melting fraction of chia oil has higher concentration of omega-3 fatty acids. Therefore, main objective of current investigation was determination of various concentration effect of olein fraction of chia oil on omega-3 fatty acids, oxidative stability and sensory characteristics of ice cream. Ice cream samples were prepared by partially replacing the milk fat with olein fraction of chia oil at 5, 10, 15 and 20% concentrations (T 1 , T 2 , T 3 and T 4 ), respectively. Ice cream prepared from 100% milk fat was kept as control. Ice cream samples stored at -18 °C for 60 days were analysed at 0, 30 and 60 days of the storage period. Fatty acid profile, total phenolic contents, total flavonoids, free fatty acids, peroxide value, anisidine value and sensory characteristics of ice cream samples was studied. Concentration of α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid in T 4 was 13.24, 0.58, 0.42 and 0.31%, respectively. Total phenolic contents of control, T 1 , T 2 , T 3 and T 4 were recorded 0.12, 1.65, 3.17, 5.19 and 7.48 mg GAE/mL, respectively. Total flavonoid content of control, T 1 , T 2 , T 3 and T 4 were found 0.08, 0.64, 1.87, 3.16 and 4.29 mg Quercetin Equivalent/mL. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of control, T 1 , T 2 , T 3 and T 4 was noted 5.61, 17.43, 36.84, 51.17 and 74.91%, respectively. After 60 days of storage period, the highest peroxide value of 1.84 (MeqO 2 /kg) was observed in T 4 , which was much less than allowable limit of 10 (MeqO 2 /kg). Flavour score was non-significant after 30 days of storage period. Supplementation of ice cream with olein fraction of chia oil enhanced the concentration of

  12. Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Tamayo-Ramos Juan Antonio

    2012-12-01

    Full Text Available Abstract Background Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. Results The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA and 2,2-azino-di(3-ethylbenzthiazoline sulfonic acid (ABTS, and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. Conclusions The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst.

  13. Glucose oxidase-functionalized fluorescent gold nanoclusters as probes for glucose

    International Nuclear Information System (INIS)

    Xia, Xiaodong; Long, Yunfei; Wang, Jianxiu

    2013-01-01

    Highlights: ► A glucose oxidase/gold nanocluster conjugates formed by etching chemistry. ► Integration of the bioactivities and fluorescence properties within a single unit. ► These conjugates serve as novel fluorescent probe for glucose. -- Abstract: Creation and application of noble metal nanoclusters have received continuous attention. By integrating enzyme activity and fluorescence for potential applications, enzyme-capped metal clusters are more desirable. This work demonstrated a glucose oxidase (an enzyme for glucose)-functionalized gold cluster as probe for glucose. Under physiological conditions, such bioconjugate was successfully prepared by an etching reaction, where tetrakis (hydroxylmethyl) phosphonium-protected gold nanoparticle and thioctic acid-modified glucose oxidase were used as precursor and etchant, respectively. These bioconjugates showed unique fluorescence spectra (λ em max = 650 nm, λ ex max = 507 nm) with an acceptable quantum yield (ca. 7%). Moreover, the conjugated glucose oxidase remained active and catalyzed reaction of glucose and dissolved O 2 to produce H 2 O 2 , which quenched quantitatively the fluorescence of gold clusters and laid a foundation of glucose detection. A linear range of 2.0 × 10 −6 –140 × 10 −6 M and a detection limit of 0.7 × 10 −6 M (S/N = 3) were obtained. Also, another horseradish peroxidase/gold cluster bioconjugate was produced by such general synthesis method. Such enzyme/metal cluster bioconjugates represented a promising class of biosensors for biologically important targets in organelles or cells

  14. On the fractionation of natural radioactivity in the production of phosphoric acid by the wet acid method

    International Nuclear Information System (INIS)

    Bolivar, J.P.; Garcia-Tenorio, R.; Garcia-Leon, M.

    1996-01-01

    The fractionation of different natural radionuclides (U-isotopes, 226 Ra and 210 Po) in the process used for the production of phosphoric acid in some factories located in the south-west of Spain is analyzed. As a consequence, different ways of natural radionuclide liberation to the environment can be evaluated due to these industrial activities. (author). 9 refs., 2 figs., 3 tabs

  15. Chemical composition of fatty acid and unsaponifiable fractions of leaves, stems and roots of Arbutus unedo and in vitro antimicrobial activity of unsaponifiable extracts.

    Science.gov (United States)

    Diba, Mohamed Amine; Paolini, Julien; Bendahou, Mourad; Varesi, Laurent; Allali, Hocine; Desjobert, Jean-Marie; Tabti, Boufeldja; Costa, Jean

    2010-07-01

    The chemical composition of the fatty acid and unsaponifiable fractions of the leaves, stems and roots of Arbutus unedo L. were determined using gas chromatography and gas chromatography-mass spectrometry. The fatty acid fractions of the leaves, stems and roots contained 38.5%, 31.3% and 14.1% palmitic acid, respectively, along with other long-chain fatty acids (up to C22). The chemical composition of the unsaponifiable fractions differed: the leaf and stem fractions contained high levels of aliphatic (32.1% and 62.6%, respectively) and terpenic compounds (49.6% and 25.7%, respectively), and the root fraction mainly contained esters, of which the most abundant was benzyl cinnamate (36.6%). The antimicrobial activities of the unsaponifiable fractions against nine species of microorganisms were assessed. The unsaponifiable leaf and stem extracts inhibited the growth of Klebsiella pneumoniae, Enterococcus faecalis and Candida albicans.

  16. D-Amino acid oxidase bio-functionalized platforms: Toward an enhanced enzymatic bio-activity

    Science.gov (United States)

    Herrera, Elisa; Valdez Taubas, Javier; Giacomelli, Carla E.

    2015-11-01

    The purpose of this work is to study the adsorption process and surface bio-activity of His-tagged D-amino acid oxidase (DAAO) from Rhodotorula gracilis (His6-RgDAAO) as the first step for the development of an electrochemical bio-functionalized platform. With such a purpose this work comprises: (a) the His6-RgDAAO bio-activity in solution determined by amperometry, (b) the adsorption mechanism of His6-RgDAAO on bare gold and carboxylated modified substrates in the absence (substrate/COO-) and presence of Ni(II) (substrate/COO- + Ni(II)) determined by reflectometry, and (c) the bio-activity of the His6-RgDAAO bio-functionalized platforms determined by amperometry. Comparing the adsorption behavior and bio-activity of His6-RgDAAO on these different solid substrates allows understanding the contribution of the diverse interactions responsible for the platform performance. His6-RgDAAO enzymatic performance in solution is highly improved when compared to the previously used pig kidney (pk) DAAO. His6-RgDAAO exhibits an amperometrically detectable bio-activity at concentrations as low as those expected on a bio-functional platform; hence, it is a viable bio-recognition element of D-amino acids to be coupled to electrochemical platforms. Moreover, His6-RgDAAO bio-functionalized platforms exhibit a higher surface activity than pkDAAO physically adsorbed on gold. The platform built on Ni(II) modified substrates present enhanced bio-activity because the surface complexes histidine-Ni(II) provide with site-oriented, native-like enzymes. The adsorption mechanism responsible of the excellent performance of the bio-functionalized platform takes place in two steps involving electrostatic and bio-affinity interactions whose prevalence depends on the degree of surface coverage.

  17. RNA Interference of 1-Aminocyclopropane-1-carboxylic Acid Oxidase (ACO1 and ACO2 Genes Expression Prolongs the Shelf Life of Eksotika (Carica papaya L. Papaya Fruit

    Directory of Open Access Journals (Sweden)

    Rogayah Sekeli

    2014-06-01

    Full Text Available The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6. Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.

  18. Isolation of Highly Purified Fractions of Plasma Membrane and Tonoplast from the Same Homogenate of Soybean Hypocotyls by Free-Flow Electrophoresis 1

    Science.gov (United States)

    Sandelius, Anna Stina; Penel, Claude; Auderset, Guy; Brightman, Andrew; Millard, Merle; Morré, D. James

    1986-01-01

    A procedure is described whereby highly purified fractions of plasma membrane and tonoplast were isolated from hypocotyls of dark-grown soybean (Glycine max L. var Wayne) by the technique of preparative free-flow electrophoresis. Fractions migrating the slowest toward the anode were enriched in thick (10 nanometers) membranes identified as plasma membranes based on ability to bind N-1-naphthylphthalamic acid (NPA), glucan synthetase-II, and K+-stimulated, vanadate-inhibited Mg2+ ATPase, reaction with phosphotungstic acid at low pH on electron microscope sections, and morphological evaluations. Fractions migrating farthest toward the anode (farthest from the point of sample injection) were enriched in membrane vesicles with thick (7-9 nanometers) membranes that did not stain with phosphotungstic acid at low pH, contained a nitrate-inhibited, Cl-stimulated ATPase and had the in situ morphological characteristics of tonoplast including the presence of flocculent contents. These vesicles neither bound NPA nor contained levels of glucan synthetase II above background. Other membranous cell components such as dictyosomes (fucosyltransferase, latent nucleosidediphosphate phosphatase), endoplasmic reticulum vesicles (NADH- and NADPH- cytochrome c reductase), mitochondria (succinate-2(p-indophenyl)-3-p-nitrophenyl)-5-phenyl tetrazolium-reductase and cytochrome oxidase) and plastids (carotenoids and monogalactosyl diglyceride synthetase) were identified on the basis of appropriate marker constituents and, except for plastid thylakoids, had thin (marker activities. From electron microscope morphometry (using both membrane measurements and staining with phosphotungstic acid at low pH) and analysis of marker enzymes, both plasma membrane and tonoplast fractions were estimated to be about 90% pure. Neither fraction appeared to be contaminated by the other by more than 3%. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 9 PMID:16664771

  19. Expression Studies of Gibberellin Oxidases in Developing Pumpkin Seeds1

    Science.gov (United States)

    Frisse, Andrea; Pimenta, Maria João; Lange, Theo

    2003-01-01

    Two cDNA clones, 3-ox and 2-ox, have been isolated from developing pumpkin (Cucurbita maxima) embryos that show significant amino acid homology to gibberellin (GA) 3-oxidases and 2-oxidases, respectively. Recombinant fusion protein of clone 3-ox converted GA12-aldehyde, GA12, GA15, GA24, GA25, and GA9 to GA14-aldehyde, GA14, GA37, GA36, GA13, and GA4, respectively. Recombinant 2-ox protein oxidized GA9, GA4, and GA1 to GA51, GA34, and GA8, respectively. Previously cloned GA 7-oxidase revealed additional 3β-hydroxylation activity of GA12. Transcripts of this gene were identified in endosperm and embryo of the developing seed by quantitative reverse transcriptase-polymerase chain reaction and localized in protoderm, root apical meristem, and quiescent center by in situ hybridization. mRNA of the previously cloned GA 20-oxidase from pumpkin seeds was localized in endosperm and in tissues of protoderm, ground meristem, and cotyledons of the embryo. However, transcripts of the recently cloned GA 20-oxidase from pumpkin seedlings were found all over the embryo, and in tissues of the inner seed coat at the micropylar end. Previously cloned GA 2β,3β-hydroxylase mRNA molecules were specifically identified in endosperm tissue. Finally, mRNA molecules of the 3-ox and 2-ox genes were found in the embryo only. 3-ox transcripts were localized in tissues of cotyledons, protoderm, and inner cell layers of the root apical meristem, and 2-ox transcripts were found in all tissues of the embryo except the root tips. These results indicate tissue-specific GA-biosynthetic pathways operating within the developing seed. PMID:12644672

  20. Pyruvate Oxidase Influences the Sugar Utilization Pattern and Capsule Production in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Carvalho, Sandra M.; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P.; Neves, Ana R.; Bijlsma, Jetta J. E.

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence,

  1. Subcellular localization of H(+)-ATPase from pumpkin hypocotyls (Cucurbita maxima L.) by membrane fractionation.

    Science.gov (United States)

    Scherer, G F

    1984-03-01

    A new method of preparing sealed vesicles from membrane fractions of pumpkin hypocotyls in ethanolamine-containing buffers was used to investigate the subcellular localization of H(+)-ATPase measured as nigericin-stimulated ATPase. In a fluorescence-quench assay, the H(+) pump was directly demonstrated. The H(+) pump was substrate-specific for Mg·ATP and 0.1 mM diethylstilbestrol completely prevented the development of a Δ pH. The presence of unsupecific phosphatase hampered the detection of nigericin-stimulated ATPase. Unspecific phosphatases could be demonstrated by comparing the broad substrate specificity of the hydrolytic activities of the fractions with the clear preference for Mg·ATP as the substrate for the proton pump. Inhibitor studies showed that neither orthovanadate nor molybdate are absolutely specific for ATPase or acid phosphatase, respectively. Diethylstilbestrol seemed to be a specific inhibitor of ATPase activity in fractions containing nigericin-stimulated ATPase, but it stimulated acid phosphatase which tended to obscure its effect on ATPase activity. Nigericin-stimulated ATPase had its optimum at pH 6.0 and the nigericin effect was K(+)-dependent. The combination of valinomycin and carbonylcyanide m-chlorophenylhydrazone had a similar effect to nigericin, but singly these ionophores were much less stimulatory. After prolonged centrifugation on linear sucrose gradients, nigericin-stimulated ATPase correlated in dense fractions with plasma membrane markers but a part of it remained at the interphase. This lessdense part of the nigericin-stimulated ATPase could be derived from tonoplast vesicles because α-mannosidase, an enzyme of the vacuolar sap, remained in the upper part of the gradient. Nigericinstimulated ATPase did not correlate with the mitochondrial marker, cytochrome c oxidase, whereas azide inhibition of ATPase activity did.

  2. Isolated sulfite oxidase deficiency.

    Science.gov (United States)

    Rupar, C A; Gillett, J; Gordon, B A; Ramsay, D A; Johnson, J L; Garrett, R M; Rajagopalan, K V; Jung, J H; Bacheyie, G S; Sellers, A R

    1996-12-01

    Isolated sulfite oxidase (SO) deficiency is an autosomal recessively inherited inborn error of sulfur metabolism. In this report of a ninth patient the clinical history, laboratory results, neuropathological findings and a mutation in the sulfite oxidase gene are described. The data from this patient and previously published patients with isolated sulfite oxidase deficiency and molybdenum cofactor deficiency are summarized to characterize this rare disorder. The patient presented neonatally with intractable seizures and did not progress developmentally beyond the neonatal stage. Dislocated lenses were apparent at 2 months. There was increased urine excretion of sulfite and S-sulfocysteine and a decreased concentration of plasma cystine. A lactic acidemia was present for 6 months. Liver sulfite oxidase activity was not detectable but xanthine dehydrogenase activity was normal. The boy died of respiratory failure at 32 months. Neuropathological findings of cortical necrosis and extensive cavitating leukoencephalopathy were reminiscent of those seen in severe perinatal asphyxia suggesting an etiology of energy deficiency. A point mutation that resulted in a truncated protein missing the molybdenum-binding site has been identified.

  3. Fractional and sequential recovery of inorganic contaminants from acid mine drainage using cryptocrystalline magnesite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-06-01

    Full Text Available This study evaluated the fractional and sequential recovery of inorganic contaminants from acid mine drainage (AMD) using cryptocrystalline magnesite. Batch experimental approach was used to fulfil the goals of this study. The obtained results...

  4. Calcium isotope fractionation in liquid chromatography with benzo-18-crown-6 resin in aqueous hydrobromic acid medium

    International Nuclear Information System (INIS)

    Sato, Takuya; Oi, Takao

    2015-01-01

    Liquid chromatography operated in a breakthrough mode was employed to study calcium isotope fractionation in the aqueous hydrobromic acid medium. Highly porous silica beads, the inner pores of which were embedded with a benzo-18-crown-6 ether resin, were used as column packing material. Enrichment of heavier isotopes of calcium was observed in the frontal part of respective calcium chromatograms. The values of the isotope fractionation coefficient were on the order of 10 -3 . The observed isotope fractionation coefficient was dependent on the concentration of hydrobromic acid in the calcium feed solution; a higher HBr concentration resulted in a smaller fractionation coefficient value. The present calcium isotope effects were most probably mass-dependent, indicating that they mostly came from isotope effects based on molecular vibration. Molecular orbital calculations supported the present experimental results in a qualitative fashion. Chromatography operated in aqueous HBr media is a better system of Ca isotope separation than that operated in aqueous HCl media. (author)

  5. Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

    Science.gov (United States)

    Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

    2015-01-01

    The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Improved production of 2,5-furandicarboxylic acid by overexpression of 5-hydroxymethylfurfural oxidase and 5-hydroxymethylfurfural/furfural oxidoreductase in Raoultella ornithinolytica BF60.

    Science.gov (United States)

    Yuan, Haibo; Li, Jianghua; Shin, Hyun-Dong; Du, Guocheng; Chen, Jian; Shi, Zhongping; Liu, Long

    2018-01-01

    2,5-Furandicarboxylic acid (FDCA) is a promising bio-based building block and can be produced by biotransformation of 5-hydroxymethylfurfural (HMF). To improve the FDCA production, two genes-one encoding HMF oxidase (HMFO; from Methylovorus sp. strain MP688) and another encoding for HMF/Furfural oxidoreductase (HmfH; from Cupriavidus basilensis HMF14)-were introduced into Raoultella ornithinolytica BF60. The FDCA production in the engineered whole-cell biocatalyst increased from 51.0 to 93.6mM, and the molar conversion ratio of HMF to FDCA increased from 51.0 to 93.6%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Interfacial electron transfer of glucose oxidase on poly(glutamic acid)-modified glassy carbon electrode and glucose sensing.

    Science.gov (United States)

    Zhou, Xuechou; Tan, Bingcan; Zheng, Xinyu; Kong, Dexian; Li, Qinglu

    2015-11-15

    The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Are colorimetric assays appropriate for measuring phenol oxidase activity in peat soils?

    Science.gov (United States)

    Magdalena M. Wiedermann; Evan S. Kane; Timothy J. Veverica; Erik A. Lilleskov

    2017-01-01

    The activity of extracellular phenol oxidases is believed to play a critical role in decomposition processes in peatlands. The water logged, acidic conditions, and recalcitrant litter from the peatland vegetation, lead to exceptionally high phenolics in the peat. In order to quantify the activity of oxidative enzymes involved in the modification and break down of...

  9. Random mutagenesis of aspergillus niger and process optimization for enhanced production of glucose oxidase

    International Nuclear Information System (INIS)

    Haq, I.; Nawaz, A.; Mukhtar, A.N.H.; Mansoor, H.M.Z.; Ameer, S.M.

    2014-01-01

    The study deals with the improvement of wild strain Aspergillus niger IIB-31 through random mutagenesis using chemical mutagens. The main aim of the work was to enhance the glucose oxidase (GOX) yield of wild strain (24.57+-0.01 U/g of cell mass) through random mutagenesis and process optimization. The wild strain of Aspergillus niger IIB-31 was treated with chemical mutagens such as Ethyl methane sulphonate (EMS) and nitrous acid for this purpose. Mutagen treated 98 variants indicating the positive results were picked and screened for the glucose oxidase production using submerged fermentation. EMS treated E45 mutant strain gave the highest glucose oxidase production (69.47 + 0.01 U/g of cell mass), which was approximately 3-folds greater than the wild strain IIB-31. The preliminary cultural conditions for the production of glucose oxidase using submerged fermentation from strain E45 were also optimized. The highest yield of GOD was obtained using 8% glucose as carbon and 0.3% peptone as nitrogen source at a medium pH of 7.0 after an incubation period of 72 hrs at 30 degree. (author)

  10. The N-terminus of amine oxidase of Hansenula polymorpha contains a peroxisomal targeting signal

    NARCIS (Netherlands)

    Faber, Klaas Nico; Keizer-Gunnink, Ineke; Pluim, Dick; Harder, Willem; AB, Geert; Veenhuis, Marten

    1995-01-01

    Here we describe the identification of the targeting sequence of peroxisomal amine oxidase (AMO) of H. polymorpha. Deletion analysis revealed that essential targeting information is located within the extreme N-terminal 16 amino acids. Moreover, this sequence can direct a reporter protein to the

  11. Glucose oxidase-functionalized fluorescent gold nanoclusters as probes for glucose

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Xiaodong [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Long, Yunfei, E-mail: l_yunfei927@163.com [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Wang, Jianxiu, E-mail: jxiuwang@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2013-04-15

    Highlights: ► A glucose oxidase/gold nanocluster conjugates formed by etching chemistry. ► Integration of the bioactivities and fluorescence properties within a single unit. ► These conjugates serve as novel fluorescent probe for glucose. -- Abstract: Creation and application of noble metal nanoclusters have received continuous attention. By integrating enzyme activity and fluorescence for potential applications, enzyme-capped metal clusters are more desirable. This work demonstrated a glucose oxidase (an enzyme for glucose)-functionalized gold cluster as probe for glucose. Under physiological conditions, such bioconjugate was successfully prepared by an etching reaction, where tetrakis (hydroxylmethyl) phosphonium-protected gold nanoparticle and thioctic acid-modified glucose oxidase were used as precursor and etchant, respectively. These bioconjugates showed unique fluorescence spectra (λ{sub em} {sub max} = 650 nm, λ{sub ex} {sub max} = 507 nm) with an acceptable quantum yield (ca. 7%). Moreover, the conjugated glucose oxidase remained active and catalyzed reaction of glucose and dissolved O{sub 2} to produce H{sub 2}O{sub 2}, which quenched quantitatively the fluorescence of gold clusters and laid a foundation of glucose detection. A linear range of 2.0 × 10{sup −6}–140 × 10{sup −6} M and a detection limit of 0.7 × 10{sup −6} M (S/N = 3) were obtained. Also, another horseradish peroxidase/gold cluster bioconjugate was produced by such general synthesis method. Such enzyme/metal cluster bioconjugates represented a promising class of biosensors for biologically important targets in organelles or cells.

  12. Exploring flavin-containing carbohydrate oxidases

    NARCIS (Netherlands)

    Ferrari, Alessandro Renato

    2017-01-01

    Oxidases are enzymes capable of removing one or more electrons from their substrate and transfer them to molecular oxygen, forming hydrogen peroxide. Due to their high regio- and enantioselectivity, their use is preferred over traditional organic chemistry methods. Among the oxidases, flavoprotein

  13. Manageable cytotoxicity of nanocapsules immobilizing D-amino acid oxidase via exogenous administration of nontoxic prodrug

    Science.gov (United States)

    Zhao, Yang; Zhu, Yingchun; Fu, Jingke

    2014-02-01

    D-Amino acid oxidase (DAO), which could catalyze generation of hydrogen peroxide with strong oxidbility and cytotoxicity, has become of interest as a biocatalyst for therapeutic treatments. Herein we report that amino-functional hollow mesoporous silica with large pore size (10.27 nm) and positively charged surface effectively immobilize DAO with negative charge. The adsorption, activity and stability of DAO are demonstrated to depend mainly on the amino-functionalization of surface. Significant cancer cell killing effect is observed when the cells are treated by the nanocapsules entrapping DAO together with D-alanine, showing distinct dose-dependency on concentration of the nanocapsules entrapping DAO or D-alanine. Nevertheless, the toxicity is completely neutralized by the addition of catalase, and anti-tumor effect is not observed when either the nanocapsules entrapping DAO or D-alanine is applied alone. The results indicate that cytotoxicity of the nanocapsules entrapping DAO could be managed by exogenous administration of nontoxic prodrug to tumor tissue, due to the stereoselectivity of DAO and the scarcity of its substrates in mammalian organisms. Thus, the method might be exploited as a potential treatment for cancer therapy.

  14. Identification of aldehyde oxidase 1 and aldehyde oxidase homologue 1 as dioxin-inducible genes

    International Nuclear Information System (INIS)

    Rivera, Steven P.; Choi, Hyun Ho; Chapman, Brett; Whitekus, Michael J.; Terao, Mineko; Garattini, Enrico; Hankinson, Oliver

    2005-01-01

    Aldehyde oxidases are a family of highly related molybdo-flavoenzymes acting upon a variety of compounds of industrial and medical importance. We have identified aldehyde oxidase 1 (AOX1) as a 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) inducible gene in the mouse hepatoma cell line Hepa-1. AOX1 mRNA levels were not increased by dioxin in mutant derivatives of the Hepa-1 cell line lacking either functional aryl hydrocarbon receptor (AHR) or aryl hydrocarbon receptor nuclear translocator (ARNT) proteins, thus demonstrating that transcriptional induction of AOX1 in response to dioxin occurs through the AHR pathway. Dioxin induction of AOX1 mRNA was also observed in mouse liver. In addition, levels of AOX1 protein as well as those of aldehyde oxidase homologue 1 (AOH1), a recently identified homolog of AOX1, were elevated in mouse liver in response to dioxin. Employing an aldehyde oxidase specific substrate, AOX1/AOH1 activity was shown to be induced by dioxin in mouse liver. This activity was inhibited by a known inhibitor of aldehyde oxidases, and eliminated by including tungstate in the mouse diet, which is known to lead to inactivation of molybdoflavoenzymes, thus confirming that the enzymatic activity was attributable to AOX1/AOH1. Our observations thus identify two additional xenobiotic metabolizing enzymes induced by dioxin

  15. Bioprospecting the Curculigoside-Cinnamic Acid-Rich Fraction from Molineria latifolia Rhizome as a Potential Antioxidant Therapeutic Agent

    Directory of Open Access Journals (Sweden)

    Der Jiun Ooi

    2016-06-01

    Full Text Available Increasing evidence from both experimental and clinical studies depicts the involvement of oxidative stress in the pathogenesis of various diseases. Specifically, disruption of homeostatic redox balance in accumulated body fat mass leads to obesity-associated metabolic syndrome. Strategies for the restoration of redox balance, potentially by exploring potent plant bioactives, have thus become the focus of therapeutic intervention. The present study aimed to bioprospect the potential use of the curculigoside-cinnamic acid-rich fraction from Molineria latifolia rhizome as an antioxidant therapeutic agent. The ethyl acetate fraction (EAF isolated from M. latifolia rhizome methanolic extract (RME contained the highest amount of phenolic compounds, particularly curculigoside and cinnamic acid. EAF demonstrated glycation inhibitory activities in both glucose- and fructose-mediated glycation models. In addition, in vitro chemical-based and cellular-based antioxidant assays showed that EAF exhibited high antioxidant activities and a protective effect against oxidative damage in 3T3-L1 preadipocytes. Although the efficacies of individual phenolics differed depending on the structure and concentration, a correlational study revealed strong correlations between total phenolic contents and antioxidant capacities. The results concluded that enriched phenolic contents in EAF (curculigoside-cinnamic acid-rich fraction contributed to the overall better reactivity. Our data suggest that this bioactive-rich fraction warrants therapeutic potential against oxidative stress-related disorders.

  16. Characterization of Coconut Oil Fractions Obtained from Solvent Fractionation Using Acetone.

    Science.gov (United States)

    Sonwai, Sopark; Rungprasertphol, Poonyawee; Nantipipat, Nantinee; Tungvongcharoan, Satinee; Laiyangkoon, Nantikan

    2017-09-01

    This work was aimed to study the solvent fraction of coconut oil (CNO). The fatty acid and triacylglycerol compositions, solid fat content (SFC) and the crystallization properties of CNO and its solid and liquid fractions obtained from fractionation at different conditions were investigated using various techniques. CNO was dissolved in acetone (1:1 w/v) and left to crystallize isothermally at 10°C for 0.5, 1 and 2 h and at 12°C for 2, 3 and 6 h. The solid fractions contained significantly lower contents of saturated fatty acids of ≤ 10 carbon atoms but considerably higher contents of saturated fatty acids with > 12 carbon atoms with respect to those of CNO and the liquid fractions. They also contained higher contents of high-melting triacylglycerol species with carbon number ≥ 38. Because of this, the DSC crystallization onset temperatures and the crystallization peak temperatures of the solid fractions were higher than CNO and the liquid fractions. The SFC values of the solid fractions were significantly higher than CNO at all measuring temperatures before reaching 0% just below the body temperature with the fraction obtained at 12°C for 2 h exhibiting the highest SFC. On the contrary, the SFC values of the liquid fractions were lower than CNO. The crystallization duration exhibited strong influence on the solid fractions. There was no effect on the crystal polymorphic structure possibly because CNO has β'-2 as a stable polymorph. The enhanced SFC of the solid fractions would allow them to find use in food applications where a specific melting temperature is desired such as sophisticated confectionery fats, and the decreased SFC of the liquid fractions would provide them with a higher cold stability which would be useful during extended storage time.

  17. Fractionation, amino acid profiles, antimicrobial and free radical scavenging activities of Citrullus lanatus seed protein.

    Science.gov (United States)

    Dash, Priyanka; Ghosh, Goutam

    2017-12-01

    In the present study, a modified Osborne fractionation method was followed to isolate albumin (C alb ), globulin (C glo ), prolamin (C pro ) and glutelin (C glu ) successively from seeds of Citrullus lanatus (watermelon). This research work was undertaken to investigate the antimicrobial and antioxidant activities of isolated protein fractions of C. lanatus seed. Amino acid composition and molecular weight distribution were determined to establish their relationship with antimicrobial and antioxidant activity. Among all the fractions, C pro was found to be most effective against A. baumannii followed by C alb and C glo . The results showed that growth of inhibition of these protein fractions differ significantly from each other (p ≤ 0.05). In view of antioxidant potential, C glo exhibited strongest antioxidant capacity while C glu showed weakest antioxidant potential.

  18. A role for NADPH oxidase in antigen presentation

    Directory of Open Access Journals (Sweden)

    Gail J Gardiner

    2013-09-01

    Full Text Available The nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressed in phagocytes is a multi-subunit enzyme complex that generates superoxide (O2.-. This radical is an important precursor of hydrogen peroxide (H2O2 and other reactive oxygen species (ROS needed for microbicidal activity during innate immune responses. Inherited defects in NADPH oxidase give rise to chronic granulomatous disease (CGD, a primary immunodeficiency characterized by recurrent infections and granulomatous inflammation. Interestingly, CGD, CGD carrier status, and oxidase gene polymorphisms have all been associated with autoinflammatory and autoimmune disorders, suggesting a potential role for NADPH oxidase in regulating adaptive immune responses. Here, NADPH oxidase function in antigen processing and presentation is reviewed. NADPH oxidase influences dendritic cell (DC crosspresentation by major histocompatibility complex class I molecules (MHC-I through regulation of the phagosomal microenvironment, while in B lymphocytes, NADPH oxidase alters epitope selection by major histocompatibility complex class II molecules (MHC-II.

  19. Oxoferryl-Porphyrin Radical Catalytic Intermediate in Cytochrome bd Oxidases Protects Cells from Formation of Reactive Oxygen Species*

    Science.gov (United States)

    Paulus, Angela; Rossius, Sebastiaan Gijsbertus Hendrik; Dijk, Madelon; de Vries, Simon

    2012-01-01

    The quinol-linked cytochrome bd oxidases are terminal oxidases in respiration. These oxidases harbor a low spin heme b558 that donates electrons to a binuclear heme b595/heme d center. The reaction with O2 and subsequent catalytic steps of the Escherichia coli cytochrome bd-I oxidase were investigated by means of ultra-fast freeze-quench trapping followed by EPR and UV-visible spectroscopy. After the initial binding of O2, the O–O bond is heterolytically cleaved to yield a kinetically competent heme d oxoferryl porphyrin π-cation radical intermediate (compound I) magnetically interacting with heme b595. Compound I accumulates to 0.75–0.85 per enzyme in agreement with its much higher rate of formation (∼20,000 s−1) compared with its rate of decay (∼1,900 s−1). Compound I is next converted to a short lived heme d oxoferryl intermediate (compound II) in a phase kinetically matched to the oxidation of heme b558 before completion of the reaction. The results indicate that cytochrome bd oxidases like the heme-copper oxidases break the O–O bond in a single four-electron transfer without a peroxide intermediate. However, in cytochrome bd oxidases, the fourth electron is donated by the porphyrin moiety rather than by a nearby amino acid. The production of reactive oxygen species by the cytochrome bd oxidase was below the detection level of 1 per 1000 turnovers. We propose that the two classes of terminal oxidases have mechanistically converged to enzymes in which the O–O bond is broken in a single four-electron transfer reaction to safeguard the cell from the formation of reactive oxygen species. PMID:22287551

  20. Synthesis and characterization of microparticles based on poly-methacrylic acid with glucose oxidase for biosensor applications.

    Science.gov (United States)

    Hervás Pérez, J P; López-Ruiz, B; López-Cabarcos, E

    2016-01-01

    In the line of the applicability of biocompatible monomers pH and temperature dependent, we assayed poly-methacrylic acid (p-MAA) microparticles as immobilization system in the design of enzymatic biosensors. Glucose oxidase was used as enzyme model for the study of microparticles as immobilization matrices and as biological material in the performance of glucose biosensors. The enzyme immobilization method was optimized by investigating the influence of monomer concentration and cross-linker content (N',N'-methylenebisacrylamide), used in the preparation of the microparticles in the response of the biosensors. The kinetics of the polymerization and the effects of the temperature were studied, also the conversion of the polymerization was determinates by a weight method. The structure of the obtained p-MAA microparticles were studied through scanning electron microscopy (SEM) and differential scanning microscopy (DSC). The particle size measurements were performed with a Galai-Cis 1 particle analyzer system. Furthermore, the influence of the swelling behavior of hydrogel matrix as a function of pH and temperature were studied. Analytical properties such as sensitivity, linear range, response time and detection limit were studied for the glucose biosensors. The sensitivity for glucose detection obtained with poly-methacrylic acid (p-MAA) microparticles was 11.98mAM(-1)cm(-2) and 10μM of detection limit. A Nafion® layer was used to eliminate common interferents of the human serum such as uric and ascorbic acids. The biosensors were used to determine glucose in human serum samples with satisfactory results. When stored in a frozen phosphate buffer solution (pH 6.0) at -4°C, the useful lifetime of all biosensors was at least 550 days. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Role of pH in oxidase variability of Aeromonas hydrophila.

    OpenAIRE

    Hunt, L K; Overman, T L; Otero, R B

    1981-01-01

    Some strains of Aeromonas hydrophila may be oxidase negative or only weakly oxidase positive by the Kovacs method taken from the surface of a differential medium, such as MacConkey agar. Six strains of A. hydrophila, two oxidase variable, one oxidase constant, and three weakly oxidase positive on MacConkey agar, were studied to determine the cause of oxidase variability. The bacteriostatic dyes in MacConkey agar were considered possible inhibitors of the oxidase reaction. The concentration of...

  2. Sorption-desorption of imidacloprid onto a lacustrine Egyptian soil and its clay and humic acid fractions.

    Science.gov (United States)

    Kandil, Mahrous M; El-Aswad, Ahmed F; Koskinen, William C

    2015-01-01

    Sorption-desorption of the insecticide imidacloprid 1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine onto a lacustrine sandy clay loam Egyptian soil and its clay and humic acid (HA) fractions was investigated in 24-h batch equilibrium experiments. Imidacloprid (IMDA) sorption-desorption isotherms onto the three sorbents were found to belong to a non-linear L-type and were best described by the Freundlich model. The value of the IMDA adsorption distribution coefficient, Kd(ads), varied according to its initial concentration and was ranged 40-84 for HA, 14-58 for clay and 1.85-4.15 for bulk soil. Freundlich sorption coefficient, Kf(ads), values were 63.0, 39.7 and 4.0 for HA, clay and bulk soil, respectively. The normalized soil Koc value for imidacloprid sorption was ∼800 indicating its slight mobility in soils. Nonlinear sorption isotherms were indicated by 1/n(ads) values imidacloprid sorption process with all tested sorbents. Gibbs free energy (ΔG) values indicated a spontaneous and physicosorption process for IMDA and a more favorable sorption to HA than clay and soil. In conclusion, although the humic acid fraction showed the highest capacity and affinity for imidacloprid sorption, the clay fraction contributed to approximately 95% of soil-sorbed insecticide. Clay and humic acid fractions were found to be the major two factors controlling IMDA sorption in soils. The slight mobility of IMDA in soils and the hysteresis phenomenon associated with the irreversibility of its sorption onto, mainly, clay and organic matter of soils make its leachability unlikely to occur.

  3. Antioxidant activity of cod (Gadus morhua) protein hydrolysates: Fractionation and characterisation of peptide fractions

    DEFF Research Database (Denmark)

    Farvin Habebullah, Sabeena; Andersen, Lisa Lystbæk; Otte, Jeanette

    2016-01-01

    This study aimed to characterise peptide fractions (>5 kDa, 3–5 kDa and fractions were dominated by Ala, Gly, Glu and Ser. The total amino acid composition had high proportions of Lys, Ala...... and Glu. The 3–5 kDa and fractions were further fractionated by size exclusion chromatography. All sub-fractions showed high Fe2+ chelating activity. The DPPH radical-scavenging activity of the 3–5 kDa fraction was exerted mainly by one sub-fraction dominated by peptides with masses below 600 Da....... The DPPH radical-scavenging activity of the fraction was exerted by sub-fractions with low molecular weight. The highest reducing power was found in a sub-fraction containing peptides rich in Arg, Tyr and Phe. Both free amino acids and low molecular weight peptides thus seemed to contribute...

  4. Hierarchical CNFs/MnCo2O4.5 nanofibers as a highly active oxidase mimetic and its application in biosensing

    Science.gov (United States)

    Gao, Mu; Lu, Xiaofeng; Nie, Guangdi; Chi, Maoqiang; Wang, Ce

    2017-12-01

    Recently, much attention has been paid on the nanomaterial-based artificial enzymes due to their tunable catalytic activity, high stability and low cost compared to the natural enzymes. Different from the peroxidase mimics which have been studied for several decades, nanomaterials with oxidase-like property are burgeoning in the recent years. In this paper, hierarchical carbon nanofibers (CNFs)/MnCo2O4.5 nanofibers as efficient oxidase mimics are reported. The products are synthesized by an electrospinning technique and an electrochemcial deposition process in which the CNFs are used as the working electrode where MnCo2O4.5 nanosheets deposit on. The resulting binary metal oxide-based nanocomposites exhibit a good oxidase-like activity toward the oxidations of 3,3‧,5,5‧tetramethylbenzi-dine (TMB), 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) salt and o-phenylenediamine (OPD) without exogenous addition of H2O2. The system of CNFs/MnCo2O4.5-TMB can be used as a candidate to detect sulfite and ascorbic acid via a colorimetric method with a high sensitivity. This work provides the efficient utilization and potential applications of binary metal oxide-based nanocomposites with oxidase activities in biosensors and other biotechnologies.

  5. Lower growth temperature increases alternative pathway capacity and alternative oxidase protein in tobacco.

    Science.gov (United States)

    Vanlerberghe, G C; McIntosh, L

    1992-09-01

    Suspension cells of NT1 tobacco (Nicotiana tabacum L. cv bright yellow) have been used to study the effect of growth temperature on the CN-resistant, salicylhydroxamic acid-sensitive alternative pathway of respiration. Mitochondria isolated from cells maintained at 30 degrees C had a low capacity to oxidize succinate via the alternative pathway, whereas mitochondria isolated from cells 24 h after transfer to 18 degrees C displayed, on average, a 5-fold increase in this capacity (from 7 to 32 nanoatoms oxygen per milligram protein per minute). This represented an increase in alternative pathway capacity from 18 to 45% of the total capacity of electron transport. This increased capacity was lost upon transfer of cells back to 30 degrees C. A monoclonal antibody to the terminal oxidase of the alternative pathway (the alternative oxidase) from Sauromatum guttatum (T.E. Elthon, R.L. Nickels, L. McIntosh [1989] Plant Physiology 89: 1311-1317) recognized a 35-kilodalton mitochondrial protein in tobacco. There was an excellent correlation between the capacity of the alternative path in isolated tobacco mitochondria and the levels of this 35-kilodalton alternative oxidase protein. Cycloheximide could inhibit both the increased level of the 35-kilodalton alternative oxidase protein and the increased alternative pathway capacity normally seen upon transfer to 18 degrees C. We conclude that transfer of tobacco cells to the lower temperature increases the capacity of the alternative pathway due, at least in part, to de novo synthesis of the 35-kilodalton alternative oxidase protein.

  6. Xanthine Oxidase Inhibitory Activity of a Plectranthus saccatus aqueous extract

    Directory of Open Access Journals (Sweden)

    Caldeira F

    2016-12-01

    Full Text Available Gout is a disease with high prevalence in developed countries, resulting from the deposition of uric acid crystals in various locations, particularly at the joints. The pharmacotherapeutic approach to chronic gout essentially consists of administration of uric acid-lowering agents. The main mechanism of action of these agents is the inhibition of xanthine oxidase (XO, the enzyme responsible for the formation of uric acid. The therapeutic alternatives available for this purpose are limited, thus justifying the interest of the discovery of potential new uric acidlowering drugs. In this regard, an aqueous extract of the plant Plectranthus saccatus has been studied for its ability to inhibit XO. The composition of the extract was determined by HPLC and rosmarinic acid was identified as the major constituent. Both the extract and rosmarinic acid have demonstrated the ability to inhibit the production of uric acid by interfering with XO activity. The results obtained herein support the continuation of the study of their uric acid-lowering properties in cell-based and in vivo models to further explore their potential in gout therapy.

  7. Biodistribution of a positron-emitting suicide inactivator of monoamine oxidase, carbon-11 pargyline, in mice and a rabbit

    International Nuclear Information System (INIS)

    Ishiwata, K.; Ido, T.; Yanai, K.; Kawashima, K.; Miura, Y.; Monma, M.; Watanuki, S.; Takahashi, T.; Iwata, R.

    1985-01-01

    Carbon-11 ( 11 C) pargyline, which is a suicide inactivator of Type B monoamine oxidase (MAO), was synthesized by the reaction of N-demethylpargyline with 11 CH 3 l. Biodistribution was investigated in mice, and positron tomographic images of the heart and lung in a rabbit were obtained. The distribution of 11 C after administration of [ 11 C]pargyline was measured in several organs and blood at various time intervals. After 30 min its concentrations in the organs were constant. Subcellular distribution studies in the brain, lung, liver, and kidney showed that 59-70% of the 11 C became acid-insoluble and 9-33% was present in the crude mitochondrial fraction at 60 min after injection. The uptakes of the 11 C in each organ except for the kidney and spleen seemed to correlate with the in vitro enzymatic activity of Type B MAO. At high loading dose a nonspecific uptake was observed

  8. Bioconversion of α-linolenic acid to n-3 LCPUFA and expression of PPAR-alpha, acyl Coenzyme A oxidase 1 and carnitine acyl transferase I are incremented after feeding rats with α-linolenic acid-rich oils.

    Science.gov (United States)

    González-Mañán, Daniel; Tapia, Gladys; Gormaz, Juan Guillermo; D'Espessailles, Amanda; Espinosa, Alejandra; Masson, Lilia; Varela, Patricia; Valenzuela, Alfonso; Valenzuela, Rodrigo

    2012-07-01

    High dietary intake of n-6 fatty acids in relation to n-3 fatty acids may generate health disorders, such as cardiovascular and other chronic diseases. Fish consumption rich in n-3 fatty acids is low in Latin America, it being necessary to seek other alternatives to provide α-linolenic acid (ALA), precursor of n-3 LCPUFA (EPA and DHA). Two innovative oils were assayed, chia (Salvia hispanica) and rosa mosqueta (Rosa rubiginosa). This study evaluated hepatic bioconversion of ALA to EPA and DHA, expression of PPAR-α, acyl-Coenzyme A oxidase 1 (ACOX1) and carnitine acyltransferase I (CAT-I), and accumulation of EPA and DHA in plasma and adipose tissue in Sprague-Dawley rats. Three experimental groups were fed 21 days: sunflower oil (SFO, control); chia oil (CO); rosa mosqueta oil (RMO). Fatty acid composition of total lipids and phospholipids from plasma, hepatic and adipose tissue was assessed by gas-liquid chromatography and TLC. Expression of PPAR-α (RT-PCR) and ACOX1 and CAT-I (Western blot). CO and RMO increased plasma, hepatic and adipose tissue levels of ALA, EPA and DHA and decreased n-6:n-3 ratio compared to SFO (p oil.

  9. Cytochrome oxidase subunit II gene in mitochondria of Oenothera has no intron

    Science.gov (United States)

    Hiesel, Rudolf; Brennicke, Axel

    1983-01-01

    The cytochrome oxidase subunit II gene has been localized in the mitochondrial genome of Oenothera berteriana and the nucleotide sequence has been determined. The coding sequence contains 777 bp and, unlike the corresponding gene in Zea mays, is not interrupted by an intron. No TGA codon is found within the open reading frame. The codon CGG, as in the maize gene, is used in place of tryptophan codons of corresponding genes in other organisms. At position 742 in the Oenothera sequence the TGG of maize is changed into a CGG codon, where Trp is conserved as the amino acid in other organisms. Homologous sequences occur more than once in the mitochondrial genome as several mitochondrial DNA species hybridize with DNA probes of the cytochrome oxidase subunit II gene. ImagesFig. 5. PMID:16453484

  10. Extracellular oxidases and the transformation of solubilised low-rank coal by wood-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, J.P. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences; Graham, L.A. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences; Catcheside, D.E.A. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences

    1996-12-31

    The involvement of extracellular oxidases in biotransformation of low-rank coal was assessed by correlating the ability of nine white-rot and brown-rot fungi to alter macromolecular material in alkali-solubilised brown coal with the spectrum of oxidases they produce when grown on low-nitrogen medium. The coal fraction used was that soluble at 3.0{<=}pH{<=}6.0 (SWC6 coal). In 15-ml cultures, Gloeophyllum trabeum, Lentinus lepideus and Trametes versicolor produced little or no lignin peroxidase, manganese (Mn) peroxidase or laccase activity and caused no change to SWC6 coal. Ganoderma applanatum and Pycnoporus cinnabarinus also produced no detectable lignin or Mn peroxidases or laccase yet increased the absorbance at 400 nm of SWC6 coal. G. applanatum, which produced veratryl alcohol oxidase, also increased the modal apparent molecular mass. SWC6 coal exposed to Merulius tremellosus and Perenniporia tephropora, which secreted Mn peroxidases and laccase and Phanerochaete chrysosporium, which produced Mn and lignin peroxidases was polymerised but had unchanged or decreased absorbance. In the case of both P. chrysosporium and M. tremellosus, polymerisation of SWC6 coal was most extensive, leading to the formation of a complex insoluble in 100 mM NaOH. Rigidoporus ulmarius, which produced only laccase, both polymerised and reduced the A{sub 400} of SWC6 coal. P. chrysosporium, M. tremellosus and P. tephropora grown in 10-ml cultures produced a spectrum of oxidases similar to that in 15-ml cultures but, in each case, caused more extensive loss of A{sub 400}, and P. chrysosporium depolymerised SWC6 coal. It is concluded that the extracellular oxidases of white-rot fungi can transform low-rank coal macromolecules and that increased oxygen availability in the shallower 10-ml cultures favours catabolism over polymerisation. (orig.)

  11. Nucleic acid metabolism in hemopoietic tissues of polycythemic rats during long-term fractionated irradiation

    International Nuclear Information System (INIS)

    Mushkacheva, G.S.; Murzina, L.D.

    1980-01-01

    A study was made of the effect of long-term fractionated exposure with a daily dose of 50 R on the nucleic acid metabolism in hemopoietic tissues (bone marrow and spleen) of rats with erythropoiesis selectively inhibited by posttransfusion polycythemia. The comparison of present and previously obtained results enables us to conclude that the pathways of changes in the nucleic acid metabolism, which is responsible for hemopoiesis compensation during long-term exposure, are, in the main, similar for both white and red compartments of hemopoiesis

  12. Synthesis of Amide and Ester Derivatives of Cinnamic Acid and Its Analogs: Evaluation of Their Free Radical Scavenging and Monoamine Oxidase and Cholinesterase Inhibitory Activities.

    Science.gov (United States)

    Takao, Koichi; Toda, Kazuhiro; Saito, Takayuki; Sugita, Yoshiaki

    2017-01-01

    A series of cinnamic acid derivatives, amides (1-12) and esters (13-22), were synthesized, and structure-activity relationships for antioxidant activity, and monoamine oxidases (MAO) A and B, acetylcholinesterase, and butyrylcholinesterase (BChE) inhibitory activities were analyzed. Among the synthesized compounds, compounds 1-10, 12-18, and rosmarinic acid (23), which contained catechol, o-methoxyphenol or 5-hydroxyindole moieties, showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Compounds 9-11, 15, 17-22 showed potent and selective MAO-B inhibitory activity. Compound 20 was the most potent inhibitor of MAO-B. Compounds 18 and 21 showed moderate BChE inhibitory activity. In addition, compound 18 showed potent antioxidant activity and MAO-B inhibitory activity. In a comparison of the cinnamic acid amides and esters, the amides exhibited more potent DPPH free radical scavenging activity, while the esters showed stronger inhibitory activities against MAO-B and BChE. These results suggested that cinnamic acid derivatives such as compound 18, p-coumaric acid 3,4-dihydroxyphenethyl ester, and compound 20, p-coumaric acid phenethyl ester, may serve as lead compounds for the development of novel MAO-B inhibitors and candidate lead compounds for the prevention or treatment of Alzheimer's disease.

  13. Compositional and functional features of humic acid-like fractions from vermicomposting of sewage sludge and cow dung

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaowei [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Xing Meiyan, E-mail: xmy5000@163.com [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Yang Jian; Huang Zhidong [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2011-01-30

    The chemical changes occurring in five different substrates of sewage sludge spiked with different proportions of cow dung after vermicomposting with Eisenia foetida for 90 days were investigated. Their humic acid-like (HAL) fractions were isolated to determine the elemental and functional composition, and structural and functional characteristics using ultraviolet/visible, Fourier transform infrared (FT-IR) and fluorescence spectroscopies and scanning electron microscopy. After vermicomposting, the total organic C and C/N ratio decreased, and the total extractable C and humic acid (HA) C increased in all substrates. In the HAL fractions, the C and H contents, C/N and C/O and aliphatic structures, proteinaceous components and carbohydrates decreased, while the O and N and acidic functional group contents and C/H ratio, aromaticity and polycondensation structures increased. Further, the results suggest that the addition of cow dung to sewage sludge could improve the quality of organic matter humification of the substrates. The structures of HAL fractions in vermicomposts resembled those typical of soil HA, especially the vermicompost of cow dung alone. Scanning electron microscopy showed the microstructure of HAL fraction in final product became close-grained and lumpy. Overall results indicate that vermicomposting was an efficient technology for promoting organic matter (OM) humification in sewage sludge and cow dung alone, as well as in mixtures of both materials, improving their quality and environmental safety as a soil OM resource for utilization as soil amendments.

  14. Compositional and functional features of humic acid-like fractions from vermicomposting of sewage sludge and cow dung.

    Science.gov (United States)

    Li, Xiaowei; Xing, Meiyan; Yang, Jian; Huang, Zhidong

    2011-01-30

    The chemical changes occurring in five different substrates of sewage sludge spiked with different proportions of cow dung after vermicomposting with Eisenia foetida for 90 days were investigated. Their humic acid-like (HAL) fractions were isolated to determine the elemental and functional composition, and structural and functional characteristics using ultraviolet/visible, Fourier transform infrared (FT-IR) and fluorescence spectroscopies and scanning electron microscopy. After vermicomposting, the total organic C and C/N ratio decreased, and the total extractable C and humic acid (HA) C increased in all substrates. In the HAL fractions, the C and H contents, C/N and C/O and aliphatic structures, proteinaceous components and carbohydrates decreased, while the O and N and acidic functional group contents and C/H ratio, aromaticity and polycondensation structures increased. Further, the results suggest that the addition of cow dung to sewage sludge could improve the quality of organic matter humification of the substrates. The structures of HAL fractions in vermicomposts resembled those typical of soil HA, especially the vermicompost of cow dung alone. Scanning electron microscopy showed the microstructure of HAL fraction in final product became close-grained and lumpy. Overall results indicate that vermicomposting was an efficient technology for promoting organic matter (OM) humification in sewage sludge and cow dung alone, as well as in mixtures of both materials, improving their quality and environmental safety as a soil OM resource for utilization as soil amendments. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Compositional and functional features of humic acid-like fractions from vermicomposting of sewage sludge and cow dung

    International Nuclear Information System (INIS)

    Li Xiaowei; Xing Meiyan; Yang Jian; Huang Zhidong

    2011-01-01

    The chemical changes occurring in five different substrates of sewage sludge spiked with different proportions of cow dung after vermicomposting with Eisenia foetida for 90 days were investigated. Their humic acid-like (HAL) fractions were isolated to determine the elemental and functional composition, and structural and functional characteristics using ultraviolet/visible, Fourier transform infrared (FT-IR) and fluorescence spectroscopies and scanning electron microscopy. After vermicomposting, the total organic C and C/N ratio decreased, and the total extractable C and humic acid (HA) C increased in all substrates. In the HAL fractions, the C and H contents, C/N and C/O and aliphatic structures, proteinaceous components and carbohydrates decreased, while the O and N and acidic functional group contents and C/H ratio, aromaticity and polycondensation structures increased. Further, the results suggest that the addition of cow dung to sewage sludge could improve the quality of organic matter humification of the substrates. The structures of HAL fractions in vermicomposts resembled those typical of soil HA, especially the vermicompost of cow dung alone. Scanning electron microscopy showed the microstructure of HAL fraction in final product became close-grained and lumpy. Overall results indicate that vermicomposting was an efficient technology for promoting organic matter (OM) humification in sewage sludge and cow dung alone, as well as in mixtures of both materials, improving their quality and environmental safety as a soil OM resource for utilization as soil amendments.

  16. Biochemical, biological and molecular characterization of an L-Amino acid oxidase (LAAO) purified from Bothrops pictus Peruvian snake venom.

    Science.gov (United States)

    Lazo, Fanny; Vivas-Ruiz, Dan E; Sandoval, Gustavo A; Rodríguez, Edith F; Kozlova, Edgar E G; Costal-Oliveira, F; Chávez-Olórtegui, Carlos; Severino, Ruperto; Yarlequé, Armando; Sanchez, Eladio F

    2017-12-01

    An L-amino acid oxidase from Peruvian Bothrops pictus (Bpic-LAAO) snake venom was purified using a combination of size-exclusion and ion-exchange chromatography. Bpic-LAAO is a homodimeric glycosylated flavoprotein with molecular mass of ∼65 kDa under reducing conditions and ∼132 kDa in its native form as analyzed by SDS-PAGE and gel filtration chromatography, respectively. N-terminal amino acid sequencing showed highly conserved residues in a glutamine-rich motif related to binding substrate. The enzyme exhibited optimal activity towards L-Leu at pH 8.5, and like other reported SV-LAAOs, it is stable until 55 °C. Kinetic studies showed that the cations Ca 2+ , Mg 2+ and Mn 2+ did not alter Bpic-LAAO activity; however, Zn 2+ is an inhibitor. Some reagents such as β-mercaptoethanol, glutathione and iodoacetate had inhibitory effect on Bpic-LAAO activity, but PMSF, EDTA and glutamic acid did not affect its activity. Regarding the biological activities of Bpic-LAAO, this enzyme induced edema in mice (MED = 7.8 μg), and inhibited human platelet aggregation induced by ADP in a dose-dependent manner and showed antibacterial activity on Gram (+) and Gram (-) bacteria. Bpic-LAAO cDNA of 1494 bp codified a mature protein with 487 amino acid residues comprising a signal peptide of 11 amino acids. Finally, the phylogenetic tree obtained with other sequences of LAAOs, evidenced its similarity to other homologous enzymes, showing two well-established monophyletic groups in Viperidae and Elapidae families. Bpic-LAAO is evolutively close related to LAAOs from B. jararacussu, B. moojeni and B. atrox, and together with the LAAO from B. pauloensis, form a well-defined cluster of the Bothrops genus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Changes in the protein fraction of Merluccius bilinearis muscle under lactic acid bacterial fermentation using a Lactobacillus Acidophilus starter culture (ESP)

    OpenAIRE

    Elizondo, Luis J.

    2016-01-01

    The effect of lactic acid bacterial fermentation on the protein fraction of Merluccius bilinearis muscle was evaluated. The non-protein fraction increased progressively with corresponding decreases in the percentage protein (dry weight) indicating proteolytic activity during fermentation. Significant increases in the percentages of the amino acids cystine, isoleucine, phenylalanine and tyrosine were observed after two months of fermentation. Percentages of arginine decreased significantly aft...

  18. Cytotoxic, Anti-Proliferative and Apoptosis Activity of l-Amino Acid Oxidase from Malaysian Cryptelytrops purpureomaculatus (CP-LAAO) Venom on Human Colon Cancer Cells.

    Science.gov (United States)

    Zainal Abidin, Syafiq Asnawi; Rajadurai, Pathmanathan; Hoque Chowdhury, Md Ezharul; Othman, Iekhsan; Naidu, Rakesh

    2018-06-08

    The aim of this study is to investigate the potential anti-cancer activity of l-amino acid oxidase (CP-LAAO) purified from the venom of Cryptelytrops purpureomaculatus on SW480 and SW620 human colon cancer cells. Mass spectrometry guided purification was able to identify and purify CP-LAAO. Amino acid variations identified from the partial protein sequence of CP-LAAO may suggest novel variants of these proteins. The activity of the purified CP-LAAO was confirmed with o-phenyldiamine (OPD)-based spectrophotometric assay. CP-LAAO demonstrated time- and dose-dependent cytotoxic activity and the EC 50 value was determined at 13 µg/mL for both SW480 and SW620 cells. Significant increase of caspase-3 activity, reduction of Bcl-2 levels, as well as morphological changes consistent with apoptosis were demonstrated by CP-LAAO. Overall, these data provide evidence on the potential anti-cancer activity of CP-LAAO from the venom of Malaysian C. purpureomaculatus for therapeutic intervention of human colon cancer.

  19. Interaction of a snake venom L-amino acid oxidase with different cell types membrane.

    Science.gov (United States)

    Abdelkafi-Koubaa, Zaineb; Aissa, Imen; Morjen, Maram; Kharrat, Nadia; El Ayeb, Mohamed; Gargouri, Youssef; Srairi-Abid, Najet; Marrakchi, Naziha

    2016-01-01

    Snake venom l-amino acid oxidases are multifunctional enzymes that exhibited a wide range of pharmacological activities. Although it has been established that these activities are primarily caused by the H2O2 generated in the enzymatic reaction, the molecular mechanism, however, has not been fully investigated. In this work, LAAO interaction with cytoplasmic membranes using different cell types and Langmuir interfacial monolayers was evaluated. The Cerastes cerastes venom LAAO (CC-LAAO) did not exhibit cytotoxic activities against erythrocytes and peripheral blood mononuclear cells (PBMC). However, CC-LAAO caused cytotoxicity on several cancer cell lines and induced platelet aggregation in dose-dependent manner. Furthermore, the enzyme showed remarkable effect against Gram-positive and Gram-negative bacteria. These activities were inhibited on the addition of catalase or substrate analogs, suggesting that H2O2 liberation× is required for these effects. Binding studies revealed that CC-LAAO binds to the cell surface and enables the production of highly localized concentration of H2O2 in or near the binding interfaces. On another hand, the interaction of CC-LAAO with a mimetic phospholipid film was evaluated, for the first time, using a monomolecular film technique. Results indicated that phospholipid/CC-LAAO interactions are not involved in their binding to membrane and in their pharmacological activities. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Estimate of serum immunoglobulin G concentration using refractometry with or without caprylic acid fractionation.

    Science.gov (United States)

    Morrill, K M; Polo, J; Lago, A; Campbell, J; Quigley, J; Tyler, H

    2013-07-01

    Objectives of this study were to develop a rapid calf-side test to determine serum IgG concentrations using caprylic acid (CA) fractionation, followed by refractometry of the IgG-rich supernatant and compare the accuracy of this method with results obtained using refractometry using raw serum. Serum samples (n=200) were obtained from 1-d-old calves, frozen (-20°C), and shipped to the laboratory. Samples were allowed to thaw for 1h at room temperature. Fractionation with CA was conducted by adding 1mL of serum to a tube containing 45, 60, or 75µL of CA and 0.5, 1.0, or 1.5mL of 0.06 M acetic acid. The tube contents were mixed well, allowed to react for 1 min, and then centrifuged at 3,300 × g for 0, 10, or 20 min at 25°C. The %Brix and refractive index of the fractionated supernatant were determined using a digital refractometer. Nonfractionated serum was analyzed for %Brix (BRn), refractive index (nDn), and IgG concentration by radial immunodiffusion. The mean serum IgG concentration was 19.0 mg/mL [standard deviation (SD)=9.7], with a range of 3.5 to 47.0 mg/mL. The mean serum BRn was 8.6 (SD=0.91), with a range of 6.8 to 11.0. The mean serum nDn was 1.34566 (SD=0.00140), with a range of 1.34300 to 1.34930. Serum nDn was positively correlated with IgG concentration (correlation coefficient=0.86; n=185). Fractionated samples treated with 1mL 0.6 M acetic acid and 60µL of CA and not centrifuged before analysis resulted in a strong relationship between the refractive index of the fractionated supernatant and IgG (correlation coefficient=0.80; n=45). Regression was used to determine cut points indicative of 10, 12, and 14 mg of IgG/mL to determine the sensitivity and specificity of refractometry to identify failure of passive transfer (serum IgG refractometry of nonfractionated calf serum provides a strong estimate of IgG concentration and 7.8% Brix may be used as the cut point to identify failure of passive transfer in 1-d-old calves. Copyright © 2013 American

  1. Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats.

    Science.gov (United States)

    Balasubramanian, Thirumalaiswamy; Senthilkumar, G P; Karthikeyan, M; Chatterjee, Tapan Kumar

    2013-07-01

    Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

  2. D-Amino acid oxidase-induced oxidative stress, 3-bromopyruvate and citrate inhibit angiogenesis, exhibiting potent anticancer effects.

    Science.gov (United States)

    El Sayed, S M; El-Magd, R M Abou; Shishido, Y; Yorita, K; Chung, S P; Tran, D H; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

    2012-10-01

    Angiogenesis is critical for cancer growth and metastasis. Steps of angiogenesis are energy consuming, while vascular endothelial cells are highly glycolytic. Glioblastoma multiforme (GBM) is a highly vascular tumor and this enhances its aggressiveness. D-amino acid oxidase (DAO) is a promising therapeutic protein that induces oxidative stress upon acting on its substrates. Oxidative stress-energy depletion (OSED) therapy was recently reported (El Sayed et al., Cancer Gene Ther, 19, 1-18, 2012). OSED combines DAO-induced oxidative stress with energy depletion caused by glycolytic inhibitors such as 3-bromopyruvate (3BP), a hexokinase II inhibitor that depleted ATP in cancer cells and induced production of hydrogen peroxide. 3BP disturbs the Warburg effect and antagonizes effects of lactate and pyruvate (El Sayed et al., J Bioenerg Biomembr, 44, 61-79, 2012). Citrate is a natural organic acid capable of inhibiting glycolysis by targeting phosphofructokinase. Here, we report that DAO, 3BP and citrate significantly inhibited angiogenesis, decreased the number of vascular branching points and shortened the length of vascular tubules. OSED delayed the growth of C6/DAO glioma cells. 3BP combined with citrate delayed the growth of C6 glioma cells and decreased significantly the number and size of C6 glioma colonies in soft agar. Human GBM cells (U373MG) were resistant to chemotherapy e.g. cisplatin and cytosine arabinoside, while 3BP was effective in decreasing the viability and disturbing the morphology of U373MG cells.

  3. Irreversible inactivation of snake venom l-amino acid oxidase by covalent modification during catalysis of l-propargylglycine☆

    Science.gov (United States)

    Mitra, Jyotirmoy; Bhattacharyya, Debasish

    2013-01-01

    Snake venom l-amino acid oxidase (SV-LAAO, a flavor-enzyme) has attracted considerable attention due to its multifunctional nature, which is manifest in diverse clinical and biological effects such as inhibition of platelet aggregation, induction of cell apoptosis and cytotoxicity against various cells. The majority of these effects are mediated by H2O2 generated during the catalytic conversion of l-amino acids. The substrate analog l-propargylglycine (LPG) irreversibly inhibited the enzyme from Crotalus adamanteus and Crotalus atrox in a dose- and time-dependent manner. Inactivation was irreversible which was significantly protected by the substrate l-phenylalanine. A Kitz–Wilson replot of the inhibition kinetics suggested formation of reversible enzyme–LPG complex, which occurred prior to modification and inactivation of the enzyme. UV–visible and fluorescence spectra of the enzyme and the cofactor strongly suggested formation of covalent adduct between LPG and an active site residue of the enzyme. A molecular modeling study revealed that the FAD-binding, substrate-binding and the helical domains are conserved in SV-LAAOs and both His223 and Arg322 are the important active site residues that are likely to get modified by LPG. Chymotrypsin digest of the LPG inactivated enzyme followed by RP-HPLC and MALDI mass analysis identified His223 as the site of modification. The findings reported here contribute towards complete inactivation of SV-LAAO as a part of snake envenomation management. PMID:23772385

  4. Comparison of inferred fractions of n-3 and n-6 polyunsaturated fatty acids in feral domestic cat diets with those in commercial feline extruded diets.

    Science.gov (United States)

    Backus, Robert C; Thomas, David G; Fritsche, Kevin L

    2013-04-01

    To compare presumed fatty acid content in natural diets of feral domestic cats (inferred from body fat polyunsatrated fatty acids content) with polyunsaturated fatty acid content of commercial feline extruded diets. Subcutaneous and intra-abdominal adipose tissue samples (approx 1 g) from previously frozen cadavers of 7 adult feral domestic cats trapped in habitats remote from human activity and triplicate samples (200 g each) of 7 commercial extruded diets representing 68% of market share obtained from retail stores. Lipid, triacylglycerol, and phospholipid fractions in adipose tissue samples and ether extracts of diet samples were determined by gas chromatography of methyl esters. Triacylglycerol and phospholipid fractions in the adipose tissue were isolated by thin-layer chromatography. Diet samples were also analyzed for proximate contents. For the adipose tissue samples, with few exceptions, fatty acids fractions varied only moderately with lipid fraction and site from which tissue samples were obtained. Linoleic, α-linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic acid fractions were 15.0% to 28.2%, 4.5% to 18.7%, 0.9% to 5.0%, feral cat diets, in which dietary n-3 and possibly n-6 polyunsaturated fatty acids were more abundant. The impact of this difference on the health of pet cats is not known.

  5. Lower Growth Temperature Increases Alternative Pathway Capacity and Alternative Oxidase Protein in Tobacco 1

    Science.gov (United States)

    Vanlerberghe, Greg C.; McIntosh, Lee

    1992-01-01

    Suspension cells of NT1 tobacco (Nicotiana tabacum L. cv bright yellow) have been used to study the effect of growth temperature on the CN-resistant, salicylhydroxamic acid-sensitive alternative pathway of respiration. Mitochondria isolated from cells maintained at 30°C had a low capacity to oxidize succinate via the alternative pathway, whereas mitochondria isolated from cells 24 h after transfer to 18°C displayed, on average, a 5-fold increase in this capacity (from 7 to 32 nanoatoms oxygen per milligram protein per minute). This represented an increase in alternative pathway capacity from 18 to 45% of the total capacity of electron transport. This increased capacity was lost upon transfer of cells back to 30°C. A monoclonal antibody to the terminal oxidase of the alternative pathway (the alternative oxidase) from Sauromatum guttatum (T.E. Elthon, R.L. Nickels, L. McIntosh [1989] Plant Physiology 89: 1311-1317) recognized a 35-kilodalton mitochondrial protein in tobacco. There was an excellent correlation between the capacity of the alternative path in isolated tobacco mitochondria and the levels of this 35-kilodalton alternative oxidase protein. Cycloheximide could inhibit both the increased level of the 35-kilodalton alternative oxidase protein and the increased alternative pathway capacity normally seen upon transfer to 18°C. We conclude that transfer of tobacco cells to the lower temperature increases the capacity of the alternative pathway due, at least in part, to de novo synthesis of the 35-kilodalton alternative oxidase protein. Images Figure 3 Figure 4 PMID:16652932

  6. Releasing Pattern of Applied Phosphorus and Distribution Change of Phosphorus Fractions in the Acid Upland Soils with Successive Resin Extraction

    Directory of Open Access Journals (Sweden)

    Arief Hartono

    2008-05-01

    Full Text Available The releasing pattern of applied P in the acid upland soils and the soil properties influencing the pattern were studied. Surface horizons of six acid upland soils from Sumatra, Java and Kalimantan were used in this study. The releasing pattern of applied P (300 mg P kg-1 of these soils were studied by successive resin extraction. P fractionation was conducted to evaluate which fractions released P to the soil solution after successive resin extraction. The cumulative of resin-Pinorganic (Pi release of soils was fitted to the first order kinetic. Regression analyses using factor scores obtained from the previous principal components analyses was applied to determine soil properties influencing P releasing pattern. The results suggested that the maximum P release was significantly (P < 0.05 increased by acidity plus 1.4 nm mineral-related factor (PC2 i.e. exchangeable Al and 1.4 nm minerals (smectite and vermiculite and decreased by oxide related factor (PC1 i.e. aluminum (Al plus 1/2 iron (Fe (by ammonium oxalate, crystalline Al and Fe oxides, cation exchange capacity, and clay content. P fractionation analysis after successive resin extraction showed that both labile and less labile in the form of NaHCO3-Pi and NaOH-Pi fractions, respectively, can be transformed into resin-Pi when in the most labile resin-Pi is depleted. Most of P released in high oxides soils were from NaOH-Pi fraction while in low oxides soils were from NaHCO3-Pi. P release from the former fraction resulted in the maximum P release lower than that of the latter one. When NaHCO3-Pi was high, NaOH-Pi was relatively more stable than NaHCO3-Pi despite resin-Pi removal. NaHCO3-Pi and NaOH-Pi are very important P fractions in replenishing resin-Pi in these acid upland soils.

  7. Covalently bound phosphate residues in bovine milk xanthine oxidase and in glucose oxidase from Aspergillus niger: A reevaluation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.L.; Rajagopalan, K.V. (Duke Univ. Medical Center, Durham, NC (USA)); London, R.E. (National Institute of Environmental Health Science, Research Triangle Park, NC (USA))

    1989-09-01

    The reported presence of covalently bound phosphate residues in flavoproteins has significant implications with regard to the catalytic mechanisms and structural stability of the specific enzymes themselves and in terms of general cellular metabolic regulation. These considerations have led to a reevaluation of the presence of covalently bound phosphorus in the flavoproteins xanthine oxidase and glucose oxidase. Milk xanthine oxidase purified by a procedure that includes anion-exchange chromatography is shown to contain three phosphate residues. All three are noncovalently associated with the protein, two with the FAD cofactor, and one with the molybdenum cofactor. Results of chemical analysis and {sup 31}P NMR spectroscopy indicate that enzyme purified by this method contains no phosphoserine residues. Xanthine oxidase preparations purified by chromatography on calcium phosphate gel in place of DEAE-Sephadex yielded higher phosphate-to-protein ratios, which could be reduced to the expected values by additional purification on a folate affinity column. Highly active, highly purified preparations of glucose oxidase are shown to contain only the two phosphate residues of the FAD cofactor. The covalently bound bridging phosphate reported by others may arise in aged or degraded preparations of the enzyme but appears not to be a constituent of functional glucose oxidase. These results suggest that the presence of covalent phosphate residues in other flavoproteins should be rigorously reevaluated as well.

  8. Covalently bound phosphate residues in bovine milk xanthine oxidase and in glucose oxidase from Aspergillus niger: A reevaluation

    International Nuclear Information System (INIS)

    Johnson, J.L.; Rajagopalan, K.V.; London, R.E.

    1989-01-01

    The reported presence of covalently bound phosphate residues in flavoproteins has significant implications with regard to the catalytic mechanisms and structural stability of the specific enzymes themselves and in terms of general cellular metabolic regulation. These considerations have led to a reevaluation of the presence of covalently bound phosphorus in the flavoproteins xanthine oxidase and glucose oxidase. Milk xanthine oxidase purified by a procedure that includes anion-exchange chromatography is shown to contain three phosphate residues. All three are noncovalently associated with the protein, two with the FAD cofactor, and one with the molybdenum cofactor. Results of chemical analysis and 31 P NMR spectroscopy indicate that enzyme purified by this method contains no phosphoserine residues. Xanthine oxidase preparations purified by chromatography on calcium phosphate gel in place of DEAE-Sephadex yielded higher phosphate-to-protein ratios, which could be reduced to the expected values by additional purification on a folate affinity column. Highly active, highly purified preparations of glucose oxidase are shown to contain only the two phosphate residues of the FAD cofactor. The covalently bound bridging phosphate reported by others may arise in aged or degraded preparations of the enzyme but appears not to be a constituent of functional glucose oxidase. These results suggest that the presence of covalent phosphate residues in other flavoproteins should be rigorously reevaluated as well

  9. Some enzymatic properties of cholesterol oxidase produced by Brevibacterium sp Algumas propriedades enzimáticas da colesterol oxidase produzida por Brevibacterium sp.

    Directory of Open Access Journals (Sweden)

    Terezinha J.G. Salva

    1999-12-01

    Full Text Available In this study we determined some properties of the cholesterol oxidase from a Brevibacterium strain isolated from buffalo's milk and identified the cholesterol degradation products by the bacterial cell. A small fraction of the enzyme synthesized by cells cultured in liquid medium for 7days was released into the medium whereas a larger fraction remained bound to the cell membrane. The extraction of this fraction was efficiently accomplished in 1 mM phosphate buffer, pH 7.0, containing 0.7% Triton X-100. The enzyme stability under freezing and at 45oC was improved by addition of 20% glycerol. The optimum temperature and pH for the enzyme activity were 53°C and 7.5, respectively. The only steroidal product from cholesterol oxidation by the microbial cell and by the crude extract of the membrane-bound enzyme was 4-colesten-3-one. Chromatographic analysis showed that minor no steroidal compounds as well as 4-colesten-3-one found in the reaction media arose during fermentation process and were extracted together with the enzyme in the buffer solution. Cholesterol oxidation by the membrane-bound enzyme was a first order reaction type.Neste trabalho foram definidas algumas propriedades da enzima colesterol oxidase produzida por uma linhagem de Brevibacterium sp. isolada de leite de búfala e foram identificados os compostos resultantes da degradação do colesterol pela bactéria. Uma pequena fração da enzima sintetizada pelas células cultivadas em meio líquido por 7 dias foi liberada no meio de cultura e uma fração maior permaneceu ligada à membrana celular. A extração desta fração foi eficientemente efetuada em tampão fosfato 1mM, pH 7,0, contendo 0,7% de triton X-100. A estabilidade da enzima congelada e a 45oC foi aumentada pela adição de 20% de glicerol. A temperatura ótima para a atividade enzimática esteve ao redor de 53(0C e o pH ótimo esteve ao redor de 7,5. O único produto da degradação do colesterol, causada pela a

  10. Bioelectrocatalytic mediatorless dioxygen reduction at carbon ceramic electrodes modified with bilirubin oxidase

    International Nuclear Information System (INIS)

    Nogala, Wojciech; Celebanska, Anna; Szot, Katarzyna; Wittstock, Gunther; Opallo, Marcin

    2010-01-01

    Carbon ceramic electrodes were prepared by sol-gel processing of a hydrophobic precursor - methyltrimethoxysilane (MTMOS) - together with dispersed graphite microparticles according to a literature procedure. Bilirubin oxidase (BOx) was adsorbed on this electrode from buffer solution and this process was followed by atomic force microscopy (AFM). The electrodes exhibited efficient mediatorless electrocatalytic activity towards dioxygen reduction. The activity depends on the time of adsorption of the enzyme and the pH. The electrode remains active in neutral solution. The bioelectrocatalytic activity is further increased when a fraction of the carbon microparticles is replaced by sulfonated carbon nanoparticles (CNPs). This additive enhances the electrical communication between the enzyme and the electronic conductor. At pH 7 the carbon ceramic electrode modified with bilirubin oxidase retains ca. half of its highest activity. The role of the modified nanoparticles is confirmed by experiments in which a film embedded in a hydrophobic silicate matrix also exhibited efficient mediatorless biocatalytic dioxygen reduction. Scanning electrochemical microscopy (SECM) of the studied electrodes indicated a rather even distribution of the catalytic activity over the electrode surface.

  11. Submitochondrial distributions and stabilities of subunits 4, 5, and 6 of yeast cytochrome oxidase in assembly defective mutants.

    Science.gov (United States)

    Glerum, D M; Tzagoloff, A

    1997-08-04

    The concentration and submitochondrial distribution of the subunit polypeptides of cytochrome oxidase have been studied in wild type yeast and in different mutants impaired in assembly of this respiratory complex. All the subunit polypeptides of the enzyme are associated with mitochondrial membranes of wild type cells, except for a small fraction of subunits 4 and 6 that is recovered in the soluble protein fraction of mitochondria. Cytochrome oxidase mutants consistently display a severe reduction in the steady-state concentration of subunit 1 due to its increased turnover. As a consequence, most of subunit 4, which normally is associated with subunit 1, is found in the soluble fraction. A similar shift from membrane-bound to soluble subunit 6 is seen in mutants blocked in expression of subunit 5a. In contrast, null mutations in COX6 coding for subunit 6 promote loss of subunit 5a. The absence of subunit 5a in the cox6 mutant is the result of proteolytic degradation rather than regulation of its expression by subunit 6. The possible role of the ATP-dependent proteases Rca1p and Afg3p in proteolysis of subunits 1 and 5a has been assessed in strains with combined mutations in COX6, RCA1, and/or AFG3. Immunochemical assays indicate that another protease(s) must be responsible for most of the proteolytic loss of these proteins.

  12. Characterization of polyphenol oxidase from blueberry (Vaccinium corymbosum L.).

    Science.gov (United States)

    Siddiq, M; Dolan, K D

    2017-03-01

    Polyphenol oxidase (PPO) was extracted and characterized from high-bush blueberries. PPO showed an optimum activity at pH 6.1-6.3 and 35°C, with the enzyme showing significant activity over a wide temperature range (25-60°C). Catechol was the most readily oxidized substrate followed by 4-methylcatechol, DL-DOPA, and dopamine. Blueberry PPO showed a K m of 15mM and V max of 2.57 ΔA 420 nm/min×10 -1 , determined with catechol. PPO was completely inactivated in 20min at 85°C, however, after 30minat 75°C it showed about 10% residual activity. Thermal treatment at 55 and 65°C for 30min resulted in the partial inactivation of PPO. Ascorbic acid, sodium diethyldithiocarbamic acid, L-cysteine, and sodium metabisulfite were effective inhibitors of PPO at 1.0mM. Benzoic acid and cinnamic acid series inhibitors showed relatively weak inhibition of PPO (21.8-27.6%), even at as high as 2.0mM concentration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Effects of hematopoietic stem cell transplantation on acyl-CoA oxidase deficiency: a sibling comparison study

    NARCIS (Netherlands)

    Wang, Raymond Y.; Monuki, Edwin S.; Powers, James; Schwartz, Phillip H.; Watkins, Paul A.; Shi, Yang; Moser, Ann; Shrier, David A.; Waterham, Hans R.; Nugent, Diane J.; Abdenur, Jose E.

    2014-01-01

    Acyl-CoA oxidase (ACOX1) deficiency is a rare disorder of peroxisomal very-long chain fatty acid oxidation. No reports detailing attempted treatment, longitudinal imaging, or neuropathology exist. We describe the natural history of clinical symptoms and brain imaging in two siblings with ACOX1

  14. Polyphenol Oxidase Enzyme and Inactivation Methods

    Directory of Open Access Journals (Sweden)

    Leman Yılmaz

    2018-03-01

    Full Text Available Polyphenol oxidase enzyme is found in vegetables and fruits, as well as in some animal organs and microorganisms. Polyphenol oxidase enzyme responsible for enzymatic browning is a group of copper proteins that catalyses the oxidation of phenolic compounds to quinones, which produce brown pigments, commonly found in fruits and vegetables. During the industrial preparation of fruits and vegetables, results of catalytic effect of polyphenol oxidase causes enzymatic browning. Enzymatic browning impairs the appearance of products containing phenolic compounds along with undesirable colour, odor and taste formation and significant loss of nutritional value of the products. This affects the acceptability of the products by the consumers and causes economic losses. In this review, some characteristics of polyphenol oxidase enzyme in different fruits and vegetables have been reviewed and information about chemical antibrowning agents, thermal applications, irradiation applications and alternative methods such as high pressure processing, pulse electric field, supercritical carbon dioxide and ultrasound applications to inactivate this enzyme has been presented.

  15. Low acid hydrothermal fractionation of Giant Miscanthus for production of xylose-rich hydrolysate and furfural.

    Science.gov (United States)

    Kim, Tae Hyun; Ryu, Hyun Jin; Oh, Kyeong Keun

    2016-10-01

    Low acid hydrothermal (LAH) fractionation was developed for the effective recovery of hemicellulosic sugar (mainly xylose) from Miscanthus sacchariflorus Goedae-Uksae 1 (M. GU-1). The xylose yield was maximized at 74.75% when the M. GU-1 was fractionated at 180°C and 0.3wt.% of sulfuric acid for 10min. At this condition, the hemicellulose (mainly xylan) degradation was 86.41%. The difference between xylan degradation and xylose recovery yield, i.e., xylan loss, was 11.66%, as indicated by the formation of decomposed products. The furfural, the value added biochemical product, was also obtained by 0.42g/L at this condition, which was 53.82% of furfural production yield based on the xylan loss. After then, the furfural production continued to increase to a maximum concentration of 1.87g/L, at which point the xylan loss corresponded to 25.87%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Study of dynamics of glucose-glucose oxidase-ferricyanide reaction

    Science.gov (United States)

    Nováková, A.; Schreiberová, L.; Schreiber, I.

    2011-12-01

    This work is focused on dynamics of the glucose-glucose oxidase-ferricyanide enzymatic reaction with or without sodium hydroxide in a continuous-flow stirred tank reactor (CSTR) and in a batch reactor. This reaction exhibits pH-variations having autocatalytic character and is reported to provide nonlinear dynamic behavior (bistability, excitability). The dynamical behavior of the reaction was examined within a wide range of inlet parameters. The main inlet parameters were the ratio of concentrations of sodium hydroxide and ferricyanide and the flow rate. In a batch reactor we observed an autocatalytic drop of pH from slightly basic to medium acidic values. In a CSTR our aim was to find bistability in the presence of sodium hydroxide. However, only a basic steady state was found. In order to reach an acidic steady state, we investigated the system in the absence of sodium hydroxide. Under these conditions the transition from the basic to the acidic steady state was observed when inlet glucose concentration was increased.

  17. The terminal oxidases of Paracoccus denitrificans

    NARCIS (Netherlands)

    de Gier, J.-W.; Lübben, M; Reijnders, W N; Tipker, C A; Slotboom, D.J.; van Spanning, R J; Stouthamer, A.H.; van der Oost, J.

    Three distinct types of terminal oxidases participate in the aerobic respiratory pathways of Paracoccus denitrificans. Two alternative genes encoding subunit I of the aa3-type cytochrome c oxidase have been isolated before, namely ctaDI and ctaDII. Each of these genes can be expressed separately to

  18. Multivariate data analysis for finding the relevant fatty acids contributing to the melting fractions of cream

    DEFF Research Database (Denmark)

    Buldo, Patrizia; Larsen, Mette Krogh; Wiking, Lars

    2013-01-01

    :0 and palmitoleic acid (C16:1) in milk fat, whereas it decreased the amount of stearic acid (C18:0) and C18:1 trans fatty acid. Average data on the melting behaviour of cream separated the farms into two groups where the main differences in feeding were the amounts of maize silage and rapeseed cake used. CONCLUSION......BACKGROUND: The melting behaviour and fatty acid composition of cream from a total of 33 cows from four farms were analysed. Multivariate data analysis was used to identify the fatty acids that contributed most to the melting points and to differentiate between creams from different practical...... feeding regimes. RESULTS: It was demonstrated that the melting point of the medium melting fraction of milk fat was positively correlated with palmitic acid (C16:0), whereas it was negatively correlated with oleic acid (C18:1 cis9), conjugated linoleic acid (CLA cis9 trans11), vaccenic acid (C18:1 trans11...

  19. Quantitation of immunoadsorbed flavoprotein oxidases by luminol-mediated chemiluminescence.

    Science.gov (United States)

    Hinkkanen, A; Maly, F E; Decker, K

    1983-04-01

    The detection of the flavoenzymes 6-hydroxy-L-nicotine oxidase and 6-hydroxy-D-nicotine oxidase at the sub-femtomol level was achieved by coupling the reaction of the immunoadsorbed proteins to the peroxidase-catalysed oxidation of luminol. The H2O2-producing oxidases retained their full activity when bound to the respective immobilized antibodies. This fact allowed the concentration of the enzymes from very dilute solutions and the quantitative assay of their activities in the microU range. Due to strict stereoselectivity and the absence of immunological cross-reactivity, the two flavoproteins could be determined in the same solution. This method was used to measure the 6-hydroxy-D-nicotine oxidase and 6-hydroxy-L-nicotine oxidase activities in Escherichia coli RR1 and different Arthrobacter strains cultured under non-inducing conditions. The same activity ratio of 6-hydroxy-L-nicotine oxidase/6-hydroxy-D-nicotine oxidase as in D L-nicotine-induced cells of A. oxidans was observed in non-induced wild type and in riboflavin-requiring (rf-) mutant cells of this aerob.

  20. Identification and characterization of aldehyde oxidases (AOXs) in the cotton bollworm

    Science.gov (United States)

    Xu, Wei; Liao, Yalin

    2017-12-01

    Aldehyde oxidases (AOXs) are a family of metabolic enzymes that oxidize aldehydes into carboxylic acids; therefore, they play critical roles in detoxification and degradation of chemicals. By using transcriptomic and genomic approaches, we successfully identified six putative AOX genes (HarmAOX1-6) from cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). In silico expression profile, reverse transcription (RT)-PCR, and quantitative PCR (qPCR) analyses showed that HarmAOX1 is highly expressed in adult antennae, tarsi, and larval mouthparts, so they may play an important role in degrading plant-derived compounds. HarmAOX2 is highly and specifically expressed in adult antennae, suggesting a candidate pheromone-degrading enzyme (PDE) to inactivate the sex pheromone components (Z)-11-hexadecenal and (Z)-9-hexadecenal. RNA sequencing data further demonstrated that a number of host plants they feed on could significantly upregulate the expression levels of HarmAOX1 in larvae. This study improves our understanding of insect aldehyde oxidases and insect-plant interactions.

  1. Changes in the protein fraction of Merluccius bilinearis muscle under lactic acid bacterial fermentation using a Lactobacillus Acidophilus starter culture (ESP

    Directory of Open Access Journals (Sweden)

    Luis J. Elizondo

    2016-03-01

    Full Text Available The effect of lactic acid bacterial fermentation on the protein fraction of Merluccius bilinearis muscle was evaluated. The non-protein fraction increased progressively with corresponding decreases in the percentage protein (dry weight indicating proteolytic activity during fermentation. Significant increases in the percentages of the amino acids cystine, isoleucine, phenylalanine and tyrosine were observed after two months of fermentation. Percentages of arginine decreased significantly after one week and again after two months of fermentation.

  2. Secreted fungal sulfhydryl oxidases: sequence analysis and characterisation of a representative flavin-dependent enzyme from Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Faccio Greta

    2010-08-01

    Full Text Available Abstract Background Sulfhydryl oxidases are flavin-dependent enzymes that catalyse the formation of de novo disulfide bonds from free thiol groups, with the reduction of molecular oxygen to hydrogen peroxide. Sulfhydryl oxidases have been investigated in the food industry to remove the burnt flavour of ultraheat-treated milk and are currently studied as potential crosslinking enzymes, aiming at strengthening wheat dough and improving the overall bread quality. Results In the present study, potential sulfhydryl oxidases were identified in the publicly available fungal genome sequences and their sequence characteristics were studied. A representative sulfhydryl oxidase from Aspergillus oryzae, AoSOX1, was expressed in the fungus Trichoderma reesei. AoSOX1 was produced in relatively good yields and was purified and biochemically characterised. The enzyme catalysed the oxidation of thiol-containing compounds like glutathione, D/L-cysteine, beta-mercaptoethanol and DTT. The enzyme had a melting temperature of 57°C, a pH optimum of 7.5 and its enzymatic activity was completely inhibited in the presence of 1 mM ZnSO4. Conclusions Eighteen potentially secreted sulfhydryl oxidases were detected in the publicly available fungal genomes analysed and a novel proline-tryptophan dipeptide in the characteristic motif CXXC, where X is any amino acid, was found. A representative protein, AoSOX1 from A. oryzae, was produced in T. reesei in an active form and had the characteristics of sulfhydryl oxidases. Further testing of the activity on thiol groups within larger peptides and on protein level will be needed to assess the application potential of this enzyme.

  3. Secreted fungal sulfhydryl oxidases: sequence analysis and characterisation of a representative flavin-dependent enzyme from Aspergillus oryzae.

    Science.gov (United States)

    Faccio, Greta; Kruus, Kristiina; Buchert, Johanna; Saloheimo, Markku

    2010-08-20

    Sulfhydryl oxidases are flavin-dependent enzymes that catalyse the formation of de novo disulfide bonds from free thiol groups, with the reduction of molecular oxygen to hydrogen peroxide. Sulfhydryl oxidases have been investigated in the food industry to remove the burnt flavour of ultraheat-treated milk and are currently studied as potential crosslinking enzymes, aiming at strengthening wheat dough and improving the overall bread quality. In the present study, potential sulfhydryl oxidases were identified in the publicly available fungal genome sequences and their sequence characteristics were studied. A representative sulfhydryl oxidase from Aspergillus oryzae, AoSOX1, was expressed in the fungus Trichoderma reesei. AoSOX1 was produced in relatively good yields and was purified and biochemically characterised. The enzyme catalysed the oxidation of thiol-containing compounds like glutathione, D/L-cysteine, beta-mercaptoethanol and DTT. The enzyme had a melting temperature of 57°C, a pH optimum of 7.5 and its enzymatic activity was completely inhibited in the presence of 1 mM ZnSO4. Eighteen potentially secreted sulfhydryl oxidases were detected in the publicly available fungal genomes analysed and a novel proline-tryptophan dipeptide in the characteristic motif CXXC, where X is any amino acid, was found. A representative protein, AoSOX1 from A. oryzae, was produced in T. reesei in an active form and had the characteristics of sulfhydryl oxidases. Further testing of the activity on thiol groups within larger peptides and on protein level will be needed to assess the application potential of this enzyme.

  4. Antiproliferative activity of king cobra (Ophiophagus hannah) venom L-amino acid oxidase.

    Science.gov (United States)

    Li Lee, Mui; Chung, Ivy; Yee Fung, Shin; Kanthimathi, M S; Hong Tan, Nget

    2014-04-01

    King cobra (Ophiophagus hannah) venom L-amino acid oxidase (LAAO), a heat-stable enzyme, is an extremely potent antiproliferative agent against cancer cells when compared with LAAO isolated from other snake venoms. King cobra venom LAAO was shown to exhibit very strong antiproliferative activities against MCF-7 (human breast adenocarcinoma) and A549 (human lung adenocarcinoma) cells, with an IC50 value of 0.04±0.00 and 0.05±0.00 μg/mL, respectively, after 72-hr treatment. In comparison, its cytotoxicity was about 3-4 times lower when tested against human non-tumourigenic breast (184B5) and lung (NL 20) cells, suggesting selective antitumour activity. Furthermore, its potency in MCF-7 and A549 cell lines was greater than the effects of doxorubicin, a clinically established cancer chemotherapeutic agent, which showed an IC50 value of 0.18±0.03 and 0.63±0.21 μg/mL, respectively, against the two cell lines. The selective cytotoxic action of the LAAO was confirmed by phycoerythrin (PE) annexin V/7-amino-actinomycin (AAD) apoptotic assay, in which a significant increase in apoptotic cells was observed in LAAO-treated tumour cells than in their non-tumourigenic counterparts. The ability of LAAO to induce apoptosis in tumour cells was further demonstrated using caspase-3/7 and DNA fragmentation assays. We also determined that this enzyme may target oxidative stress in its killing of tumour cells, as its cytotoxicity was significantly reduced in the presence of catalase (a H2O2 scavenger). In view of its heat stability and selective and potent cytotoxic action on cancer cells, king cobra venom LAAO can be potentially developed for treating solid tumours. © 2013 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  5. Evaluation of the antifungal activity and mode of action of Lafoensia pacari A. St.-Hil., Lythraceae, stem-bark extracts, fractions and ellagic acid

    Directory of Open Access Journals (Sweden)

    Iberê F. Silva Junior

    Full Text Available Stem-bark extracts, fractions and the isolated constituent, ellagic acid of Lafoensia pacari St. Hil. (Lythraceae were in vitro assayed for antifungal activity against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the microbroth dilution method. The EtOH extract and its fractions and ellagic acid exhibited activity against Candida spp and Saccharomyces cerevisiae with MIC values between 250-1000 µg/mL, but they showed no action against filamentous fungi and dermatophytes (MIC>1000 µg/mL. Active extracts were evaluated in Neurospora crassa hyphal growth inhibition and sorbitol assays and then the effect of ergosterol on the MIC of ellagic acid was studied. The active extracts and its fractions and ellagic acid showed a blotchy zone around the paper disk and induced malformations of the hypha. Besides, MIC of the ellagic acid against the Saccharomyces cerevisiae was raised from 62 to 250 µg/mL in the presence of sorbitol 0.8 M, suggesting that the ellagic acid would probably exert its action on fungal cell wall. These results indicate that ellagic acid might be the main active antifungal compound of Lafoensia pacari and further suggest that the mode of antifungal action of these extracts and ellagic acid could be associated with the inhibition of fungal cell wall.

  6. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost

    Energy Technology Data Exchange (ETDEWEB)

    Scaglia, Barbara, E-mail: barbara.scaglia@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira [Laboratório de Química Ambiental, Universidade de São Paulo, Instituto de Química de São Carlos, Avenida Trabalhador São Carlense, 400, São Carlos (Brazil); Tambone, Fulvia [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Adani, Fabrizio, E-mail: fabrizio.adani@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy)

    2016-08-15

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100–6000 mg carbon L{sup −1}. {sup 13}C CPMAS-NMR and GC–MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS {sup 13}CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R{sup 2} = − 0.85; p < 0.01, n = 6). - Highlights: • Vermicomposting converts waste into organic fertilizer. • Vermicomposts can have biostimulating effect for the presence of hormone-like molecules. • Auxine-like activity was associated to the vermicompost humic acid fraction (HA). • HA carboxylic acids and amino acids, were reported to act as auxin-like molecules. • A linear regression was found between molecules and auxin-like activity.

  7. Purification and characterization of amine oxidase from soybean seedlings.

    Science.gov (United States)

    Vianello, F; Di Paolo, M L; Stevanato, R; Gasparini, R; Rigo, A

    1993-11-15

    A simple and rapid procedure for purification of soybean seedling amine oxidase is reported. The crude enzyme, obtained by ammonium sulfate fractionation was purified by ion-exchange chromatography on a cellulose phosphate column and batch affinity chromatography on 6-aminohexyl-Sepharose. Cyclohexylamine, a competitive inhibitor, was utilized to elute the enzyme. A homogeneous enzyme was obtained with a yield higher than 25%, the content of minor components being lauryl sulfate-polyacrylamide gel electrophoresis. The enzyme is a dimer and contains two Cu2+ ion per molecule. Its EPR spectrum is typical of Cu2+ in a tetragonal symmetry. The enzyme oxidizes cadaverine at high rate, the specific activity being 4.3 mukat/mg. Molecular, spectroscopic, and kinetic properties of this enzyme are reported.

  8. Inhibition of MAO by fractions and constituents of hypericum extract.

    Science.gov (United States)

    Bladt, S; Wagner, H

    1994-10-01

    The inhibition of monoamine oxidase (MAO) by six fractions from hypericum extract and three characteristic constituents (as pure substances) were analyzed in vitro and ex vivo to study the antidepressive mechanism of action. Rat brain homogenates were used as the in vitro model, while the ex vivo analysis was performed after intraperitoneal application of the test substances to albino rats. Massive inhibition of MAO-A could be shown with the total extract and all fractions only at the concentration of 10(-3) mol/L. At 10(-4) mol/L, one fraction rich in flavonoides showed an inhibition of 39%, and all other fractions demonstrated less than 25% inhibition. Using pure hypericin as well as in all ex vivo experiments, no relevant inhibiting effects could be shown. From the results it can be concluded that the clinically proven antidepressive effect of hypericum extract cannot be explained in terms of MAO inhibition.

  9. Fluorescence of soil humic acids and their fractions obtained by tandem size exclusion chromatography-polyacrylamide gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Trubetskaya, O. [Russian Academy of Sciences, Moscow Region (Russian Federation). Shemyakin and Ovchinnikov Inst. of Bioorganic Chemistry; Trubetskoj, O. [Russian Academy of Sciences, Moscow Region (Russian Federation). Inst. of Basic Biological Problems; Guyot, G.; Richard, C. [UMR CNRS 6505, Aubiere (France). Lab. de Photochimie Moleculaire et Macromoleculaire; Andreux, F. [Centre des Sciences de la Terre, Dijon (France)

    2002-07-01

    Humic acids (HAs) extracted from soils of different origin (chernozem, ferralsol and ranker) and their fractions (A, B and C+D) obtained by tandem size exclusion chromatography-polyacrylamide gel electrophoresis were investigated by steady-state fluorescence spectroscopy in the emission mode. Independently of HA source, high molecular size fractions A and B are shown to be weakly fluorescent. The main fluorophores, especially those emitting at long wavelength (around 500-510 nm), are contained in the polar and low molecular size fractions C+D. As indicated by the observed pH effect, aromatic structures bearing carboxylate and OH substituents may be involved in these longer wavelength emissions. [author].

  10. Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Thirumalaiswamy Balasubramanian

    2013-07-01

    Full Text Available Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST, alanine transaminase (ALT, and serum alkaline phosphatase (SALP were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS, reduced glutathione (GSH, superoxide dismutase (SOD, and catalase (CAT. It was found that administration of ethyl acetate fraction (200 and 400 mg/kg produced a significant (P<0.001 fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

  11. Purification and antibacterial activities of an L-amino acid oxidase from king cobra (Ophiophagus hannah venom

    Directory of Open Access Journals (Sweden)

    CS Phua

    2012-01-01

    Full Text Available Some constituents of snake venom have been found to display a variety of biological activities. The antibacterial property of snake venom, in particular, has gathered increasing scientific interest due to antibiotic resistance. In the present study, king cobra venom was screened against three strains of Staphylococcus aureus [including methicillin-resistant Staphylococcus aureus (MRSA], three other species of gram-positive bacteria and six gram-negative bacteria. King cobra venom was active against all the 12 bacteria tested, and was most effective against Staphylococcus spp. (S. aureus and S. epidermidis. Subsequently, an antibacterial protein from king cobra venom was purified by gel filtration, anion exchange and heparin chromatography. Mass spectrometry analysis confirmed that the protein was king cobra L-amino acid oxidase (Oh-LAAO. SDS-PAGE showed that the protein has an estimated molecular weight of 68 kDa and 70 kDa under reducing and non-reducing conditions, respectively. The minimum inhibitory concentrations (MIC of Oh-LAAO for all the 12 bacteria were obtained using radial diffusion assay method. Oh-LAAO had the lowest MIC value of 7.5 µg/mL against S. aureus ATCC 25923 and ATCC 29213, MRSA ATCC 43300, and S. epidermidis ATCC 12228. Therefore, the LAAO enzyme from king cobra venom may be useful as an antimicrobial agent.

  12. Gamma irradiation of mushrooms, preliminary studies: effect on O-diphenyl oxidase activity and amino acid content

    International Nuclear Information System (INIS)

    Bachman, S.; Gebicka, L.

    1992-01-01

    Mushrooms are a valuable food raw materials because of their nutritional and taste values. Post-harvest ripening, chemical composition (94% water) and possible microbial contamination decrease not only organoleptic and nutritional value, but also the shelf-life. As an objective method of evaluation of irradiated mushrooms we adopted activity determination of o-diphenyl oxidase (o-DPO) which is responsible for discoloration of the edible mushrooms and altered qualitative and quantitative content of amino acids. It was observed that doses up to 2 kGy did not cause any increase in the activity of o-DPO; irradiation also did not affect the taste. Mushrooms irradiated with doses up to 4 kGy were of good quality after 5 days of storage at 4 C, while the control samples (unirradiated) after the same time were considerably changed, probably due too post-harvest ripening. Immediately after exposure the activity of o-DPO increased in proportion to the dose used. During subsequent storage, however, no increase in o-DPO activity was observed. Irradiation used in the range from 0.2 to 0.4 kGy did not affect the nutritional value of the raw material. The results are an additional confirmation that radiation can be used for efficient preservation of mushrooms. (author). 14 refs, 6 tabs

  13. A review of fractional-order techniques applied to lithium-ion batteries, lead-acid batteries, and supercapacitors

    Science.gov (United States)

    Zou, Changfu; Zhang, Lei; Hu, Xiaosong; Wang, Zhenpo; Wik, Torsten; Pecht, Michael

    2018-06-01

    Electrochemical energy storage systems play an important role in diverse applications, such as electrified transportation and integration of renewable energy with the electrical grid. To facilitate model-based management for extracting full system potentials, proper mathematical models are imperative. Due to extra degrees of freedom brought by differentiation derivatives, fractional-order models may be able to better describe the dynamic behaviors of electrochemical systems. This paper provides a critical overview of fractional-order techniques for managing lithium-ion batteries, lead-acid batteries, and supercapacitors. Starting with the basic concepts and technical tools from fractional-order calculus, the modeling principles for these energy systems are presented by identifying disperse dynamic processes and using electrochemical impedance spectroscopy. Available battery/supercapacitor models are comprehensively reviewed, and the advantages of fractional types are discussed. Two case studies demonstrate the accuracy and computational efficiency of fractional-order models. These models offer 15-30% higher accuracy than their integer-order analogues, but have reasonable complexity. Consequently, fractional-order models can be good candidates for the development of advanced battery/supercapacitor management systems. Finally, the main technical challenges facing electrochemical energy storage system modeling, state estimation, and control in the fractional-order domain, as well as future research directions, are highlighted.

  14. Enhanced drought and heat stress tolerance of tobacco plants with ectopically enhanced cytokinin oxidase/dehydrogenase gene expression

    Czech Academy of Sciences Publication Activity Database

    Macková, Hana; Hronková, Marie; Dobrá, Jana; Turečková, Veronika; Novák, Ondřej; Lubovská, Zuzana; Motyka, Václav; Haisel, Daniel; Hájek, Tomáš; Prášil, I.T.; Gaudinová, Alena; Štorchová, Helena; Ge, Eva; Werner, T.; Schmülling, T.; Vaňková, Radomíra

    2013-01-01

    Roč. 64, č. 10 (2013), s. 2805-2815 ISSN 0022-0957 R&D Projects: GA ČR GA206/09/2062 Institutional support: RVO:61389030 ; RVO:60077344 ; RVO:67985939 Keywords : cytokinin oxidase * cytokinin * Abscisic acid Subject RIV: ED - Physiology Impact factor: 5.794, year: 2013

  15. Confirmation of a blocked amino terminus of sulfhydryl oxidase

    International Nuclear Information System (INIS)

    Janolino, V.G.; Morrison-Rowe, S.J.; Swaisgood, H.E.

    1990-01-01

    The isolation of sulfhydryl oxidase from bovine milk in a suitably pure form for sequencing was carried out by transient covalent affinity chromatography of diafiltered whey using cysteinylsuccinamidopropyl-glass as matrix. The glutathione-eluted proteins were separated by SDS-PAGE. By radiolabeling the affinity chromatography-purified enzyme with [ 14 C]iodoacetate before subjecting to SDS-PAGE, the sulfhydryl oxidase band was identified, because sulfhydryl oxidase is known to be inactivated by alkylation of one sulfhydryl group per mole. The results confirmed that sulfhydryl oxidase corresponds to the 85 (± 5)-kDa band observed on SDS-PAGE. The protein band corresponding to radiolabeled sulfhydryl oxidase was recovered from SDS-PAGE gels by electrophoretic elution and by electroblotting on polyvinylidene difluoride membrane and subjected to gas phase sequencing. Precautions were taken during electrophoretic elution to prevent reactions that result in N-terminal blocking. Both methods of protein recovery yielded negative results when subjected to sequence analysis indicating that the N-terminus of sulfhydryl oxidase is blocked

  16. Polyphenol oxidase activity and antioxidant properties of Yomra apple (Malus communis L.) from Turkey.

    Science.gov (United States)

    Can, Zehra; Dincer, Barbaros; Sahin, Huseyin; Baltas, Nimet; Yildiz, Oktay; Kolayli, Sevgi

    2014-12-01

    In this study, firstly, antioxidant and polyphenol oxidase (PPO) properties of Yomra apple were investigated. Seventeen phenolic constituents were measured by reverse phase-high-performance liquid chromatography (RP-HPLC). Total phenolic compounds (TPCs), ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activities were performed to measure antioxidant capacity. Some kinetic parameters (Km, Vmax), and inhibition behaviors against five different substrates were measured in the crude extract. Catechin and chlorogenic acid were found as the major components in the methanolic extract, while ferulic acid, caffeic acid, p-hydroxybenzoic acid, quercetin and p-coumaric acid were small quantities. Km values ranged from 0.70 to 10.10 mM in the substrates, and also 3-(4-hydroxyphenyl) propanoic acid (HPPA) and L-DOPA showed the highest affinity. The inhibition constant of Ki were ranged from 0.05 to 14.90 mM against sodium metabisulphite, ascorbic acid, sodium azide and benzoic acid, while ascorbic acid and sodium metabisulphite were the best inhibitors.

  17. Immobilization of oxidases and their analytical applications

    International Nuclear Information System (INIS)

    Yasinzai, M.

    2007-01-01

    Immobilized enzymes are replacing their soluble counter-parts in nearly every field of application. These enzyme modifications have evolved from a research curiosity into an entire branch of Biotechnology. An immobilization method for flavin containing oxidases and their use in flow injection system is described. An electrochemical detector for H/sub 2/O/sub 2/ is assembled which is used effectively for the determination of glucose using more common glucose oxidase and the simultaneous determination of sugars. The combination of oxidases with hydrolases have been used for the determination of maltose and starch. (author)

  18. NADPH Oxidases: Progress and Opportunities

    OpenAIRE

    San Martin, Alejandra; Griendling, Kathy K.

    2014-01-01

    From the initial discovery in 1999 that NADPH oxidases comprise a family of enzymes to our current focus on drug development to treat multiple pathologies related to this enzyme family, progress has been swift and impressive. We have expanded our understanding of the extent of the family, the basic enzymatic biochemistry, the multiple cellular functions controlled by NADPH oxidases, and their varied roles in physiology and diseases. We have developed numerous cell culture tools, animal models...

  19. A single mutation in the castor Δ9-18:0-desaturase changes reaction partitioning from desaturation to oxidase chemistry

    Science.gov (United States)

    Guy, Jodie E.; Abreu, Isabel A.; Moche, Martin; Lindqvist, Ylva; Whittle, Edward; Shanklin, John

    2006-01-01

    Sequence analysis of the diiron cluster-containing soluble desaturases suggests they are unrelated to other diiron enzymes; however, structural alignment of the core four-helix bundle of desaturases to other diiron enzymes reveals a conserved iron binding motif with similar spacing in all enzymes of this structural class, implying a common evolutionary ancestry. Detailed structural comparison of the castor desaturase with that of a peroxidase, rubrerythrin, shows remarkable conservation of both identity and geometry of residues surrounding the diiron center, with the exception of residue 199. Position 199 is occupied by a threonine in the castor desaturase, but the equivalent position in rubrerythrin contains a glutamic acid. We previously hypothesized that a carboxylate in this location facilitates oxidase chemistry in rubrerythrin by the close apposition of a residue capable of facilitating proton transfer to the activated oxygen (in a hydrophobic cavity adjacent to the diiron center based on the crystal structure of the oxygen-binding mimic azide). Here we report that desaturase mutant T199D binds substrate but its desaturase activity decreases by ≈2 × 103-fold. However, it shows a >31-fold increase in peroxide-dependent oxidase activity with respect to WT desaturase, as monitored by single-turnover stopped-flow spectrometry. A 2.65-Å crystal structure of T199D reveals active-site geometry remarkably similar to that of rubrerythrin, consistent with its enhanced function as an oxidase enzyme. That a single amino acid substitution can switch reactivity from desaturation to oxidation provides experimental support for the hypothesis that the desaturase evolved from an ancestral oxidase enzyme. PMID:17088542

  20. Catalytic Cycle of Multicopper Oxidases Studied by Combined Quantum- and Molecular-Mechanical Free-Energy Perturbation Methods

    Czech Academy of Sciences Publication Activity Database

    Li, J.; Farrokhnia, M.; Rulíšek, Lubomír; Ryde, U.

    2015-01-01

    Roč. 119, č. 26 (2015), s. 8268-8284 ISSN 1520-6106 R&D Projects: GA ČR(CZ) GA14-31419S Institutional support: RVO:61388963 Keywords : multi-copper oxidases * QM/MM calculations * reduction potentials * pKa acidity constants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.187, year: 2015

  1. Antiulcer effects of aqueous extract and a fraction of phyllanthus embelic fruit on gastric acid secretion and mucosal defence factors in albino rats

    International Nuclear Information System (INIS)

    Akhtar, M.S.; Zaman, R.U.; Khan, M.S.

    2004-01-01

    Phyllanthus emblica (Euphorbiaceae) fruit has been empirically used since centuries in folkloric medicine to treat gastrointestinal disorders including the gastric ulcers. In the present study, anti-ulcerogenic properties of the fruit, its aqueous extract and a purified fraction were determined in albino rats. Aqueous extract of the fruit protected rats against gastric ulcers induced by indomethacin. Partition of the water extract yielded fractions for which anti-ulcerogenic activity evaluation studies were conducted to find out the most effective fraction. Thin layer chromatography yielded the most purified active fraction, which was found to exert anti-ulcerogenic activity in the chemically induced and stress-induced gastric ulcers in albino rats. In addition, effect of the purified fraction on gastric secretion volume, pH, acid output, ulcer index, mucus secretion and peptic activity revealed it to be the most potent anti-ulcer fraction with efficacy comparable to the reference drug, famotidine. It may be suggested that anti-ulcerogenic activities of P. emblica fruit, Its aqueous extract and the purified fraction could be due to elevation of gastric mucus secretion and inhibition of gastric acid secretion. (author)

  2. Lipid and fatty acid fractions in Lingula anatina (Brachiopoda): an intertidal benthic fauna in the West Bengal-Orissa coast, India

    OpenAIRE

    Samaresh Samanta; Tapas Kumar Das; Amalesh Choudhury; Susanta Kumar Chakraborty

    2014-01-01

    Objective: To record the fractional components of lipid and polyunsaturated fatty acids of Lingula anatina (L. anatina), a Precambrian intertidal benthic brachiopod, giving emphasis on -ω series group especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) alongside assessing their biotransformation within the population and mangrove-estuarine associated community. Methods: Different biological samples after being collected from three contrasting study sites viz. ...

  3. Modulation of NADPH oxidase activity by known uraemic retention solutes

    DEFF Research Database (Denmark)

    Schulz, Anna Marta; Terne, Cindy; Jankowski, Vera

    2014-01-01

    chloride (DPI), an inhibitor of NADPH oxidase. The effect on enzymatic activity of NADPH oxidase was quantified within an incubation time of 120 min. RESULTS: Thirty-nine of the 48 uraemic retention solutes tested had a significant decreasing effect on NADPH oxidase activity. Oxalate has been characterized......BACKGROUND: Uraemia and cardiovascular disease appear to be associated with an increased oxidative burden. One of the key players in the genesis of reactive oxygen species (ROS) is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Based on initial experiments demonstrating a decreased...... inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. METHODS: Mononuclear leucocytes...

  4. Characterization of polyphenol oxidase from Cape gooseberry (Physalis peruviana L.) fruit.

    Science.gov (United States)

    Bravo, Karent; Osorio, Edison

    2016-04-15

    Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued, however it is a very rich source of polyphenol oxidase (PPO). In this study, Cape gooseberry PPO was isolated and biochemically characterized. The enzyme was extracted and purified using acetone and aqueous two-phase systems. The data indicated that PPO had the highest substrate affinity for chlorogenic acid, 4-methylcatechol and catechol. Chlorogenic acid was the most suitable substrate (Km=0.56±0.07 mM and Vmax=53.15±2.03 UPPO mL(-1) min(-1)). The optimal pH values were 5.5 for catechol and 4-methylcatechol and 5.0 for chlorogenic acid. Optimal temperatures were 40°C for catechol, 25°C for 4-methylcatechol and 20°C for chlorogenic acid. In inhibition tests, the most potent inhibitor was found to be ascorbic acid followed by L-cysteine and quercetin. This study shows possible treatments that can be implemented during the processing of Cape gooseberry fruits to prevent browning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Gravity Responsive NADH Oxidase of the Plasma Membrane

    Science.gov (United States)

    Morre, D. James (Inventor)

    2002-01-01

    A method and apparatus for sensing gravity using an NADH oxidase of the plasma membrane which has been found to respond to unit gravity and low centrifugal g forces. The oxidation rate of NADH supplied to the NADH oxidase is measured and translated to represent the relative gravitational force exerted on the protein. The NADH oxidase of the plasma membrane may be obtained from plant or animal sources or may be produced recombinantly.

  6. Involvement of NADH Oxidase in Competition and Endocarditis Virulence in Streptococcus sanguinis.

    Science.gov (United States)

    Ge, Xiuchun; Yu, Yang; Zhang, Min; Chen, Lei; Chen, Weihua; Elrami, Fadi; Kong, Fanxiang; Kitten, Todd; Xu, Ping

    2016-05-01

    Here, we report for the first time that the Streptococcus sanguinis nox gene encoding NADH oxidase is involved in both competition with Streptococcus mutans and virulence for infective endocarditis. An S. sanguinis nox mutant was found to fail to inhibit the growth of Streptococcus mutans under microaerobic conditions. In the presence of oxygen, the recombinant Nox protein of S. sanguinis could reduce oxygen to water and oxidize NADH to NAD(+) The oxidation of NADH to NAD(+) was diminished in the nox mutant. The nox mutant exhibited decreased levels of extracellular H2O2; however, the intracellular level of H2O2 in the mutant was increased. Furthermore, the virulence of the nox mutant was attenuated in a rabbit endocarditis model. The nox mutant also was shown to be more sensitive to blood killing, oxidative and acid stresses, and reduced growth in serum. Thus, NADH oxidase contributes to multiple phenotypes related to competitiveness in the oral cavity and systemic virulence. Copyright © 2016 Ge et al.

  7. Interactions between stepwise-eluted sub-fractions of fulvic acids and protons revealed by fluorescence titration combined with EEM-PARAFAC.

    Science.gov (United States)

    Song, Fanhao; Wu, Fengchang; Guo, Fei; Wang, Hao; Feng, Weiying; Zhou, Min; Deng, Yanghui; Bai, Yingchen; Xing, Baoshan; Giesy, John P

    2017-12-15

    In aquatic environments, pH can control environmental behaviors of fulvic acid (FA) via regulating hydrolysis of functional groups. Sub-fractions of FA, eluted using pyrophosphate buffers with initial pHs of 3.0 (FA 3 ), 5.0 (FA 5 ), 7.0 (FA 7 ), 9.0 (FA 9 ) and 13.0 (FA 13 ), were used to explore interactions between the various, operationally defined, FA fractions and protons, by use of EEM-PARAFAC analysis. Splitting of peaks (FA 3 and FA 13 ), merging of peaks (FA 7 ), disappearance of peaks (FA 9 and FA 13 ), and red/blue-shifting of peaks were observed during fluorescence titration. Fulvic-like components were identified from FA 3 -FA 13 , and protein-like components were observed in fractions FA 9 and FA 13 . There primary compounds (carboxylic-like, phenolic-like, and protein-like chromophores) in PARAFAC components were distinguished based on acid-base properties. Dissociation constants (pK a ) for fulvic-like components with proton ranged from 2.43 to 4.13 in an acidic pH and from 9.95 to 11.27 at basic pH. These results might be due to protonation of di-carboxylate and phenolic functional groups. At basic pH, pK a values of protein-like components (9.77-10.13) were similar to those of amino acids. However, at acidic pH, pK a values of protein-like components, which ranged from 3.33 to 4.22, were 1-2units greater than those of amino acids. Results presented here, will benefit understanding of environmental behaviors of FA, as well as interactions of FA with environmental contaminants. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Calcium transport in vesicles energized by cytochrome oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Rosier, Randy N. [Univ. of Rochester, NY (United States)

    1979-01-01

    Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K+ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K+ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

  9. Peroxisomal Polyamine Oxidase and NADPH-Oxidase cross-talk for ROS homeostasis which affects respiration rate in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Efthimios A. Andronis

    2014-04-01

    Full Text Available Homeostasis of reactive oxygen species (ROS in the intracellular compartments is of critical importance as ROS have been linked with nearly all cellular processes and more importantly with diseases and aging. PAs are nitrogenous molecules with an evolutionary conserved role in the regulation of metabolic and energetic status of cells. Recent evidence also suggests that polyamines (PA are major regulators of ROS homeostasis. In Arabidopsis the backconversion of the PAs spermidine (Spd and spermine (Spm to putrescine (Put and Spd, respectively is catalyzed by two peroxisomal PA oxidases (AtPAO. However, the physiological role of this pathway remains largely elusive. Here we explore the role of peroxisomal PA backconversion and in particular that catalyzed by the highly expressed AtPAO3 in the regulation of ROS homeostasis and mitochondrial respiratory burst. Exogenous PAs exert an NADPH-oxidase dependent stimulation of oxygen consumption, with Spd exerting the strongest effect. This increase is attenuated by treatment with the NADPH-oxidase blocker diphenyleneiodonium iodide (DPI. Loss-of-function of AtPAO3 gene results to increased NADPH-oxidase-dependent production of superoxide anions (O2.-, but not H2O2, which activate the mitochondrial alternative oxidase pathway (AOX. On the contrary, overexpression of AtPAO3 results to an increased but balanced production of both H2O2 and O2.-. These results suggest that the ratio of O2.-/H2O2 regulates respiratory chain in mitochondria, with PA-dependent production of O2.- by NADPH-oxidase tilting the balance of electron transfer chain in favor of the AOX pathway. In addition, AtPAO3 seems to be an important component in the regulating module of ROS homeostasis, while a conserved role for PA backconversion and ROS across kingdoms is discussed.

  10. The use of glucose oxidase and catalase for the enzymatic reduction of the potential ethanol content in wine.

    Science.gov (United States)

    Röcker, Jessica; Schmitt, Matthias; Pasch, Ludwig; Ebert, Kristin; Grossmann, Manfred

    2016-11-01

    Due to the increase of sugar levels in wine grapes as one of the impacts of climate change, alcohol reduction in wines becomes a major focus of interest. This study combines the use of glucose oxidase and catalase activities with the aim of rapid conversion of glucose into non-fermentable gluconic acid. The H2O2 hydrolysing activity of purified catalase is necessary in order to stabilize glucose oxidase activity. After establishing the adequate enzyme ratio, the procedure was applied in large-scale trials (16L- and 220L-scale) of which one was conducted in a winery under industrial wine making conditions. Both enzyme activity and wine flavour were clearly influenced by the obligatory aeration in the different trials. With the enzyme treatment an alcohol reduction of 2%vol. was achieved after 30h of aeration. However the enzyme treated wines were significantly more acidic and less typical. Copyright © 2016. Published by Elsevier Ltd.

  11. A structured understanding of cellobiohydrolase I binding to poplar lignin fractions after dilute acid pretreatment.

    Science.gov (United States)

    Yao, Lan; Yoo, Chang Geun; Meng, Xianzhi; Li, Mi; Pu, Yunqiao; Ragauskas, Arthur J; Yang, Haitao

    2018-01-01

    Cellulase adsorption to lignin is considered a cost barrier for bioethanol production; however, its detailed association mechanism is still not fully understood. In this study, two natural poplar variants with high and low sugar release performance were selected as the low and high recalcitrant raw materials (named L and H , respectively). Three different lignin fractions were extracted using ethanol, followed by p -dioxane and then cellulase treatment from the dilute acid pretreated poplar solids (fraction 1, 2, and 3, respectively). Each lignin fraction had different physicochemical properties. Ethanol-extracted lignin had the lowest weight average molecular weight, while the molecular weights for the other two lignin fractions were similar. 31 P NMR analysis revealed that lignin fraction with higher molecular weight contained more aliphatic hydroxyl groups and less phenolic hydroxyl groups. Semi-quantitative analysis by 2D HSQC NMR indicated that the lignin fractions isolated from the natural variants had different contents of syringyl (S), guaiacyl (G) and interunit linkages. Lignin extracted by ethanol contained the largest amount of S units, the smallest amounts of G and p -hydroxybenzoate (PB) subunits, while the contents of these lignin subunits in the other two lignin fractions were similar. The lignin fraction obtained after cellulase treatment was primarily comprised of β- O -4 linkages with small amounts of β-5 and β-β linkages. The binding strength of these three lignin fractions obtained by Langmuir equations were in the order of L 1  >  L 3  >  L 2 for the low recalcitrance poplar and H 1  >  H 2  >  H 3 for the high recalcitrance poplar. Overall, adsorption ability of lignin was correlated with the sugar release of poplar. Structural features of lignin were associated with its binding to CBH. For natural poplar variants, lignin fractions with lower molecular weight and polydispersity index (PDI) exhibited more CBH adsorption

  12. Kinetic Resolution of sec-Thiols by Enantioselective Oxidation with Rationally Engineered 5-(Hydroxymethyl)furfural Oxidase.

    Science.gov (United States)

    Pickl, Mathias; Swoboda, Alexander; Romero, Elvira; Winkler, Christoph K; Binda, Claudia; Mattevi, Andrea; Faber, Kurt; Fraaije, Marco W

    2018-03-05

    Various flavoprotein oxidases were recently shown to oxidize primary thiols. Herein, this reactivity is extended to sec-thiols by using structure-guided engineering of 5-(hydroxymethyl)furfural oxidase (HMFO). The variants obtained were employed for the oxidative kinetic resolution of racemic sec-thiols, thus yielding the corresponding thioketones and nonreacted R-configured thiols with excellent enantioselectivities (E≥200). The engineering strategy applied went beyond the classic approach of replacing bulky amino acid residues with smaller ones, as the active site was additionally enlarged by a newly introduced Thr residue. This residue established a hydrogen-bonding interaction with the substrates, as verified in the crystal structure of the variant. These strategies unlocked HMFO variants for the enantioselective oxidation of a range of sec-thiols. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Modulation of NADPH oxidase activity by known uraemic retention solutes.

    Science.gov (United States)

    Schulz, Anna Marta; Terne, Cindy; Jankowski, Vera; Cohen, Gerald; Schaefer, Mandy; Boehringer, Falko; Tepel, Martin; Kunkel, Desiree; Zidek, Walter; Jankowski, Joachim

    2014-08-01

    Uraemia and cardiovascular disease appear to be associated with an increased oxidative burden. One of the key players in the genesis of reactive oxygen species (ROS) is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Based on initial experiments demonstrating a decreased inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. Mononuclear leucocytes isolated from buffy coats of healthy volunteers were isolated, lysed and incubated with NADH in the presence of plasma from healthy controls and patients with CKD-5D. Furthermore, the leucocytes were lysed and incubated in the presence of uraemic retention solute of interest and diphenyleneiodonium chloride (DPI), an inhibitor of NADPH oxidase. The effect on enzymatic activity of NADPH oxidase was quantified within an incubation time of 120 min. Thirty-nine of the 48 uraemic retention solutes tested had a significant decreasing effect on NADPH oxidase activity. Oxalate has been characterized as the strongest inhibitor of NADPH oxidase (90% of DPI inhibition). Surprisingly, none of the uraemic retention solutes we investigated was found to increase NADPH oxidase activity. Furthermore, plasma from patients with CKD-5D before dialysis caused significantly higher inhibitory effect on NADPH oxidase activity compared with plasma from healthy subjects. However, this effect was significantly decreased in plasma from patients with CKD-5D after dialysis. The results of this study show that uraemic retention solutes modulated the activity of the NADPH oxidase. The results of this study might be the basis for the development of inhibitors applicable as drug in the situation of increased oxidative stress. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

  14. Lysyl oxidase in colorectal cancer

    DEFF Research Database (Denmark)

    Cox, Thomas R; Erler, Janine T

    2013-01-01

    Colorectal cancer is the third most prevalent form of cancer worldwide and fourth-leading cause of cancer-related mortality, leading to ~600,000 deaths annually, predominantly affecting the developed world. Lysyl oxidase is a secreted, extracellular matrix-modifying enzyme previously suggested...... to act as a tumor suppressor in colorectal cancer. However, emerging evidence has rapidly implicated lysyl oxidase in promoting metastasis of solid tumors and in particular colorectal cancer at multiple stages, affecting tumor cell proliferation, invasion, and angiogenesis. This emerging research has...... advancements in the field of colorectal cancer....

  15. Characterization of the cytochrome c oxidase in isolated and purified plasma membranes from the cyanobacterium Anacystis nidulans

    International Nuclear Information System (INIS)

    Peschek, G.A.; Wastyn, M.; Trnka, M.; Molitor, V.; Fry, I.V.; Packer, L.

    1989-01-01

    Functionally intact plasma membranes were isolated from the cyanobacterium (blue-green alga) Anacystis nidulans through French pressure cell extrusion of lysozyme/EDTA-treated cells, separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation, and purified by repeated recentrifugation. Origin and identity of the chlorophyll-free plasma membrane fraction were confirmed by labeling of intact cells with impermeant protein markers, [ 35 S]diazobenzenesulfonate and fluorescamine, prior to membrane isolation. Rates of oxidation of reduced horse heart cytochrome c by purified plasma and thylakoid membranes were 90 and 2 nmol min -1 (mg of protein) -1 , respectively. The cytochrome oxidase in isolated plasma membranes was identified as a copper-containing aa 3 -type enzyme from the properties of its redox-active and EDTA-resistant Cu 2+ ESR signal, the characteristic inhibition profile, reduced minus oxidized difference spectra, carbon monoxide difference spectra, photoaction and photodissociation spectra of the CO-inhibited enzyme, and immunological cross-reaction of two subunits of the enzyme with antibodies against subunits I and II, and the holoenzyme, of Paracoccus denitrificans aa 3 -type cytochrome oxidase. The data presented are the first comprehensive evidence for the occurrence of aa 3 -type cytochrome oxidase in the plasma membrane of a cyanobacterium similar to the corresponding mitochondrial enzyme

  16. Fractional filling with the microdepot technique as an alternative to bolus hyaluronic acid injections in facial volume restoration.

    Science.gov (United States)

    Lim, Adrian C; Lowe, Patricia M

    2011-05-01

    For volume restoration of the face, hyaluronic acid is conventionally injected through long, large-bore, 18-gauge needles because of the higher viscosity subtypes required. These hyaluronic acids are either more highly cross-linked or larger in particle size than the less-viscous subtypes. The microdepot injection technique involves using the 31-gauge BD insulin syringe (Becton-Dickinson, North Ryde, NSW Australia) to deposit small amounts of filler (0.05-0.1 mL) throughout the area of volume loss. The procedure is extremely well tolerated, requiring only topical and ice anaesthesia. Using this method, volume restoration can be achieved naturally and progressively over a period of time. Fractional filling every 3-4 months is continued until the desired level of volume correction is attained. Patients undergoing fractional filling followed over a 12-month period did not indicate any observable compromise in filler longevity, even when highly viscous hyaluronic acid fillers were injected through small-bore, 31-gauge insulin syringes. © 2011 The Authors. Australasian Journal of Dermatology © 2011 The Australasian College of Dermatologists.

  17. D-amino acid oxidase gene therapy sensitizes glioma cells to the antiglycolytic effect of 3-bromopyruvate.

    Science.gov (United States)

    El Sayed, S M; Abou El-Magd, R M; Shishido, Y; Chung, S P; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

    2012-01-01

    Glioma tumors are refractory to conventional treatment. Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans. In this study, we introduce oxidative stress-energy depletion (OSED) therapy as a new suggested treatment for glioblastoma. OSED utilizes D-amino acid oxidase (DAO), which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide (H2O2). OSED combines DAO with 3-bromopyruvate (3BP), a hexokinase II (HK II) inhibitor that interferes with Warburg effect, a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis. Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action. C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation, clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes. DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley (SD) rats, especially after combination with 3BP. OSED treatment was safe and tolerable in SD rats. OSED therapy may be a promising therapeutic modality for glioma.

  18. FRACTIONATION AND CHARACTERISATION OF TECHNICAL AMMONIUM LIGNOSULPHONATE

    Directory of Open Access Journals (Sweden)

    Cheryl Ann Leger

    2010-08-01

    Full Text Available It is difficult to use lignin in any analytical methodology without reducing its considerable polydispersity by fractionation. An ammonium lignosulphonate sample was fractionated using a method of partial solubility in solutions of isopropanol increasingly diluted with distilled water, effectively fractionating by polarity. Selected fractions were characterised by gravimetric determination of the fractions, and determination of acid insoluble lignin, soluble lignin, and carbohydrate contents. Acid-insoluble lignin content was very low, and soluble lignin provided the majority of the lignin content, as should be expected from sulphonated lignin. Carbohydrate contents were also fairly low, the highest percentage at 14.5 being in Fraction 2, with the bulk lignin and Fraction 3 having 6.5% and 3.2%, respectively. Differences in the composition of each fraction support the efficacy of the fractionation process and permitted selection of fractions for use in subsequent studies.

  19. Enhancement of oleic acid in butter oil by high oleic fraction of moringa oleifera oil

    International Nuclear Information System (INIS)

    Nadeem, M.; Ullah, R.

    2016-01-01

    Oleic acid in butter oil (BO) was enhanced by a high oleic acid fraction (HOF) of Moringa oleifera oil (MOO). HOF was blended with BO at four different concentrations i.e. 5%, 10 percent, 15% and 20% (HOF-5, HOF-10, HOF-15 and HOF-20, respectively), compared with a control (BO). The oleic acid in HOF increased from 71.55 percent to 80.25%. DPPH free radical scavenging activity and total flavonoid content of HOF was 76.88% and 34.52 mg/100 g. Supplementation of butter oil with 20% HOF, decreased the cholesterol from 224 to 177 mg/100 g. Peroxide value of three months stored HOF-20 was 1.18 (meqO/sub 2/ kg) as compared to control, 3.15 (meqO/sub 2/kg). Induction period of HOF-20 was 4.07 h greater than control. These results evidenced that oleic acid in butter oil can be substantially increased by HOF of MOO. (author)

  20. Estimate of colostral immunoglobulin G concentration using refractometry without or with caprylic acid fractionation.

    Science.gov (United States)

    Morrill, K M; Conrad, E; Polo, J; Lago, A; Campbell, J; Quigley, J; Tyler, H

    2012-07-01

    Our objectives were to evaluate the use of refractometry as a means of estimating immunoglobulin G (IgG) concentration of bovine maternal colostrum (MC) and determine if fractionation of MC using caprylic acid (CA) improved estimates of IgG. Samples (n=85) of MC were collected from a single dairy in California and used to determine the method of CA fraction that produced the best prediction of IgG based on CA fractionation followed by refractometry. Subsequently, samples of MC (n=827) were collected from 67 farms in 12 states to compare refractometry with or without CA fractionation as methods to estimate IgG concentration. Samples were collected from the feeding pool and consisted of fresh (n=196), previously frozen (n=479), or refrigerated (n=152) MC. Samples were further classified by the number freeze-thaw cycles before analysis. Fractionation with CA was conducted by adding 1 mL of MC to a tube containing 75 μL of CA and 1 mL of 0.06 M acetic acid. The tube was shaken and allowed to react for 1 min. Refractive index of the IgG-rich supernatant (nDf) was determined using a digital refractometer. Whole, nonfractionated MC was analyzed for IgG by radial immunodiffusion (RID) and refractive index (nDw). The relationship between nDf and IgG (r=0.53; n=805) was weak, whereas that between nDw and IgG was stronger (r=0.73; n=823). Fresh samples analyzed by refractometry that subsequently went through 1 freeze-thaw cycle before RID analysis resulted in the strongest relationship between IgG and nDf or nDw (r=0.93 and 0.90, respectively). The MC samples collected fresh on the farm but frozen 2 or more times before analysis by refractometry or RID had low correlations between IgG and nDf and nDw (r=0.09 and 0.01). Samples refrigerated or frozen on the farm before analysis had weaker relationships between RID and nDf or nDw (r=0.38 to 0.80), regardless of the number of freeze-thaw cycles. Breed and lactation number did not affect the accuracy of either test. These

  1. Production of rabbit antibodies against purified Glucose oxidase

    Directory of Open Access Journals (Sweden)

    Muhammad Anjum Zia

    2012-02-01

    Full Text Available Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex G-200 column for gel filtration chromatography. It was observed that enzyme achieved 59.37 U mg-1of specific activity with 27.08 fold purity and 64.36% recovery. Purified glucose oxidase was injected into rabbits through intravenous route, to raise the glucose oxidase antibodies. After 30 days incubation period, the rabbits were slaughtered and serum was separated from blood. The antibodies were isolated by ammonium sulfate precipitation and confirmed by agar gel precipitation test. This could be a convenient and low cost alternate assay for the estimation of glucose oxidase in biological fluids. Moreover, such antibodies against the said enzyme could be used in various therapeutic and diagnostic applications.

  2. Bioassay-directed fractionation of a blood coagulation factor Xa inhibitor, betulinic acid from Lycopus lucidus

    Directory of Open Access Journals (Sweden)

    Tan Yin-Feng

    2018-03-01

    Full Text Available Thrombosis is a major cause of morbidity and mortality worldwide and plays a pivotal role in the pathogenesis of several cardiovascular disorders, including acute coronary syndrome, unstable angina, myocardial infarction, sudden cardiac death, peripheral arterial occlusion, ischemic stroke, deep-vein thrombosis, and pulmonary embolism. Anticoagulants, antiplatelet agents, and fibrinolytics can reduce the risks of these clinical events. Especially, the blood coagulation factor Xa (FXa inhibitor is a proven anticoagulant. Promoting blood circulation, using traditional Chinese medicine (TCM, for the treatment of these diseases has been safely used for thousands of years in clinical practice. Therefore, highly safe and effective anticoagulant ingredients, including FXa inhibitors, could be found in TCM for activating the blood circulation. One FXa inhibitor, a pentacyclic triterpene (compound 1, betulinic acid characterized by IR, MS and NMR analyses, was isolated from the ethyl acetate fraction of Lycopus lucidus by bioassay-directed fractionation. Compound 1 exhibited an inhibitory effect on FXa with IC50 25.05 μmol/L and reduced the thrombus weight in an animal model at 25-100 mg/kg. These results indicate that betulinic acid could be the potential for anticoagulant therapy.

  3. Promising perspectives for ruminal protection of polyunsaturated fatty acids through polyphenol-oxidase-mediated crosslinking of interfacial protein in emulsions.

    Science.gov (United States)

    De Neve, N; Vlaeminck, B; Gadeyne, F; Claeys, E; Van der Meeren, P; Fievez, V

    2018-03-16

    Previously, polyunsaturated fatty acids (PUFA) from linseed oil were effectively protected (>80%) against biohydrogenation through polyphenol-oxidase-mediated protein crosslinking of an emulsion, prepared with polyphenol oxidase (PPO) extract from potato tuber peelings. However, until now, emulsions of only 2 wt% oil have been successfully protected, which implies serious limitations both from a research perspective (e.g. in vivo trials) as well as for further upscaling toward practical applications. Therefore, the aim of this study was to increase the oil/PPO ratio. In the original protocol, the PPO extract served both an emulsifying function as well as a crosslinking function. Here, it was first evaluated whether alternative protein sources could replace the emulsifying function of the PPO extract, with addition of PPO extract and 4-methylcatechol (4MC) to induce crosslinking after emulsion preparation. This approach was then further used to evaluate protection of emulsions with higher oil content. Five candidate emulsifiers (soy glycinin, gelatin, whey protein isolate (WPI), bovine serum albumin and sodium caseinate) were used to prepare 10 wt% oil emulsions, which were diluted five times (w/w) with PPO extract (experiment 1). As a positive control, 2 wt% oil emulsions were prepared directly with PPO extract according to the original protocol. Further, emulsions of 2, 4, 6, 8 and 10 wt% oil were prepared, with 80 wt% PPO extract (experiment 2), or with 90, 80, 70, 60 and 50 wt% PPO extract, respectively (experiment 3) starting from WPI-stabilized emulsions. Enzymatic crosslinking was induced by 24-h incubation with 4MC. Ruminal protection efficiency was evaluated by 24-h in vitro batch simulation of the rumen metabolism. In experiment 1, protection efficiencies were equal or higher than the control (85.5% to 92.5% v. 81.3%). In both experiments 2 and 3, high protection efficiencies (>80%) were achieved, except for emulsions containing 10 wt% oil emulsions

  4. [Comparative characteristics of the amino acid composition of the protein fractions of the hydrogen bacteria Hydrogenomonas eutropha in meat and wheat].

    Science.gov (United States)

    Barashkov, V A; Trubachev, I N; Gitel'zon, I I

    1976-01-01

    An attempt was made to compare the biological value of the biological mass of the hydrogen bacteria Tydrogenomas eutropha, of meat and wheat on the ground of the fractional and amino acids composition of their proteins. Substantial differences in the distribution of proteins and amino acids in all of the three objects examined were revealed. It is shown that more than one half of the entire protein contained in the biological mass of the hydrogen bacteria is made up of poorly soluble structural proteins difficultly amenable to the action of digestive enzymes. It is this fraction where the bulk of essential amino acids is concentrated. The data obtained imply that the biological value of the biological mass of hydrogen bacteria is higher than in wheat, but lower than in meat.

  5. A new l-amino acid oxidase from Bothrops jararacussu snake venom: Isolation, partial characterization, and assessment of pro-apoptotic and antiprotozoal activities.

    Science.gov (United States)

    Carone, Sante E I; Costa, Tássia R; Burin, Sandra M; Cintra, Adélia C O; Zoccal, Karina F; Bianchini, Francine J; Tucci, Luiz F F; Franco, João J; Torqueti, Maria R; Faccioli, Lúcia H; Albuquerque, Sérgio de; Castro, Fabíola A de; Sampaio, Suely V

    2017-10-01

    A new l-amino acid oxidase (LAAO) from Bothrops jararacussu venom (BjussuLAAO-II) was isolated by using a three-step chromatographic procedure based on molecular exclusion, hydrophobicity, and affinity. BjussuLAAO-II is an acidic enzyme with pI=3.9 and molecular mass=60.36kDa that represents 0.3% of the venom proteins and exhibits high enzymatic activity (4884.53U/mg/mim). We determined part of the primary sequence of BjussuLAAO-II by identifying 96 amino acids, from which 34 compose the N-terminal of the enzyme (ADDRNPLEECFRETDYEEFLEIARNGLSDTDNPK). Multiple alignment of the partial BjussuLAAO-II sequence with LAAOs deposited in the NCBI database revealed high similarity (95-97%) with other LAAOs isolated from Bothrops snake venoms. BjussuLAAO-II exerted a strong antiprotozoal effect against Leishmania amazonensis (IC 50 =4.56μg/mL) and Trypanosoma cruzi (IC 50 =4.85μg/mL). This toxin also induced cytotoxicity (IC 50 =1.80μg/mL) and apoptosis in MCF7 cells (a human breast adenocarcinoma cell line) by activating the intrinsic and extrinsic apoptosis pathways, but were not cytotoxic towards MCF10A cells (a non-tumorigenic human breast epithelial cell line). The results reported herein add important knowledge to the field of Toxinology, especially for the development of new therapeutic agents. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Purification and characterization of polyphenol oxidase from jackfruit ( Artocarpus heterophyllus ) bulbs.

    Science.gov (United States)

    Tao, Yi-Ming; Yao, Le-Yi; Qin, Qiu-Yan; Shen, Wang

    2013-12-26

    Polyphenol oxidase (PPO) from jackfruit bulb was purified through acetone precipitation, ion-exchange column, and gel filtration column. PPO was a dimer with the molecular weight of 130 kDa determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration. The Km was 8.3 and 18.2 mM using catechol and 4-methylcatechol as substrates, respectively. The optimum pH was 7.0 (catechol as the substrate) or 6.5 (4-methylcatechol as the substrate). The optimum temperature was 8 °C. The enzyme was stable below 40 °C. The activation energy (Ea) of heat inactivation was estimated to be 103.30 kJ/mol. The PPO activity was activated by Mn(2+), SDS, Tween-20, Triton X-100, citric acid, and malic acid but inhibited by K(+), Zn(2+), Mg(2+), Ca(2+), Ba(2+), cetyl trimethyl ammonium bromide (CTAB), kojic acid, tropolone, glutathione (GSH), cysteine (Cys), and ascorbic acid (AA). Cys and AA were effective to reduce browning of jackfruit bulbs during the storage at 8 °C for 15 days.

  7. Xanthine oxidase inhibitors from Archidendron clypearia (Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants

    Institute of Scientific and Technical Information of China (English)

    Nguyen Thuy Duong; Pham Duc Vinh; Phuong Thien Thuong; Nguyen Thi Hoai; Le Nguyen Thanh; Tran The Bach; Nguyen Hai Nam; Nguyen Hoang Anh

    2017-01-01

    Objective:To screen Vietnamese medicinal plants for xanthine oxidase (XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant.Methods: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, includingn-hexane, ethyl acetate, andn-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. Results:Three hundreds and eleven methanol extracts (CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/mL with inhibition rates of over 50%. The extracts of Archidendron clypearia,Smilax poilanei,Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC50 values below 30 μg/mL. Chemical study performed on the extract ofArchidendron clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and (?)-7-O-galloyltricetiflavan. The compound (?)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC50 value of 25.5 μmol/L.Conclusions:From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC50 values of the methanol extracts below 30 μg/mL. Compound (?)-7-O-galloyltricetiflavan was identified as an XO inhibitor from Archidendron clypearia with IC50 value of 25.5 μmol/L.

  8. Minimizing the effects of oxygen interference on l-lactate sensors by a single amino acid mutation in Aerococcus viridansl-lactate oxidase.

    Science.gov (United States)

    Hiraka, Kentaro; Kojima, Katsuhiro; Lin, Chi-En; Tsugawa, Wakako; Asano, Ryutaro; La Belle, Jeffrey T; Sode, Koji

    2018-04-30

    l-lactate biosensors employing l-lactate oxidase (LOx) have been developed mainly to measure l-lactate concentration for clinical diagnostics, sports medicine, and the food industry. Some l-lactate biosensors employ artificial electron mediators, but these can negatively impact the detection of l-lactate by competing with the primary electron acceptor: molecular oxygen. In this paper, a strategic approach to engineering an AvLOx that minimizes the effects of oxygen interference on sensor strips was reported. First, we predicted an oxygen access pathway in Aerococcus viridans LOx (AvLOx) based on its crystal structure. This was subsequently blocked by a bulky amino acid substitution. The resulting Ala96Leu mutant showed a drastic reduction in oxidase activity using molecular oxygen as the electron acceptor and a small increase in dehydrogenase activity employing an artificial electron acceptor. Secondly, the Ala96Leu mutant was immobilized on a screen-printed carbon electrode using glutaraldehyde cross-linking method. Amperometric analysis was performed with potassium ferricyanide as an electron mediator under argon or atmospheric conditions. Under argon condition, the response current increased linearly from 0.05 to 0.5mM l-lactate for both wild-type and Ala96Leu. However, under atmospheric conditions, the response of wild-type AvLOx electrode was suppressed by 9-12% due to oxygen interference. The Ala96Leu mutant maintained 56-69% of the response current at the same l-lactate level and minimized the relative bias error to -19% from -49% of wild-type. This study provided significant insight into the enzymatic reaction mechanism of AvLOx and presented a novel approach to minimize oxygen interference in sensor applications, which will enable accurate detection of l-lactate concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Lipid and fatty acid fractions in Lingula anatina (Brachiopoda: an intertidal benthic fauna in the West Bengal-Orissa coast, India

    Directory of Open Access Journals (Sweden)

    Samaresh Samanta

    2014-05-01

    Full Text Available Objective: To record the fractional components of lipid and polyunsaturated fatty acids of Lingula anatina (L. anatina, a Precambrian intertidal benthic brachiopod, giving emphasis on -ω series group especially eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA alongside assessing their biotransformation within the population and mangrove-estuarine associated community. Methods: Different biological samples after being collected from three contrasting study sites viz. SI, SII and SIII at Talsari (Longitude 87°5′ E to 88°5′ E and Latitude 20°30′ N to 22°2′ N were stored at -20 °C until analyzed. Total lipids were extracted from each sample following Bligh and Dryer method. Identification and conformation of fatty acids were done by following Ackman method. Results: On analyzing different collected samples, muscles of L. anatina exhibited the highest amount of total lipids (2.95% of which 54.03% belongs to phospholipid groups. Different body parts of studied species contained appreciable and greater amount of EPA and DHA than α-linolenic acid. Conclusions: Different collected samples exhibited variabilities in respect of total lipids and its fractional fatty acid components. The muscles of L. anatina showed maximum storage of lipids and fatty acids. Differential occurrences of EPA and DHA in different body parts of L. anatina are supposed to be due to the biotransformation process converting the α-linolenic acid from its primary food sources.

  10. Laboratory-evolved vanillyl-alcohol oxidase produces natural vanillin

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Berg, van den W.A.M.; Rovida, S.; Berkel, van W.J.H.

    2004-01-01

    The flavoenzyme vanillyl-alcohol oxidase was subjected to random mutagenesis to generate mutants with enhanced reactivity to creosol (2-methoxy-4-methylphenol). The vanillyl-alcohol oxidase-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol

  11. Biological activities of Suaeda heterophylla and Bergenia stracheyi

    Directory of Open Access Journals (Sweden)

    Iftikhar Ali

    2014-09-01

    Full Text Available Objective: To evaluate the antioxidant, phytotoxic, antimicrobial, insecticidal, cytotoxic, antiglycative, and xanthine oxidase activities of different extracts of Suaeda heterophylla (S. heterophylla and Bergenia stracheyi (B. stracheyi. Methods: The extracts of S. heterophylla and B. stracheyi were evaluated for antioxidant, phytotoxic, antimicrobial, insecticidal, cytotoxic, antiglycative, and xanthine oxidase activities using standard experimental methods. Results: The overall antioxidant potential of ethyl acetate extract of S. heterophylla was the strongest, followed by chloroform extract, methanolic extract and n-hexane extract. It is interesting to note that ethyl acetate fraction showed 94.98% inhibition at concentration of 60 µg/mL while standard ascorbic acid showed 98.49% inhibition at same concentration. The crude methanol extracts of S. heterophylla and B. stracheyi showed significant phytotoxic activity at the highest dose. Moreover, methanol extract of B. stracheyi possessed strong activity in xanthine oxidase enzyme inhibition. Conclusions: Antioxidant, phytotoxic, and xanthine oxidase activities of different fractions of S. heterophylla and B. stracheyi clearly demonstrate that these fractions possess great potential for the food, cosmetic and pharmaceutical industries.

  12. Surface-enhanced Raman spectroscopy of chernozem humic acid and their fractions obtained by coupled size exclusion chromatography-polyacrylamide gel electrophoresis (SEC-PAGE).

    Science.gov (United States)

    Sanchez-Cortes, S; Corrado, G; Trubetskaya, O E; Trubetskoj, O A; Hermosin, B; Saiz-Jimenez, C

    2006-01-01

    A humic acid extracted from a chernozem soil was fractionated combining size exclusion chromatography and polyacrylamide electrophoresis (SEC-PAGE). Three fractions named A, B, and C+D, with different electrophoretic mobilities and molecular sizes (MS), were obtained and subsequently characterized by thermochemolysis and surface-enhanced Raman spectroscopy (SERS). The data confirmed that fraction A, with the higher MS, was more aliphatic than fractions B and C+D and, in turn, fractions with lower MS (B and C+D) denoted an enrichment in lignin residues. These structural features explain conformational changes when varying the pH in the humic fraction A and indicated that combination of the two techniques is a good approach for characterizing humic substances.

  13. Putting together a plasma membrane NADH oxidase: a tale of three laboratories.

    Science.gov (United States)

    Löw, Hans; Crane, Frederick L; Morré, D James

    2012-11-01

    The observation that high cellular concentrations of NADH were associated with low adenylate cyclase activity led to a search for the mechanism of the effect. Since cyclase is in the plasma membrane, we considered the membrane might have a site for NADH action, and that NADH might be oxidized at that site. A test for NADH oxidase showed very low activity, which could be increased by adding growth factors. The plasma membrane oxidase was not inhibited by inhibitors of mitochondrial NADH oxidase such as cyanide, rotenone or antimycin. Stimulation of the plasma membrane oxidase by iso-proterenol or triiodothyronine was different from lack of stimulation in endoplasmic reticulum. After 25 years of research, three components of a trans membrane NADH oxidase have been discovered. Flavoprotein NADH coenzyme Q reductases (NADH cytochrome b reductase) on the inside, coenzyme Q in the middle, and a coenzyme Q oxidase on the outside as a terminal oxidase. The external oxidase segment is a copper protein with unique properties in timekeeping, protein disulfide isomerase and endogenous NADH oxidase activity, which affords a mechanism for control of cell growth by the overall NADH oxidase and the remarkable inhibition of oxidase activity and growth of cancer cells by a wide range of anti-tumor drugs. A second trans plasma membrane electron transport system has been found in voltage dependent anion channel (VDAC), which has NADH ferricyanide reductase activity. This activity must be considered in relation to ferricyanide stimulation of growth and increased VDAC antibodies in patients with autism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. NADPH oxidase AtrbohD and AtrbohF genes function in ROS-dependent ABA signaling in Arabidopsis

    Science.gov (United States)

    Kwak, June M.; Mori, Izumi C.; Pei, Zhen-Ming; Leonhardt, Nathalie; Torres, Miguel Angel; Dangl, Jeffery L.; Bloom, Rachel E.; Bodde, Sara; Jones, Jonathan D.G.; Schroeder, Julian I.

    2003-01-01

    Reactive oxygen species (ROS) have been proposed to function as second messengers in abscisic acid (ABA) signaling in guard cells. However, the question whether ROS production is indeed required for ABA signal transduction in vivo has not yet been addressed, and the molecular mechanisms mediating ROS production during ABA signaling remain unknown. Here, we report identification of two partially redundant Arabidopsis guard cell-expressed NADPH oxidase catalytic subunit genes, AtrbohD and AtrbohF, in which gene disruption impairs ABA signaling. atrbohD/F double mutations impair ABA-induced stomatal closing, ABA promotion of ROS production, ABA-induced cytosolic Ca2+ increases and ABA- activation of plasma membrane Ca2+-permeable channels in guard cells. Exogenous H2O2 rescues both Ca2+ channel activation and stomatal closing in atrbohD/F. ABA inhibition of seed germination and root elongation are impaired in atrbohD/F, suggesting more general roles for ROS and NADPH oxidases in ABA signaling. These data provide direct molecular genetic and cell biological evidence that ROS are rate-limiting second messengers in ABA signaling, and that the AtrbohD and AtrbohF NADPH oxidases function in guard cell ABA signal transduction. PMID:12773379

  15. gamma-Aminobutyric acid stimulates ethylene biosynthesis in sunflower

    International Nuclear Information System (INIS)

    Kathiresan, A.; Tung, P.; Chinnappa, C.C.; Reid, D.M.

    1997-01-01

    gamma-Aminobutyric acid (GABA), a nonprotein amino acid, is often accumulated in plants following environmental stimuli that can also cause ethylene production. We have investigated the relationship between GABA and ethylene production in excised sunflower (Helianthus annuus L.) tissues. Exogenous GABA causes up to a 14-fold increase in the ethylene production rate after about 12 h. Cotyledons fed with [14C]GABA did not release substantial amounts of radioactive ethylene despite its chemical similarity to 1-aminocyclopropane-1-carboxylic acid (ACC), indicating that GABA is not likely to be an alternative precursor for ethylene. GABA causes increases in ACC synthase mRNA accumulation, ACC levels, ACC oxidase mRNA levels, and in vitro ACC oxidase activity. In the presence of aminoethoxyvinylglycine or alpha-aminoisobutyric acid, GABA did not stimulate ethylene production. We therefore conclude that GABA stimulates ethylene biosynthesis mainly by promoting ACC synthase transcript abundance. Possible roles of GABA as a signal transducer are suggested

  16. Isolation and fractionation of soil humin using alkaline urea and dimethylsulphoxide plus sulphuric acid

    Science.gov (United States)

    Song, Guixue; Hayes, Michael H. B.; Novotny, Etelvino H.; Simpson, Andre J.

    2011-01-01

    Humin, the most recalcitrant and abundant organic fraction of soils and of sediments, is a significant contributor to the stable carbon pool in soils and is important for the global carbon budget. It has significant resistance to transformations by microorganisms. Based on the classical operational definition, humin can include any humic-type substance that is not soluble in water at any pH. We demonstrate in this study how sequential exhaustive extractions with 0.1 M sodium hydroxide (NaOH) + 6 M urea, followed by dimethylsulphoxide (DMSO) + 6% ( v/ v) sulphuric acid (H2SO4) solvent systems, can extract 70-80% of the residual materials remaining after prior exhaustive extractions in neutral and aqueous basic media. Solid-state 13C NMR spectra have shown that the components isolated in the base + urea system were compositionally similar to the humic and fulvic acid fractions isolated at pH 12.6 in the aqueous media. The NMR spectra indicated that the major components isolated in the DMSO + H2SO4 medium had aliphatic hydrocarbon associated with carboxyl functionalities and with lesser amounts of carbohydrate and peptide and minor amounts of lignin-derived components. The major components will have significant contributions from long-chain fatty acids, waxes, to cuticular materials. The isolates in the DMSO + H2SO4 medium were compositionally similar to the organic components that resisted solvation and remained associated with the soil clays. It is concluded that the base + urea system released humic and fulvic acids held by hydrogen bonding or by entrapment within the humin matrix. The recalcitrant humin materials extracted in DMSO + H2SO4 are largely biological molecules (from plants and the soil microbial population) that are likely to be protected from degradation by their hydrophobic moieties and by sorption on the soil clays. Thus, the major components of humin do not satisfy the classical definitions for humic substances which emphasise that these arise from

  17. Silicon Isotope Fractionation During Acid Water-Igneous Rock Interaction

    Science.gov (United States)

    van den Boorn, S. H.; van Bergen, M. J.; Vroon, P. Z.

    2007-12-01

    Silica enrichment by metasomatic/hydrothermal alteration is a widespread phenomenon in crustal environments where acid fluids interact with silicate rocks. High-sulfidation epithermal ore deposits and acid-leached residues at hot-spring settings are among the best known examples. Acid alteration acting on basalts has also been invoked to explain the relatively high silica contents of the surface of Mars. We have analyzed basaltic-andesitic lavas from the Kawah Ijen volcanic complex (East Java, Indonesia) that were altered by interaction with highly acid (pH~1) sulfate-chloride water of its crater lake and seepage stream. Quantitative removal of major elements during this interaction has led to relative increase in SiO2 contents. Our silicon isotope data, obtained by HR-MC-ICPMS and reported relative to the NIST RM8546 (=NBS28) standard, show a systematic increase in &δ&&30Si from -0.2‰ (±0.3, 2sd) for unaltered andesites and basalts to +1.5‰ (±0.3, 2sd) for the most altered/silicified rocks. These results demonstrate that silicification induced by pervasive acid alteration is accompanied by significant Si isotope fractionation, so that alterered products become isotopically heavier than the precursor rocks. Despite the observed enrichment in SiO2, the rocks have experienced an overall net loss of silicon upon alteration, if Nb is considered as perfectly immobile. The observed &δ&&30Si values of the alteration products appeared to correlate well with the inferred amounts of silicon loss. These findings would suggest that &28Si is preferentially leached during water-rock interaction, implying that dissolved silica in the ambient lake and stream water is isotopically light. However, layered opaline lake sediments, that are believed to represent precipitates from the silica-saturated water show a conspicuous &30Si-enrichment (+1.2 ± 0.2‰). Because anorganic precipitation is known to discriminate against the heavy isotope (e.g. Basile- Doelsch et al., 2006

  18. Isotopic fractionation of NBS oxalic acid and its influence in the calculated age of materials

    International Nuclear Information System (INIS)

    Nehmi, V.A.

    1979-10-01

    The intensity of the isotopic fractionation during the oxidation of NBS oxalic acid to carbon dioxide was checked. 30 reactions of oxidation of NBS oxalic acid with potassium permanganate were made. The resultant isotopic composition of CO 2 has been determined with a mass-spectrometer. A conclusion has been reached that the average of Δ 13 C is - 18.9% o with variation between - 17.7 and - 21.2%o. For values of Δ 13 C equal to - 22.0%o, the calculated age with isotopic correction shows the following deviations in relation to non-corrected age: 4% for materials of 1,000 years and 0.3% for 20,000 years.(Author) [pt

  19. Monoamine Oxidase Inhibitors (MAOIs)

    Science.gov (United States)

    ... health-medications/index.shtml. Accessed May 16, 2016. Hirsch M, et al. Monoamine oxidase inhibitors (MAOIs) for ... www.uptodate.com/home. Accessed May 16, 2016. Hirsch M, et al. Discontinuing antidepressant medications in adults. ...

  20. In situ acidity and pH of size-fractionated aerosols during a recent smoke-haze episode in Southeast Asia.

    Science.gov (United States)

    Behera, Sailesh N; Cheng, Jinping; Balasubramanian, Rajasekhar

    2015-10-01

    The characterization of aerosol acidity has received increased attention in recent years due to its influence on atmospheric visibility, climate change and human health. Distribution of water soluble inorganic (WSI) ions in 12 different size fractions of aerosols was investigated under two different atmospheric conditions (smoke-haze and non-haze periods) in 2012 using the Micro-Orifice Uniform Deposit Impactor (MOUDI) and nano-MOUDI for the first time in Singapore. To estimate the in situ acidity ([H(+)]Ins) and in situ aerosol pH (pHIS), the Aerosol Inorganic Model version-IV under deliquescent mode of airborne particles was used at prevailing ambient temperature and relative humidity. The study revealed an increase in the levels of airborne particulate matter (PM) mass and concentrations of WSI ions for all size fractions during the smoke-haze period, which was caused by the trans-boundary transport of biomass burning-impacted air masses from Indonesia. A bimodal distribution was observed for concentrations of SO4(2-), NO3(-), Cl(-), K(+) and Na(+), whereas concentrations of NH4(+), Ca(2+) and Mg(2+) showed a single mode distribution. The concentration of WSI ions in PM1.8 during the smoke-haze period increased by 3.8 (for SO4(2-)) to 10.5 (for K(+)) times more than those observed during the non-haze period. The pHIS were observed to be lower during the smoke-haze period than that during the non-haze period for all size fractions of PM, indicating that atmospheric aerosols were more acidic due to the influence of biomass burning emissions. The particles in the accumulation mode were more acidic than those in the coarse mode.

  1. Visual expression analysis of the responses of the alternative oxidase gene (aox1) to heat shock, oxidative, and osmotic stresses in conidia of citric acid-producing Aspergillus niger.

    Science.gov (United States)

    Honda, Yuki; Hattori, Takasumi; Kirimura, Kohtaro

    2012-03-01

    The citric acid-producing filamentous fungus Aspergillus niger WU-2223L shows cyanide-insensitive respiration catalyzed by alternative oxidase in addition to the cytochrome pathway. Sequence analysis of the 5' flanking region of the alternative oxidase gene (aox1) revealed a potential heat shock element (HSE) and a stress response element (STRE). We have previously confirmed aox1 expression in conidia. In this study, to confirm whether the upstream region of aox1 responds to various stresses, we used a visual expression analysis system for single-cell conidia of the A. niger strain AOXEGFP-1. This strain harbored a fusion gene comprising aox1 and egfp, which encodes the enhanced green fluorescent protein (EGFP). The fluorescence intensity of EGFP increased in conidia of A. niger AOXEGFP-1 that were subjected to heat shock at 35-45 °C, oxidative stress by exposure to 5mM paraquat or 1 mM t-butylhydroperoxide, or osmotic stresses by exposure to 0.5 M KCl or 1.0 M mannitol. These results indicate that the putative HSE and STRE in the upstream region of aox1 directly or indirectly respond to heat shock, oxidative, and osmotic stresses. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. White clover fractions as protein source for monogastrics: dry matter digestibility and protein digestibility-corrected amino acid scores.

    Science.gov (United States)

    Stødkilde, Lene; Damborg, Vinni K; Jørgensen, Henry; Laerke, Helle N; Jensen, Søren K

    2018-05-01

    The present study aimed to evaluate the use of white clover as an alternative protein source for monogastrics. White clover plant and leaves were processed using a screw-press resulting in a solid pulp and a juice from which protein was acid-precipitated. The chemical composition of all fractions was determined and digestibility of dry matter (DM) and protein was assessed in an experiment with growing rats. Protein concentrates were produced with crude protein (CP) contents of 451 g kg -1 and 530 g kg -1 DM for white clover plant and leaves, respectively, and a pulp with CP contents of 313 and 374 g kg -1 DM from plant and leaves, respectively. The amino acid composition ranged from 4.72 to 6.49 g per 16 g of nitrogen (N) for lysine, 1.82-2.6 g per 16 g N for methionine and cysteine, and 3.66-5.24 g per 16 g N for threonine. True faecal digestibility of protein varied from 0.81 to 0.88, whereas DM digestibility was in the range 0.72-0.80. Methionine and cysteine were found to be limiting in all fractions, regardless of the reference group used. A high digestibility of white clover protein was found irrespective of the physical fractionation. Together with a well-balanced amino acid composition, this makes white clover a promising protein source for monogastrics. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Apocynin: Chemical and Biophysical Properties of a NADPH Oxidase Inhibitor

    Directory of Open Access Journals (Sweden)

    Valdecir F. Ximenes

    2013-03-01

    Full Text Available Apocynin is the most employed inhibitor of NADPH oxidase (NOX, a multienzymatic complex capable of catalyzing the one-electron reduction of molecular oxygen to the superoxide anion. Despite controversies about its selectivity, apocynin has been used as one of the most promising drugs in experimental models of inflammatory and neurodegenerative diseases. Here, we aimed to study the chemical and biophysical properties of apocynin. The oxidation potential was determined by cyclic voltammetry (Epa = 0.76V, the hydrophobicity index was calculated (logP = 0.83 and the molar absorption coefficient was determined (e275nm = 1.1 × 104 M−1 cm−1. Apocynin was a weak free radical scavenger (as measured using the DPPH, peroxyl radical and nitric oxide assays when compared to protocatechuic acid, used here as a reference antioxidant. On the other hand, apocynin was more effective than protocatechuic acid as scavenger of the non-radical species hypochlorous acid. Apocynin reacted promptly with the non-radical reactive species H2O2 only in the presence of peroxidase. This finding is relevant, since it represents a new pathway for depleting H2O2 in cellular experimental models, besides the direct inhibition of NADPH oxidase. This could be relevant for its application as an inhibitor of NOX4, since this isoform produces H2O2 and not superoxide anion. The binding parameters calculated by fluorescence quenching showed that apocynin binds to human serum albumin (HSA with a binding affinity of 2.19 × 104 M−1. The association did not alter the secondary and tertiary structure of HSA, as verified by synchronous fluorescence and circular dichroism. The displacement of fluorescent probes suggested that apocynin binds to site I and site II of HSA. Considering the current biomedical applications of this phytochemical, the dissemination of these chemical and biophysical properties can be very helpful for scientists and physicians interested in the use of apocynin.

  4. Identification of anti-HIV active dicaffeoylquinic- and tricaffeoylquinic acids in Helichrysum populifolium by NMR-based metabolomic guided fractionation.

    Science.gov (United States)

    Heyman, Heino Martin; Senejoux, François; Seibert, Isabell; Klimkait, Thomas; Maharaj, Vinesh Jaichand; Meyer, Jacobus Johannes Marion

    2015-06-01

    South Africa being home to more than 35% of the world's Helichrysum species (c.a. 244) of which many are used in traditional medicine, is seen potentially as a significant resource in the search of new anti-HIV chemical entities. It was established that five of the 30 Helichrysum species selected for this study had significant anti-HIV activity ranging between 12 and 21 μg/mL (IC50) by using an in-house developed DeCIPhR method on a full virus model. Subsequent toxicity tests also revealed little or no toxicity for these active extracts. With the use of NMR-based metabolomics, the search for common chemical characteristics within the plant extract was conducted, which resulted in specific chemical shift areas identified that could be linked to the anti-HIV activity of the extracts. The NMR chemical shifts associated with the activity were identified to be 2.56-3.08 ppm, 5.24-6.28 ppm, 6.44-7.04 ppm and 7.24-8.04 ppm. This activity profile was then used to guide the fractionation process by narrowing down and focusing the fractionation and purification processes to speed up the putative identification of five compounds with anti-HIV activity in the most active species, Helichrysum populifolium. The anti-HIV compounds identified for the first time from H. populifolium were three dicaffeoylquinic acid derivatives, i.e. 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid as well as two tricaffeoylquinic acid derivatives i.e. 1,3,5-tricaffeoylquinic acid and either 5-malonyl-1,3,4-tricaffeoylquinic or 3-malonyl-1,4,5-tricaffeoylquinic acid, with the latter being identified for the first time in the genus. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Extraction of ascorbate oxidase from Cucurbita maxima by continuous process in perforated rotating disc contactor using aqueous two-phase systems.

    Science.gov (United States)

    Porto, T S; Marques, P P; Porto, C S; Moreira, K A; Lima-Filho, J L; Converti, A; Pessoa, A; Porto, A L F

    2010-02-01

    The ascorbate oxidase is the enzyme used to determine the content of ascorbic acid in the pharmaceutical and food industries and clinics analyses. The techniques currently used for the purification of this enzyme raise its production cost. Thus, the development of alternative processes and with the potential to reduce costs is interesting. The application of aqueous two-phase system is proposed as an alternative to purification because it enables good separation of biomolecules. The objective of this study was to determine the conditions to continuously pre-purify the enzyme ascorbate oxidase by an aqueous two-phase system (PEG/citrate) using rotating column provided with perforated discs. Under the best conditions (20,000 g/mol PEG molar mass, 10% PEG concentration, and 25% citrate concentration), the system showed satisfactory results (partition coefficient, 3.35; separation efficiency, 54.98%; and purification factor, 1.46) and proved suitable for the pre-purification of ascorbate oxidase in continuous process.

  6. Bioassay-guided fractionation of Melastoma malabathricum Linn. leaf solid phase extraction fraction and its anticoagulant activity.

    Science.gov (United States)

    Khoo, Li Teng; Abdullah, Janna Ong; Abas, Faridah; Tohit, Eusni Rahayu Mohd; Hamid, Muhajir

    2015-02-24

    The aims of this study were to examine the bioactive component(s) responsible for the anticoagulant activity of M. malabathricum Linn. leaf hot water crude extract via bioassay-guided fractionation and to evaluate the effect of bioactive component(s) on the intrinsic blood coagulation pathway. The active anticoagulant fraction of F3 was subjected to a series of chromatographic separation and spectroscopic analyses. Furthermore, the effect of the bioactive component(s) on the intrinsic blood coagulation pathway was studied through immediate and time incubation mixing studies. Through Activated Partial Thromboplastin Time (APTT) assay-guided fractionation, Subfraction B was considered the most potent anticoagulant fraction. Characterisation of Subfraction B indicated that anticoagulant activity could partly be due to the presence of cinnamic acid and a cinnamic acid derivative. APTT assays for both the immediate and time incubation mixing were corrected back into normal clotting time range (35.4-56.3 s). In conclusion, cinnamic acid and cinnamic acid derivative from Subfraction B were the first such compounds to be discovered from M. malabathricum Linn. leaf hot water crude extract that possess anticoagulant activity. This active anticoagulant Subfraction B prolonged blood clotting time by causing factor(s) deficiency in the intrinsic blood coagulation pathway.

  7. An Adaptation to Low Copper in Candida albicans Involving SOD Enzymes and the Alternative Oxidase.

    Directory of Open Access Journals (Sweden)

    Chynna N Broxton

    Full Text Available In eukaryotes, the Cu/Zn superoxide dismutase (SOD1 is a major cytosolic cuproprotein with a small fraction residing in the mitochondrial intermembrane space (IMS to protect against respiratory superoxide. Curiously, the opportunistic human fungal pathogen Candida albicans is predicted to express two cytosolic SODs including Cu/Zn containing SOD1 and manganese containing SOD3. As part of a copper starvation response, C. albicans represses SOD1 and induces the non-copper alternative SOD3. While both SOD1 and SOD3 are predicted to exist in the same cytosolic compartment, their potential role in mitochondrial oxidative stress had yet to be investigated. We show here that under copper replete conditions, a fraction of the Cu/Zn containing SOD1 localizes to the mitochondrial IMS to guard against mitochondrial superoxide. However in copper starved cells, localization of the manganese containing SOD3 is restricted to the cytosol leaving the mitochondrial IMS devoid of SOD. We observe that during copper starvation, an alternative oxidase (AOX form of respiration is induced that is not coupled to ATP synthesis but maintains mitochondrial superoxide at low levels even in the absence of IMS SOD. Surprisingly, the copper-dependent cytochrome c oxidase (COX form of respiration remains high with copper starvation. We provide evidence that repression of SOD1 during copper limitation serves to spare copper for COX and maintain COX respiration. Overall, the complex copper starvation response of C. albicans involving SOD1, SOD3 and AOX minimizes mitochondrial oxidative damage whilst maximizing COX respiration essential for fungal pathogenesis.

  8. Enzymatic oxidation of 2-phenylethylamine to phenylacetic acid and 2-phenylethanol with special reference to the metabolism of its intermediate phenylacetaldehyde.

    Science.gov (United States)

    Panoutsopoulos, Georgios I; Kouretas, Demetrios; Gounaris, Elias G; Beedham, Christine

    2004-12-01

    2-phenylethylamine is an endogenous constituent of the human brain and is implicated in cerebral transmission. This bioactive amine is also present in certain foodstuffs such as chocolate, cheese and wine and may cause undesirable side effects in susceptible individuals. Metabolism of 2-phenylethylamine to phenylacetaldehyde is catalysed by monoamine oxidase B but the oxidation to its acid is usually ascribed to aldehyde dehydrogenase and the contribution of aldehyde oxidase and xanthine oxidase, if any, is ignored. The objective of this study was to elucidate the role of the molybdenum hydroxylases, aldehyde oxidase and xanthine oxidase, in the metabolism of phenylacetaldehyde derived from its parent biogenic amine. Treatments of 2-phenylethylamine with monoamine oxidase were carried out for the production of phenylacetaldehyde, as well as treatments of synthetic or enzymatic-generated phenylacetaldehyde with aldehyde oxidase, xanthine oxidase and aldehyde dehydrogenase. The results indicated that phenylacetaldehyde is metabolised mainly to phenylacetic acid with lower concentrations of 2-phenylethanol by all three oxidising enzymes. Aldehyde dehydrogenase was the predominant enzyme involved in phenylacetaldehyde oxidation and thus it has a major role in 2-phenylethylamine metabolism with aldehyde oxidase playing a less prominent role. Xanthine oxidase does not contribute to the oxidation of phenylacetaldehyde due to low amounts being present in guinea pig. Thus aldehyde dehydrogenase is not the only enzyme oxidising xenobiotic and endobiotic aldehydes and the role of aldehyde oxidase in such reactions should not be ignored.

  9. Amino Acid Composition, Molecular Weight Distribution and Gel Electrophoresis of Walnut (Juglans regia L. Proteins and Protein Fractionations

    Directory of Open Access Journals (Sweden)

    Xiaoying Mao

    2014-01-01

    Full Text Available As a by-product of oil production, walnut proteins are considered as an additional source of plant protein for human food. To make full use of the protein resource, a comprehensive understanding of composition and characteristics of walnut proteins are required. Walnut proteins have been fractionated and characterized in this study. Amino acid composition, molecular weight distribution and gel electrophoresis of walnut proteins and protein fractionations were analyzed. The proteins were sequentially separated into four fractions according to their solubility. Glutelin was the main component of the protein extract. The content of glutelin, albumin, globulin and prolamin was about 72.06%, 7.54%, 15.67% and 4.73% respectively. Glutelin, albumin and globulin have a balanced content of essential amino acids, except for methionine, with respect to the FAO pattern recommended for adults. SDS-PAGE patterns of albumin, globulin and glutelin showed several polypeptides with molecular weights 14.4 to 66.2 kDa. The pattern of walnut proteins in two-dimension electrophoresis (2-DE showed that the isoelectric point was mainly in the range of 4.8–6.8. The results of size exclusion chromatogram indicated molecular weight of the major components of walnut proteins were between 3.54 and 81.76 kDa.

  10. Cytochrome cbb3 of Thioalkalivibrio is a Na+-pumping cytochrome oxidase

    NARCIS (Netherlands)

    Muntyan, M.S.; Cherepanov, D.A.; Malinen, A.M.; Bloch, D.A.; Sorokin, D.Y.; Severina, I.I.; Ivashina, T.V.; Lahti, R.; Muyzer, G.; Skulachev, V.P.

    2015-01-01

    Cytochrome c oxidases (Coxs) are the basic energy transducers in the respiratory chain of the majority of aerobic organisms. Coxs studied to date are redox-driven proton-pumping enzymes belonging to one of three subfamilies: A-, B-, and C-type oxidases. The C-type oxidases (cbb3 cytochromes), which

  11. Comparison of chemical characteristics of high oleic acid fraction of moringa oleifera oil with some vegetable oils

    International Nuclear Information System (INIS)

    Rahman, F.; Nadeem, M.; Zahoor, Y.

    2014-01-01

    Chemical characteristics of High oleic acid fraction (HOF) of Moringa oleifera oil (MOO) was compared with sunflower, soybean and canola oils. HOF of MOO was obtained by dry fractionation at 0 degree C. Iodine value and C18:1 in HOF increased from 61.55 to 82.47 points and 70.29% to 81.15%, respectively. Cloud point of HOF was 1.1 degree C as compared to 10.2 degree C in MOO. The induction period of HOF was greater than all the vegetable oils tested in this investigation. HOF can be used as a source of edible oil with better health attributes and superior storage stability. (author)

  12. Serum diamine oxidase activity in patients with histamine intolerance.

    Science.gov (United States)

    Manzotti, G; Breda, D; Di Gioacchino, M; Burastero, S E

    2016-03-01

    Intolerance to various foods, excluding bona fide coeliac disease and lactose intolerance, represents a growing cause of patient visits to allergy clinics.Histamine intolerance is a long-known, multifaceted clinical condition triggered by histamine-rich foods and alcohol and/or by drugs that liberate histamine or block diamine oxidase (DAO), the main enzyme involved in the metabolism of ingested histamine. Histamine limitation diets impose complex, non-standardized restrictions that may severely impact the quality of life of patients. We retrospectively evaluated 14 patients who visited allergy outpatient facilities in northern Italy with a negative diagnosis for IgE-mediated food hypersensitivity, coeliac disease, conditions related to gastric hypersecretion, and systemic nickel hypersensitivity, and who previously underwent a histamine limitation diet with benefits for their main symptoms. Serum diamine oxidase levels and the clinical response to diamine oxidase supplementation were investigated. We found that 10 out of 14 patients had serum DAO activityintolerance. Moreover, 13 out of 14 patients subjectively reported a benefit in at least one of the disturbances related to food intolerances following diamine oxidase supplementation. The mean value (±SD) of diamine oxidase activity in the cohort of patients with histamine intolerance symptoms was 7.04±6.90 U/mL compared to 39.50±18.16 U/mL in 34 healthy controls (P=0.0031). In patients with symptoms triggered by histamine-rich food, measuring the serum diamine oxidase activity can help identify subjects who can benefit from a histamine limitation diet and/or diamine oxidase supplementation.Properly designed, controlled studies investigating histamine intolerance that include histamine provocation are indispensable for providing insights into the area of food intolerances, which are currently primarily managed with non-scientific approaches in Italy. © The Author(s) 2015.

  13. Structure and activity of Aspergillus nidulans copper amine oxidase

    DEFF Research Database (Denmark)

    McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

    2011-01-01

    Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

  14. Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.

    Directory of Open Access Journals (Sweden)

    Young-Moo Choo

    Full Text Available Antennae-specific odorant-degrading enzymes (ODEs are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs. Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW, Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.

  15. Expression and Chloroplast Targeting of Cholesterol Oxidase in Transgenic Tobacco Plants

    Science.gov (United States)

    Corbin, David R.; Grebenok, Robert J.; Ohnmeiss, Thomas E.; Greenplate, John T.; Purcell, John P.

    2001-01-01

    Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism. PMID:11457962

  16. Influence of different nominal molecular weight fractions of humic acids on phenol oxidation by permanganate.

    Science.gov (United States)

    He, Di; Guan, Xiaohong; Ma, Jun; Yu, Min

    2009-11-01

    The effects of humic acid (HA) and its different nominal molecular weight (NMW) fractions on the phenol oxidation by permanganate were studied. Phenol oxidation by permanganate was enhanced by the presence of HA at pH 4-8, while slightly inhibited at pH 9-10. The effects of HA on phenol oxidation by permanganate were dependent on HA concentration and permanganate/phenol molar ratios. The high NMW fractions of HA enhanced phenol oxidation by permanganate at pH 7 more significantly than the low fractions of HA. The apparent second-order rate constants of phenol oxidation by permanganate in the presence of HA correlated well with their specific ultraviolet absorption (SUVA) at 254 nm and specific violet absorption (SVA) at 465 or 665 nm. High positive correlation coefficients (R(2) > 0.72) implied that pi-electrons of HA strongly influenced the reactivity of phenol towards permanganate oxidation which agreed well with the information provided by fluorescence spectroscopy. The FTIR analysis indicated that the HA fractions rich in aliphatic character, polysaccharide-like substances, and the amount of carboxylate groups had less effect on phenol oxidation by permanganate. The negative correlation between the rate constants of phenol oxidation by permanganate and O/C ratios suggested that the oxidation of phenol increased with a decrease in the content of oxygen-containing functional groups.

  17. Treatment of acidic mine water at uranium mine No. 711 by barium chloride-sludge recycle-fractional neutralization process

    International Nuclear Information System (INIS)

    Yang Chaowen; Wang Benyi; Ding Tongsen; Zhong Pingru; Liao Yongbing; Li Xiaochu; Lu Guohua

    1994-01-01

    The barium chloride-sludge recycle-fractional neutralization process for disposal of acidic mine water at Uranium Mine No. 711 was checked through laboratory and enlarged tests and one-year industrial trial-run. The results showed that the presented technology can meet the requirements of production and environmental protection

  18. An integrated scheme for the simultaneous determination of biogenic amines, precursor amino acids, and related metabolites by liquid chromatography with electrochemical detection.

    Science.gov (United States)

    Oka, K; Kojima, K; Togari, A; Nagatsu, T; Kiss, B

    1984-06-08

    A new method using high-performance liquid chromatography with electrochemical detection (HPLC-ED) for the simultaneous determination of monoamines, their precursor amino acids, and related major metabolites in small samples of brain tissue weighing from 0.5 to 50 mg is described. The method is based on the preliminary isolation of monoamines (dopamine, norepinephrine, epinephrine, and serotonin), their precursor amino acids (tyrosine, 3,4-dihydroxyphenylalanine, tryptophan and 5-hydroxytryptophan), and their major metabolites (3-methoxytyramine, normetanephrine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, vanillylmandelic acid, 3-methoxy-4-hydroxyphenylethyleneglycol, and 5-hydroxyindoleacetic acid) by chromatography on small columns of Amberlite CG-50 and Dowex 50W, and by ethyl acetate extraction. All the compounds in the four isolated fractions were measured by HPLC-ED on a reversed-phase column under four different conditions. The sensitivity was from 0.1 to 40 pmol, depending on the substances analysed. This newly established method was applied to the study of the effects of an aromatic L-amino acid decarboxylase inhibitor (NSD-1015) and a monoamine oxidase inhibitor (pargyline) on the levels of monoamines, their precursor amino acids and their major metabolites in brain regions of mice.

  19. Synergistic effect of Aspergillus tubingensis CTM 507 glucose oxidase in presence of ascorbic acid and alpha amylase on dough properties, baking quality and shelf life of bread.

    Science.gov (United States)

    Kriaa, Mouna; Ouhibi, Rabeb; Graba, Héla; Besbes, Souhail; Jardak, Mohamed; Kammoun, Radhouane

    2016-02-01

    The impact of Aspergillus tubingensis glucose oxidase (GOD) in combination with α-amylase and ascorbic acid on dough properties, qualities and shelf life of bread was investigated. Regression models of alveograph and texture parameters of dough and bread were adjusted. Indeed, the mixture of GOD (44 %) and ascorbic acid (56 %) on flour containing basal improver showed its potential as a corrective action to get better functional and rheological properties of dough and bread texture. Furthermore, wheat flour containing basal additives and enriched with GOD (63.8 %), ascorbic acid (32 %) and α- amylase (4.2 %) led to high technological bread making parameters, to decrease the crumb firmness and chewiness and to improve elasticity, adhesion, cohesion and specific volume of bread. In addition to that, the optimized formulation addition significantly reduced water activity and therefore decreased bread susceptibility to microbial spoilage. These findings demonstrated that GOD could partially substitute not only ascorbic acid but also α-amylase. The generated models allowed to predict the behavior of wheat flour containing additives in the range of values tested and to define the additives formula that led to desired rheological and baking qualities of dough. This fact provides new perspectives to compensate flour quality deficiencies at the moment of selecting raw materials and technological parameters reducing the production costs and facilitating gluten free products development. Graphical abstractᅟ.

  20. Fractionation of fulvic acid by iron and aluminum oxides: influence on copper toxicity to Ceriodaphnia dubia

    Science.gov (United States)

    Smith, Kathleen S.; Ranville, James F.; Lesher, Emily K.; Diedrich, Daniel J.; McKnight, Diane M.; Sofield, Ruth M.

    2014-01-01

    This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on ,i>Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.6 μg Cu/L) than were the unfractionated dissolved FAs (EC50 39 ± 0.4 and 41 ± 1.2 μg Cu/L). The fractionation is a consequence of preferential sorption of molecules having strong metal-binding (more aromatic) moieties to precipitating Fe- and Al-rich oxyhydroxides, causing the remaining dissolved FA to be depleted in these functional groups. As a result, there is more bioavailable dissolved Cu in the water and hence greater potential for Cu toxicity to aquatic organisms. In predicting Cu toxicity, biotic ligand models (BLMs) take into account dissolved organic carbon (DOC) concentration; however, unless DOC characteristics are accounted for, model predictions can underestimate acute Cu toxicity for water containing fractionated dissolved FA. This may have implications for water-quality criteria in systems containing Fe- and Al-rich sediment, and in mined and mineralized areas in particular. Optical measurements, such as specific ultraviolet absorbance at 254 nm (SUVA254), show promise for use as spectral indicators of DOC chemical fractionation and inferred increased Cu toxicity.

  1. Plasma diamine oxidase levels in pregnancy complicated by threatened abortion.

    OpenAIRE

    Legge, M; Duff, G B

    1981-01-01

    Plasma diamine oxidase levels were assayed in 66 patients who presented with pregnancy complicated by threatened abortion. Levels within the normal range were associated with continuing pregnancies, whereas levels below the normal range were associated with subsequent abortion. Among those patients in whom gestation was greater than eight weeks, 66.6% of diamine oxidase levels correctly predicted the pregnancy outcome. Assay of the diamine oxidase levels at eight weeks of gestation or less ga...

  2. Crystallization and preliminary crystallographic analysis of a flavoprotein NADH oxidase from Lactobacillus brevis

    International Nuclear Information System (INIS)

    Kuzu, Mutlu; Niefind, Karsten; Hummel, Werner; Schomburg, Dietmar

    2005-01-01

    The water-forming flavoenzyme NADH oxidase was crystallized successfully for the first time. The crystals diffract X-rays to at least 4.0 Å resolution. NADH oxidase (NOX) from Lactobacillus brevis is a homotetrameric flavoenzyme composed of 450 amino acids per subunit. The molecular weight of each monomer is 48.8 kDa. The enzyme catalyzes the oxidation of two equivalents of NADH and reduces one equivalent of oxygen to yield two equivalents of water, without releasing hydrogen peroxide after the reduction of the first equivalent of NADH. Crystals of this protein were grown in the presence of 34% polyethylene glycol monomethyl ether 2000, 0.1 M sodium acetate and 0.2 M ammonium sulfate at pH 5.4. They belong to the tetragonal space group P4 3 2 1 2, with unit-cell parameters a = 74.8, b = 95.7, c = 116.9 Å, α = γ = 90, β = 103.8°. The current diffraction limit is 4.0 Å. The self-rotation function of the native data set is consistent with a NOX tetramer in the asymmetric unit

  3. Contribution of bacterial cell nitrogen to soil humic fractions

    International Nuclear Information System (INIS)

    Knowles, R.; Barro, L.

    1981-01-01

    Living cells of Serratia marcescens, uniformly labelled with 15 N, were added to samples of maple (Acer saccharum) and black spruce (Picea mariana) forest soils. After different periods of incubation from zero time to 100 days, the soils were subjected to alkali-acid and phenol extraction to provide humic acid, fulvic acid, humin and 'humoprotein' fractions. Significant amounts of the cell nitrogen were recovered in the humic and fulvic acids immediately after addition. After incubation, less cell nitrogen appeared in the humic acid and more in the fulvic acid. The amount of cell nitrogen recovered in the humin fraction increased with incubation. Roughly 5 to 10 per cent of the added cell nitrogen was found as amino acid nitrogen from humoprotein in a phenol extract of the humic acid. The data are consistent with the occurrence of co-precipitation of biologically labile biomass nitrogen compounds with humic polymers during the alkaline extraction procedure involved in the humic-fulvic fractionation. (orig.)

  4. Electrochemical Glucose Biosensor Based on Glucose Oxidase Displayed on Yeast Surface.

    Science.gov (United States)

    Wang, Hongwei; Lang, Qiaolin; Liang, Bo; Liu, Aihua

    2015-01-01

    The conventional enzyme-based biosensor requires chemical or physical immobilization of purified enzymes on electrode surface, which often results in loss of enzyme activity and/or fractions immobilized over time. It is also costly. A major advantage of yeast surface display is that it enables the direct utilization of whole cell catalysts with eukaryote-produced proteins being displayed on the cell surface, providing an economic alternative to traditional production of purified enzymes. Herein, we describe the details of the display of glucose oxidase (GOx) on yeast cell surface and its application in the development of electrochemical glucose sensor. In order to achieve a direct electrochemistry of GOx, the entire cell catalyst (yeast-GOx) was immobilized together with multiwalled carbon nanotubes on the electrode, which allowed sensitive and selective glucose detection.

  5. Priming of the neutrophil NADPH oxidase activation: role of p47phox phosphorylation and NOX2 mobilization to the plasma membrane.

    Science.gov (United States)

    El-Benna, Jamel; Dang, Pham My-Chan; Gougerot-Pocidalo, Marie-Anne

    2008-07-01

    Neutrophils play an essential role in host defense against microbial pathogens and in the inflammatory reaction. Upon activation, neutrophils produce superoxide anion (O*2), which generates other reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (OH*) and hypochlorous acid (HOCl), together with microbicidal peptides and proteases. The enzyme responsible for O2* production is called the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two trans-membrane proteins (p22phox and gp91phox/NOX2, which form the cytochrome b558), three cytosolic proteins (p47phox, p67phox, p40phox) and a GTPase (Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate factors. Three major events accompany NAPDH oxidase activation: (1) protein phosphorylation, (2) GTPase activation, and (3) translocation of cytosolic components to the plasma membrane to form the active enzyme. Actually, the neutrophil NADPH oxidase exists in different states: resting, primed, activated, or inactivated. The resting state is found in circulating blood neutrophils. The primed state can be induced by neutrophil adhesion, pro-inflammatory cytokines, lipopolysaccharide, and other agents and has been characterized as a "ready to go" state, which results in a faster and higher response upon exposure to a second stimulus. The active state is found at the inflammatory or infection site. Activation is induced by the pathogen itself or by pathogen-derived formylated peptides and other agents. Finally, inactivation of NADPH oxidase is induced by anti-inflammatory agents to limit inflammation. Priming is a "double-edged sword" process as it contributes to a rapid and efficient elimination of the pathogens but can also induce the generation of large quantities of toxic ROS by hyperactivation of

  6. Carbon-13 fractionation observed in thermal decarboxylation of pure phenylpropiolic acid (PPA) dissolved in phenylacetylene

    International Nuclear Information System (INIS)

    Zielinska, A.; Zielinski, M.; Papiernik-Zielinska, H.

    2003-01-01

    The determinations of the 13 C fractionation in the decarboxylation of pure phenylpropiolic acid (PPA) above its melting point has been extended to higher degrees of decomposition of PPA by carrying out two-step decarboxylations to establish the maximum possible yield of carbon dioxide in the temperature interval of 423-475 K (58%). The result was compared with the yields of CO 2 for decarboxylation of PPA in phenylacetylene solvent (PA) (much smaller, temperature dependent, and equal to 11% at 406 K). The ratios of carbon isotope ratios, R so /R pf , all smaller than 1.009 in the temperature interval 405-475 K, have been analyzed formally within the branched decomposition scheme of PPA, providing carbon dioxide and a decarboxylation resistant solid chemical compound enriched in 13 C with respect to CO 2 . A general discussion of the 13 C fractionation in the decarboxylation of pure PPA and PPA dissolved in PA is supplemented by the model calculation of the maximized skeletal 13 C KIEs, in the linear chain propagation of the acetylene polymerization process. Further studies of the 13 C fractionation in condensed phases and in different hydrogen deficient and hydrogen rich media have been suggested. (author)

  7. Reengineered glucose oxidase for amperometric glucose determination in diabetes analytics.

    Science.gov (United States)

    Arango Gutierrez, Erik; Mundhada, Hemanshu; Meier, Thomas; Duefel, Hartmut; Bocola, Marco; Schwaneberg, Ulrich

    2013-12-15

    Glucose oxidase is an oxidoreductase exhibiting a high β-D-glucose specificity and high stability which renders glucose oxidase well-suited for applications in diabetes care. Nevertheless, GOx activity is highly oxygen dependent which can lead to inaccuracies in amperometric β-D-glucose determinations. Therefore a directed evolution campaign with two rounds of random mutagenesis (SeSaM followed by epPCR), site saturation mutagenesis studies on individual positions, and one simultaneous site saturation library (OmniChange; 4 positions) was performed. A diabetes care well suited mediator (quinone diimine) was selected and the GOx variant (T30V I94V) served as starting point. For directed GOx evolution a microtiter plate detection system based on the quinone diimine mediator was developed and the well-known ABTS-assay was applied in microtiter plate format to validate oxygen independency of improved GOx variants. Two iterative rounds of random diversity generation and screening yielded to two subsets of amino acid positions which mainly improved activity (A173, A332) and oxygen independency (F414, V560). Simultaneous site saturation of all four positions with a reduced subset of amino acids using the OmniChange method yielded finally variant V7 with a 37-fold decreased oxygen dependency (mediator activity: 7.4 U/mg WT, 47.5 U/mg V7; oxygen activity: 172.3 U/mg WT, 30.1 U/mg V7). V7 is still highly β-D-glucose specific, highly active with the quinone diimine mediator and thermal resistance is retained (prerequisite for GOx coating of diabetes test stripes). The latter properties and V7's oxygen insensitivity make V7 a very promising candidate to replace standard GOx in diabetes care applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Plasma diamine oxidase levels in pregnancy complicated by threatened abortion.

    Science.gov (United States)

    Legge, M; Duff, G B

    1981-02-01

    Plasma diamine oxidase levels were assayed in 66 patients who presented with pregnancy complicated by threatened abortion. Levels within the normal range were associated with continuing pregnancies, whereas levels below the normal range were associated with subsequent abortion. Among those patients in whom gestation was greater than eight weeks, 66.6% of diamine oxidase levels correctly predicted the pregnancy outcome. Assay of the diamine oxidase levels at eight weeks of gestation or less gave little useful information.

  9. Theoretical isotopic fractionation between structural boron in carbonates and aqueous boric acid and borate ion

    Science.gov (United States)

    Balan, Etienne; Noireaux, Johanna; Mavromatis, Vasileios; Saldi, Giuseppe D.; Montouillout, Valérie; Blanchard, Marc; Pietrucci, Fabio; Gervais, Christel; Rustad, James R.; Schott, Jacques; Gaillardet, Jérôme

    2018-02-01

    The 11B/10B ratio in calcite and aragonite is an important proxy of oceanic water pH. However, the physico-chemical mechanisms underpinning this approach are still poorly known. In the present study, we theoretically determine the equilibrium isotopic fractionation properties of structural boron species in calcium carbonates, BO33-, BO2(OH)2- and B(OH)4- anions substituted for carbonate groups, as well as those of B(OH)4- and B(OH)3 species in vacuum. Significant variability of equilibrium isotopic fractionation properties is observed among these structural species which is related to their contrasted coordination state, Bsbnd O bond lengths and atomic-scale environment. The isotopic composition of structural boron does not only depend on its coordination number but also on its medium range environment, i.e. farther than its first coordination shell. The isotopic fractionation between aqueous species and their counterparts in vacuum are assessed using previous investigations based on similar quantum-mechanical modeling approaches. At 300 K, the equilibrium isotope composition of structural trigonal species is 7-15‰ lighter than that of aqueous boric acid molecules, whereas substituted tetrahedral borate ions are heavier than their aqueous counterparts by 10-13‰. Although significant uncertainties are known to affect the theoretical prediction of fractionation factors between solids and solutions, the usually assumed lack of isotopic fractionation during borate incorporation in carbonates is challenged by these theoretical results. The present theoretical equilibrium fractionation factors between structural boron and aqueous species differ from those inferred from experiments which may indicate that isotopic equilibrium, unlike chemical equilibrium, was not reached in most experiments. Further research into the isotopic fractionation processes at the interface between calcium carbonates and aqueous solution as well as long duration experiments aimed at

  10. Chemical research of lipophilic fractions of sickle alfalfa herbs

    Directory of Open Access Journals (Sweden)

    S. V. Kovalev

    2013-06-01

    Full Text Available Lipophilic fraction (LF of known medicinal plants are still less studied, despite the fact that they have a unique group of biological active compounds (BAC. The main active substances of LF are chlorophylls, carotenoids, tocopherols, sterols, unsaturated fatty acids, phospholipids, and other bioactive substances that exhibit a wide spectrum of pharmacological action. In this regard, a comprehensive study of advanced plant of flora of Ukraine to increase the assortments of herbal remedies is an urgent problem. The aim of this work was to obtain and chemical research of lipophilic fractions of sickle alfalfa herbs. The alfalfa herb harvested throughout the growing season in Kharkov and Poltava regions in 2011-2012. Lipophilic fraction was obtained by extraction with chloroform in a Soxhlet apparatus. Detection of carotenoids and chlorophylls by thin layer chromatography (TLC on plates of "Silufol" in one-dimensional and two-dimensional variants, the solvent system were: hexane: acetone (6:2 - I way, hexane-acetone (6:4 - II way. Assay of the lipophilic fraction by three-dimensional fluorescence spectroscopy (3DF-spectroscopy was used for the analysis of mixtures containing fluorescent components. 3DF-spectres, that have the appearance of the surface, are characterized by a functions I = f (λexc, λem, recorded in the ultraviolet and visible ranges. Assay of the carotenoids and chlorophylls carried out by spectrophotometry. The reference solution was chloroform. Assay of fatty acids was performed by gas-liquid chromatography (GLC of methyl esters of fatty acids via chromatograph with flame ionization detector "Shimadzu GC-14B". 20.0 g crushed sickle alfalfa herbs were exhaustively extracted with chloroform in a Soxhlet apparatus for produce a lipophilic fractions. The chloroform extract was evaporated in order to remove the extractant. The percentage of lipophilic fraction in the herbs was 7.5%. Quantity of the carotenoids and chlorophylls

  11. Increased Production of Hydrogen Peroxide by Lactobacillus delbrueckii subsp. bulgaricus upon Aeration: Involvement of an NADH Oxidase in Oxidative Stress

    Science.gov (United States)

    Marty-Teysset, C.; de la Torre, F.; Garel, J.-R.

    2000-01-01

    The growth of Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii subsp. bulgaricus) on lactose was altered upon aerating the cultures by agitation. Aeration caused the bacteria to enter early into stationary phase, thus reducing markedly the biomass production but without modifying the maximum growth rate. The early entry into stationary phase of aerated cultures was probably related to the accumulation of hydrogen peroxide in the medium. Indeed, the concentration of hydrogen peroxide in aerated cultures was two to three times higher than in unaerated ones. Also, a similar shift from exponential to stationary phase could be induced in unaerated cultures by adding increasing concentrations of hydrogen peroxide. A significant fraction of the hydrogen peroxide produced by L. delbrueckii subsp. bulgaricus originated from the reduction of molecular oxygen by NADH catalyzed by an NADH:H2O2 oxidase. The specific activity of this NADH oxidase was the same in aerated and unaerated cultures, suggesting that the amount of this enzyme was not directly regulated by oxygen. Aeration did not change the homolactic character of lactose fermentation by L. delbrueckii subsp. bulgaricus and most of the NADH was reoxidized by lactate dehydrogenase with pyruvate. This indicated that NADH oxidase had no (or a very small) energetic role and could be involved in eliminating oxygen. PMID:10618234

  12. Biofabrication Using Pyrrole Electropolymerization for the Immobilization of Glucose Oxidase and Lactate Oxidase on Implanted Microfabricated Biotransducers

    Directory of Open Access Journals (Sweden)

    Christian N. Kotanen

    2014-03-01

    Full Text Available The dual responsive Electrochemical Cell-on-a-Chip Microdisc Electrode Array (ECC MDEA 5037 is a recently developed electrochemical transducer for use in a wireless, implantable biosensor system for the continuous measurement of interstitial glucose and lactate. Fabrication of the biorecognition membrane via pyrrole electropolymerization and both in vitro and in vivo characterization of the resulting biotransducer is described. The influence of EDC-NHS covalent conjugation of glucose oxidase with 4-(3-pyrrolyl butyric acid (monomerization and with 4-sulfobenzoic acid (sulfonization on biosensor performance was examined. As the extent of enzyme conjugation was increased sensitivity decreased for monomerized enzymes but increased for sulfonized enzymes. Implanted biotransducers were examined in a Sprague-Dawley rat hemorrhage model. Resection after 4 h and subsequent in vitro re-characterization showed a decreased sensitivity from 0.68 (±0.40 to 0.22 (±0.17 µA·cm−2·mM−1, an increase in the limit of detection from 0.05 (±0.03 to 0.27 (±0.27 mM and a six-fold increase in the response time from 41 (±18 to 244 (±193 s. This evidence reconfirms the importance of biofouling at the bio-abio interface and the need for mitigation strategies to address the foreign body response.

  13. Novel insights into the inhibitory mechanism of kaempferol on xanthine oxidase.

    Science.gov (United States)

    Wang, Yajie; Zhang, Guowen; Pan, Junhui; Gong, Deming

    2015-01-21

    Xanthine oxidase (XO), a key enzyme in purine catabolism, is widely distributed in human tissues. It can catalyze xanthine to generate uric acid and cause hyperuricemia and gout. Inhibition kinetics assay showed that kaempferol inhibited XO activity reversibly in a competitive manner. Strong fluorescence quenching and conformational changes of XO were found due to the formation of a kaempferol-XO complex, which was driven mainly by hydrophobic forces. The molecular docking further revealed that kaempferol inserted into the hydrophobic cavity of XO to interact with some amino acid residues. The main inhibition mechanism of kaempferol on XO activity may be due to the insertion of kaempferol into the active site of XO occupying the catalytic center of the enzyme to avoid the entrance of the substrate and inducing conformational changes of XO. In addition, luteolin exhibited a stronger synergistic effect with kaempferol than did morin at the lower concentration.

  14. Development of preparative and analytical methods of the hop bitter acid oxide fraction and chemical properties of its components.

    Science.gov (United States)

    Taniguchi, Yoshimasa; Matsukura, Yasuko; Taniguchi, Harumi; Koizumi, Hideki; Katayama, Mikio

    2015-01-01

    The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS(2) revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides.

  15. Fractionation of gamma-emitting fission products absorbed by red kidney beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    D'Souza, T.J.; Mistry, K.B.

    1980-01-01

    The gamma-emitting fission product nuclides 106 Ru, 125 Sb, 137 Cs and 144 Ce that accumulated in the edible pods of bean (Phaseolus vulgaris L.) plants grown in nutrient culture were subjected to chemical fractionation. The results indicated that the largest fraction of 106 Ru, 125 Sb and 144 Ce was associated with ionic forms including salts of organic acids, phosphates, carbonates and some protein-bound forms extracted with dilute mineral acids (acid fraction). The association of these radionuclides with lipids including lipophyllic pigments, free amino acids and amino sugars (ethanol fraction) was next in significance. The association of 137 Cs was, however, greater with the ethanol fraction than with the acid fraction. Considerably reduced amounts of the fission products were present in the pectates, proteins, polysaccharides and nucleic acids. (U.K.)

  16. Antidepressant-like effects of the xanthine oxidase enzyme inhibitor allopurinol in rats. A comparison with fluoxetine.

    Science.gov (United States)

    Gürbüz Özgür, Börte; Aksu, Hatice; Birincioğlu, Mustafa; Dost, Turhan

    2015-11-01

    Allopurinol is a xanthine oxidase enzyme inhibitor that is widely used for the treatment of hyperuricemia and gout. The activity of tryptophan 2,3-dioxygenase, which metabolizes tryptophan (TRP), is decreased by xanthine oxidase inhibitors, causing TRP levels in the body to be increased. Increases in TRP levels in the brain might have antidepressant effects. The purpose of this study is to evaluate the antidepressant effects of allopurinol compared to those of fluoxetine, which is a proven antidepressant. Thirty-two Wistar albino male rats were divided into four groups (control, 10mg/kg fluoxetine, 50mg/kg allopurinol, 50mg/kg allopurinol+10 mg/kg fluoxetine; n=8 per group), and forced swimming tests were performed before and after 14days of drug administration. Serotonin, 5-hydroxyindolacetic acid and uric acid levels were measured in blood samples after the final treatment. When allopurinol and fluoxetine were administered separately, a decrease in the duration of immobility and an increased duration of swimming were observed in the forced swimming test. The results showed similar antidepressant efficacies between allopurinol and fluoxetine. However, we found no statistically significant difference in the antidepressant effect of the combined therapy versus single drug therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. A Glucose Sensor Based on Glucose Oxidase Immobilized by Electrospinning Nanofibrous Polymer Membranes Modified with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    You Wang

    2013-05-01

    Full Text Available A glucose biosensor based on glucose oxidase immobilized by electrospinning nanofibrous membranes has been developed. Nanofibrous membranes were electrospun from the solution of poly(acrylonitrile-co-acrylic acid containing carbon nanotubes suspension and directly deposited on Pt electrodes for immobilizing glucose oxidase. The morphologies and structure of the nanofibrous membranes with or without carbon nanotubes were characterized by scanning electron microscopy. The fabrication parameters of nanofibers were optimized such as thickness of the nanofibrous membranes and mass ration of carbon nanotubes. The biosensor showed the relationship with a concentration range of 0.1–10 mM and response time was 60 s. The sensitivity of carbon nanotubes modified biosensors was two times larger than which of no carbon nanotubes modified ones. The pH effect, interference and lifetime of biosensors were discussed.

  18. Conductivity-Dependent Flow Field-Flow Fractionation of Fulvic and Humic Acid Aggregates

    Directory of Open Access Journals (Sweden)

    Martha J. M. Wells

    2015-09-01

    Full Text Available Fulvic (FAs and humic acids (HAs are chemically fascinating. In water, they have a strong propensity to aggregate, but this research reveals that tendency is regulated by ionic strength. In the environment, conductivity extremes occur naturally—freshwater to seawater—warranting consideration at low and high values. The flow field flow fractionation (flow FFF of FAs and HAs is observed to be concentration dependent in low ionic strength solutions whereas the corresponding flow FFF fractograms in high ionic strength solutions are concentration independent. Dynamic light scattering (DLS also reveals insight into the conductivity-dependent behavior of humic substances (HSs. Four particle size ranges for FAs and humic acid aggregates are examined: (1 <10 nm; (2 10 nm–6 µm; (3 6–100 µm; and (4 >100 µm. Representative components of the different size ranges are observed to dynamically coexist in solution. The character of the various aggregates observed—such as random-extended-coiled macromolecules, hydrogels, supramolecular, and micellar—as influenced by electrolytic conductivity, is discussed. The disaggregation/aggregation of HSs is proposed to be a dynamic equilibrium process for which the rate of aggregate formation is controlled by the electrolytic conductivity of the solution.

  19. Bioconversion of Airborne Methylamine by Immobilized Recombinant Amine Oxidase from the Thermotolerant Yeast Hansenula polymorpha

    Directory of Open Access Journals (Sweden)

    Sasi Sigawi

    2014-01-01

    Full Text Available Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health. The primary amine oxidase (primary amine : oxygen oxidoreductase (deaminating or amine oxidase, AMO; EC 1.4.3.21, a copper-containing enzyme from the thermotolerant yeast Hansenula polymorpha which was overexpressed in baker’s yeast Saccharomyces cerevisiae, was tested for its ability to oxidize airborne methylamine. A continuous fluidized bed bioreactor (CFBR was designed to enable bioconversion of airborne methylamine by AMO immobilized in calcium alginate (CA beads. The results demonstrated that the bioreactor with immobilized AMO eliminates nearly 97% of the airborne methylamine. However, the enzymatic activity of AMO causes formation of formaldehyde. A two-step bioconversion process was therefore proposed. In the first step, airborne methylamine was fed into a CFBR which contained immobilized AMO. In the second step, the gas flow was passed through another CFBR, with alcohol oxidase from the yeast H. polymorpha immobilized in CA, in order to decompose the formaldehyde formed in the first step. The proposed system provided almost total elimination of the airborne methylamine and the formaldehyde.

  20. 21 CFR 866.2420 - Oxidase screening test for gonorrhea.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxidase screening test for gonorrhea. 866.2420... screening test for gonorrhea. (a) Identification. An oxidase screening test for gonorrhea is an in vitro... of gonorrhea. (b) Classification. Class III (premarket approval) (transitional device). (c) Date PMA...

  1. The dynamics of acid-soluble phosphorus compounds in the course of winter and spring wheat germination under various thermic conditions. Part II. Labile phosphorus after hydrolysis of the acid-soluble fraction

    Directory of Open Access Journals (Sweden)

    A. Barbaro

    2015-06-01

    Full Text Available The changes in labile phosphorus compounds content during germination of wheat were investigated. These compounds were determined in acid-soluble germ extracts separated into fractions according to the solubility of their barium salts. Low germination temperature was found to raise the labile phosphorus content in the fraction of insoluble barium salts. If we assume that labile P of this fraction consisted mainly of adenosinedi- and triphosphates, it would seem that the rise, in the ATP and ADP level under the influence of low temperature may be essential for initiating flowering in winter varieties.

  2. Purification and characterization of polyphenol oxidase from cauliflower (Brassica oleracea L.).

    Science.gov (United States)

    Rahman, Andi Nur Faidah; Ohta, Mayumi; Nakatani, Kazuya; Hayashi, Nobuyuki; Fujita, Shuji

    2012-04-11

    Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).

  3. Catalytic aspects of a copper(II) complex: biological oxidase to ...

    Indian Academy of Sciences (India)

    BISWAJIT CHOWDHURY

    2017-10-03

    Oct 3, 2017 ... made with a Jasco model V-730 UV-Vis spectrophotometer. ..... Ligand-induced coordination changes ... Fet3 protein from yeast, a multinuclear copper oxidase ... of mutants of the multicopper oxidase Fet3p Biochem-.

  4. Platelet monoamine oxidase: specific activity and turnover number in headache

    International Nuclear Information System (INIS)

    Summers, K.M.; Brown, G.K.; Craig, I.W.; Peatfield, R.; Rose, F.C.

    1982-01-01

    Monoamine oxidase turnover numbers (molecules of substrate converted to product per minute per active site) have been calculated for the human platelet enzyme using [ 3 H]pargyline. Headache patients with high and low monoamine oxidase specific activities relative to controls were found to have turnover numbers very close to those for controls. This finding suggests that their specific activities vary because of differences in the concentration of active monoamine oxidase molecules, rather than differences in the ability of those enzyme molecules to catalyse the deamination reaction. (Auth.)

  5. Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

    Directory of Open Access Journals (Sweden)

    Francisco Palma Rennó

    2013-11-01

    Full Text Available The objective of this study was to evaluate the utilization of different sources of unsaturated long-chain fatty acids in diets for dairy cows during the transition period and early lactation on the milk fatty acid profile and composition of the protein fraction. Thirty-six Holstein cows were divided into three groups, fed the following diets: control (C; soybean oil (SO; and calcium salts of long-chain unsaturated fatty acids (CS. The milk samples utilized for analysis were obtained weekly from parturition to twelve weeks of lactation; each one of the samples originated from two daily milkings. Milk composition and total nitrogen, non-protein nitrogen and non-casein nitrogen levels were analyzed. The cows receiving the diet with calcium salts had lower concentrations of non-protein nitrogen (%CP in milk compared with the animals fed the diet with soybean oil. There was a decrease in concentration of medium-chain fatty acids C12-C16, and a concomitant increase in concentrations of long-chain fatty acids >C18 in milk fat for the animals fed the diets CS and SO when compared with diet C. Soybean oil and CS diets increased milk-fat concentrations of the acids C18: 1 trans-11, C18: 2 cis-9, trans-11 and C18: 2 trans-10 cis-12 in relation to diet C. The utilization of sources of long-chain fatty acids in the diet of dairy cows increases the biological value of milk in early lactation due to higher concentrations of specific fatty acids such as CLA C18: 2cis-9, trans-11.

  6. Xanthine oxidase in human skeletal muscle following eccentric exercise

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Frandsen, Ulrik; Orthenblad, N.

    1997-01-01

    the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase...

  7. Isolation of a polyphenol oxidase (PPO) cDNA from artichoke and expression analysis in wounded artichoke heads.

    Science.gov (United States)

    Quarta, Angela; Mita, Giovanni; Durante, Miriana; Arlorio, Marco; De Paolis, Angelo

    2013-07-01

    The polyphenol oxidase (PPO) enzyme, which can catalyze the oxidation of phenolics to quinones, has been reported to be involved in undesirable browning in many plant foods. This phenomenon is particularly severe in artichoke heads wounded during the manufacturing process. A full-length cDNA encoding for a putative polyphenol oxidase (designated as CsPPO) along with a 1432 bp sequence upstream of the starting ATG codon was characterized for the first time from [Cynara cardunculus var. scolymus (L.) Fiori]. The 1764 bp CsPPO sequence encodes a putative protein of 587 amino acids with a calculated molecular mass of 65,327 Da and an isoelectric point of 5.50. Analysis of the promoter region revealed the presence of cis-acting elements, some of which are putatively involved in the response to light and wounds. Expression analysis of the gene in wounded capitula indicated that CsPPO was significantly induced after 48 h, even though the browning process had started earlier. This suggests that the early browning event observed in artichoke heads was not directly related to de novo mRNA synthesis. Finally, we provide the complete gene sequence encoding for polyphenol oxidase and the upstream regulative region in artichoke. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

    NARCIS (Netherlands)

    Tamayo Ramos, J.A.; Berkel, van W.J.H.; Graaff, de L.H.

    2012-01-01

    BACKGROUND: Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. RESULTS: The

  9. Purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) pulp.

    Science.gov (United States)

    Yang, C P; Fujita, S; Ashrafuzzaman, M; Nakamura, N; Hayashi, N

    2000-07-01

    Polyphenol oxidase (EC 1.10.3.1, PPO) in the pulp of banana (Musa sapientum L.) was purified to 636-fold with a recovery of 3.0%, using dopamine as substrate. The purified enzyme exhibited a clear single band on polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. The molecular weight of the enzyme was estimated to be about 41000 and 42000 by gel filtration and SDS-PAGE, respectively. The enzyme quickly oxidized dopamine, and its K(m) value for dopamine was 2.8 mM. The optimum pH was at 6.5, and the enzyme activity was stable in the range of pH 5-11 at 5 degrees C for 48 h. The enzyme had an optimum temperature of 30 degrees C and was stable even after a heat treatment at 70 degrees C for 30 min. The enzyme activity was completely inhibited by L-ascorbic acid, cysteine, sodium diethyldithiocarbamate, and potassium cyanide. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.

  10. Gluconic Acid: Properties, Applications and Microbial Production

    Directory of Open Access Journals (Sweden)

    Sumitra Ramachandran

    2006-01-01

    Full Text Available Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction. The reaction is facilitated by the enzyme glucose oxidase (fungi and glucose dehydrogenase (bacteria such as Gluconobacter. Microbial production of gluconic acid is the preferred method and it dates back to several decades. The most studied and widely used fermentation process involves the fungus Aspergillus niger. Gluconic acid and its derivatives, the principal being sodium gluconate, have wide applications in food and pharmaceutical industry. This article gives a review of microbial gluconic acid production, its properties and applications.

  11. Microwave Acid Extraction to Analyze K and Mg Reserves in the Clay Fraction of Soils

    Directory of Open Access Journals (Sweden)

    Araína Hulmann Batista

    Full Text Available ABSTRACT: Extraction of K and Mg with boiling 1 mol L-1 HNO3 in an open system for predicting K and Mg uptake by plants is a method of low reproducibility. The aim of this study was to compare the extraction capacity of different acid methods relative to hydrofluoric acid extraction for K and Mg. A further objective was to develop a chemical extraction method using a closed system (microwave for nonexchangeable and structural forms of these nutrients in order to replace the traditional method of extraction with boiling HNO3 on a hot plate (open system. The EPA 3051A method can be used to estimate the total content of K in the clay fraction of soils developed from carbonate and phyllite/mica schist rocks. In the clay fraction of soils developed from basalt, recoveries of K by the EPA 3051A (pseudo-total method were higher than for the EPA 3052 (total hydrofluoric extraction method. The relative abundance of K and Mg for soils in carbonate rocks, phyllite/mica schist, granite/gneiss, and basalt determined by aqua regia digestion is unreliable. The method using 1 mol L-1 HNO3 in an closed system (microwave showed potential for replacing the classical method of extraction of nonexchangeable forms of K (boiling 1 mol L-1 HNO3 in an open system - hot plate and reduced the loss of Si by volatilization.

  12. Incorporation of 14CO2 and 15NH4 into amino acids of the two subunits of fraction 1 protein in spinach leaves

    International Nuclear Information System (INIS)

    Sano, Chiaki; Ito, Osamu; Yoneyama, Tadakatsu; Kumazawa, Kikuo

    1978-01-01

    14 Co 2 and 15 NH 4 were applied to spinach leaf discs, and the incorporation of 14 C and 15 N into the constituent amino acids of subunits in Fraction 1 protein was traced. The solution containing NaH 14 CO 3 and ( 15 NH 4 ) 2 SO 4 was vacuum-infiltrated into leaf discs, which were then incubated under light condition for 8 hr. The leaf discs were immediately frozen with liquid nitrogen after the incubation. The Fraction 1 protein was isolated and purified according to Kawashima's method, and separated into two subunits by his method. These subunits were hydrolyzed, and the hydrolyzates were analyzed by amino acid analyzer. The determination of 14 C activity and 15 N content in each amino acid was performed as previously described. Glycine and aspartic acid showed the highest 14 C specific activity among free amino acids. The distribution pattern of 14 C in bound amino acids almost reflected the distribution in free amino acids, though the 14 C specific activity in the former was lower than that in the latter. There was some difference in the 14 C specific activity of large and small subunits. The 15 N content of glutamine was the highest among free amino acids. This result coincides with the previous conclusion that when ammonium was applied to the free cells separated from spinach leaves, it was initially incorporated into glutamine in the sequence of its assimilation. Glutamic acid and serine showed the highest 15 N content among bound amino acids. (Kobatake, H.)

  13. Homogenization versus homogenization-free method to measure muscle glycogen fractions.

    Science.gov (United States)

    Mojibi, N; Rasouli, M

    2016-12-01

    The glycogen is extracted from animal tissues with or without homogenization using cold perchloric acid. Three methods were compared for determination of glycogen in rat muscle at different physiological states. Two groups of five rats were kept at rest or 45 minutes muscular activity. The glycogen fractions were extracted and measured by using three methods. The data of homogenization method shows that total glycogen decreased following 45 min physical activity and the change occurred entirely in acid soluble glycogen (ASG), while AIG did not change significantly. Similar results were obtained by using "total-glycogen-fractionation methods". The findings of "homogenization-free method" indicate that the acid insoluble fraction (AIG) was the main portion of muscle glycogen and the majority of changes occurred in AIG fraction. The results of "homogenization method" are identical with "total glycogen fractionation", but differ with "homogenization-free" protocol. The ASG fraction is the major portion of muscle glycogen and is more metabolically active form.

  14. Possible role for abscisic acid in regulation of photosynthetic and photorespiratory carbon metabolism in barley leaves

    International Nuclear Information System (INIS)

    Popova, L.P.; Tsonev, T.D.; Vaklinova, S.G.

    1987-01-01

    The influence of abscisic acid (ABA) on carbon metabolism, rate of photorespiration, and the activity of the photorespiratory enzymes ribulose bisphosphate oxygenase and glycolate oxidase in 7-day-old barley seedlings (Hordeum vulgare L. var. Alfa) was investigated. Plants treated with ABA had enhanced incorporation of labeled carbon from 14 CO 2 into glycolic acid, glycine, and serine, while 14 C incorporation into 3-phosphoglyceric acid and sugarphosphate esters was depressed. Parallel with this effect, treated plants showed a rise in activity of RuBP oxygenase and glycolic acid oxidase. The rate of photorespiration was increased twofold by ABA treatment at IO -6 molar while the CO 2 -compensation point increased 46% and stomatal resistance increased more than twofold over control plants

  15. Evaluation of soluble fraction and enzymatic residual fraction of dilute dry acid, ethylenediamine, and steam explosion pretreated corn stover on the enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Qin, Lei; Liu, Li; Li, Wen-Chao; Zhu, Jia-Qing; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-06-01

    This study is aimed to examine the inhibition of soluble fraction (SF) and enzymatic residual fraction (ERF) in dry dilute acid (DDA), ethylenediamine (EDA) and steam explosion (SE) pretreated corn stover (CS) on the enzymatic digestibility of cellulose. SF of DDA, EDA and SE pretreated CS has high xylose, soluble lignin and xylo-oligomer content, respectively. SF of EDA pretreated CS leads to the highest inhibition, followed by SE and DDA pretreated CS. Inhibition of ERF of DDA and SE pretreated CS is higher than that of EDA pretreated CS. The inhibition degree (A0/A) of SF is 1.76 and 1.21 times to that of ERF for EDA and SE pretreated CS, respectively. The inhibition degree of ERF is 1.05 times to that of SF in DDA pretreated CS. The quantitative analysis shows that SF of EDA pretreated CS, SF and ERF of SE pretreated CS cause significant inhibition during enzymatic hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Characterization of pea (Pisum sativum) seed protein fractions.

    Science.gov (United States)

    Rubio, Luis A; Pérez, Alicia; Ruiz, Raquel; Guzmán, M Ángeles; Aranda-Olmedo, Isabel; Clemente, Alfonso

    2014-01-30

    Legume seed proteins have to be chemically characterized in order to properly link their nutritional effects with their chemical structure. Vicilin and albumin fractions devoid of cross-contamination, as assessed by mass peptide fingerprinting analysis, were obtained from defatted pea (Pisum sativum cv. Bilbo) meal. The extracted protein fractions contained 56.7-67.7 g non-starch polysaccharides kg⁻¹. The vicilin fraction was higher than legumins in arginine, isoleucine, leucine, phenylalanine and lysine. The most abundant amino acids in the albumin fraction were aspartic acid, glutamic acid, lysine and arginine, and the amounts of methionine were more than double than those in legumins and vicilins. The pea albumin fraction showed a clear enrichment of protease inhibitory activity when compared with the seed meal. In vitro digestibility values for pea proteins were 0.63 ±  0.04, 0.88 ±  0.04 and 0.41 ±  0.23 for legumins, vicilins and albumins respectively. Vicilin and albumin fractions devoid of cross-contamination with other proteins were obtained from pea seed meal. The vicilin fraction also contained low amounts of soluble non-starch polysaccharides and was enriched in isoleucine, leucine, phenylalanine and lysine. In vitro digestibility values for pea proteins were similar or even numerically higher than those for control proteins. © 2013 Society of Chemical Industry.

  17. Phospholipid alterations in cardiac sarcoplasmic reticulum induced by xanthine oxidase: contamination of commercial preparations of xanthine oxidase by phospholipase A2

    International Nuclear Information System (INIS)

    Gamache, D.A.; Kornberg, L.J.; Bartolf, M.; Franson, R.C.

    1986-01-01

    Incubation of cardiac sarcoplasmic reticulum with xanthine oxidase alone at pH 7.0 resulted in a loss of lipid phosphorus that was potentiated by the addition of xanthine. Using autoclaved E.coli with 1- 14 C-oleate in the 2-acyl position of membrane phospholipids, the authors demonstrate that many, but not all, commercial preparations of xanthine oxidase contain significant phospholipase A 2 (PLA 2 ) activity (64.3-545.6 nmols/min/mg). The PLA 2 was maximally active in the neutral-alkaline pH range, was Ca 2+ -dependent, and was unaffected by the addition of xanthine. PLA 2 activity was totally inhibited by 1mM EDTA whereas radical production by optimal concentrations of xanthine/xanthine oxidase (X/XO) was unaffected by EDTA. Chromatographically purified xanthine oxidase (Sigma Grade III) contained high levels of PLA 2 activity (64.3 nmols/min/mg) compared to endogenous levels of neutral-active, Ca 2+ -dependent PLA 2 measured in various tissue homogenates (≤ 0.5 nmols/ min/mg). Because X/XO mixtures are used extensively to study oxygen free radical-induced cell injury and membrane phospholipid alterations, the presence of a potent extracellular PLA 2 may have influenced previously published reports, and such studies should be interpreted cautiously

  18. Role of ascorbic acid in the inhibition of polyphenol oxidase and the prevention of browning in different browning-sensitive Lactuca sativa var. capitata (L.) and Eruca sativa (Mill.) stored as fresh-cut produce.

    Science.gov (United States)

    Landi, Marco; Degl'Innocenti, Elena; Guglielminetti, Lorenzo; Guidi, Lucia

    2013-06-01

    Polyphenol oxidase (PPO) and, to a minor extent, peroxidase (POD) represent the key enzymes involved in enzymatic browning, a negative process induced by cutting fresh-cut produce such as lettuce (Lactuca sativa) and rocket salad (Eruca sativa). Although ascorbic acid is frequently utilised as an anti-browning agent, its mechanism in the prevention of the browning phenomenon is not clearly understood. The activity of PPO and POD and their isoforms in lettuce (a high-browning and low-ascorbic acid species) and rocket salad (a low-browning and high-ascorbic species) was characterised. The kinetic parameters of PPO and in vitro ascorbic acid-PPO inhibition were also investigated. In rocket salad, PPO activity was much lower than that in lettuce and cutting induced an increase in PPO activity only in lettuce. Exogenous ascorbic acid (5 mmol L(-1)) reduced PPO activity by about 90% in lettuce. POD did not appear to be closely related to browning in lettuce. PPO is the main enzyme involved in the browning phenomenon; POD appears to play a minor role. The concentration of endogenous ascorbic acid in rocket salad was related to its low-browning sensitivity after cutting. In lettuce, the addition of ascorbic acid directly inhibited PPO activity. The results suggest that the high ascorbic acid content found in rocket salad plays an effective role in reducing PPO activity. © 2012 Society of Chemical Industry.

  19. Fabrication of Amperometric Glucose Sensor Using Glucose Oxidase-Cellulose Nanofiber Aqueous Solution.

    Science.gov (United States)

    Yasuzawa, Mikito; Omura, Yuya; Hiura, Kentaro; Li, Jiang; Fuchiwaki, Yusuke; Tanaka, Masato

    2015-01-01

    Cellulose nanofiber aqueous solution, which remained virtually transparent for more than one week, was prepared by using the clear upper layer of diluted cellulose nanofiber solution produced by wet jet milling. Glucose oxidase (GOx) was easily dissolved in this solution and GOx-immobilized electrode was easily fabricated by simple repetitious drops of GOx-cellulose solution on the surface of a platinum-iridium electrode. Glucose sensor properties of the obtained electrodes were examined in phosphate buffer solution of pH 7.4 at 40°C. The obtained electrode provided a glucose sensor response with significantly high response speed and good linear relationship between glucose concentration and response current. After an initial decrease of response sensitivity for a few days, relatively constant sensitivity was obtained for about 20 days. Nevertheless, the influence of electroactive compounds such as ascorbic acid, uric acid and acetoaminophen were not negletable.

  20. Relative age and age sequence of fractions of soil organic matter

    International Nuclear Information System (INIS)

    Scharpenseel, H.W.

    1975-01-01

    Natural radiocarbon measurements on soil fractions provide information regarding the chances of separating the ''old biologically inert carbon'' out of samples of recent soil material. Beyond this, the relative fraction ages are scrutinized for the sequential order of the origin of the fractions within the biosynthetic reaction chain of soil humic matter. Among all fractions compared (classic humic matter fractionation by alkali and acid treatment; successive extraction with organic solvents of increasing polarity; separation according to particle size by Sephadex gel filtration; hydrolysis residue) the 6 n HCl hydrolysis residue shows the most consistent significant age increment. Repeated exhaustive hydrolysis treatment of the same sample material is still pending. All other fraction types indicate an age pattern under strong predetermination by method of origin, e.g., existence or lack of hydromorphy, without an evident enrichment of the ''old biologically inert carbon''. Among the organic extracts, no persistent age hierarchy is noticeable, whereas the classical fractions follow an age sequence mainly parallel to an increase of the molecular weight. Hymatomelanic acids appear rejuvenated by relics of recent carbon derived from the extractant ethanol. Grey humic acids are older than the brown humic acids, humines from fully terrestrial soil environment are older than humic acids, while in hydromorphic soils, cold alkali insoluble young C-compounds seem to be conserved which are liable to falsify rejuvenation of the humines

  1. Fractionation and analysis of allergenicity of allergens from Prosopis juliflora pollen.

    Science.gov (United States)

    Thakur, I S

    1989-01-01

    Prosopis juliflora pollen allergen extract was prepared, and its crude allergen extract was fractionated by Sephadex G-100 gel filtration. Six different fractions were obtained which was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Protein and carbohydrate content of each fraction were estimated. Fraction E (MW 20,000) showed a 25% carbohydrate concentration. The amino acid analysis indicated that this fraction was rich in glutamic acid and alanine. Antigenicity or allergenicity of fractionated allergens were checked by gel diffusion test, rocket immunoelectrophoresis, skin prick test, and radioallergosorbent test. All these test indicate that fraction E consisted mainly of allergenic molecules (MW 20,000) of P. juliflora pollen.

  2. Inhibition of acetylcholinesterase and cytochrome oxidase activity in Fasciola gigantica cercaria by phytoconstituents.

    Science.gov (United States)

    Sunita, Kumari; Habib, Maria; Kumar, P; Singh, Vinay Kumar; Husain, Syed Akhtar; Singh, D K

    2016-02-01

    Fasciolosis is an important cattle and human disease caused by Fasciola hepatica and Fasciola gigantica. One of the possible methods to control this problem is to interrupt the life cycle of Fasciola by killing its larva (redia and cercaria) in host snail. Molecular identification of cercaria larva of F. gigantica was done by comparing the nucleotide sequencing with adult F. gigantica. It was noted that nucleotide sequencing of cercaria larva and adult F. gigantica were 99% same. Every month during the year 2011-2012, in vivo treatment with 60% of 4 h LC50 of phyto cercaricides citral, ferulic acid, umbelliferone, azadirachtin and allicin caused significant inhibition of acetylcholinesterase (AChE) and cytochrome oxidase activity in the treated cercaria larva of F. gigantica. Whereas, activity of both enzymes were not significantly altered in the nervous tissues of vector snail Lymnaea acuminata exposed to same treatments. Maximum reduction in AChE (1.35% of control in month of June) and cytochrome oxidase (3.71% of control in the month of July) activity were noted in the cercaria exposed to 60% of 4 h LC50 of azadirachtin and allicin, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Neutrophils to the ROScue: Mechanisms of NADPH Oxidase Activation and Bacterial Resistance

    Directory of Open Access Journals (Sweden)

    Giang T. Nguyen

    2017-08-01

    Full Text Available Reactive oxygen species (ROS generated by NADPH oxidase play an important role in antimicrobial host defense and inflammation. Their deficiency in humans results in recurrent and severe bacterial infections, while their unregulated release leads to pathology from excessive inflammation. The release of high concentrations of ROS aids in clearance of invading bacteria. Localization of ROS release to phagosomes containing pathogens limits tissue damage. Host immune cells, like neutrophils, also known as PMNs, will release large amounts of ROS at the site of infection following the activation of surface receptors. The binding of ligands to G-protein-coupled receptors (GPCRs, toll-like receptors, and cytokine receptors can prime PMNs for a more robust response if additional signals are encountered. Meanwhile, activation of Fc and integrin directly induces high levels of ROS production. Additionally, GPCRs that bind to the bacterial-peptide analog fMLP, a neutrophil chemoattractant, can both prime cells and trigger low levels of ROS production. Engagement of these receptors initiates intracellular signaling pathways, resulting in activation of downstream effector proteins, assembly of the NADPH oxidase complex, and ultimately, the production of ROS by this complex. Within PMNs, ROS released by the NADPH oxidase complex can activate granular proteases and induce the formation of neutrophil extracellular traps (NETs. Additionally, ROS can cross the membranes of bacterial pathogens and damage their nucleic acids, proteins, and cell membranes. Consequently, in order to establish infections, bacterial pathogens employ various strategies to prevent restriction by PMN-derived ROS or downstream consequences of ROS production. Some pathogens are able to directly prevent the oxidative burst of phagocytes using secreted effector proteins or toxins that interfere with translocation of the NADPH oxidase complex or signaling pathways needed for its activation

  4. Sorption of selected organic compounds from water to a peat soil and its humic-acid and humin fractions: Potential sources of the sorption nonlinearity

    Science.gov (United States)

    Chiou, C.T.; Kile, D.E.; Rutherford, D.W.; Sheng, G.; Boyd, S.A.

    2000-01-01

    The sorption isotherms of ethylene dibromide (EDB), diuron (DUN), and 3,5-dichlorophenol (DCP) from water on the humic acid and humin fractions of a peat soil and on the humic-acid of a muck soil have been measured. The data were compared with those of the solutes with the whole peat from which the humic-acid (HA) and humin (HM) fractions were derived and on which the sorption of the solutes exhibited varying extents of nonlinear capacities at low relative concentrations (C(e)/S(w)). The HA fraction as prepared by the density-fractionated method is relatively pure and presumably free of high- surface-area carbonaceous material (HSACM) that is considered to be responsible for the observed nonlinear sorption for nonpolar solutes (e.g., EDB) on the peat; conversely, the base-insoluble HM fraction as prepared is presumed to be enriched with HSACM, as manifested by the greatly higher BET- (N2) surface area than that of the whole peat. The sorption of EDB on HA exhibits no visible nonlinear effect, whereas the sorption on HM shows an enhanced nonlinearity over that on the whole peat. The sorption of polar DUN and DCP on HA and HM display nonlinear effects comparable with those on the whole peat; the effects are much more significant than those with nonpolar EDB. These results conform to the hypothesis that adsorption onto a small amount of strongly adsorbing HSACM is largely responsible for the nonlinear sorption of nonpolar solutes on soils and that additional specific interactions with the active groups of soil organic matter are responsible for the generally higher nonlinear sorption of the polar solutes.

  5. Protein structural development of threadfin bream ( Nemipterus spp.) surimi gels induced by glucose oxidase.

    Science.gov (United States)

    Wang, Lei; Fan, Daming; Fu, Lulu; Jiao, Xidong; Huang, Jianlian; Zhao, Jianxin; Yan, Bowen; Zhou, Wenguo; Zhang, Wenhai; Ye, Weijian; Zhang, Hao

    2018-01-01

    This study investigated the effect of glucose oxidase on the gel properties of threadfin bream surimi. The gel strength of surimi increased with the addition of 0.5‰ glucose oxidase after two-step heating. Based on the results of the chemical interactions, the hydrophobic interaction and disulfide bond of glucose oxidase-treated surimi samples increased compared with the control samples at the gelation temperature and gel modori temperature. The surface hydrophobicity of samples with glucose oxidase and glucose increased significantly ( p glucose oxidase induced more α-helixes to turn into a more elongated random and flocculent structure. Glucose oxidase changes the secondary structure of the surimi protein, making more proteins depolarize and stretch and causing actomyosin to accumulate to each other, resulting in the formation of surimi gel.

  6. Xanthine oxidase inhibitors from Archidendron clypearia (Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants.

    Science.gov (United States)

    Duong, Nguyen Thuy; Vinh, Pham Duc; Thuong, Phuong Thien; Hoai, Nguyen Thi; Thanh, Le Nguyen; Bach, Tran The; Nam, Nguyen Hai; Anh, Nguyen Hoang

    2017-06-01

    To screen Vietnamese medicinal plants for xanthine oxidase (XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. Three hundreds and eleven methanol extracts (CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/mL with inhibition rates of over 50%. The extracts of Archidendron clypearia (A. clypearia), Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC 50 values below 30 μg/mL. Chemical study performed on the extract of A. clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and (-)-7-O-galloyltricetiflavan. The compound (-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC 50 value of 25.5 μmol/L. From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC 50 values of the methanol extracts below 30 μg/mL. Compound (-)-7-O- galloyltricetiflavan was identified as an XO inhibitor from A. clypearia with IC 50 value of 25.5 μmol/L. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  7. Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

    2009-01-01

    The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

  8. DEUTERIUM FRACTIONATION DURING AMINO ACID FORMATION BY PHOTOLYSIS OF INTERSTELLAR ICE ANALOGS CONTAINING DEUTERATED METHANOL

    Energy Technology Data Exchange (ETDEWEB)

    Oba, Yasuhiro; Watanabe, Naoki; Kouchi, Akira [Institute of Low Temperature Science, Hokkaido University, N19W8, Kita-ku, Sapporo, Hokkaido 060-0819 (Japan); Takano, Yoshinori, E-mail: oba@lowtem.hokudai.ac.jp [Department of Biogeochemistry, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Yokosuka, Kanagawa 237-0061 (Japan)

    2016-08-10

    Deuterium (D) atoms in interstellar deuterated methanol might be distributed into complex organic molecules through molecular evolution by photochemical reactions in interstellar grains. In this study, we use a state-of-the-art high-resolution mass spectrometer coupled with a high-performance liquid chromatography system to quantitatively analyze amino acids and their deuterated isotopologues formed by the photolysis of interstellar ice analogs containing singly deuterated methanol CH{sub 2}DOH at 10 K. Five amino acids (glycine, α -alanine, β -alanine, sarcosine, and serine) and their deuterated isotopologues whose D atoms are bound to carbon atoms are detected in organic residues formed by photolysis followed by warming up to room temperature. The abundances of singly deuterated amino acids are in the range of 0.3–1.1 relative to each nondeuterated counterpart, and the relative abundances of doubly and triply deuterated species decrease with an increasing number of D atoms in a molecule. The abundances of amino acids increase by a factor of more than five upon the hydrolysis of the organic residues, leading to decreases in the relative abundances of deuterated species for α -alanine and β -alanine. On the other hand, the relative abundances of the deuterated isotopologues of the other three amino acids did not decrease upon hydrolysis, indicating different formation mechanisms of these two groups upon hydrolysis. The present study facilitates both qualitative and quantitative evaluations of D fractionation during molecular evolution in the interstellar medium.

  9. DEUTERIUM FRACTIONATION DURING AMINO ACID FORMATION BY PHOTOLYSIS OF INTERSTELLAR ICE ANALOGS CONTAINING DEUTERATED METHANOL

    International Nuclear Information System (INIS)

    Oba, Yasuhiro; Watanabe, Naoki; Kouchi, Akira; Takano, Yoshinori

    2016-01-01

    Deuterium (D) atoms in interstellar deuterated methanol might be distributed into complex organic molecules through molecular evolution by photochemical reactions in interstellar grains. In this study, we use a state-of-the-art high-resolution mass spectrometer coupled with a high-performance liquid chromatography system to quantitatively analyze amino acids and their deuterated isotopologues formed by the photolysis of interstellar ice analogs containing singly deuterated methanol CH 2 DOH at 10 K. Five amino acids (glycine, α -alanine, β -alanine, sarcosine, and serine) and their deuterated isotopologues whose D atoms are bound to carbon atoms are detected in organic residues formed by photolysis followed by warming up to room temperature. The abundances of singly deuterated amino acids are in the range of 0.3–1.1 relative to each nondeuterated counterpart, and the relative abundances of doubly and triply deuterated species decrease with an increasing number of D atoms in a molecule. The abundances of amino acids increase by a factor of more than five upon the hydrolysis of the organic residues, leading to decreases in the relative abundances of deuterated species for α -alanine and β -alanine. On the other hand, the relative abundances of the deuterated isotopologues of the other three amino acids did not decrease upon hydrolysis, indicating different formation mechanisms of these two groups upon hydrolysis. The present study facilitates both qualitative and quantitative evaluations of D fractionation during molecular evolution in the interstellar medium.

  10. Production of rabbit antibodies against purified Glucose oxidase

    OpenAIRE

    Zia,Muhammad Anjum; Ain,Qurat-ul; Iftikhar,Tehreema; Abbas,Rao Zahid; Rahman,Khalil-ur

    2012-01-01

    Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose) resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex ...

  11. The use of galactose oxidase in lipid labeling

    International Nuclear Information System (INIS)

    Radin, N.S.; Evangelatos, G.P.

    1981-01-01

    Galactose oxidase can be used to oxidize the terminal carbon atom of lipids containing galactose or N-acetylgalactosamine, and the resultant aldehyde group can be reduced back to the original carbinol with radioactive borohydride. The efficiency of the first reaction has been investigated systematically by using [6- 3 H]galactosyl ceramide as substrate and measuring the amount of radioactive water formed. This enabled us to establish that the addition of catalase and peroxidase greatly speeded the oxidation, that phosphate and PIPES buffers were the best among those tested, that the reaction continued for 24 hr without a second addition of galactose oxidase, and that the optimum concentration of organic solvent (tetrahydrofuran) was 50%. The suggestion if made that a similar set of variables be studied for each lipid or nonlipid by the same basic technique: labeling by the oxidase/borohydride method and use of the resultant compound as substrate

  12. Identification, expression, and taxonomic distribution of alternative oxidases in non-angiosperm plants.

    Science.gov (United States)

    Neimanis, Karina; Staples, James F; Hüner, Norman P A; McDonald, Allison E

    2013-09-10

    Alternative oxidase (AOX) is a terminal ubiquinol oxidase present in the respiratory chain of all angiosperms investigated to date, but AOX distribution in other members of the Viridiplantae is less clear. We assessed the taxonomic distribution of AOX using bioinformatics. Multiple sequence alignments compared AOX proteins and examined amino acid residues involved in AOX catalytic function and post-translational regulation. Novel AOX sequences were found in both Chlorophytes and Streptophytes and we conclude that AOX is widespread in the Viridiplantae. AOX multigene families are common in non-angiosperm plants and the appearance of AOX1 and AOX2 subtypes pre-dates the divergence of the Coniferophyta and Magnoliophyta. Residues involved in AOX catalytic function are highly conserved between Chlorophytes and Streptophytes, while AOX post-translational regulation likely differs in these two lineages. We demonstrate experimentally that an AOX gene is present in the moss Physcomitrella patens and that the gene is transcribed. Our findings suggest that AOX will likely exert an influence on plant respiration and carbon metabolism in non-angiosperms such as green algae, bryophytes, liverworts, lycopods, ferns, gnetophytes, and gymnosperms and that further research in these systems is required. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Miracle Fruit (Synsepalum dulcificum Exhibits as a Novel Anti-Hyperuricaemia Agent

    Directory of Open Access Journals (Sweden)

    Yeu-Ching Shi

    2016-01-01

    Full Text Available Miracle fruit (Synsepalum dulcificum belongs to the Sapotaceae family. It can change flavors on taste buds, transforming acidic tastes to sweet. We evaluated various miracle fruit extracts, including water, butanol, ethyl acetate (EA, and hexane fractions, to determine its antioxidant effects. These extracts isolated from miracle fruit exerted potential for reduction of uric acid and inhibited xanthine oxidase activity in vitro and in monosodiumurate (MSU-treated RAW264.7 macrophages. Moreover, we also found that the butanol extracts of miracle fruit attenuated oxonic acid potassium salt-induced hyperuricaemia in ICR mice by lowering serum uric acid levels and activating hepatic xanthine oxidase. These effects were equal to those of allopurinol, suggesting that the butanol extract of miracle fruit could be developed as a novel anti-hyperuricaemia agent or health food.

  14. Molecular Basis for Converting (2S-Methylsuccinyl-CoA Dehydrogenase into an Oxidase

    Directory of Open Access Journals (Sweden)

    Simon Burgener

    2017-12-01

    Full Text Available Although flavoenzymes have been studied in detail, the molecular basis of their dioxygen reactivity is only partially understood. The members of the flavin adenosine dinucleotide (FAD-dependent acyl-CoA dehydrogenase and acyl-CoA oxidase families catalyze similar reactions and share common structural features. However, both enzyme families feature opposing reaction specificities in respect to dioxygen. Dehydrogenases react with electron transfer flavoproteins as terminal electron acceptors and do not show a considerable reactivity with dioxygen, whereas dioxygen serves as a bona fide substrate for oxidases. We recently engineered (2S-methylsuccinyl-CoA dehydrogenase towards oxidase activity by rational mutagenesis. Here we characterized the (2S-methylsuccinyl-CoA dehydrogenase wild-type, as well as the engineered (2S-methylsuccinyl-CoA oxidase, in detail. Using stopped-flow UV-spectroscopy and liquid chromatography-mass spectrometry (LC-MS based assays, we explain the molecular base for dioxygen reactivity in the engineered oxidase and show that the increased oxidase function of the engineered enzyme comes at a decreased dehydrogenase activity. Our findings add to the common notion that an increased activity for a specific substrate is achieved at the expense of reaction promiscuity and provide guidelines for rational engineering efforts of acyl-CoA dehydrogenases and oxidases.

  15. The increasing role of monoamine oxidase type B inhibitors in Parkinson's disease therapy.

    Science.gov (United States)

    Elmer, Lawrence W; Bertoni, John M

    2008-11-01

    The role of monoamine oxidase type B inhibitors in the treatment of Parkinson's disease has expanded with the new monoamine oxidase B inhibitor rasagiline and a new formulation, selegiline oral disintegrating tablets. As primary therapy in early disease monoamine oxidase B inhibitors reduce motor disability and delay the need for levodopa. In more advanced disease requiring levodopa, adjunctive monoamine oxidase B inhibitors reduce 'off' time and may improve gait and freezing. Rasagiline and selegiline oral disintegrating tablets may reduce the safety risks associated with the amfetamine and methamfetamine metabolites of conventional oral selegiline while retaining or improving therapeutic efficacy. Articles were identified by searches of PubMed and searches on the Internet and reviewed. All articles and other referenced materials were retrieved using the keywords 'Parkinson's disease', 'treatment' and 'monoamine oxidase B inhibitor' and were published between 1960 and 2007, with older references selected for historical significance. Only papers published in English were reviewed. Accumulating data support the use of monoamine oxidase B inhibitors as monotherapy for early and mild Parkinson's disease and as adjunctive therapy for more advanced Parkinson's disease with levodopa-associated motor fluctuations. The recently released monoamine oxidase B inhibitor rasagiline and a new formulation, selegiline oral disintegrating tablets, have potential advantages over conventional oral selegiline.

  16. Amine oxidase from lentil seedlings: energetic domains and effect of temperature on activity.

    Science.gov (United States)

    Moosavi-Nejad, S Z; Rezaei-Tavirani, M; Padiglia, A; Floris, G; Moosavi-Movahedi, A A

    2001-07-01

    Copper/TPQ amine oxidases from mammalian and plant sources have shown many differences in substrate specificity and molecular properties. In this work the activity of lentil seedling amine oxidase was followed at various temperatures in 100 mM potassium phosphate buffer, pH 7, using benzylamine as substrate. The discontinuous Arrhenius plot of lentil amine oxidase showed two distinct phases with a jump between them. Thermal denaturation of the enzyme, using differential scanning calorimetry under the same experimental conditions, showed a transition at the same temperature ranges in the absence of substrate, indicating the occurrence of conformational changes, with an enthalpy change of about 175.9 kJ/mole. The temperature-induced changes of the activity of lentil amine oxidase are compared with those of bovine serum amine oxidase (taken from the literature).

  17. Antioxidant Potential of the Extracts, Fractions and Oils Derived from Oilseeds

    Directory of Open Access Journals (Sweden)

    Shagufta Ishtiaque

    2013-10-01

    Full Text Available The polyphenolic extracts and oils were obtained from ajwain, mustard, fenugreek and poppy seeds. The extracts were partitioned into acidic and neutral polyphenolic fractions and following estimation of total phenolics in the crude extract, acidic and neutral fractions and oil, all were analyzed for their DPPH (2,2-diphenyl-1-picrylhydrazyl scavenging potential, ferric reducing ability and chelating power. The highest amount of polyphenols was found in ajwain (8330 ± 107, then in mustard seeds (2844 ± 56.00 and in fenugreek (1130 ± 29.00, and least in poppy seeds (937 ± 18.52. The higher amounts of polyphenols were estimated in neutral fraction compared to acidic (p fenugreek and least by poppy seed extracts (p < 0.05. The reducing power and the chelating effect of the oilseeds followed the same order as DPPH, but higher % chelation was shown by neutral than acidic fraction (p < 0.05. Though low in polyphenols, the oil fractions were as strong antioxidants as the acidic one. Though oilseeds are used in very small quantity in food, they are potential sources of natural antioxidants and may replace synthetic ones.

  18. Fractionation of equine antivenom using caprylic acid precipitation in combination with cationic ion-exchange chromatography.

    Science.gov (United States)

    Raweerith, Rutai; Ratanabanangkoon, Kavi

    2003-11-01

    A combined process of caprylic acid (CA) precipitation and ion-exchange chromatography on SP-Sepharose was studied as a means to fractionate pepsin-digested horse antivenom F(ab')(2) antibody. In the CA precipitation, the optimal concentration for fractionation of F(ab')(2) from pepsin-digested horse plasma was 2%, in which 89.61% of F(ab')(2) antibody activity was recovered in the supernatant with 1.5-fold purification. A significant amount of pepsin was not precipitated and remained active under these conditions. An analytical cation exchanger Protein-Pak SP 8HR HPLC column was tested to establish optimal conditions for the effective separation of IgG, albumin, pepsin and CA from the F(ab')(2) product. From these results, the supernatant from CA precipitation of pepsin-digested plasma was subjected to a SP-Sepharose column chromatography using a linear salt gradient. With stepwise elution, a peak containing F(ab')(2) antibody could be obtained by elution with 0.25 M NaCl. The total recovery of antibody was 65.56% with 2.91-fold purification, which was higher than that achieved by ammonium sulfate precipitation. This process simultaneously and effectively removed residual pepsin, high molecular weight aggregates and CA in the final F(ab')(2) product, and should be suitable for large-scale fractionation of therapeutic equine antivenoms.

  19. Temperature dependence of carbon isotope fractionation in CAM plants

    International Nuclear Information System (INIS)

    Deleens, E.; Treichel, I.; O'Leary, M.H.

    1985-01-01

    The carbon isotope fractionation associated with nocturnal malic acid synthesis in Kalanchoë daigremontiana and Bryophyllum tubiflorum was calculated from the isotopic composition of carbon-4 of malic acid, after appropriate corrections. In the lowest temperature treatment (17 degrees C nights, 23 degrees C days), the isotope fractionation for both plants is -4 per thousand (that is, malate is enriched in (13)C relative to the atmosphere). For K. daigremontiana, the isotope fractionation decreases with increasing temperature, becoming approximately 0 per thousand at 27 degrees C/33 degrees C. Detailed analysis of temperature effects on the isotope fractionation indicates that stomatal aperture decreases with increasing temperature and carboxylation capacity increases. For B. tubiflorum, the temperature dependence of the isotope fractionation is smaller and is principally attributed to the normal temperature dependences of the rates of diffusion and carboxylation steps. The small change in the isotopic composition of remaining malic acid in both species which is observed during deacidification indicates that malate release, rather than decarboxylation, is rate limiting in the deacidification process

  20. Temperature dependence of carbon isotope fractionation in CAM plants

    Energy Technology Data Exchange (ETDEWEB)

    Deleens, E.; Treichel, I.; O' Leary, M.H.

    1985-09-01

    The carbon isotope fractionation associated with nocturnal malic acid synthesis in Kalanchoe daigremontiana and Bryophyllum tubiflorum was calculated from the isotopic composition of carbon-4 of malic acid, after appropriate corrections. In the lowest temperature treatment (17/sup 0/C nights, 23/sup 0/C days), the isotope fractionation for both plants is -4% per thousand (that is, malate is enriched in /sup 13/C relative to the atmosphere). For K. daigremontiana, the isotope fractionation decreases with increasing temperature, becoming approximately 0% per thousand at 27/sup 0/C/33/sup 0/C. Detailed analysis of temperature effects on the isotope fractionation indicates that stomatal aperture decreases with increasing temperature and carboxylation capacity increases. For B. tubiflorum, the temperature dependence of the isotope fractionation is smaller and is principally attributed to the normal temperature dependences of the rates of diffusion and carboxylation steps. The small change in the isotopic composition of remaining malic acid in both species which is observed during deacidification indicates that malate release, rather than decarboxylation, is rate limiting in the deacidification process. 28 references, 1 figure, 4 tables.

  1. IN VITRO INHIBITION OF CELERY (Apium graveolens L. EXTRACT ON THE ACTIVITY OF XANTHINE OXIDASE AND DETERMINATION OF ITS ACTIVE COMPOUND

    Directory of Open Access Journals (Sweden)

    Dyah Iswantini

    2012-12-01

    Full Text Available The objective of this study was to determine the inhibition effect of celery extracts toward xanthine oxidase by in vitro method, and its active compounds. Roots and herb of celery were extracted using water and ethanol solvents. Results indicated that the herbal ethanol extract had the highest inhibition effect (91.40% at 1400 ppm. The components contained in the herbal ethanol extract were then separated by column chromatography using the best eluent (chloroform : ethyl acetate at 7:3. All of the fractions had inhibition effect greater than 50%. The fraction number 4 was the one with the highest inhibition effect followed by fraction 5 with inhibition percentage of both fractions at 200 ppm were 88.62 and 85.44%, respectively. The analysis of the ultraviolet spectrum of fraction 4 showed the presence of π-π* transition which was resulted by the aromatic C=C, -OH, and C-O chromophores, and also showing the n-σ* transition which was given by -C=O chromophore. The infrared spectrum analysis indicated the presence of aromatic -C=C, -OH, and C=O functional groups. Based on the phytochemical assay and both instrumental spectrums, it was thought that the active compounds of fraction 4 and 5 were in the flavonoid group.

  2. Investigation of the impact of trace elements on anaerobic volatile fatty acid degradation using a fractional factorial experimental design.

    Science.gov (United States)

    Jiang, Ying; Zhang, Yue; Banks, Charles; Heaven, Sonia; Longhurst, Philip

    2017-11-15

    The requirement of trace elements (TE) in anaerobic digestion process is widely documented. However, little is understood regarding the specific requirement of elements and their critical concentrations under different operating conditions such as substrate characterisation and temperature. In this study, a flask batch trial using fractional factorial design is conducted to investigate volatile fatty acids (VFA) anaerobic degradation rate under the influence of the individual and combined effect of six TEs (Co, Ni, Mo, Se, Fe and W). The experiment inoculated with food waste digestate, spiked with sodium acetate and sodium propionate both to 10 g/l. This is followed by the addition of a selection of the six elements in accordance with a 2 6-2 fractional factorial principle. The experiment is conducted in duplicate and the degradation of VFA is regularly monitored. Factorial effect analysis on the experimental results reveals that within these experimental conditions, Se has a key role in promoting the degradation rates of both acetic and propionic acids; Mo and Co are found to have a modest effect on increasing propionic acid degradation rate. It is also revealed that Ni shows some inhibitory effects on VFA degradation, possibly due to its toxicity. Additionally, regression coefficients for the main and second order effects are calculated to establish regression models for VFA degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Activity and functional interaction of alternative oxidase and uncoupling protein in mitochondria from tomato fruit

    Directory of Open Access Journals (Sweden)

    F.E. Sluse

    2000-03-01

    Full Text Available Cyanide-resistant alternative oxidase (AOX is not limited to plant mitochondria and is widespread among several types of protists. The uncoupling protein (UCP is much more widespread than previously believed, not only in tissues of higher animals but also in plants and in an amoeboid protozoan. The redox energy-dissipating pathway (AOX and the proton electrochemical gradient energy-dissipating pathway (UCP lead to the same final effect, i.e., a decrease in ATP synthesis and an increase in heat production. Studies with green tomato fruit mitochondria show that both proteins are present simultaneously in the membrane. This raises the question of a specific physiological role for each energy-dissipating system and of a possible functional connection between them (shared regulation. Linoleic acid, an abundant free fatty acid in plants which activates UCP, strongly inhibits cyanide-resistant respiration mediated by AOX. Moreover, studies of the evolution of AOX and UCP protein expression and of their activities during post-harvest ripening of tomato fruit show that AOX and plant UCP work sequentially: AOX activity decreases in early post-growing stages and UCP activity is decreased in late ripening stages. Electron partitioning between the alternative oxidase and the cytochrome pathway as well as H+ gradient partitioning between ATP synthase and UCP can be evaluated by the ADP/O method. This method facilitates description of the kinetics of energy-dissipating pathways and of ATP synthase when state 3 respiration is decreased by limitation of oxidizable substrate.

  4. An Oxidase-Based Electrochemical Fluidic Sensor with High-Sensitivity and Low-Interference by On-Chip Oxygen Manipulation

    Directory of Open Access Journals (Sweden)

    Chang-Soo Kim

    2012-06-01

    Full Text Available Utilizing a simple fluidic structure, we demonstrate the improved performance of oxidase-based enzymatic biosensors. Electrolysis of water is utilized to generate bubbles to manipulate the oxygen microenvironment close to the biosensor in a fluidic channel. For the proper enzyme reactions to occur, a simple mechanical procedure of manipulating bubbles was developed to maximize the oxygen level while minimizing the pH change after electrolysis. The sensors show improved sensitivities based on the oxygen dependency of enzyme reaction. In addition, this oxygen-rich operation minimizes the ratio of electrochemical interference signal by ascorbic acid during sensor operation (i.e., amperometric detection of hydrogen peroxide. Although creatinine sensors have been used as the model system in this study, this method is applicable to many other biosensors that can use oxidase enzymes (e.g., glucose, alcohol, phenol, etc. to implement a viable component for in-line fluidic sensor systems.

  5. New insights into the molecular mechanism of Boletus edulis ribonucleic acid fraction (BE3) concerning antiproliferative activity on human colon cancer cells.

    Science.gov (United States)

    Lemieszek, Marta Kinga; Ribeiro, Miguel; Marques, Guilhermina; Nunes, Fernando Milheiro; Pożarowski, Piotr; Rzeski, Wojciech

    2017-05-24

    One of the relatively new and promising strategies of cancer treatment is chemoprevention, which involves the use of natural or synthetic compounds to block, inhibit or reverse carcinogenesis. A valuable and still untapped source of chemopreventive compounds seems to be edible mushrooms belonging to higher Basidiomycetes. Boletus edulis biopolymers extracted with hot water and purified by anion-exchange chromatography showed antiproliferative activity in colon cancer cells, but only fraction BE3, mostly composed of ribonucleic acids, was able to inhibit DNA synthesis in HT-29 cells. The present work aims to elucidate the molecular mechanism of this Boletus edulis ribonucleic acid fraction and in this sense flow cytometry and western blotting were applied to cell cycle analysis in HT-29 cells. We found that the antiproliferative ability of fraction BE3 observed in HT-29 cells was associated with the modulation of expression of cell cycle regulatory proteins (Cyclin D1, Cyclin A, p21 and p27) leading to cell accumulation in the S phase of the cell cycle. Furthermore, the BE3 fraction showed effective silencing of the signal transduction in an MAPK/Erk pathway in HT-29 and LS180 colon cancer cell lines. Thus, the previously and currently obtained results indicate that the BE3 fraction from Boletus edulis has great potential and needs to be further exploited through animal and clinical studies in order to develop a new efficient and safe therapeutic strategy for people who have been threatened by or suffered from colon cancer.

  6. Polysaccharide rich fractions from barks of Ximenia americana inhibit peripheral inflammatory nociception in mice Antinociceptive effect of Ximenia americana polysaccharide rich fractions

    Directory of Open Access Journals (Sweden)

    Kaira E.S. da Silva-Leite

    Full Text Available Abstract Ximenia americana L., Olacaceae, barks are utilized in folk medicine as analgesic and anti-inflammatory. The objective was to evaluate the toxicity and antinociceptive effect of polysaccharides rich fractions from X. americana barks. The fractions were obtained by extraction with NaOH, followed by precipitation with ethanol and fractionation by ion exchange chromatography. They were administered i.v. or p.o. before nociception tests (writhing, formalin, carragenan-induced hypernociception, hot plate, or during 14 days for toxicity assay. The total polysaccharides fraction (TPL-Xa: 8.1% yield presented 43% carbohydrate (21% uronic acid and resulted in two main fractions after chromatography (FI: 12%, FII: 22% yield. FII showed better homogeneity/purity, content of 44% carbohydrate, including 39% uronic acid, arabinose and galactose as major monosaccharides, and infrared spectra with peaks in carbohydrate range for COO- groups of uronic acid. TPL-Xa (10 mg/kg and FII (0.1 and 1 mg/kg presented inhibitory effect in behavior tests that evaluate nociception induced by chemical and mechanical, but not thermal stimuli. TPL-Xa did not alter parameters of systemic toxicity. In conclusion, polysaccharides rich fractions of X. americana barks inhibit peripheral inflammatory nociception, being well tolerated by animals.

  7. Lysyl oxidase in cancer research

    DEFF Research Database (Denmark)

    Perryman, Lara; Erler, Janine Terra

    2014-01-01

    Metastasis is the main reason for cancer-associated deaths and therapies are desperately needed to target the progression of cancer. Lysyl oxidase (LOX) plays a pivotal role in cancer progression, including metastasis, and is therefore is an attractive therapeutic target. In this review we...

  8. Angiotensin II inhibits the Na+-K+ pump via PKC-dependent activation of NADPH oxidase.

    Science.gov (United States)

    White, Caroline N; Figtree, Gemma A; Liu, Chia-Chi; Garcia, Alvaro; Hamilton, Elisha J; Chia, Karin K M; Rasmussen, Helge H

    2009-04-01

    The sarcolemmal Na(+)-K(+) pump, pivotal in cardiac myocyte function, is inhibited by angiotensin II (ANG II). Since ANG II activates NADPH oxidase, we tested the hypothesis that NADPH oxidase mediates the pump inhibition. Exposure to 100 nmol/l ANG II increased superoxide-sensitive fluorescence of isolated rabbit ventricular myocytes. The increase was abolished by pegylated superoxide dismutase (SOD), by the NADPH oxidase inhibitor apocynin, and by myristolated inhibitory peptide to epsilon-protein kinase C (epsilonPKC), previously implicated in ANG II-induced Na(+)-K(+) pump inhibition. A role for epsilonPKC was also supported by an ANG II-induced increase in coimmunoprecipitation of epsilonPKC with the receptor for the activated kinase and with the cytosolic p47(phox) subunit of NADPH oxidase. ANG II decreased electrogenic Na(+)-K(+) pump current in voltage-clamped myocytes. The decrease was abolished by SOD, by the gp91ds inhibitory peptide that blocks assembly and activation of NADPH oxidase, and by epsilonPKC inhibitory peptide. Since colocalization should facilitate NADPH oxidase-dependent regulation of the Na(+)-K(+) pump, we examined whether there is physical association between the pump subunits and NADPH oxidase. The alpha(1)-subunit coimmunoprecipitated with caveolin 3 and with membrane-associated p22(phox) and cytosolic p47(phox) NADPH oxidase subunits at baseline. ANG II had no effect on alpha(1)/caveolin 3 or alpha(1)/p22(phox) interaction, but it increased alpha(1)/p47(phox) coimmunoprecipitation. We conclude that ANG II inhibits the Na(+)-K(+) pump via PKC-dependent NADPH oxidase activation.

  9. Safety of protein hydrolysates, fractions thereof and

    NARCIS (Netherlands)

    Gertjan Schaafsma

    2009-01-01

    This paper evaluates the safety for humans with regard to consumption of protein hydrolysates and fractions thereof, including bioactive peptides. The available literature on the safety of protein, protein hydrolysates, fractions thereof and free amino acids on relevant food legislation is reviewed

  10. Comparative investigation to see the efficacy of polyphenol oxidase inhibitors parallel to sulphite for control of enzymatic browning in guava juice

    International Nuclear Information System (INIS)

    Zai, M.N.K.A.

    2008-01-01

    Comparative study was conducted to determine the efficacy of polyphenol oxidase inhibitors to control browning in guava juice/concentrates parallel to sulfite. Although sulfites are highly effective to control the browning but these have shown adverse effect on health particularly to those who have pulmonary disorder like asthma. Filtration with useful filter aid and juicing agents are found to be helpful in removing browning residue particulates fractions to extend the shelf life of the juice. Non-enzymatic browning can be prevented by cold blanching. (author)

  11. Systemic Manifestations in Pyridox(am)ine 5'-Phosphate Oxidase Deficiency.

    Science.gov (United States)

    Guerriero, Réjean M; Patel, Archana A; Walsh, Brian; Baumer, Fiona M; Shah, Ankoor S; Peters, Jurriaan M; Rodan, Lance H; Agrawal, Pankaj B; Pearl, Phillip L; Takeoka, Masanori

    2017-11-01

    Pyridoxine is converted to its biologically active form pyridoxal-5-phosphate (P5P) by the enzyme pyridox(am)ine 5'-phosphate oxidase and serves as a cofactor in nearly 200 reactions in the central nervous system. Pyridox(am)ine 5'-phosphate oxidase deficiency leads to P5P dependent epilepsy, typically a neonatal- or infantile-onset epileptic encephalopathy treatable with P5P or in some cases, pyridoxine. Following identification of retinopathy in a patient with pyridox(am)ine 5'-phosphate oxidase deficiency that was reversible with P5P therapy, we describe the systemic manifestations of pyridox(am)ine 5'-phosphate oxidase deficiency. A series of six patients with homozygous mutations of PNPO, the gene coding pyridox(am)ine 5'-phosphate oxidase, were evaluated in our center over the course of two years for phenotyping of neurological and systemic manifestations. Five of six were born prematurely, three had anemia and failure to thrive, and two had elevated alkaline phosphatase. A movement disorder was observed in two children, and a reversible retinopathy was observed in the most severely affected infant. All patients had neonatal-onset epilepsy and were on a continuum of developmental delay to profound encephalopathy. Electroencephalographic features included background slowing and disorganization, absent sleep features, and multifocal and generalized epileptiform discharges. All the affected probands carried a homozygous PNPO mutation (c.674 G>T, c.686 G>A and c.352G>A). In addition to the well-described epileptic encephalopathy, pyridox(am)ine 5'-phosphate oxidase deficiency causes a range of neurological and systemic manifestations. A movement disorder, developmental delay, and encephalopathy, as well as retinopathy, anemia, and failure to thrive add to the broadening clinical spectrum of P5P dependent epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Effect of temperature stress on polyphenol oxidase activity in grains of some wheat cultivars

    International Nuclear Information System (INIS)

    Kayani, W.K.

    2011-01-01

    Color is a key quality trait of wheat-based products and polyphenol oxidase (PPO) is implicated to play a significant role in their undesirable darkening. Polyphenol oxidase catalyzes the oxidation of phenols to quinines, which auto oxidize and polymerize with amino acid of cellular proteins resulting brown and black pigmentation propounding reduced nutritional values. In present study, the PPO activity in 50 different Pakistani wheat cultivars was investigated and grouped into three categories viz; low, medium and high PPO activity cultivars. PPO is a heat labile enzyme. To investigate effect of heat stress, nine cultivars from each category were chosen for treatment at 30, 40 and 50 deg. C for 30, 60, and 120 minutes each. A substantial change was experienced in PPO activity as compared to room temperature. Two wheat cultivar Wafaq-2001 and AS-2002 showed a compromising attitude of minimum PPO activity at 30 deg. C for a period of 30 and 60 minutes of incubation. In general, an incubation of 30 deg. C or 60 deg. C (low or high) for a period of 30 minutes can be recommended for suppressing PPO activity. (author)

  13. ABTS assay of phenol oxidase activity in soil.

    Science.gov (United States)

    Floch, Carine; Alarcon-Gutiérrez, Enrique; Criquet, Stéven

    2007-12-01

    Phenol oxidases (PO) are involved in degradation of many recalcitrant aromatic compounds and may be sensitive to some pollutants. Hence, their activities may be a useful indicator for evaluating soil quality and health. To this end, the aim of this study was to develop a simple method to assay PO activity directly in bulk samples by spectrophotometric test using 2,2'-azinobis-(-3 ethylbenzothiazoline-6-sulfononic acid) diammonium salt (ABTS) as the substrate. Three Mediterranean soils were used as models. For each soil, we studied the kinetic parameters and the effects of certain factors (i.e. amount of soil, pH, temperature, incubation time and substrate concentration) in order to determine the optimum conditions for the ABTS assay. Results showed that PO attain their optimum activities when incubating 0.1 g of soil at 30 degrees C for 5 min with 10 ml of a Modified Universal Buffer (MUB) at pH 2 and 200 microl of a 0.1 M ABTS solution.

  14. Fluorescent Probes for Analysis and Imaging of Monoamine Oxidase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dokyoung; Jun, Yong Woong; Ahn, Kyo Han [POSTECH, Pohang (Korea, Republic of)

    2014-05-15

    Monoamine oxidases catalyze the oxidative deamination of dietary amines and amine neurotransmitters, and assist in maintaining the homeostasis of the amine neurotransmitters in the brain. Dysfunctions of these enzymes can cause neurological and behavioral disorders including Parkinson's and Alzheimer's diseases. To understand their physiological roles, efficient assay methods for monoamine oxidases are essential. Reviewed in this Perspective are the recent progress in the development of fluorescent probes for monoamine oxidases and their applications to enzyme assays in cells and tissues. It is evident that still there is strong need for a fluorescent probe with desirable substrate selectivity and photophysical properties to challenge the much unsolved issues associated with the enzymes and the diseases.

  15. Mutation spectrum of homogentisic acid oxidase (HGD) in alkaptonuria.

    Science.gov (United States)

    Vilboux, Thierry; Kayser, Michael; Introne, Wendy; Suwannarat, Pim; Bernardini, Isa; Fischer, Roxanne; O'Brien, Kevin; Kleta, Robert; Huizing, Marjan; Gahl, William A

    2009-12-01

    Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder, characterized by accumulation of homogentisic acid, leading to darkened urine, pigmentation of connective tissue (ochronosis), joint and spine arthritis, and destruction of cardiac valves. AKU is due to mutations in the homogentisate dioxygenase gene (HGD) that converts homogentisic acid to maleylacetoacetic acid in the tyrosine catabolic pathway. Here we report a comprehensive mutation analysis of 93 patients enrolled in our study, as well as an extensive update of all previously published HGD mutations associated with AKU. Within our patient cohort, we identified 52 HGD variants, of which 22 were novel. This yields a total of 91 identified HGD variations associated with AKU to date, including 62 missense, 13 splice site, 10 frameshift, 5 nonsense, and 1 no-stop mutation. Most HGD variants reside in exons 3, 6, 8, and 13. We assessed the potential effect of all missense variations on protein function, using five bioinformatic tools specifically designed for interpretation of missense variants (SIFT, POLYPHEN, PANTHER, PMUT, and SNAP). We also analyzed the potential effect of splice-site variants using two different tools (BDGP and NetGene2). This study provides valuable resources for molecular analysis of alkaptonuria and expands our knowledge of the molecular basis of this disease.

  16. EPA:DHA 6:1 prevents angiotensin II-induced hypertension and endothelial dysfunction in rats: role of NADPH oxidase- and COX-derived oxidative stress.

    Science.gov (United States)

    Niazi, Zahid Rasul; Silva, Grazielle C; Ribeiro, Thais Porto; León-González, Antonio J; Kassem, Mohamad; Mirajkar, Abdur; Alvi, Azhar; Abbas, Malak; Zgheel, Faraj; Schini-Kerth, Valérie B; Auger, Cyril

    2017-12-01

    Eicosapentaenoic acid:docosahexaenoic acid (EPA:DHA) 6:1, an omega-3 polyunsaturated fatty acid formulation, has been shown to induce a sustained formation of endothelial nitric oxide (NO) synthase-derived NO, a major vasoprotective factor. This study examined whether chronic intake of EPA:DHA 6:1 prevents hypertension and endothelial dysfunction induced by angiotensin II (Ang II) in rats. Male Wister rats received orally corn oil or EPA:DHA 6:1 (500 mg kg -1 per day) before chronic infusion of Ang II (0.4 mg kg -1 per day). Systolic blood pressure was determined by tail cuff sphingomanometry, vascular reactivity using a myograph, oxidative stress using dihydroethidium and protein expression by immunofluorescence and western blot analysis. Ang II-induced hypertension was associated with reduced acetylcholine-induced relaxations of secondary branch mesenteric artery rings affecting the endothelium-dependent hyperpolarization (EDH)- and the NO-mediated relaxations, both of which were improved by the NADPH oxidase inhibitor VAS-2870. The Ang II treatment induced also endothelium-dependent contractile responses (EDCFs), which were abolished by the cyclooxygenase (COX) inhibitor indomethacin. An increased level of vascular oxidative stress and expression of NADPH oxidase subunits (p47 phox and p22 phox ), COX-1 and COX-2, endothelial NO synthase and Ang II type 1 receptors were observed in the Ang II group, whereas SK Ca and connexin 37 were downregulated. Intake of EPA:DHA 6:1 prevented the Ang II-induced hypertension and endothelial dysfunction by improving both the NO- and EDH-mediated relaxations, and by reducing EDCFs and the expression of target proteins. The present findings indicate that chronic intake of EPA:DHA 6:1 prevented the Ang II-induced hypertension and endothelial dysfunction in rats, most likely by preventing NADPH oxidase- and COX-derived oxidative stress.

  17. Cloning and expression analysis of the Ccrboh gene encoding respiratory burst oxidase in Citrullus colocynthis and grafting onto Citrullus lanatus (watermelon).

    Science.gov (United States)

    Si, Ying; Dane, Fenny; Rashotte, Aaron; Kang, Kwonkyoo; Singh, Narendra K

    2010-06-01

    A full-length drought-responsive gene Ccrboh, encoding the respiratory burst oxidase homologue (rboh), was cloned in Citrullus colocynthis, a very drought-tolerant cucurbit species. The robh protein, also named NADPH oxidase, is conserved in plants and animals, and functions in the production of reactive oxygen species (ROS). The Ccrboh gene accumulated in a tissue-specific pattern when C. colocynthis was treated with PEG, abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), or NaCl, while the homologous rboh gene did not show any change in C. lanatus var. lanatus, cultivated watermelon, during drought. Grafting experiments were conducted using C. colocynthis or C. lanatus as the rootstock or scion. Results showed that the rootstock significantly affects gene expression in the scion, and some signals might be transported from the root to the shoot. Ccrboh in C. colocynthis was found to function early during plant development, reaching high mRNA transcript levels 3 d after germination. The subcellular location of Ccrboh was investigated by transient expression of the 35S::Ccrboh::GFP fusion construct in protoplasts. The result confirmed that Ccrboh is a transmembrane protein. Our data suggest that Ccrboh might be functionally important during the acclimation of plants to stress and also in plant development. It holds great promise for improving drought tolerance of other cucurbit species.

  18. Molecular mechanism of cell death induced by king cobra (Ophiophagus hannah) venom l-amino acid oxidase.

    Science.gov (United States)

    Fung, Shin Yee; Lee, Mui Li; Tan, Nget Hong

    2015-03-01

    Snake venom LAAOs have been reported to exhibit a wide range of pharmacological activities, including cytotoxic, edema-inducing, platelet aggregation-inducing/platelet aggregation-inhibiting, bactericidal and antiviral activities. A heat-stable form of l-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom (OH-LAAO) has been shown to exhibit very potent cytotoxicity against human tumorigenic cells but not in their non-tumorigenic counterparts, and the cytotoxicity was due to the apoptosis-inducing effect of the enzyme. In this work, the molecular mechanism of cell death induced by OH-LAAO was investigated. The enzyme exerts its apoptosis-inducing effect presumably via both intrinsic and extrinsic pathways as suggested by the increase in caspase-8 and -9 activities. Oligonucleotide microarray analysis showed that the expression of a total of 178 genes was significantly altered as a result of oxidative stress induced by the hydrogen peroxide generated by the enzyme. Of the 178 genes, at least 27 genes are involved in apoptosis and cell death. These alterations of gene expression was presumably caused by the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidative modifications of signaling molecules that eventually lead to apoptosis and cell death. The very substantial up-regulation of cytochrome P450 genes may also contribute to the potent cytotoxic action of OH-LAAO by producing excessive reactive oxygen species (ROS). In conclusion, the potent apoptosis inducing activity of OH-LAAO was likely due to the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidation of signalling molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. QSYQ Attenuates Oxidative Stress and Apoptosis Induced Heart Remodeling Rats through Different Subtypes of NADPH-Oxidase

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2013-01-01

    Full Text Available We aim to investigate the therapeutic effects of QSYQ, a drug of heart failure (HF in clinical practice in China, on a rat heart failure (HF model. 3 groups were divided: HF model group (LAD ligation, QSYQ group (LAD ligation and treated with QSYQ, and sham-operated group. After 4 weeks, rats were sacrificed for cardiac injury measurements. Rats with HF showed obvious histological changes including necrosis and inflammation foci, elevated ventricular remodeling markers levels(matrix metalloproteinases-2, MMP-2, deregulated ejection fraction (EF value, increased formation of oxidative stress (Malondialdehyde, MDA, and up-regulated levels of apoptotic cells (caspase-3, p53 and tunnel in myocardial tissue. Treatment of QSYQ improved cardiac remodeling through counter-acting those events. The improvement of QSYQ was accompanied with a restoration of NADPH oxidase 4 (NOX4 and NADPH oxidase 2 (NOX2 pathways in different patterns. Administration of QSYQ could attenuate LAD-induced HF, and AngII-NOX2-ROS-MMPs pathway seemed to be the critical potential targets for QSYQ to reduce the remodeling. Moreover, NOX4 was another key targets to inhibit the p53 and Caspase3, thus to reduce the hypertrophy and apoptosis, and eventually provide a synergetic cardiac protective effect.

  20. [Experimental rationale for the parameters of a rapid method for oxidase activity determination].

    Science.gov (United States)

    Butorina, N N

    2010-01-01

    Experimental rationale is provided for the parameters of a rapid (1-2-min) test to concurrently determine the oxidase activity of all bacteria grown on the membrane filter after water filtration. Oxidase reagents that are the aqueous solutions of tetramethyl-p-phenylenediamine dihydrochloride and demethyl-p-phenylenediamine dihydrochloride have been first ascertained to exert no effect on the viability and enzymatic activity of bacteria after one-hour contact. An algorithm has been improved for the rapid oxidase activity test: the allowable time for bacteria to contact oxidase reagents and procedures for minimizing the effect on bacterial biochemical activity following the contact. An accelerated method based on lactose medium with tergitol 7 and Endo agar has been devised to determine coliform bacteria, by applying the rapid oxidase test: the time of a final response is 18-24 hours. The method has been included into GOST 52426-2005.

  1. A new fatal case of pyridox(am)ine 5'-phosphate oxidase (PNPO) deficiency.

    Science.gov (United States)

    Ruiz, Angeles; García-Villoria, Judit; Ormazabal, Aida; Zschocke, Johannes; Fiol, Miquel; Navarro-Sastre, Aleix; Artuch, Rafael; Vilaseca, Maria Antonia; Ribes, Antonia

    2008-02-01

    We present a patient with severe pyridox(am)ine 5'-phosphate oxidase deficiency and homozygosity for a novel nonsense-mutation, p.A174X, in the PNPO gene who died with pyridoxal phosphate (PLP) treatment despite initial clinical recovery. He presented neonatally, with the classical clinical symptoms of the disease. Increase of urinary vanillactate was the first biochemical factor of alert. Amino acid and neurotransmitter analysis in CSF indicated reduced activity of several PLP-dependent enzymes. The diagnosis was confirmed by mutational studies. From this and the other reported patients it may be concluded that the administration of PLP should not be delayed until the complete biochemical evidence is obtained.

  2. Action of DCCD on the H+/O stoichiometry of mitoplast cytochrome c oxidase.

    Science.gov (United States)

    Lehninger, A L; Reynafarje, B; Costa, L

    1985-01-01

    The mechanistic H+/O ejection stoichiometry of the cytochrome c oxidase reaction in rat liver mitoplasts is close to 4 at level flow when the reduced oxidase is pulsed with O2. Dicyclohexylcarbodiimide (DCCD) up to 30 nmol/mg protein fails to influence the rate of electron flow through the mitoplast oxidase, but inhibits H+ ejection. The inhibition of H+ ejection appears to be biphasic; ejection of 2-3 H+ per O is completely inhibited by very low DCCD, whereas inhibition of the remaining H+ ejection requires very much higher concentrations of DCCD. This effect suggests the occurrence of two types of H+ pumps in the native cytochrome oxidase of mitoplasts.

  3. Isolation and Characterization of Chinese Standard Fulvic Acid Sub-fractions Separated from Forest Soil by Stepwise Elution with Pyrophosphate Buffer

    Science.gov (United States)

    Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P.

    2015-01-01

    XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants. PMID:25735451

  4. Vanillyl-alcohol oxidase, a tasteful biocatalyst

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Fraaije, M.W.; Mattevi, A.; Laane, C.; Berkel, van W.J.H.

    2001-01-01

    The covalent flavoenzyme vanillyl-alcohol oxidase (VAO) is a versatile biocatalyst. It converts a wide range of phenolic compounds by catalysing oxidation, deamination, demethylation, dehydrogenation and hydroxylation reactions. The production of natural vanillin, 4-hydroxybenzaldehyde, coniferyl

  5. Analysis of Chlorogenic Acid Oxidation Pathway in Simulated ...

    African Journals Online (AJOL)

    Purpose: To investigate the pathways involved in the oxidation of chlorogenic acid (CA) and phenol metabolism in honeysuckle buds. Methods: A model that mimics CA oxidation by honeysuckle polyphenol oxidase (PPO) by controlling the reaction temperature or reaction duration was employed, and the resulting products ...

  6. Changes in the activity of the alternative oxidase in Orobanche seeds during conditioning and their possible physiological function.

    Science.gov (United States)

    Bar Nun, Nurit; Plakhine, Dina; Joel, Daniel M; Mayer, Alfred M

    2003-09-01

    The appearance of the activity of the cyanide insensitive, alternative oxidase (AOX), pathway of oxygen uptake was followed in seeds of Orobanche aegyptiaca during conditioning. The pathway becomes operative during conditioning, up to day three as determined by inhibition of oxygen uptake of the seeds by propyl gallate. At the same time an increasing percentage of oxygen uptake is insensitive to cyanide and an increased oxygen uptake, responsive to propyl gallate, is induced by brief salicylic acid treatment of seeds. By day six of conditioning, these responses decrease and the AOX pathway could not be detected in germinating seeds, after treatment with a germination stimulant. These results were confirmed by following the reaction of extracts of fractions enriched with mitochondria from the conditioned seeds, using a specific antibody against AOX. Treatment of the seeds with inhibitors of AOX during conditioning significantly inhibited their subsequent germination. Addition of hydrogen peroxide after 4 and 7 days of conditioning resulted in reduced germination. In addition treatment of seed with propyl or octyl gallate during conditioning reduced the infection of tomato plants by Orobanche seeds and the development of tubercles of the parasite on the host roots. These results together indicate that the operation of AOX during conditioning has a significant function on the subsequent germination behaviour and pathogenicity of the root parasite. Some potential practical applications of these findings are discussed.

  7. Lysyl Oxidase and the Tumor Microenvironment

    Directory of Open Access Journals (Sweden)

    Tong-Hong Wang

    2016-12-01

    Full Text Available The lysyl oxidase (LOX family of oxidases contains a group of extracellular copper-dependent enzymes that catalyze the cross-linking of collagen and elastin by oxidation, thus maintaining the rigidity and structural stability of the extracellular matrix (ECM. Aberrant expression or activation of LOX alters the cellular microenvironment, leading to many diseases, including atherosclerosis, tissue fibrosis, and cancer. Recently, a number of studies have shown that LOX is overexpressed in most cancers and that it is involved in the regulation of tumor progression and metastasis. In contrast, a few reports have also indicated the tumor-suppressing role of LOX. In this short review, we discuss recent research on the correlations between LOX and cancer. Further, the role of LOX in tumor microenvironment remodeling, tumorigenesis, and metastasis and the underlying mechanisms have also been elucidated.

  8. Electrochemical characterization of adsorbed bilirubin oxidase on Vulcan XC 72R for the biocathode preparation in a glucose/O2 biofuel cell

    International Nuclear Information System (INIS)

    Habrioux, A.; Napporn, T.; Servat, K.; Tingry, S.; Kokoh, K.B.

    2010-01-01

    A new biocathode was built and tested. It consisted of bilirubin oxidase adsorbed on Vulcan XC 72 R and immobilized into a Nafion matrix. The possibility of direct electron transfer between bilirubin oxidase and Vulcan XC 72 R was also demonstrated. The kinetics on biocathode were enhanced by including 2,2'-azinobis-3-ethylbenzothiazoline-5-sulfonic acid in the catalytic film. A first order reaction rate was observed for oxygen concentrations lower than 22%. A complete kinetic investigation of the system was shown. A biofuel cell test performed with this biocathode and Au 70 Pt 30 nanoparticles as anode catalyst permitted to reach a power density of 170 μW cm -2 at a cell voltage of 0.6 V, which is superior to what can be obtained with the concentric design.

  9. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species

    Directory of Open Access Journals (Sweden)

    Saima Rafiq

    2016-07-01

    Full Text Available Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%, solid-not-fat (11.24%±0.02%, total solids (18.05%±0.05%, protein (5.15%±0.06% and casein (3.87%±0.04% contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%, buffalo (0.68%±0.02% and sheep (0.66%±0.02% milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82, cow (r = 0.88, sheep (r = 0.86 and goat milk (r = 0.98. The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g, camel (96±2.2 mg/g and buffalo (90±2.4 mg/g milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products.

  10. Plasma amine oxidase activities in Norrie disease patients with an X-chromosomal deletion affecting monoamine oxidase.

    Science.gov (United States)

    Murphy, D L; Sims, K B; Karoum, F; Garrick, N A; de la Chapelle, A; Sankila, E M; Norio, R; Breakefield, X O

    1991-01-01

    Two individuals with an X-chromosomal deletion were recently found to lack the genes encoding monoamine oxidase type A (MAO-A) and MAO-B. This abnormality was associated with almost total (90%) reductions in the oxidatively deaminated urinary metabolites of the MAO-A substrate, norepinephrine, and with marked (100-fold) increases in an MAO-B substrate, phenylethylamine, confirming systemic functional consequences of the genetic enzyme deficiency. However, urinary concentrations of the deaminated metabolites of dopamine and serotonin (5-HT) were essentially normal. To investigate other deaminating systems besides MAO-A and MAO-B that might produce these metabolites of dopamine and 5-HT, we examined plasma amine oxidase (AO) activity in these two patients and two additional patients with the same X-chromosomal deletion. Normal plasma AO activity was found in all four Norrie disease-deletion patients, in four patients with classic Norrie disease without a chromosomal deletion, and in family members of patients from both groups. Marked plasma amine metabolite abnormalities and essentially absent platelet MAO-B activity were found in all four Norrie disease-deletion patients, but in none of the other subjects in the two comparison groups. These results indicate that plasma AO is encoded by gene(s) independent of those for MAO-A and MAO-B, and raise the possibility that plasma AO, and perhaps the closely related tissue AO, benzylamine oxidase, as well as other atypical AOs or MAOs encoded independently from MAO-A and MAO-B may contribute to the oxidative deamination of dopamine and 5-HT in humans.

  11. Inactivation of 1-aminocyclopropane-1-carboxylate oxidase involves oxidative modifications.

    Science.gov (United States)

    Barlow, J N; Zhang, Z; John, P; Baldwin, J E; Schofield, C J

    1997-03-25

    1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final step in the biosynthesis of the plant signaling molecule ethylene. It is a member of the ferrous iron dependent family of oxidases and dioxygenases and is unusual in that it displays a very short half-life under catalytic conditions, typically less than 20 min, and a requirement for CO2 as an activator. The rates of inactivation of purified, recombinant ACC oxidase from tomato under various combinations of substrates and cofactors were measured. Inactivation was relatively slow in the presence of buffer alone (t1/2 > 1 h), but fast in the presence of ferrous iron and ascorbate (t1/2 approximately 10 min). The rate of iron/ascorbate-mediated inactivation was increased by the addition of ACC, unaffected by the addition of CO2 at saturation (supplied as bicarbonate) but decreased by the addition of catalase or ACC + CO2 at saturation (supplied as bicarbonate). Iron/ascorbate-mediated inactivation was accompanied by partial proteolysis as observed by SDS-PAGE analysis. The fragmentation pattern was altered when ACC was also included, suggesting that ACC can bind to ACC oxidase in the absence of bicarbonate. N-terminal sequencing of fragments resulted in identification of an internal cleavage site which we propose is proximate to active-site bound iron. Thus, ACC oxidase inactivates via relatively slow partial unfolding of the catalytically active conformation, oxidative damage mediated via hydrogen peroxide which is catalase protectable and oxidative damage to the active site which results in partial proteolysis and is not catalase protectable.

  12. Phytochemical Profiling of Flavonoids, Phenolic Acids, Terpenoids, and Volatile Fraction of a Rosemary (Rosmarinus officinalis L. Extract

    Directory of Open Access Journals (Sweden)

    Pedro Mena

    2016-11-01

    Full Text Available This paper presents a comprehensive analysis of the phytochemical profile of a proprietary rosemary (Rosmarinus officinalis L. extract rich in carnosic acid. A characterization of the (polyphenolic and volatile fractions of the extract was carried out using mass spectrometric techniques. The (polyphenolic composition was assessed by ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MSn and a total of 57 compounds were tentatively identified and quantified, 14 of these being detected in rosemary extract for the first time. The rosemary extract contained 24 flavonoids (mainly flavones, although flavonols and flavanones were also detected, 5 phenolic acids, 24 diterpenoids (carnosic acid, carnosol, and rosmanol derivatives, 1 triterpenoid (betulinic acid, and 3 lignans (medioresinol derivatives. Carnosic acid was the predominant phenolic compound. The volatile profile of the rosemary extract was evaluated by head space solid-phase microextraction (HS-SPME linked to gas chromatography-mass spectrometry (GC-MS. Sixty-three volatile molecules (mainly terpenes, alcohols, esters, aldehydes, and ketones were identified. This characterization extends the current knowledge on the phytochemistry of Rosmarinus officinalis and is, to our knowledge, the broadest profiling of its secondary metabolites to date. It can assist in the authentication of rosemary extracts or rosemary-containing products or in testing its bioactivity. Moreover, this methodological approach could be applied to the study of other plant-based food ingredients.

  13. Phytochemical Profiling of Flavonoids, Phenolic Acids, Terpenoids, and Volatile Fraction of a Rosemary (Rosmarinus officinalis L.) Extract.

    Science.gov (United States)

    Mena, Pedro; Cirlini, Martina; Tassotti, Michele; Herrlinger, Kelli A; Dall'Asta, Chiara; Del Rio, Daniele

    2016-11-19

    This paper presents a comprehensive analysis of the phytochemical profile of a proprietary rosemary ( Rosmarinus officinalis L.) extract rich in carnosic acid. A characterization of the (poly)phenolic and volatile fractions of the extract was carried out using mass spectrometric techniques. The (poly)phenolic composition was assessed by ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS n ) and a total of 57 compounds were tentatively identified and quantified, 14 of these being detected in rosemary extract for the first time. The rosemary extract contained 24 flavonoids (mainly flavones, although flavonols and flavanones were also detected), 5 phenolic acids, 24 diterpenoids (carnosic acid, carnosol, and rosmanol derivatives), 1 triterpenoid (betulinic acid), and 3 lignans (medioresinol derivatives). Carnosic acid was the predominant phenolic compound. The volatile profile of the rosemary extract was evaluated by head space solid-phase microextraction (HS-SPME) linked to gas chromatography-mass spectrometry (GC-MS). Sixty-three volatile molecules (mainly terpenes, alcohols, esters, aldehydes, and ketones) were identified. This characterization extends the current knowledge on the phytochemistry of Rosmarinus officinalis and is, to our knowledge, the broadest profiling of its secondary metabolites to date. It can assist in the authentication of rosemary extracts or rosemary-containing products or in testing its bioactivity. Moreover, this methodological approach could be applied to the study of other plant-based food ingredients.

  14. Genetics Home Reference: isolated sulfite oxidase deficiency

    Science.gov (United States)

    ... and Management Resources (1 link) GeneReview: Isolated Sulfite Oxidase Deficiency General Information from MedlinePlus (5 links) Diagnostic Tests Drug Therapy Genetic Counseling Palliative Care Surgery and ...

  15. Up-Streaming Process for Glucose Oxidase by Thermophilic Penicillium sp. in Shake Flask

    OpenAIRE

    Muhammad Mohsin JAVED; Aroosh SHABIR; Sana ZAHOOR; Ikram UL-HAQ

    2012-01-01

    The present study is concerned with the production of glucose oxidase (GOD) from thermophilic Penicillium sp. in 250 mL shake flask. Fourteen different strains of thermophilic Penicillium sp. were isolated from the soil and were screened for glucose oxidase production. IIBP-13 strain gave maximum extra-cellular glucose oxidase production as compared to other isolates. Effect of submerged fermentation in shaking and static conditions, different carbon sources and incubation period on the produ...

  16. NADPH oxidases as novel pharmacologic targets against influenza A virus infection.

    Science.gov (United States)

    Vlahos, Ross; Selemidis, Stavros

    2014-12-01

    Influenza A viruses represent a major global health care challenge, with imminent pandemics, emerging antiviral resistance, and long lag times for vaccine development, raising a pressing need for novel pharmacologic strategies that ideally target the pathology irrespective of the infecting strain. Reactive oxygen species (ROS) pervade all facets of cell biology with both detrimental and protective properties. Indeed, there is compelling evidence that activation of the NADPH oxidase 2 (NOX2) isoform of the NADPH oxidase family of ROS-producing enzymes promotes lung oxidative stress, inflammation, injury, and dysfunction resulting from influenza A viruses of low to high pathogenicity, as well as impeding virus clearance. By contrast, the dual oxidase isoforms produce ROS that provide vital protective antiviral effects for the host. In this review, we propose that inhibitors of NOX2 are better alternatives than broad-spectrum antioxidant approaches for treatment of influenza pathologies, for which clinical efficacy may have been limited owing to poor bioavailability and inadvertent removal of beneficial ROS. Finally, we briefly describe the current suite of NADPH oxidase inhibitors and the molecular features of the NADPH oxidase enzymes that could be exploited by drug discovery for development of more specific and novel inhibitors to prevent or treat disease caused by influenza. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

  17. A catechol oxidase AcPPO from cherimoya (Annona cherimola Mill.) is localized to the Golgi apparatus.

    Science.gov (United States)

    Olmedo, Patricio; Moreno, Adrián A; Sanhueza, Dayan; Balic, Iván; Silva-Sanzana, Christian; Zepeda, Baltasar; Verdonk, Julian C; Arriagada, César; Meneses, Claudio; Campos-Vargas, Reinaldo

    2018-01-01

    Cherimoya (Annona cherimola) is an exotic fruit with attractive organoleptic characteristics. However, it is highly perishable and susceptible to postharvest browning. In fresh fruit, browning is primarily caused by the polyphenol oxidase (PPO) enzyme catalyzing the oxidation of o-diphenols to quinones, which polymerize to form brown melanin pigment. There is no consensus in the literature regarding a specific role of PPO, and its subcellular localization in different plant species is mainly described within plastids. The present work determined the subcellular localization of a PPO protein from cherimoya (AcPPO). The obtained results revealed that the AcPPO- green fluorescent protein co-localized with a Golgi apparatus marker, and AcPPO activity was present in Golgi apparatus-enriched fractions. Likewise, transient expression assays revealed that AcPPO remained active in Golgi apparatus-enriched fractions obtained from tobacco leaves. These results suggest a putative function of AcPPO in the Golgi apparatus of cherimoya, providing new perspectives on PPO functionality in the secretory pathway, its effects on cherimoya physiology, and the evolution of this enzyme. Copyright © 2017. Published by Elsevier B.V.

  18. Catabolism of caffeine and purification of a xanthine oxidade responsible for methyluric acids production in Pseudomonas putida L Catabolismo de cafeína e purificação de xantina oxidase responsável pela produção de ácidos metilúricos em Pseudomonas putida L

    Directory of Open Access Journals (Sweden)

    Dirce Mithico Yamaoka-Yano

    1999-01-01

    Full Text Available Caffeine catabolism and a xanthine oxidase involved in the alkaloid breakdown were studied in Pseudomonas putida L, a strain displaying high ability to grow on this substrate. Cells cultured with unlabelled caffeine and 14C labeled caffeine and xanthine showed that this alkaloid was broken-down via theobromine/paraxanthine -> 7-methylxanthine -> xanthine -> uric acid -> allantoin -> allantoic acid. Methyluric acids were formed from the oxidation of theobromine, paraxanthine and 7-methylxanthine, although no bacterial growth was observed on these compounds, indicating that this might be due to a wide substrate specificity of xanthine oxidase. This was confirmed by activity staining in PAGE where activity was observed with theophylline and 3-methylxanthine, which are not involved in the alkaloid breakdown. A single band of activity was detected without addition of NAD+, showing an oxidase form of the enzyme. The enzyme optimum temperature and pH were 30oC and 7.0, respectively. The determined Km was 169 µM, and the pI 3.1 - 4.0. The molecular weight determined by side by side comparison of activity staining of the enzyme in PAGE and PAGE of BSA was 192 kDa, which was coincident with the sum (198.4 kDa of three subunits (71, 65.6 and 61.8 kDa of the purified protein.O catabolismo de cafeína e a enzima xantina oxidase, envolvida na sua degradação, foram estudados em Pseudomonas putida L, uma linhagem com alta capacidade para utilizar este substrato como fonte de energia. Células crescidas na presença de cafeína e xantina marcadas com 14C, e cafeína não marcada, mostraram que este alcalóide foi degradado via teobromina/paraxantina -> 7-metilxantina -> xantina -> ácido úrico -> alantoína -> ácido alantóico. Ácidos metilúricos foram formados a partir de teobromina, paraxantina e 7-metilxantina, embora nenhum crescimento bacteriano ter sido observado quando estes compostos foram usados como substratos, indicando que a xantina oxidase

  19. High resolution crystal structure of rat long chain hydroxy acid oxidase in complex with the inhibitor 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1, 2, 3-thiadiazole. Implications for inhibitor specificity and drug design

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhi-wei; Vignaud, Caroline; Jaafar, Adil; Lévy, Bernard; Guéritte, Françoise; Guénard, Daniel; Lederer, Florence; Mathews, F. Scott (CNRS-UMR); (WU-MED)

    2012-05-24

    Long chain hydroxy acid oxidase (LCHAO) is responsible for the formation of methylguanidine, a toxic compound with elevated serum levels in patients with chronic renal failure. Its isozyme glycolate oxidase (GOX), has a role in the formation of oxalate, which can lead to pathological deposits of calcium oxalate, in particular in the disease primary hyperoxaluria. Inhibitors of these two enzymes may have therapeutic value. These enzymes are the only human members of the family of FMN-dependent L-2-hydroxy acid-oxidizing enzymes, with yeast flavocytochrome b{sub 2} (Fcb2) among its well studied members. We screened a chemical library for inhibitors, using in parallel rat LCHAO, human GOX and the Fcb2 flavodehydrogenase domain (FDH). Among the hits was an inhibitor, CCPST, with an IC{sub 50} in the micromolar range for all three enzymes. We report here the crystal structure of a complex between this compound and LCHAO at 1.3 {angstrom} resolution. In comparison with a lower resolution structure of this enzyme, binding of the inhibitor induces a conformational change in part of the TIM barrel loop 4, as well as protonation of the active site histidine. The CCPST interactions are compared with those it forms with human GOX and those formed by two other inhibitors with human GOX and spinach GOX. These compounds differ from CCPST in having the sulfur replaced with a nitrogen in the five-membered ring as well as different hydrophobic substituents. The possible reason for the {approx}100-fold difference in affinity between these two series of inhibitors is discussed. The present results indicate that specificity is an issue in the quest for therapeutic inhibitors of either LCHAO or GOX, but they may give leads for this quest.

  20. Sensory and chromatographic evaluations of water soluble fractions from air-dried sausages

    DEFF Research Database (Denmark)

    Henriksen, Anders Peter; Stahnke, Marie Louise Heller

    1997-01-01

    Low molecular weight water soluble compounds were extracted from Danish salami, Italian sausage, and Spanish Chorizo. The extracts were fractionated by gel filtration chromatography revealing peptides with a molecular weight less than 4200 Dalton. Fractions consisting of smaller peptides and free...... amino acids had enhanced savory taste impressions described as mainly bouillon, bitter, sour, salty and plastic with odor notes of boiled potato. Determination of amino acids in the fractions before and after hydrolysis revealed the presence of mainly hydrophilic peptides in all fractions. Partial least...

  1. Two X-linked chronic granulomatous disease patients with unusual NADPH oxidase properties

    NARCIS (Netherlands)

    Wolach, Baruch; Broides, Arnon; Zeeli, Tal; Gavrieli, Ronit; de Boer, Martin; van Leeuwen, Karin; Levy, Jacov; Roos, Dirk

    2011-01-01

    Chronic granulomatous disease (CGD) is an immune deficiency syndrome caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme that generates reactive oxygen species (ROS) in phagocytizing leukocytes. This study evaluates the NADPH oxidase capacity in two

  2. An amperometric enzyme electrode and its biofuel cell based on a glucose oxidase-poly(3-anilineboronic acid)-Pd nanoparticles bionanocomposite for glucose biosensing.

    Science.gov (United States)

    Sun, Lingen; Ma, Yixuan; Zhang, Pei; Chao, Long; Huang, Ting; Xie, Qingji; Chen, Chao; Yao, Shouzhuo

    2015-06-01

    A new amperometric enzyme electrode and its biofuel cell were fabricated based on a glucose oxidase (GOx)-poly(3-anilineboronic acid) (PABA)-Pd nanoparticles (PdNPs) bionanocomposite for biosensing of glucose. Briefly, Pd was electroplated on a multiwalled carbon nanotubes (MWCNTs)-modified Au electrode, and the GOx-PABA-PdNPs bionanocomposite was prepared on the Pd(plate)/MWCNTs/Au electrode through the chemical oxidation of a GOx-3-anilineboronic acid adduct by Na2PdCl4, followed by electrode-modification with an outer-layer chitosan (CS) film. The thus-prepared CS/GOx-PABA-PdNPs/Pd(plate)/MWCNTs/Au electrode exhibited a linear amperometric response to glucose concentration from 2.0 μM to 4.5 mM with a sensitivity of 160 μA/mM/cm(2), sub-μM detection limit, and excellent operation/storage stability in the first-generation biosensing mode, as well as excellent analytical performance in the second-generation biosensing mode. The good recoveries of glucose obtained from spiked urine samples revealed the application potential of our amperometric enzyme electrode. In addition, a glucose/O2 biofuel cell was constructed using this enzyme electrode as the anode and a Pt/MWCNTs/Au electrode as the cathode, and this biofuel cell as a self-powered biosensing device showed a linear voltage response to glucose concentration from 100 μM to 13.5 mM with a sensitivity of 43.5 mV/mM/cm(2) and excellent operation/storage stability. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Purification, characterization and decolorization of bilirubin oxidase from Myrothecium verrucaria 3.2190

    Science.gov (United States)

    Myrothecium verrucaria 3.2190 is a nonligninolytic fungus that produces bilirubin oxidase. Both Myrothecium verrucaria and the extracellular bilirubin oxidase were tested for their ability to decolorize indigo carmine. The biosorption and biodegradation of the dye were detected during the process of...

  4. Blockade of TGF-β 1 Signalling Inhibits Cardiac NADPH Oxidase Overactivity in Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    José Luis Miguel-Carrasco

    2012-01-01

    Full Text Available NADPH oxidases constitute a major source of superoxide anion (⋅O2 - in hypertension. Several studies suggest an important role of NADPH oxidases in different effects mediated by TGF-β 1. In this study we show that chronic administration of P144, a peptide synthesized from type III TGF-β 1 receptor, significantly reduced the cardiac NADPH oxidase expression and activity as well as in the nitrotyrosine levels observed in control spontaneously hypertensive rats (V-SHR to levels similar to control normotensive Wistar Kyoto rats. In addition, P144 was also able to reduce the significant increases in the expression of collagen type I protein and mRNA observed in hearts from V-SHR. In addition, positive correlations between collagen expression, NADPH oxidase activity, and nitrotyrosine levels were found in all animals. Finally, TGF-β 1-stimulated Rat-2 exhibited significant increases in NADPH oxidase activity that was inhibited in the presence of P144. It could be concluded that the blockade of TGF-β 1 with P144 inhibited cardiac NADPH oxidase in SHR, thus adding new data to elucidate the involvement of this enzyme in the profibrotic actions of TGF-β 1.

  5. Herbivore-plant interactions: mixed-function oxidases and secondary plant substances.

    Science.gov (United States)

    Brattsten, L B; Wilkinson, C F; Eisner, T

    1977-06-17

    The mixed-function oxidases of a polyphagous insect larva (the southern armyworm, Spodoptera eridania) were found to be induced by a diversity of secondary plant substances. The induction proceeds rapidly and in response to a small quantity of secondary substance. Following induction, the larva is less susceptible to dietary poisoning. It is argued that mixed-function oxidases play a major role in protecting herbivores against chemical stress from secondary plant substances.

  6. Partial purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) peel.

    Science.gov (United States)

    Yang, C P; Fujita, S; Kohno, K; Kusubayashi, A; Ashrafuzzaman, M; Hayashi, N

    2001-03-01

    Polyphenol oxidase (EC 1.10.3.1, o-diphenol: oxygen oxidoreductase, PPO) of banana (Musa sapientum L.) peel was partially purified about 460-fold with a recovery of 2.2% using dopamine as substrate. The enzyme showed a single peak on Toyopearl HW55-S chromatography. However, two bands were detected by staining with Coomassie brilliant blue on PAGE: one was very clear, and the other was faint. Molecular weight for purified PPO was estimated to be about 41 000 by gel filtration. The enzyme quickly oxidized dopamine, and its Km value (Michaelis constant) for dopamine was 3.9 mM. Optimum pH was 6.5 and the PPO activity was quite stable in the range of pH 5-11 for 48 h. The enzyme had an optimum temperature at 30 degrees C and was stable up to 60 degrees C after heat treatment for 30 min. The enzyme activity was strongly inhibited by sodium diethyldithiocarbamate, potassium cyanide, L-ascorbic acid, and cysteine at 1 mM. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.

  7. Cloning and molecular analyses of a gibberellin 20-oxidase gene expressed specifically in developing seeds of watermelon.

    Science.gov (United States)

    Kang, H G; Jun, S H; Kim, J; Kawaide, H; Kamiya, Y; An, G

    1999-10-01

    To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA(12) at C-20 to the C(19) compound GA(9), a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the beta-glucuronidase (GUS) gene. In a transient expression system, beta-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds.

  8. Neonatal epileptic encephalopathy caused by mutations in the PNPO gene encoding pyridox(am)ine 5'-phosphate oxidase.

    Science.gov (United States)

    Mills, Philippa B; Surtees, Robert A H; Champion, Michael P; Beesley, Clare E; Dalton, Neil; Scambler, Peter J; Heales, Simon J R; Briddon, Anthony; Scheimberg, Irene; Hoffmann, Georg F; Zschocke, Johannes; Clayton, Peter T

    2005-04-15

    In the mouse, neurotransmitter metabolism can be regulated by modulation of the synthesis of pyridoxal 5'-phosphate and failure to maintain pyridoxal phosphate (PLP) levels results in epilepsy. This study of five patients with neonatal epileptic encephalopathy suggests that the same is true in man. Cerebrospinal fluid and urine analyses indicated reduced activity of aromatic L-amino acid decarboxylase and other PLP-dependent enzymes. Seizures ceased with the administration of PLP, having been resistant to treatment with pyridoxine, suggesting a defect of pyridox(am)ine 5'-phosphate oxidase (PNPO). Sequencing of the PNPO gene identified homozygous missense, splice site and stop codon mutations. Expression studies in Chinese hamster ovary cells showed that the splice site (IVS3-1g>a) and stop codon (X262Q) mutations were null activity mutations and that the missense mutation (R229W) markedly reduced pyridox(am)ine phosphate oxidase activity. Maintenance of optimal PLP levels in the brain may be important in many neurological disorders in which neurotransmitter metabolism is disturbed (either as a primary or as a secondary phenomenon).

  9. An investigation of inorganic antimony species and antimony associated with soil humic acid molar mass fractions in contaminated soils

    International Nuclear Information System (INIS)

    Steely, Sarah; Amarasiriwardena, Dulasiri; Xing Baoshan

    2007-01-01

    The presence of antimony compounds is often suspected in the soil of apple orchards contaminated with lead arsenate pesticide and in the soil of shooting ranges. Nitric acid (1 M) extractable Sb from the shooting range (8300 μg kg -1 ) and the apple orchard (69 μg kg -1 ) had considerably higher surface Sb levels than the control site ( -1 ), and Sb was confined to the top ∼30 cm soil layer. Sb(V) was the principal species in the shooting range and the apple orchard surface soils. Size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) analysis of humic acids isolated from the two contaminated soils demonstrated that Sb has complexed to humic acid molar mass fractions. The results also indicate that humic acids have the ability to arrest the mobility of Sb through soils and would be beneficial in converting Sb(III) to a less toxic species, Sb(V), in contaminated areas. - The soil surface and depth distribution Sb(V) and Sb(III) species in a contaminated apple orchard and a shooting range, and the effect soil humic acids on inorganic antimony species is reported

  10. Functional heterogeneity of NADPH oxidase-mediated contractions to endothelin with vascular aging.

    Science.gov (United States)

    Meyer, Matthias R; Barton, Matthias; Prossnitz, Eric R

    2014-11-24

    Aging, a physiological process and main risk factor for cardiovascular and renal diseases, is associated with endothelial cell dysfunction partly resulting from NADPH oxidase-dependent oxidative stress. Because increased formation of endothelium-derived endothelin-1 (ET-1) may contribute to vascular aging, we studied the role of NADPH oxidase function in age-dependent contractions to ET-1. Renal arteries and abdominal aortas from young and old C57BL6 mice (4 and 24 months of age) were prepared for isometric force measurements. Contractions to ET-1 (0.1-100 nmol/L) were determined in the presence and absence of the NADPH oxidase-selective inhibitor gp91ds-tat (3 μmol/L). To exclude age-dependent differential effects of NO bioactivity between vascular beds, all experiments were conducted in the presence of the NO synthase inhibitor L-NAME (300 μmol/L). In young animals, ET-1-induced contractions were 6-fold stronger in the renal artery than in the aorta (prenal artery and aorta, respectively (pAging had no effect on NADPH oxidase-dependent and -independent contractions to ET-1 in the renal artery. In contrast, contractions to ET-1 were markedly reduced in the aged aorta (5-fold, page-dependent heterogeneity of NADPH oxidase-mediated vascular contractions to ET-1, demonstrating an inherent resistance to functional changes in the renal artery but not in the aorta with aging. Thus, local activity of NADPH oxidase differentially modulates responses to ET-1 with aging in distinct vascular beds. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of the Expression of Amine Oxidase Proteins in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Woo Young Sun

    2017-12-01

    Full Text Available We aimed to evaluate the expression of amine oxidase proteins in breast cancer and their clinical implications. We performed immunohistochemical staining of amine oxidase proteins (LOX, lysyl oxidase, AOC3, amine oxidase, MAOA, monoamine oxidase A, MAOB, monoamine oxidase B. Based on their hormone receptors, such as estrogen receptor (ER and progesterone receptor (PR, human epidermal growth factor receptor 2 (HER-2, and Ki-67 immunohistochemical staining, breast cancer was divided into four molecular subtypes: luminal A, luminal B, HER-2 type, and triple-negative breast cancer (TNBC. Luminal A was observed in 380 cases (49.4%, luminal B in 224 (29.1%, HER-2 type in 68 (8.8%, and TNBC in 98 (12.7%. Stromal AOC3, MAO-A, and MAO-B expression varied according to molecular subtypes. Stromal AOC3 expression was high in luminal B and HER-2 type and MAO-A expression was high in luminal A and luminal B (p < 0.001. MAO-B expression was higher in TNBC than in other subtypes (p = 0.020. LOX positivity was associated with high histological grade (p < 0.001 and high Ki-67 labeling index (LI (p = 0.009, and stromal AOC3 positivity was associated with high histological grade (p = 0.001, high Ki-67 LI (p < 0.001, and HER-2 positivity (p = 0.002. MAO-A positivity was related to low histological grade (p < 0.001, ER positivity, PR positivity (p < 0.001, and low Ki-67 LI (p < 0.001. In univariate analysis, MAO-A positivity was related to short disease-free survival in HER-2 type (p = 0.013, AOC3 negativity was related to short disease-free survival and overall survival in ER-positive breast cancer, PR-positive breast cancer, HER-2-negative breast cancer, and lymph node metastasis. In conclusion, the expression of amine oxidase proteins varies depending on the molecular subtype of breast cancer. Stromal AOC3 expression was high in luminal B and HER-2 type, and MAO-A expression was high in luminal A and luminal B.

  12. Targeting NADPH oxidase decreases oxidative stress in the transgenic sickle cell mouse penis.

    Science.gov (United States)

    Musicki, Biljana; Liu, Tongyun; Sezen, Sena F; Burnett, Arthur L

    2012-08-01

    Sickle cell disease (SCD) is a state of chronic vasculopathy characterized by endothelial dysfunction and increased oxidative stress, but the sources and mechanisms responsible for reactive oxygen species (ROS) production in the penis are unknown. We evaluated whether SCD activates NADPH oxidase, induces endothelial nitric oxide synthase (eNOS) uncoupling, and decreases antioxidants in the SCD mouse penis. We further tested the hypothesis that targeting NADPH oxidase decreases oxidative stress in the SCD mouse penis. SCD transgenic (sickle) mice were used as an animal model of SCD. Hemizygous (hemi) mice served as controls. Mice received an NADPH oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Penes were excised at baseline for molecular studies. Markers of oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NADPH oxidase subunits p67(phox) , p47(phox) , and gp91(phox) ), and enzymatic antioxidants (superoxide dismutase [SOD]1, SOD2, catalase, and glutathione peroxidase-1 [GPx1]) were measured by Western blot in penes. Sources of ROS, oxidative stress, and enzymatic antioxidants in the SCD penis. Relative to hemi mice, SCD increased (Ppenis. Apocynin treatment of sickle mice reversed (P0.05) prevented eNOS uncoupling in the penis. Apocynin treatment of hemi mice did not affect any of these parameters. NADPH oxidase and eNOS uncoupling are sources of oxidative stress in the SCD penis; decreased GPx1 further contributes to oxidative stress. Inhibition of NADPH oxidase upregulation decreases oxidative stress, implying a major role for NADPH oxidase as a ROS source and a potential target for improving vascular function in the SCD mouse penis. © 2012 International Society for Sexual Medicine.

  13. Characterization of the polyphenol oxidase gene family reveals a novel microRNA involved in posttranscriptional regulation of PPOs in Salvia miltiorrhiza

    OpenAIRE

    Li, Caili; Li, Dongqiao; Li, Jiang; Shao, Fenjuan; Lu, Shanfa

    2017-01-01

    Salvia miltiorrhiza is a well-known material of traditional Chinese medicine. Understanding the regulatory mechanisms of phenolic acid biosynthesis and metabolism are important for S. miltiorrhiza quality improvement. We report here that S. miltiorrhiza contains 19 polyphenol oxidases (PPOs), forming the largest PPO gene family in plant species to our knowledge. Analysis of gene structures and sequence features revealed the conservation and divergence of SmPPOs. SmPPOs were differentially exp...

  14. Characterization of wheat germin (oxalate oxidase) expressed by Pichia pastoris

    International Nuclear Information System (INIS)

    Pan, Heng-Yen; Whittaker, Mei M.; Bouveret, Romaric; Berna, Anne; Bernier, Francois; Whittaker, James W.

    2007-01-01

    High-level secretory expression of wheat (Triticum aestivum) germin/oxalate oxidase was achieved in Pichia pastoris fermentation cultures as an α-mating factor signal peptide fusion, based on the native wheat cDNA coding sequence. The oxalate oxidase activity of the recombinant enzyme is substantially increased (7-fold) by treatment with sodium periodate, followed by ascorbate reduction. Using these methods, approximately 1 g (4 x 10 4 U) of purified, activated enzyme was obtained following eight days of induction of a high density Pichia fermentation culture, demonstrating suitability for large-scale production of oxalate oxidase for biotechnological applications. Characterization of the recombinant protein shows that it is glycosylated, with N-linked glycan attached at Asn47. For potential biomedical applications, a nonglycosylated (S49A) variant was also prepared which retains essentially full enzyme activity, but exhibits altered protein-protein interactions

  15. Multi-Copper Oxidases and Human Iron Metabolism

    Science.gov (United States)

    Vashchenko, Ganna; MacGillivray, Ross T. A.

    2013-01-01

    Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651

  16. Antioxidant Capacities of Fractions of Bamboo Shaving Extract and Their Antioxidant Components.

    Science.gov (United States)

    Gong, Jinyan; Huang, Jun; Xiao, Gongnian; Chen, Feng; Lee, Bolim; Ge, Qing; You, Yuru; Liu, Shiwang; Zhang, Ying

    2016-07-30

    This research was conducted for evaluation of antioxidant activities of four fractions from bamboo shavings extract (BSE) and their antioxidant components. The antioxidant capacities of BSE and four fractions on ABTS, DPPH, FRAP and total antioxidant capacity assays exhibited the following descending order: DF > n-butanol fraction (BF) > BSE ≈ ethyl acetate fraction (AF) > water fraction (WF). Among the identified phenolic compounds, caffeic acid exhibited the highest antioxidant capacities on DPPH, FRAP and total antioxidant capacity assays. An extremely significant positive correlation between the antioxidant activities with the contents of total flavonoids, total phenolic acids, or total phenolics was observed in this study. The result indicated that the bamboo shaving extract and its solvent fractions could act as natural antioxidants in light of their potent antioxidant activities.

  17. Better Rooting Procedure to Enhance Survival Rate of Field Grown Malaysian Eksotika Papaya Transformed with 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Gene

    Science.gov (United States)

    Sekeli, Rogayah; Abdullah, Janna Ong; Namasivayam, Parameswari; Muda, Pauziah; Abu Bakar, Umi Kalsom

    2013-01-01

    A high survival rate for transformed papaya plants when transferred to the field is useful in the quest for improving the commercial quality traits. We report in this paper an improved rooting method for the production of transformed Malaysian Eksotika papaya with high survival rate when transferred to the field. Shoots were regenerated from embryogenic calli transformed with antisense and RNAi constructs of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) genes using the Agrobacterium tumefaciens-mediated transformation method. Regenerated transformed shoots, each measuring approximately 3-4 cm in height, were cultured in liquid half-strength Murashige and Skoog (MS) medium or sterile distilled water, and with either perlite or vermiculite supplementation. All the culturing processes were conducted either under sterile or nonsterile condition. The results showed that rooting under sterile condition was better. Shoots cultured in half-strength MS medium supplemented with vermiculite exhibited a 92.5% rooting efficiency while perlite showed 77.5%. The survival rate of the vermiculite-grown transformed papaya plantlets after transfer into soil, contained in polybags, was 94%, and the rate after transfer into the ground was 92%. Morpho-histological analyses revealed that the tap roots were more compact, which might have contributed to the high survival rates of the plantlets. PMID:25969786

  18. Better rooting procedure to enhance survival rate of field grown malaysian eksotika papaya transformed with 1-aminocyclopropane-1-carboxylic Acid oxidase gene.

    Science.gov (United States)

    Sekeli, Rogayah; Abdullah, Janna Ong; Namasivayam, Parameswari; Muda, Pauziah; Abu Bakar, Umi Kalsom

    2013-01-01

    A high survival rate for transformed papaya plants when transferred to the field is useful in the quest for improving the commercial quality traits. We report in this paper an improved rooting method for the production of transformed Malaysian Eksotika papaya with high survival rate when transferred to the field. Shoots were regenerated from embryogenic calli transformed with antisense and RNAi constructs of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) genes using the Agrobacterium tumefaciens-mediated transformation method. Regenerated transformed shoots, each measuring approximately 3-4 cm in height, were cultured in liquid half-strength Murashige and Skoog (MS) medium or sterile distilled water, and with either perlite or vermiculite supplementation. All the culturing processes were conducted either under sterile or nonsterile condition. The results showed that rooting under sterile condition was better. Shoots cultured in half-strength MS medium supplemented with vermiculite exhibited a 92.5% rooting efficiency while perlite showed 77.5%. The survival rate of the vermiculite-grown transformed papaya plantlets after transfer into soil, contained in polybags, was 94%, and the rate after transfer into the ground was 92%. Morpho-histological analyses revealed that the tap roots were more compact, which might have contributed to the high survival rates of the plantlets.

  19. Characterization of isolated fractions of dissolved organic matter derived from municipal solid waste compost.

    Science.gov (United States)

    Yu, Minda; He, Xiaosong; Liu, Jiaomei; Wang, Yuefeng; Xi, Beidou; Li, Dan; Zhang, Hui; Yang, Chao

    2018-04-14

    Understanding the heterogeneous evolution characteristics of dissolved organic matter fractions derived from compost is crucial to exploring the composting biodegradation process and the possible applications of compost products. Herein, two-dimensional correlation spectroscopy integrated with reversed-phase high performance liquid chromatography and size exclusion chromatography were utilized to obtain the molecular weight (MW) and polarity evolution characteristics of humic acid (HA), fulvic acid (FA), and the hydrophilic (HyI) fractions during composting. The high-MW humic substances and building blocks in the HA fraction degraded faster during composting than polymers, proteins, and organic colloids. Similarly, the low MW acid FA factions transformed faster than the low weight neutral fractions, followed by building blocks, and finally polymers, proteins, and organic colloids. The evolutions of HyI fractions during composting occurred first for building blocks, followed by low MW acids, and finally low weight neutrals. With the progress of composting, the hydrophobic properties of the HA and FA fractions were enhanced. The degradation/humification process of the hydrophilic and transphilic components was faster than that of the hydrophobic component. Compared with the FA and HyI fractions, the HA fraction exhibited a higher MW and increased hydrophobicity. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Biocatalytic Resolution of Enantiomeric Mixtures of 1-Aminoethanephosphonic Acid

    Directory of Open Access Journals (Sweden)

    Paweł Kafarski

    2011-07-01

    Full Text Available Several fungal strains, namely Bauveria bassiana, Cuninghamella echinulata, Aspergillus fumigatus, Penicillium crustosum and Cladosporium herbarum, were used as biocatalysts to resolve racemic mixtures of 1-aminoethanephosphonic acid using L/D amino acid oxidase activity. The course of reaction was analyzed by 31P-NMR in the presence of cyclodextrin used as chiral discriminating agent. The best result (42% e.e of R-isomer was obtained with a strain of Cuninghamella echinulata.

  1. Shared features of S100B immunohistochemistry and cytochrome oxidase histochemistry in the ventroposterior thalamus and lateral habenula in neonatal rats.

    Science.gov (United States)

    Muneoka, Katsumasa; Funahashi, Hisayuki; Ogawa, Tetsuo; Whitaker-Azmitia, Patricia M; Shioda, Seiji

    2012-10-01

    The ventroposterior thalamus and the habenular nuclei of the epithalamus are relevant to the monoaminergic system functionally and anatomically. The glia-derived S100B protein plays a critical role in the development of the nervous system including the monoaminergic systems. In this study, we performed an immunohistochemical study of glia-related proteins including S100B, serotonin transporter, and microtubule-associated protein 2, as well as cytochrome oxidase histochemistry in neonatal rats. Results showed the same findings for S100B immunohistochemistry between the ventroposterior thalamus and the lateral habenula at postnatal day 7: intense staining in cell bodies of astrocytes, diffusely spread immunoproduct in the intercellular space, and S100B-free areas as well as a strong reaction to cytochrome oxidase histochemistry. Further common features were the scarcity of glial fibrillary acidic protein-positive astrocytes and the few apoptotic cells observed. The results of the cytochrome oxidase reaction suggested that S100B is released actively into intercellular areas in restricted brain regions showing high neuronal activity at postnatal day 7. Pathology of the ventroposterior thalamus and the habenula is suggested in mental disorders, and S100B might be a key factor for investigations in these areas. Copyright © 2012 ISDN. Published by Elsevier Ltd. All rights reserved.

  2. Chlorella induces stomatal closure via NADPH oxidase-dependent ROS production and its effects on instantaneous water use efficiency in Vicia faba.

    Directory of Open Access Journals (Sweden)

    Yan Li

    Full Text Available Reactive oxygen species (ROS have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs. Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2 scavenger, catalase (CAT, significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI, and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM, suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi in Vicia faba via a reduction in leaf transpiration rate (E without a parallel reduction in net photosynthetic rate (Pn assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.

  3. Radio-isotopic determination of platelet monoamine oxidase and regulation of its activity by an indigenous drug

    International Nuclear Information System (INIS)

    Dubey, G.P.; Srivastava, V.K.; Agrawal, A.; Udupa, K.N.

    1988-01-01

    Platelet monoamine oxidase is a mitochondrial enzyme taking part in the deamination reaction of total catecholamine. Recent studies of monoamine oxidase inhibitors have gained its importance in the control of variety of psychosomatic disorders like mental depression, arterial hypertension and anxiety neurosis. 30 apparently normal individuals and 42 diagnosed cases of essential hypertension were selected for the present study. The platelet monoamine oxidase activity was measured by using 14 C-tryptamine bisuccinate. Comparatively low activity of platelet monoamine oxidase was noticed in hypertension cases than in the normal. After oral administration of an indigenous drug 'Geriforte' for three months, a significant rise in platelet monoamine oxidase activity was noticed in hypertension cases. It can be concluded that this indigenous formulation has the capacity to regulate the monoamine oxidase activity, as such, it may provide an alternative remedy in the management of psychosomatic disorders. (author). 11 refs

  4. Lipid peroxidation inhibition and antiradical activities of some leaf fractions of Mangifera indica.

    Science.gov (United States)

    Badmus, Jelili A; Adedosu, Temitope O; Fatoki, John O; Adegbite, Victor A; Adaramoye, Oluwatosin A; Odunola, Oyeronke A

    2011-01-01

    This study was undertaken to assess in vitro lipid peroxidation inhibitions and anti-radical activities of methanolic, chloroform, ethyl acetate and water fractions of Mangifera indica leaf. Inhibition of Fe(2+)-induced lipid peroxidation (LPO) in egg, brain, and liver homogenates, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl (OH-) radical scavenging activities were evaluated. Total phenol was assessed in all fractions, and the reducing power of methanolic fraction was compared to gallic acid and ascorbic acid. The results showed that Fe2+ induced significant lipid peroxidation (LPO) in all the homogenates. Ethyl acetate fraction showed the highest percentage inhibition of LPO in both egg yolk (68.3%) and brain (66.3%), while the aqueous fraction exerted the highest inhibition in liver homogenate (89.1%) at a concentration of 10 microg/mL. These observed inhibitions of LPO by these fractions were higher than that of ascorbic acid used as a standard. The DPPH radical scavenging ability exhibited by ethyl acetate fraction was found to be the highest with IC50 value of 1.5 microg/mL. The ethyl acetate and methanolic fractions had the highest OH- radical scavenging ability with the same IC50 value of 5 microg/mL. The total phenol content of ethyl acetate fraction was the highest with 0.127 microg/mg gallic acid equivalent (GAE). The reductive potential of methanolic fraction showed a concentration-dependent increase. This study showed that inhibition of LPO and the DPPH and OH- radicals scavenging abilities of Mangifera indica leaf could be related to the presence of phenolic compounds. Therefore, the ethyl acetate fraction of the leaf may be a good source of natural antioxidative agent.

  5. The substrate oxidation mechanism of pyranose 2-oxidase and other related enzymes in the glucose-methanol-choline superfamily.

    Science.gov (United States)

    Wongnate, Thanyaporn; Chaiyen, Pimchai

    2013-07-01

    Enzymes in the glucose-methanol-choline (GMC) oxidoreductase superfamily catalyze the oxidation of an alcohol moiety to the corresponding aldehyde. In this review, the current understanding of the sugar oxidation mechanism in the reaction of pyranose 2-oxidase (P2O) is highlighted and compared with that of other enzymes in the GMC family for which structural and mechanistic information is available, including glucose oxidase, choline oxidase, cholesterol oxidase, cellobiose dehydrogenase, aryl-alcohol oxidase, and pyridoxine 4-oxidase. Other enzymes in the family that have been newly discovered or for which less information is available are also discussed. A large primary kinetic isotope effect was observed for the flavin reduction when 2-d-D-glucose was used as a substrate, but no solvent kinetic isotope effect was detected for the flavin reduction step. The reaction of P2O is consistent with a hydride transfer mechanism in which there is stepwise formation of d-glucose alkoxide prior to the hydride transfer. Site-directed mutagenesis of P2O and pH-dependence studies indicated that His548 is a catalytic base that facilitates the deprotonation of C2-OH in D-glucose. This finding agrees with the current mechanistic model for aryl-alcohol oxidase, glucose oxidase, cellobiose dehydrogenase, methanol oxidase, and pyridoxine 4-oxidase, but is different from that of cholesterol oxidase and choline oxidase. Although all of the GMC enzymes share similar structural folding and use the hydride transfer mechanism for flavin reduction, they appear to have subtle differences in the fine-tuned details of how they catalyze substrate oxidation. © 2013 The Authors Journal compilation © 2013 FEBS.

  6. Cotton Ascorbate Oxidase Promotes Cell Growth in Cultured Tobacco Bright Yellow-2 Cells through Generation of Apoplast Oxidation

    Science.gov (United States)

    Li, Rong; Xin, Shan; Tao, Chengcheng; Jin, Xiang; Li, Hongbin

    2017-01-01

    Ascorbate oxidase (AO) plays an important role in cell growth through the modulation of reduction/oxidation (redox) control of the apoplast. Here, a cotton (Gossypium hirsutum) apoplastic ascorbate oxidase gene (GhAO1) was obtained from fast elongating fiber tissues. GhAO1 belongs to the multicopper oxidase (MCO) family and includes a signal peptide and several transmembrane regions. Analyses of quantitative real-time polymerase chain reaction (QRT-PCR) and enzyme activity showed that GhAO1 was expressed abundantly in 15-day post-anthesis (dpa) wild-type (WT) fibers in comparison with fuzzless-lintless (fl) mutant ovules. Subcellular distribution analysis in onion cells demonstrated that GhAO1 is localized in the cell wall. In transgenic tobacco bright yellow-2 (BY-2) cells with ectopic overexpression of GhAO1, the enhancement of cell growth with 1.52-fold increase in length versus controls was indicated, as well as the enrichment of both total ascorbate in whole-cells and dehydroascorbate acid (DHA) in apoplasts. In addition, promoted activities of AO and monodehydroascorbate reductase (MDAR) in apoplasts and dehydroascorbate reductase (DHAR) in whole-cells were displayed in transgenic tobacco BY-2 cells. Accumulation of H2O2, and influenced expressions of Ca2+ channel genes with the activation of NtMPK9 and NtCPK5 and the suppression of NtTPC1B were also demonstrated in transgenic tobacco BY-2 cells. Finally, significant induced expression of the tobacco NtAO gene in WT BY-2 cells under indole-3-acetic acid (IAA) treatment appeared; however, the sensitivity of the NtAO gene expression to IAA disappeared in transgenic BY-2 cells, revealing that the regulated expression of the AO gene is under the control of IAA. Taken together, these results provide evidence that GhAO1 plays an important role in fiber cell elongation and may promote cell growth by generating the oxidation of apoplasts, via the auxin-mediated signaling pathway. PMID:28644407

  7. Direct comparison of gluco-oligosaccharide oxidase variants and glucose oxidase: substrate range and H2O2 stability.

    Science.gov (United States)

    Vuong, Thu V; Foumani, Maryam; MacCormick, Benjamin; Kwan, Rachel; Master, Emma R

    2016-11-21

    Glucose oxidase (GO) activity is generally restricted to glucose and is susceptible to inactivation by H 2 O 2 . By comparison, the Y300A variant of gluco-oligosaccharide oxidase (GOOX) from Sarocladium strictum showed broader substrate range and higher H 2 O 2 stability. Specifically, Y300A exhibited up to 40 times higher activity on all tested sugars except glucose, compared to GO. Moreover, fusion of the Y300A variant to a family 22 carbohydrate binding module from Clostridium thermocellum (CtCBM22A) nearly doubled its catalytic efficiency on glucose, while retaining significant activity on oligosaccharides. In the presence of 200 mM of H 2 O 2 , the recombinant CtCBM22A_Y300A retained 80% of activity on glucose and 100% of activity on cellobiose, the preferred substrate for this enzyme. By contrast, a commercial glucose oxidase reported to contain ≤0.1 units catalase/ mg protein, retained 60% activity on glucose under the same conditions. GOOX variants appear to undergo a different mechanism of inactivation, as a loss of histidine instead of methionine was observed after H 2 O 2 incubation. The addition of CtCBM22A also promoted functional binding of the fusion enzyme to xylan, facilitating its simultaneous purification and immobilization using edible oat spelt xylan, which might benefit the usage of this enzyme preparation in food and baking applications.

  8. Size-selective QD@MOF core-shell nanocomposites for the highly sensitive monitoring of oxidase activities.

    Science.gov (United States)

    Wang, Ke; Li, Nan; Zhang, Jing; Zhang, Zhiqi; Dang, Fuquan

    2017-01-15

    In this work, we proposed a novel and facile method to monitor oxidase activities based on size-selective fluorescent quantum dot (QD)@metal-organic framework (MOF) core-shell nanocomposites (CSNCPs). The CSNCPs were synthesized from ZIF-8 and CdTe QDs in aqueous solution in 40min at room temperature with stirring. The prepared CdTe@ZIF-8 CSNCPs , which have excellent water dispersibility and stability, displays distinct fluorescence responses to hole scavengers of different molecular sizes (e.g., H 2 O 2 , substrate, and oxidase) due to the aperture limitation of the ZIF-8 shell. H 2 O 2 can efficiently quench the fluorescence of CdTe@ZIF-8 CSNCPs over a linearity range of 1-100nM with a detection limit of 0.29nM, whereas large molecules such as substrate and oxidase have very little effect on its fluorescence. Therefore, the highly sensitive detection of oxidase activities was achieved by monitoring the fluorescence quenching of CdTe@ZIF-8 CSNCPs by H 2 O 2 produced in the presence of substrate and oxidase, which is proportional to the oxidase activities. The linearity ranges of the uricase and glucose oxidase activity are 0.1-50U/L and 1-100U/L, respectively, and their detection limits are 0.024U/L and 0.26U/L, respectively. Therefore, the current QD@MOF CSNCPs based sensing system is a promising, widely applicable means of monitoring oxidase activities in biochemical research. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The antioxidant properties, cytotoxicity and monoamine oxidase ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... Department of Pharmaceutical Chemistry, North-West University, Private Bag X6001, Potchefstroom 2520, ..... on the inhibition of the catabolism of serotonin, .... Structure of human monoamine oxidase B, a drug target for.

  10. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Sandra M Carvalho

    Full Text Available Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  11. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Science.gov (United States)

    Carvalho, Sandra M; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P; Neves, Ana R; Bijlsma, Jetta J E

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps) transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  12. Investigation of antihemolytic, xanthine oxidase inhibition ...

    African Journals Online (AJOL)

    Abbreviations: SVEs: Salvia Verbenaca L. aerial part Extracts; CrE: Crud Extract; ChE: Chloroform Extract ; EAE: Ethyl Acetate Extract; AqE : Aqueous Extract ; ROS: Reactive Oxygen Spices; AAPH : 2,2, -Azobis (2-AmidinoPropane) Dihydrochloride ; DPPH: DiPhenyl- Picryl-Hydrazyl; XO: Xanthine Oxidase; Gen: Gentamicin ...

  13. In vitro antiproliferative effect of fractions from the caribbean marine sponge Myrmekioderma gyroderma

    Directory of Open Access Journals (Sweden)

    Diana Márquez Fernández

    Full Text Available Introduction: studies performed to Myrmekioderma genus sponges show phospholipid fatty acids, volatile compounds, sterols, bioactive cyclic diterpenes, sesquiterpenes, lineal diterpenes and glycolipid ethers. Objetive: to evaluate the antiproliferative effect of seven fractions (F1-F7 obtained by flash column chromatography from the most bioactive extract of the sponge Myrmekioderma gyroderma, and to analyze the chemical composition of the most active fraction. Methods: samples of dried sponge were extracted with two different solvents: CH2Cl2 (2 x 50 mL, and CH3OH (2 x 50 mL. Each fraction was evaluated on tumor cell derived cell lines; and the cell growth, and viability were determined by a colorimeter assay using sulforhodamine B. Fatty acids structure of the most active fraction was possible by GC-MS analysis of the methyl ester, and pyrrolidine derivatives. Results: the fraction with higher activity on the assessed tumor cell lines is F4 due to it totally inhibited MDA-MB-231, and HT29 cell line growth to 5, and 25 µg/mL concentration (IC50< 1 µg/mL. Fatty acids identified in bioactive F4 fraction of the M. gyroderma sponge can be classified on the following groups: lineal chain saturated, branched-saturated, unsaturated, and a 3-hydroxy acid. Conclusions: 43 fatty acids among saturated, branched-saturated, and unsaturated were identified out of the F4 fraction with activity on the cell lines derived of breast cancer MDA-MB-231, colon carcinoma HT29, and lung carcinoma cells A-549. These results show the growth inhibitory effect shown by the fractions, on the tumor cell lines, depends on the dose.

  14. Biphenyl Modulates the Expression and Function of Respiratory Oxidases in the Polychlorinated-Biphenyls Degrader Pseudomonas pseudoalcaligenes KF707

    Directory of Open Access Journals (Sweden)

    Federica Sandri

    2017-06-01

    Full Text Available Pseudomonas pseudoalcaligenes KF707 is a soil bacterium which is known for its capacity to aerobically degrade harmful organic compounds such as polychlorinated biphenyls (PCBs using biphenyl as co-metabolite. Here we provide the first genetic and functional analysis of the KF707 respiratory terminal oxidases in cells grown with two different carbon sources: glucose and biphenyl. We identified five terminal oxidases in KF707: two c(caa3 type oxidases (Caa3 and Ccaa3, two cbb3 type oxidases (Cbb31 and Cbb32, and one bd type cyanide-insensitive quinol oxidase (CIO. While the activity and expression of both Cbb31 and Cbb32 oxidases was prevalent in glucose grown cells as compared to the other oxidases, the activity and expression of the Caa3 oxidase increased considerably only when biphenyl was used as carbon source in contrast to the Cbb32 oxidase which was repressed. Further, the respiratory activity and expression of CIO was up-regulated in a Cbb31 deletion strain as compared to W.T. whereas the CIO up-regulation was not present in Cbb32 and C(caa3 deletion mutants. These results, together, reveal that both function and expression of cbb3 and caa3 type oxidases in KF707 are modulated by biphenyl which is the co-metabolite needed for the activation of the PCBs-degradation pathway.

  15. Hydrogen solubility measurements of analyzed tall oil fractions and a solubility model

    International Nuclear Information System (INIS)

    Uusi-Kyyny, Petri; Pakkanen, Minna; Linnekoski, Juha; Alopaeus, Ville

    2017-01-01

    Highlights: • Hydrogen solubility was measured in four tall oil fractions between 373 and 597 K. • Continuous flow synthetic isothermal and isobaric method was used. • A Henry’s law model was developed for the distilled tall oil fractions. • The complex composition of the samples was analyzed and is presented. - Abstract: Knowledge of hydrogen solubility in tall oil fractions is important for designing hydrotreatment processes of these complex nonedible biobased materials. Unfortunately measurements of hydrogen solubility into these fractions are missing in the literature. This work reports hydrogen solubility measured in four tall oil fractions between 373 and 597 K and at pressures from 5 to 10 MPa. Three of the fractions were distilled tall oil fractions their resin acids contents are respectively 2, 20 and 23 in mass-%. Additionally one fraction was a crude tall oil (CTO) sample containing sterols as the main neutral fraction. Measurements were performed using a continuous flow synthetic isothermal and isobaric method based on the visual observation of the bubble point. Composition of the flow was changed step-wise for the bubble point composition determination. We assume that the tall oil fractions did not react during measurements, based on the composition analysis performed before and after the measurements. Additionally the densities of the fractions were measured at atmospheric pressure from 293.15 to 323.15 K. A Henry’s law model was developed for the distilled tall oil fractions describing the solubility with an absolute average deviation of 2.1%. Inputs of the solubility model are temperature, total pressure and the density of the oil at 323.15 K. The solubility of hydrogen in the CTO sample can be described with the developed model with an absolute average deviation of 3.4%. The solubility of hydrogen increases both with increasing pressure and/or increasing temperature. The more dense fractions of the tall oil exhibit lower hydrogen

  16. Steady-state kinetics of substrate binding and iron release in tomato ACC oxidase.

    Science.gov (United States)

    Thrower, J S; Blalock, R; Klinman, J P

    2001-08-14

    1-Aminocyclopropane-1-carboxylate oxidase (ACC oxidase) catalyzes the last step in the biosynthetic pathway of the plant hormone, ethylene. This unusual reaction results in the oxidative ring cleavage of 1-aminocyclopropane carboxylate (ACC) into ethylene, cyanide, and CO2 and requires ferrous ion, ascorbate, and molecular oxygen for catalysis. A new purification procedure and assay method have been developed for tomato ACC oxidase that result in greatly increased enzymatic activity. This method allowed us to determine the rate of iron release from the enzyme and the effect of the activator, CO2, on this rate. Initial velocity studies support an ordered kinetic mechanism where ACC binds first followed by O2; ascorbate can bind after O2 or possibly before ACC. This kinetic mechanism differs from one recently proposed for the ACC oxidase from avocado.

  17. Phytochemical Composition, Antioxidant and Xanthine Oxidase Inhibitory Activities of Amaranthus cruentus L. and Amaranthus hybridus L. Extracts

    Directory of Open Access Journals (Sweden)

    Jeanne F. Millogo

    2012-06-01

    Full Text Available This paper describes a preliminary assessment of the nutraceutical value of Amaranthus cruentus (A. cruentus and Amaranthus hybridus (A. hybridus, two food plant species found in Burkina Faso. Hydroacetonic (HAE, methanolic (ME, and aqueous extracts (AE from the aerial parts were screened for in vitro antioxidant and xanthine oxidase inhibitory activities. Phytochemical analyses revealed the presence of polyphenols, tannins, flavonoids, steroids, terpenoids, saponins and betalains. Hydroacetonic extracts have shown the most diversity for secondary metabolites. The TLC analyses of flavonoids from HAE extracts showed the presence of rutin and other unidentified compounds. The phenolic compound contents of the HAE, ME and AE extracts were determined using the Folin–Ciocalteu method and ranged from 7.55 to 10.18 mg Gallic acid equivalent GAE/100 mg. Tannins, flavonoids, and flavonols ranged from 2.83 to 10.17 mg tannic acid equivalent (TAE/100 mg, 0.37 to 7.06 mg quercetin equivalent (QE /100 mg, and 0.09 to 1.31 mg QE/100 mg, respectively. The betacyanin contents were 40.42 and 6.35 mg Amaranthin Equivalent/100 g aerial parts (dry weight in A. cruentus and A. hybridus, respectively. Free-radical scavenging activity expressed as IC50 (DPPH method and iron reducing power (FRAP method ranged from 56 to 423 µg/mL and from 2.26 to 2.56 mmol AAE/g, respectively. Xanthine oxidase inhibitory activities of extracts of A. cruentus and A. hybridus were 3.18% and 38.22%, respectively. The A. hybridus extract showed the best antioxidant and xanthine oxidase inhibition activities. The results indicated that the phytochemical contents of the two species justify their traditional uses as nutraceutical food plants.

  18. Purification and partial biochemical characterization of polyphenol oxidase from mango (Mangifera indica cv. Manila).

    Science.gov (United States)

    Palma-Orozco, Gisela; Marrufo-Hernández, Norma A; Sampedro, José G; Nájera, Hugo

    2014-10-08

    Polyphenol oxidase (PPO) is an enzyme widely distributed in the plant kingdom that has been detected in most fruits and vegetables. PPO was extracted and purified from Manila mango (Mangifera indica), and its biochemical properties were studied. PPO was purified 216-fold by hydrophobic interaction and ion exchange chromatography. PPO was purified to homogeneity, and the estimated PPO molecular weight (MW) by SDS-PAGE was ≈31.5 kDa. However, a MW of 65 kDa was determined by gel filtration, indicating a dimeric structure for the native PPO. The isolated PPO showed the highest affinity to pyrogallol (Km = 2.77 mM) followed by 4-methylcatechol (Km = 3.14 mM) and catechol (Km = 15.14 mM). The optimum pH for activity was 6.0. PPO was stable in the temperature range of 20-70 °C. PPO activity was completely inhibited by tropolone, ascorbic acid, sodium metabisulfite, and kojic acid at 0.1 mM.

  19. Molecular Dynamic Studies of the Complex Polyethylenimine and Glucose Oxidase

    Directory of Open Access Journals (Sweden)

    Beata Szefler

    2016-10-01

    Full Text Available Glucose oxidase (GOx is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H2O2. GOx has found several commercial applications in chemical and pharmaceutical industries including novel biosensors that use the immobilized enzyme on different nanomaterials and/or polymers such as polyethylenimine (PEI. The problem of GOx immobilization on PEI is retaining the enzyme native activity despite its immobilization onto the polymer surface. Therefore, the molecular dynamic (MD study of the PEI ligand (C14N8_07_B22 and the GOx enzyme (3QVR was performed to examine the final complex PEI-GOx stabilization and the affinity of the PEI ligand to the docking sites of the GOx enzyme. The docking procedure showed two places/regions of major interaction of the protein with the polymer PEI: (LIG1 of −5.8 kcal/mol and (LIG2 of −4.5 kcal/mol located inside the enzyme and on its surface, respectively. The values of enthalpy for the PEI-enzyme complex, located inside of the protein (LIG1 and on its surface (LIG2 were computed. Docking also discovered domains of the GOx protein that exhibit no interactions with the ligand or have even repulsive characteristics. The structural data clearly indicate some differences in the ligand PEI behavior bound at the two places/regions of glucose oxidase.

  20. Molecular Dynamic Studies of the Complex Polyethylenimine and Glucose Oxidase.

    Science.gov (United States)

    Szefler, Beata; Diudea, Mircea V; Putz, Mihai V; Grudzinski, Ireneusz P

    2016-10-27

    Glucose oxidase (GOx) is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state) to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H₂O₂). GOx has found several commercial applications in chemical and pharmaceutical industries including novel biosensors that use the immobilized enzyme on different nanomaterials and/or polymers such as polyethylenimine (PEI). The problem of GOx immobilization on PEI is retaining the enzyme native activity despite its immobilization onto the polymer surface. Therefore, the molecular dynamic (MD) study of the PEI ligand (C14N8_07_B22) and the GOx enzyme (3QVR) was performed to examine the final complex PEI-GOx stabilization and the affinity of the PEI ligand to the docking sites of the GOx enzyme. The docking procedure showed two places/regions of major interaction of the protein with the polymer PEI: (LIG1) of -5.8 kcal/mol and (LIG2) of -4.5 kcal/mol located inside the enzyme and on its surface, respectively. The values of enthalpy for the PEI-enzyme complex, located inside of the protein (LIG1) and on its surface (LIG2) were computed. Docking also discovered domains of the GOx protein that exhibit no interactions with the ligand or have even repulsive characteristics. The structural data clearly indicate some differences in the ligand PEI behavior bound at the two places/regions of glucose oxidase.

  1. Aortic wall damage in mice unable to synthesize ascorbic acid

    OpenAIRE

    Maeda, Nobuyo; Hagihara, Hiroyuki; Nakata, Yukiko; Hiller, Sylvia; Wilder, Jennifer; Reddick, Robert

    2000-01-01

    By inactivating the gene for l-gulono-γ-lactone oxidase, a key enzyme in ascorbic acid synthesis, we have generated mice that, like humans, depend on dietary vitamin C. Regular chow, containing about 110 mg/kg of vitamin C, is unable to support the growth of the mutant mice, which require l-ascorbic acid supplemented in their drinking water (330 mg/liter). Upon withdrawal of supplementation, plasma and tissue ascorbic acid levels decreased to 10–15% of normal within 2 weeks, and after 5 weeks...

  2. Taste and chemical characteristics of low molecular weight fractions from tofuyo - Japanese fermented soybean curd.

    Science.gov (United States)

    Lioe, Hanifah Nuryani; Kinjo, Ayano; Yasuda, Shin; Kuba-Miyara, Megumi; Tachibana, Shinjiro; Yasuda, Masaaki

    2018-06-30

    Tofuyo, a Japanese traditional food, is a fermented soybean curd manufactured in Okinawa region. Due to its original cheese-like flavor, the current study was designed to evaluate the sensory and chemical characteristics of three stepwise ultrafiltration fractions, using 10,000, 3000 and 500 Da membranes and further chromatographic fractions from tofuyo. The results showed that umami, sweet and salty were the characteristic tastes of all fractions, with umami intensity evaluated for the fraction with MW less than 500 Da (F-500) as the most prominent among the three fractions. Subsequent Sephadex G-25 SF fractions and RP-HPLC fractions were subjected to sensory and chemical analyses. The tastiest fraction contained sodium chloride, sugars, organic acids, umami and sweet free amino acids, at concentrations above their thresholds. The abundant presence of umami and sweet free amino acids with certain concentrations of sodium chloride and glucose might provide the typical savory taste of tofuyo. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Bioactivity-guided fractionation for anti-inflammatory and analgesic properties and constituents of Xanthium strumarium L.

    Science.gov (United States)

    Han, T; Li, H-L; Zhang, Q-Y; Han, P; Zheng, H-C; Rahman, K; Qin, L-P

    2007-12-01

    The aim of this study was to fractionate an extract of Xanthium strumarium L. (EXS) and to investigate the anti-inflammatory and analgesic properties of the extract and its fractions. The ethanol extract of X. strumarium (EXS) was fractionated on the basis of polarity. Among the different fractions, the n-butanol fraction showed the highest anti-inflammatory activity in the croton-oil-induced ear edema test and furthermore reduced the number of writhings induced by acetic acid in mice in a dose-dependent manner. This indicates that the n-butanol fraction of X. strumarium possesses potent analgesic effects which are likely to be mediated by its anti-inflammatory activity. Bioassay-guided fractionation of EXS led to the isolation and identification of ten caffeoylquinic acids and three heterocyclics by HPLC-DAD-MS(n) from the active n-butanol fraction, implying that the active compounds are polar in nature. The isolated caffeoylquinic acids could partially explain the antinociceptive effect of X. strumarium polar extract.

  4. Glucose oxidase probe as a surface-enhanced Raman scattering sensor for glucose.

    Science.gov (United States)

    Qi, Guohua; Wang, Yi; Zhang, Biying; Sun, Dan; Fu, Cuicui; Xu, Weiqing; Xu, Shuping

    2016-10-01

    Glucose oxidase (GOx) possessing a Raman-active chromophore (flavin adenine dinucleotide) is used as a signal reporter for constructing a highly specific "turn off" surface-enhanced Raman scattering (SERS) sensor for glucose. This sensing chip is made by the electrostatic assembly of GOx over silver nanoparticle (Ag NP)-functionalized SERS substrate through a positively charged polyelectrolyte linker under the pH of 6.86. To trace glucose in blood serum, owing to the reduced pH value caused by the production of gluconic acid in the GOx-catalyzed oxidation reaction, the bonding force between GOx and polyelectrolyte weakens, making GOx drop off from the sensing chip. As a result, the SERS intensity of GOx on the chip decreases along with the concentration of glucose. This glucose SERS sensor exhibits excellent selectivity based on the specific GOx/glucose catalysis reaction and high sensitivity to 1.0 μM. The linear sensing range is 2.0-14.0 mM, which also meets the requirement on the working range of the human blood glucose detection. Using GOx as a probe shows superiority over other organic probes because GOx almost has no toxicity to the biological system. This sensing mechanism can be applied for intracellular in vivo SERS monitoring of glucose in the future. Graphical abstract Glucose oxidase is used as a Raman signal reporter for constructing a highly specific glucose surface-enhanced Raman scattering (SERS) sensor.

  5. Oxidative decarboxylation of glycolic and phenylacetic acids with cerium(4) catalyzed by silver ions in the sulfuric acid media

    International Nuclear Information System (INIS)

    Venkatesvar Rao, G.; Nagardzhun Rao, Ch.; Sajprakash, P.K.

    1981-01-01

    Oxidative decarboxylation of glycolic and phenylacetic acids by cerium (4) in the presence of Ag + ions is studied. The Ce(4) order equals 1, glycolic acid order in the absence of a catalyst also equals 1 and is fractional (0.5) for a catalytic reaction. The phenylacetic acid order is fractional (0.75). The Ag + ion reaction order is fractional and constitutes 0.32 for glycolic and 0.36 for phenylacetic acids. The reaction mechanism is proposed [ru

  6. Metabolic engineering of β-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis.

    Science.gov (United States)

    Veiga, Tânia; Gombert, Andreas K; Landes, Nils; Verhoeven, Maarten D; Kiel, Jan A K W; Krikken, Arjen M; Nijland, Jeroen G; Touw, Hesselien; Luttik, Marijke A H; van der Toorn, John C; Driessen, Arnold J M; Bovenberg, Roel A L; van den Berg, Marco A; van der Klei, Ida J; Pronk, Jack T; Daran, Jean-Marc

    2012-07-01

    Industrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via β-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of β-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of β-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Studying of distribution of 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm according to the organic acids fractions of the alienation zone soils

    International Nuclear Information System (INIS)

    Odintsov, A.A.; Sazhenyuk, A.D.

    2004-01-01

    The paper deals with data of research on the distribution of the radionuclides 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm of ''the Chornobyl rains'' by the fractions of the organic matters of derno-podzolic sandy, derno-meadow and peat soils sampled in the alienation zone of the Chornobyl NPP. Functioning of organic matters was carried according to Tyurin's method. It is stressed that, independently on soil type, 137Cs is connected with the mineral contituent by 80-95%. It is found out that, independently on the soil type, 50-70% 137Sr and 15-45% 241Am are associated with fulvic acid fractions. The 241Am and 244Cm distribution according to organic acids taking into account deviations while carrying out determinations is unambiguous. It is found out that in all the soils tested the main quality of 239+24Pu is connected with humic acids

  8. Cloning and Molecular Analyses of a Gibberellin 20-Oxidase Gene Expressed Specifically in Developing Seeds of Watermelon1

    Science.gov (United States)

    Kang, Hong-Gyu; Jun, Sung-Hoon; Kim, Junyul; Kawaide, Hiroshi; Kamiya, Yuji; An, Gynheung

    1999-01-01

    To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA12 at C-20 to the C19 compound GA9, a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the β-glucuronidase (GUS) gene. In a transient expression system, β-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds. PMID:10517828

  9. Phytochemical Compositions and In vitro Assessments of Antioxidant and Antidiabetic Potentials of Fractions from Ehretia cymosa Thonn.

    Science.gov (United States)

    Ogundajo, Akintayo; Ashafa, Anofi Tom

    2017-10-01

    Ehretia cymosa Thonn. is a popular medicinal plant used in different parts of West Africa for the treatment of various ailments including diabetes mellitus. The current study investigates bioactive constituents and in vitro antioxidant and antidiabetic potentials of fractions from extract of E. cymosa . Phytochemical investigation and antioxidant assays were carried out using standard procedures. Antidiabetic potential was assessed by evaluating the inhibitory effects of the fractions on the activities of α-amylase and α-glucosidase, while bioactive constituent's identification was carried out using gas chromatography-mass spectrometric (GC-MS) analysis. The phytochemistry tests of the fractions revealed the presence of tannins, phenols, flavonoids, steroids, terpene, alkaloid, and cardiac glycosides. Methanol fraction shows higher phenolic (27.44 mg gallic acid/g) and flavonoid (235.31 mg quercetin/g) contents, while ethyl acetate fraction revealed higher proanthocyanidins (28.31 mg catechin/g). Methanol fraction displayed higher ( P fractions displayed higher inhibition ( P fraction also inhibited α-amylase and α-glucosidase in competitive and noncompetitive modes, respectively. The GC-MS chromatogram of the methanol fraction revealed 24 compounds, which include phytol (1.78%), stearic acid (1.02%), and 2-hexadecyloxirane (34.18%), which are known antidiabetic and antioxidant agents. The results indicate E. cymosa leaves as source of active phytochemicals with therapeutic potentials in the management of diabetes. E. cymosa fractions possess antioxidant and antidiabetic activities. Hence, it is a source of active phytochemicals with therapeutic potentials in the management of diabetesThe high flavonoid, phenolic, and proanthocyanidin contents of fractions from E. cymosa also contribute to its antioxidant and antidiabetic propertiesMethanol fraction of E. cymosa displayed better antidiabetic activities compared to acarbose as revealed by their half maximal

  10. Brain monoamine oxidase B and A in human parkinsonian dopamine deficiency disorders.

    Science.gov (United States)

    Tong, Junchao; Rathitharan, Gausiha; Meyer, Jeffrey H; Furukawa, Yoshiaki; Ang, Lee-Cyn; Boileau, Isabelle; Guttman, Mark; Hornykiewicz, Oleh; Kish, Stephen J

    2017-09-01

    See Jellinger (doi:10.1093/awx190) for a scientific commentary on this article. The enzyme monoamine oxidases (B and A subtypes, encoded by MAOB and MAOA, respectively) are drug targets in the treatment of Parkinson's disease. Inhibitors of MAOB are used clinically in Parkinson's disease for symptomatic purposes whereas the potential disease-modifying effect of monoamine oxidase inhibitors is debated. As astroglial cells express high levels of MAOB, the enzyme has been proposed as a brain imaging marker of astrogliosis, a cellular process possibly involved in Parkinson's disease pathogenesis as elevation of MAOB in astrocytes might be harmful. Since brain monoamine oxidase status in Parkinson's disease is uncertain, our objective was to measure, by quantitative immunoblotting in autopsied brain homogenates, protein levels of both monoamine oxidases in three different degenerative parkinsonian disorders: Parkinson's disease (n = 11), multiple system atrophy (n = 11), and progressive supranuclear palsy (n = 16) and in matched controls (n = 16). We hypothesized that if MAOB is 'substantially' localized to astroglial cells, MAOB levels should be generally associated with standard astroglial protein measures (e.g. glial fibrillary acidic protein). MAOB levels were increased in degenerating putamen (+83%) and substantia nigra (+10%, non-significant) in multiple system atrophy; in caudate (+26%), putamen (+27%), frontal cortex (+31%) and substantia nigra (+23%) of progressive supranuclear palsy; and in frontal cortex (+33%), but not in substantia nigra of Parkinson's disease, a region we previously reported no increase in astrocyte protein markers. Although the magnitude of MAOB increase was less than those of standard astrocytic markers, significant positive correlations were observed amongst the astrocyte proteins and MAOB. Despite suggestions that MAOA (versus MAOB) is primarily responsible for metabolism of dopamine in dopamine neurons, there was no loss of the

  11. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  12. Discovery, characterization, and kinetic analysis of an alditol oxidase from streptomyces coelicolor

    NARCIS (Netherlands)

    Heuts, Dominic P. H. M.; van Hellemond, Erik W.; Janssen, Dick B.; Fraaije, Marco W.

    2007-01-01

    A gene encoding an alditol oxidase was found in the genome of Streptomyces coelicolor A3(2). This newly identified oxidase, AldO, was expressed at extremely high levels in Escherichia coli when fused to maltose-binding protein. AldO is a soluble monomeric flavoprotein with subunits of 45.1 kDa, each

  13. Flavonoid glycosides isolated from unique legume plant extracts as novel inhibitors of xanthine oxidase.

    Directory of Open Access Journals (Sweden)

    Chrysoula Spanou

    Full Text Available Legumes and the polyphenolic compounds present in them have gained a lot of interest due to their beneficial health implications. Dietary polyphenolic compounds, especially flavonoids, exert antioxidant properties and are potent inhibitors of xanthine oxidase (XO activity. XO is the main contributor of free radicals during exercise but it is also involved in pathogenesis of several diseases such as vascular disorders, cancer and gout. In order to discover new natural, dietary XO inhibitors, some polyphenolic fractions and pure compounds isolated from two legume plant extracts were tested for their effects on XO activity. The fractions isolated from both Vicia faba and Lotus edulis plant extracts were potent inhibitors of XO with IC(50 values range from 40-135 µg/mL and 55-260 µg/mL, respectively. All the pure polyphenolic compounds inhibited XO and their K(i values ranged from 13-767 µM. Ten of the compounds followed the non competitive inhibitory model whereas one of them was a competitive inhibitor. These findings indicate that flavonoid isolates from legume plant extracts are novel, natural XO inhibitors. Their mode of action is under investigation in order to examine their potential in drug design for diseases related to overwhelming XO action.

  14. Antibacterial and antifungal activities of the polyphenolic fractions isolated from the seed coat of Abrus precatorius and Caesalpinia crista.

    Science.gov (United States)

    Mobin, Lubna; Saeed, Syed Asad; Ali, Rashida; Saeed, Syed Ghufran; Ahmed, Rahil

    2017-09-26

    Crude seed coat extracts from Abrus precatorius and Caesalpinia crista were purified into four different fractions namely phenolic acids, flavonols, flavanols and anthocyanin which were then examined for their polyphenol contents and antimicrobial potentials. The fractions derived from seed coat of A. precatorius were found more potent with high phenolic and flavonoid contents as compared to C. crista fractions. The significant antibacterial activity was observed against all strain tested by the fractions of both samples apart from anthocyanin fraction. It was interesting to note that the phenolic acid fractions of both samples was found more active against gram-negative bacteria, while gram-positive bacteria were found to be more sensitive towards flavonol fractions. The phenolic acid and flavonol fractions being potent antibacterial were selected to demonstrate the antifungal capacity of two samples. Among them, phenolic acid fraction of both samples was found active towards all the fungal strain.

  15. Controversial Effects of D-Amino Acid Oxidase Activator (DAOA)/G72 on D-Amino Acid Oxidase (DAO) Activity in Human Neuronal, Astrocyte and Kidney Cell Lines: The N-methyl D-aspartate (NMDA) Receptor Hypofunction Point of View.

    Science.gov (United States)

    Jagannath, Vinita; Brotzakis, Zacharias Faidon; Parrinello, Michele; Walitza, Susanne; Grünblatt, Edna

    2017-01-01

    Dysfunction of D-amino acid oxidase ( DAO ) and DAO activator ( DAOA )/ G72 genes have been linked to neuropsychiatric disorders. The glutamate hypothesis of schizophrenia has proposed that increased DAO activity leads to decreased D-serine, which subsequently may lead to N-methyl-D-aspartate (NMDA) receptor hypofunction. It has been shown that DAOA binds to DAO and increases its activity. However, there are also studies showing DAOA decreases DAO activity. Thus, the effect of DAOA on DAO is controversial. We aimed to understand the effect of DAOA on DAO activity in neuron-like (SH-SY5Y), astrocyte-like (1321N1) and kidney-like (HEK293) human cell lines. DAO activity was measured based on the release of hydrogen peroxide and its interaction with Amplex Red reagent. We found that DAOA increases DAO activity only in HEK293 cells, but has no effect on DAO activity in SH-SY5Y and 1321N1 cells. This might be because of different signaling pathways, or due to lower DAO and DAOA expression in SH-SY5Y and 1321N1 cells compared to HEK293 cells, but also due to different compartmentalization of the proteins. The lower DAO and DAOA expression in neuron-like SH-SY5Y and astrocyte-like 1321N1 cells might be due to tightly regulated expression, as previously reported in the human post-mortem brain. Our simulation experiments to demonstrate the interaction between DAOA and human DAO (hDAO) showed that hDAO holoenzyme [hDAO with flavine adenine dinucleotide (FAD)] becomes more flexible and misfolded in the presence of DAOA, whereas DAOA had no effect on hDAO apoprotein (hDAO without FAD), which indicate that DAOA inactivates hDAO holoenzyme. Furthermore, patch-clamp analysis demonstrated no effect of DAOA on NMDA receptor activity in NR1/NR2A HEK293 cells. In summary, the interaction between DAO and DAOA seems to be cell type and its biochemical characteristics dependent which still needs to be elucidated.

  16. Controversial Effects of D-Amino Acid Oxidase Activator (DAOA/G72 on D-Amino Acid Oxidase (DAO Activity in Human Neuronal, Astrocyte and Kidney Cell Lines: The N-methyl D-aspartate (NMDA Receptor Hypofunction Point of View

    Directory of Open Access Journals (Sweden)

    Vinita Jagannath

    2017-10-01

    Full Text Available Dysfunction of D-amino acid oxidase (DAO and DAO activator (DAOA/G72 genes have been linked to neuropsychiatric disorders. The glutamate hypothesis of schizophrenia has proposed that increased DAO activity leads to decreased D-serine, which subsequently may lead to N-methyl-D-aspartate (NMDA receptor hypofunction. It has been shown that DAOA binds to DAO and increases its activity. However, there are also studies showing DAOA decreases DAO activity. Thus, the effect of DAOA on DAO is controversial. We aimed to understand the effect of DAOA on DAO activity in neuron-like (SH-SY5Y, astrocyte-like (1321N1 and kidney-like (HEK293 human cell lines. DAO activity was measured based on the release of hydrogen peroxide and its interaction with Amplex Red reagent. We found that DAOA increases DAO activity only in HEK293 cells, but has no effect on DAO activity in SH-SY5Y and 1321N1 cells. This might be because of different signaling pathways, or due to lower DAO and DAOA expression in SH-SY5Y and 1321N1 cells compared to HEK293 cells, but also due to different compartmentalization of the proteins. The lower DAO and DAOA expression in neuron-like SH-SY5Y and astrocyte-like 1321N1 cells might be due to tightly regulated expression, as previously reported in the human post-mortem brain. Our simulation experiments to demonstrate the interaction between DAOA and human DAO (hDAO showed that hDAO holoenzyme [hDAO with flavine adenine dinucleotide (FAD] becomes more flexible and misfolded in the presence of DAOA, whereas DAOA had no effect on hDAO apoprotein (hDAO without FAD, which indicate that DAOA inactivates hDAO holoenzyme. Furthermore, patch-clamp analysis demonstrated no effect of DAOA on NMDA receptor activity in NR1/NR2A HEK293 cells. In summary, the interaction between DAO and DAOA seems to be cell type and its biochemical characteristics dependent which still needs to be elucidated.

  17. Mediation of glycosylated and partially-deglycosylated glucose oxidase of Aspergillus niger by a ferrocene-derivatised detergent.

    Science.gov (United States)

    Fraser, D M; Zakeeruddin, S M; Grätzel, M

    1992-01-30

    A ferrocene-derivatised detergent, (11-ferrocenylundecyl) trimethylammonium bromide (FTMAB), when oxidised to the corresponding ferricinium ion, was found by electrochemical studies to be an effective electron acceptor for reduced glucose oxidase of Aspergillus niger (EC 1.13.4) and thus acts as a electron-transfer mediator between glucose oxidase and a working electrode held at a potential sufficiently positive to reoxidise reduced FTMAB. An increase in mediating activity was produced when FTMAB was present in concentrations above its critical micelle concentration. An 'enzyme electrode' was formed by adsorption of glucose oxidase and FTMAB surfactant on a graphite rod. The electrode functioned as an amperometric biosensor for glucose in phosphate-buffered saline solution. A mixed micelle of glucose oxidase and FTMAB, probably adsorbed on the electrode surface, appears to be advantageous for the amperometric determination of glucose. Additionally, glucose oxidase was treated with alpha-mannosidase. When this partially-deglycosylated glucose oxidase was incorporated in an enzyme electrode, a 100-fold increase in the second-order rate constant (k) for electron transfer between the enzyme and FTMAB was observed, together with increased current densities, with respect to the equivalent values for FTMAB and commercial glucose oxidase. The use of deglycosylated enzymes in biosensors is suggested.

  18. A preliminary neutron diffraction study of rasburicase, a recombinant urate oxidase enzyme, complexed with 8-azaxanthin

    Energy Technology Data Exchange (ETDEWEB)

    Budayova-Spano, Monika, E-mail: spano@embl-grenoble.fr [European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France); Institut Laue-Langevin, 6 Rue Jules Horowitz, BP 156, 38042 Grenoble (France); Bonneté, Françoise; Ferté, Natalie [Centre de Recherche en Matière Condensée et Nanosciences, Campus de Luminy, Case 913, 13288 Marseille (France); El Hajji, Mohamed [Sanofi-Aventis, 371 Rue du Professeur Blayac, 34184 Montpellier (France); Meilleur, Flora [Institut Laue-Langevin, 6 Rue Jules Horowitz, BP 156, 38042 Grenoble (France); Blakeley, Matthew Paul [European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France); Castro, Bertrand [Sanofi-Aventis, 371 Rue du Professeur Blayac, 34184 Montpellier (France); European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France)

    2006-03-01

    Neutron diffraction data of hydrogenated recombinant urate oxidase enzyme (Rasburicase), complexed with a purine-type inhibitor 8-azaxanthin, was collected to 2.1 Å resolution from a crystal grown in D{sub 2}O by careful control and optimization of crystallization conditions via knowledge of the phase diagram. Deuterium atoms were clearly seen in the neutron-scattering density map. Crystallization and preliminary neutron diffraction measurements of rasburicase, a recombinant urate oxidase enzyme expressed by a genetically modified Saccharomyces cerevisiae strain, complexed with a purine-type inhibitor (8-azaxanthin) are reported. Neutron Laue diffraction data were collected to 2.1 Å resolution using the LADI instrument from a crystal (grown in D{sub 2}O) with volume 1.8 mm{sup 3}. The aim of this neutron diffraction study is to determine the protonation states of the inhibitor and residues within the active site. This will lead to improved comprehension of the enzymatic mechanism of this important enzyme, which is used as a protein drug to reduce toxic uric acid accumulation during chemotherapy. This paper illustrates the high quality of the neutron diffraction data collected, which are suitable for high-resolution structural analysis. In comparison with other neutron protein crystallography studies to date in which a hydrogenated protein has been used, the volume of the crystal was relatively small and yet the data still extend to high resolution. Furthermore, urate oxidase has one of the largest primitive unit-cell volumes (space group I222, unit-cell parameters a = 80, b = 96, c = 106 Å) and molecular weights (135 kDa for the homotetramer) so far successfully studied with neutrons.

  19. Synthesis, crystal structures, molecular docking, in vitro monoamine oxidase-B inhibitory activity of transition metal complexes with 2-{4-[bis (4-fluorophenyl)methyl]piperazin-1-yl} acetic acid

    Science.gov (United States)

    Yang, Dan-dan; Wang, Riu; Zhu, Jin-long; Cao, Qi-yue; Qin, Jie; Zhu, Hai-liang; Qian, Shao-song

    2017-01-01

    Three novel complexes, [Cu(L)2(H2O)](1), [Zn(L)2(H2O)2]·CH3OH·1.5H2O(2), and [Ni(L)2(H2O)1.8]·CH3OH·1.2H2O (3) (HL = 2-{4-[bis(4-fluorophenyl)methyl]pipera-zin-1-yl} acetic acid), were synthesized and structurally determined by single-crystal X-ray diffraction. Molecular docking study preliminarily revealed that complex 1 had potential Monoamine oxidase B inhibitory activity. All acquired compounds were tested against rat brain MAO-B in vitro. In accordance with the result of calculation, it showed complex 1 (IC50 = 1.85 ± 0.31 μM) have good inhibitory activity against MAO-B at the same micromolar concentrations with positive control Iproniazid Phosphate (IP, IC50 = 7.59 ± 1.17 μM). These results indicated that complex 1 was a potent MAO-B inhibitor.

  20. Analysis of electrophoretic soil humic acids fractions by reversed-phase high performance liquid chromatography with on-line absorbance and fluorescence detection.

    Science.gov (United States)

    Trubetskoj, Oleg A; Richard, Claire; Guyot, Ghislain; Voyard, Guillaume; Trubetskaya, Olga E

    2012-06-22

    A combination of reversed-phase high performance liquid chromatography (RP HPLC) with on-line absorbance and fluorescence detection was used for analysis of chernozem soil humic acids (HAs) and their fractions A, B and C+D with different electrophoretic mobility (EM) and molecular size (MS). Samples were injected onto the column at the identical volume and absorbance. All chromatograms exhibit the resolution of seven peaks. The estimation of relative recovery of HAs and fractions from the reverse-phase column has been done. High MS fraction A, which possesses the low EM, is essentially more hydrophobic (73% of the fraction amount remained adsorbed on the column) and aliphatic than medium MS and EM fraction B (33% of the fraction amount remained adsorbed on the column). The most hydrophilic and aromatic properties belong to low MS fraction C+D, which possess the highest EM and practically was not adsorbed on the column. The hydrophobicity of the bulk HAs lies within the range of fractions hydrophobicity. The absorption spectra of bulk HAs, electrophoretic fractions A, B, C+D and corresponding RP HPLC peaks were featureless but had differences in the values of absorbance ratio at 300 and 400 nm (A3/A4). For fractions A and B this ratio gradually decreased from peak 1 to 7 (from 3.05 to 2.80 and 3.00 to 2.40, respectively). This trend was less pronounced in HAs and practically absent in fraction C+D, where ratio A3/A4 varied within a small range. The strong relationship between fluorescence properties, EM, MS, polarity and aliphaticity/aromaticity of HAs fractions was found. Humic and protein-like fluorescence had different polarity nature. The protein-like fluorescence is located in humic material which irreversibly adsorbed on the reverse-phase column and not subjected to RP HPLC characterization. The humic-like fluorescence at Ex/Em 270/450 nm is mostly located in the hydrophilic peak of low MS fraction C+D. Taking into account that high MS fraction A consisted