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Sample records for ii detoxification enzymes

  1. Enzyme therapeutics for systemic detoxification.

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    Liu, Yang; Li, Jie; Lu, Yunfeng

    2015-08-01

    Life relies on numerous biochemical processes working synergistically and correctly. Certain substances disrupt these processes, inducing living organism into an abnormal state termed intoxication. Managing intoxication usually requires interventions, which is referred as detoxification. Decades of development on detoxification reveals the potential of enzymes as ideal therapeutics and antidotes, because their high substrate specificity and catalytic efficiency are essential for clearing intoxicating substances without adverse effects. However, intrinsic shortcomings of enzymes including low stability and high immunogenicity are major hurdles, which could be overcome by delivering enzymes with specially designed nanocarriers. Extensive investigations on protein delivery indicate three types of enzyme-nanocarrier architectures that show more promise than others for systemic detoxification, including liposome-wrapped enzymes, polymer-enzyme conjugates, and polymer-encapsulated enzymes. This review highlights recent advances in these nano-architectures and discusses their applications in systemic detoxifications. Therapeutic potential of various enzymes as well as associated challenges in achieving effective delivery of therapeutic enzymes will also be discussed.

  2. Detoxification of Hg(II) from aqueous and enzyme media: Pristine vs. tailored calcium alginate hydrogels.

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    Sarkar, Kangkana; Ansari, Zarina; Sen, Kamalika

    2016-10-01

    Calcium alginate (CA) hydrogels were tailored using phenolic compounds (PC) like, thymol, morin, catechin, hesperidin, during their preparation. The PC incorporated gels show modified surface features as indicated by scanning electron microscopic images (SEM). The rheological studies show that excepting the hesperidin incorporated gels all the other kinds including calcium alginate pristine have similar mechanical strength. The hesperidine incorporated CA gels had the maximum capacity to adsorb Hg. The Freundlich adsorption isotherms show higher values of adsorption capacity for all PC incorporated CA beads than the pristine CA (PCA). The hesperidin incorporated CA gels were found to show the best adsorption condition at neutral pH and an optimum contact time of 2.5h at 25°C. Considering the possibility of ingested Hg detoxification from human alimentary tract, the hesperidin and morin incorporated CA beads were further modified through incorporation of cod liver oil as the digestion time of fat in stomach is higher. In vitro uptake capacities of Hg in pepsin and pancreatin containing enzyme media were studied with hesperidin and morin incorporated beads and their corresponding fat incorporated beads also. In the pepsin medium, there was no uptake by hesperidin and fat-hesperidin incorporated beads, which is possibly due to the higher acidity of the medium. But in pancreatin medium Hg was taken up by both kinds of beads. Morin and morin-fat incorporated beads were efficient to uptake Hg from both the pepsin and pancreatin medium. The tailored CA beads may therefore serve as efficient scaffolds to rescue Hg ingested individuals.

  3. Influence of bacterial N-acyl-homoserinelactones on growth parameters, pigments, antioxidative capacities and the xenobiotic phase II detoxification enzymes in barley and yam bean

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    Christine eGoetz-Roesch

    2015-04-01

    Full Text Available Bacteria are able to communicate with each other and sense their environment in a population density dependent mechanism known as quorum sensing (QS. N-acyl-homoserine lactones (AHLs are the QS signalling compounds of Gram-negative bacteria which are frequent colonizers of rhizospheres. While cross-kingdom signalling and AHL-dependent gene expression in plants has been confirmed, the responses of enzyme activities in the eukaryotic host upon AHLs are unknown. Since AHL are thought to be used as so-called plant boosters or strengthening agents, which might change their resistance towards radiation and/or xenobiotic stress, we have examined the plants’ pigment status and their antioxidative and detoxifying capacities upon AHL treatment. Because the yield of a crop plant should not be negatively influenced, we have also checked for growth and root parameters.We investigated the influence of three different AHLs, namely N-hexanoyl- (C6-HSL, N-octanoyl- (C8-HSL and N-decanoyl- homoserine lactone (C10-HSL on two agricultural crop plants. The AHL-effects on Hordeum vulgare (L. as an example of a monocotyledonous crop and on the tropical leguminous crop plant Pachyrhizus erosus (L were compared. While plant growth and pigment contents in both plants showed only small responses to the applied AHLs, AHL treatment triggered tissue- and compound-specific changes in the activity of important detoxification enzymes. The activity of dehydroascorbate reductase (DHAR in barley shoots after C10-HSL treatment for instance increased up to 384% of control plant levels, whereas superoxide dismutase (SOD activity in barley roots was decreased down to 23% of control levels upon C6-HSL treatment. Other detoxification enzymes reacted similarly within this range, with interesting clusters of positive or negative answers towards AHL treatment. In general the changes on the enzyme level were more severe in barley than in yam bean which might be due to the different

  4. Strategies for enzyme saving during saccharification of pretreated lignocellulo-starch biomass: effect of enzyme dosage and detoxification chemicals

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    M.G. Mithra

    2017-08-01

    Full Text Available Two strategies leading to enzyme saving during saccharification of pretreated lignocellulo-starch biomass (LCSB was investigated which included reducing enzyme dosage by varying their levels in enzyme cocktails and enhancing the fermentable sugar yield in enzyme-reduced systems using detoxification chemicals. Time course release of reducing sugars (RS during 24–120 h was significantly higher when an enzyme cocktail containing full dose of cellulase (16 FPU/g cellulose along with half dose each of xylanase (1.5 mg protein/g hemicelluloses and Stargen (12.5 μl/g biomass was used to saccharify conventional dilute sulphuric acid (DSA pretreated biomass compared to a parallel system where only one-fourth the dose of the latter two enzymes was used. The reduction in RS content in the 120 h saccharified mash to the extent of 3–4 g/L compared to the system saccharified with full complement of the three enzymes could be overcome considerably by supplementing the system (half dose of two enzymes with detoxification chemical mix incorporating Tween 20, PEG 4000 and sodium borohydride. Microwave (MW-assisted DSA pretreated biomass on saccharification with enzyme cocktail having full dose of cellulase and half dose of Stargen along with detoxification chemicals gave significantly higher RS yield than DSA pretreated system saccharified using three enzymes. The study showed that xylanase could be eliminated during saccharification of MW-assisted DSA pretreated biomass without affecting RS yield when detoxification chemicals were also supplemented. The Saccharification Efficiency and Overall Conversion Efficiency were also high for the MW-assisted DSA pretreated biomass. Since whole slurry saccharifcation of pretreated biomass is essential to conserve fermentable sugars in LCSB saccharification, detoxification of soluble inhibitors is equally important as channelling out of insoluble lignin remaining in the residue. As one of the major factors contributing

  5. Detoxification enzymes associated with insecticide resistance in laboratory strains of Anopheles arabiensis of different geographic origin

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    Nardini Luisa

    2012-06-01

    Full Text Available Abstract Background The use of insecticides to control malaria vectors is essential to reduce the prevalence of malaria and as a result, the development of insecticide resistance in vector populations is of major concern. Anopheles arabiensis is one of the main African malaria vectors and insecticide resistance in this species has been reported in a number of countries. The aim of this study was to investigate the detoxification enzymes that are involved in An. arabiensis resistance to DDT and pyrethroids. Methods The detoxification enzyme profiles were compared between two DDT selected, insecticide resistant strains of An. arabiensis, one from South Africa and one from Sudan, using the An. gambiae detoxification chip, a boutique microarray based on the major classes of enzymes associated with metabolism and detoxification of insecticides. Synergist assays were performed in order to clarify the roles of over-transcribed detoxification genes in the observed resistance phenotypes. In addition, the presence of kdr mutations in the colonies under investigation was determined. Results The microarray data identifies several genes over-transcribed in the insecticide selected South African strain, while in the Sudanese population, only one gene, CYP9L1, was found to be over-transcribed. The outcome of the synergist experiments indicate that the over-transcription of detoxification enzymes is linked to deltamethrin resistance, while DDT and permethrin resistance are mainly associated with the presence of the L1014F kdr mutation. Conclusions These data emphasise the complexity associated with resistance phenotypes and suggest that specific insecticide resistance mechanisms cannot be extrapolated to different vector populations of the same species.

  6. An efficient treatment for detoxification process of cassava starch by plant cell wall-degrading enzymes.

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    Sornyotha, Somphit; Kyu, Khin Lay; Ratanakhanokchai, Khanok

    2010-01-01

    The objective of this work was to remove linamarin in starch from cassava (Manihot esculenta Crantz cv. KU-50) roots, a high-cyanogen variety by using plant cell wall-degrading enzymes, xylanase and cellulase. The combination of xylanase from Bacillus firmus K-1 and xylanase and cellulase from Paenibacillus curdlanolyticus B-6 at the ratio of 1:9 showed the maximum synergism at 1.8 times for hydrolyzing cassava cortex cell walls and releasing linamarase. Combined enzyme treatment enhanced linamarin liberation from the parenchyma by 90%. In addition, when the combined enzymes were applied for detoxification during cassava starch production, a low-cyanide-product was obtained with decreased linamarin concentration (96%) compared to non-enzyme treated tissues. Based on these results, xylanase and cellulase treatment is a good method for low-cyanide-cassava starch production and could be applied for detoxification of cassava products during processing.

  7. response of anopheles gambiae detoxification enzymes to levels of ...

    African Journals Online (AJOL)

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    enzymes to levels of various physico-chemical environmental factors present in their breeding sites. ... the sampled larvae were reared to pupae and adult life stages. Levels of 7 ...... established the role of agriculture as source of selection ...

  8. Detoxification of azo dyes by bacterial oxidoreductase enzymes.

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    Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Mahmood, Tariq; Crowley, David E

    2016-08-01

    Azo dyes and their intermediate degradation products are common contaminants of soil and groundwater in developing countries where textile and leather dye products are produced. The toxicity of azo dyes is primarily associated with their molecular structure, substitution groups and reactivity. To avoid contamination of natural resources and to minimize risk to human health, this wastewater requires treatment in an environmentally safe manner. This manuscript critically reviews biological treatment systems and the role of bacterial reductive and oxidative enzymes/processes in the bioremediation of dye-polluted wastewaters. Many studies have shown that a variety of culturable bacteria have efficient enzymatic systems that can carry out complete mineralization of dye chemicals and their metabolites (aromatic compounds) over a wide range of environmental conditions. Complete mineralization of azo dyes generally involves a two-step process requiring initial anaerobic treatment for decolorization, followed by an oxidative process that results in degradation of the toxic intermediates that are formed during the first step. Molecular studies have revealed that the first reductive process can be carried out by two classes of enzymes involving flavin-dependent and flavin-free azoreductases under anaerobic or low oxygen conditions. The second step that is carried out by oxidative enzymes that primarily involves broad specificity peroxidases, laccases and tyrosinases. This review focuses, in particular, on the characterization of these enzymes with respect to their enzyme kinetics and the environmental conditions that are necessary for bioreactor systems to treat azo dyes contained in wastewater.

  9. Study on the biochemical characterization of herbicide detoxification enzyme, glutathione S-transferase.

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    Cho, Hyun-Young; Kong, Kwang-Hoon

    2007-01-01

    To gain further insight into herbicide detoxification, we studied the herbicide activity and specificity toward glutathione S-transferases from human and rice. In this study, the genes of the plant specific phi and tau class GST enzymes from Oryza sativa (OsGST) and human pi class GST enzyme (hGSTP1-1) were cloned and expressed in Escherichia coli with the pET and pKK vector systems, respectively. The gene products were purified to homogeneity by GSH Sepharose affinity column chromatography. The herbicide specificity of the enzymes was investigated by enzyme-catalyzed conjugation of GSH with chloroacetanilide, diphenylether and chloro-s-triazine herbicides. The hGSTP1-1 showed very high specific activity toward atrazine. On the other hand, the phi class OsGST enzymes showed high specific activity toward chloroacetanilide herbicides, acetochlor, alachlor and metolachlor. The tau class GST enzymes displayed remarkable activity toward the diphenylether herbicide, fluorodifen. From these results, we conclude that the phi and the tau class GST enzymes show herbicide specificities and also they play an important role in the detoxification reaction of plant toward herbicides.

  10. Hepatic expression of detoxification enzymes is decreased in human obstructive cholestasis due to gallstone biliary obstruction.

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    Jin Chai

    Full Text Available Levels of bile acid metabolic enzymes and membrane transporters have been reported to change in cholestasis. These alterations (e.g. CYP7A1 repression and MRP4 induction are thought to be adaptive responses that attenuate cholestatic liver injury. However, the molecular mechanisms of these adaptive responses in human obstructive cholestasis due to gallstone biliary obstruction remain unclear.We collected liver samples from cholestatic patients with biliary obstruction due to gallstones and from control patients without liver disease (n = 22 per group. The expression levels of bile acid synthetic and detoxification enzymes, membrane transporters, and the related nuclear receptors and transcriptional factors were measured.The levels of bile acid synthetic enzymes, CYP7B1 and CYP8B1, and the detoxification enzyme CYP2B6 were increased in cholestatic livers by 2.4-fold, 2.8-fold, and 1.9-fold, respectively (p<0.05. Conversely, the expression levels of liver detoxification enzymes, UGT2B4/7, SULT2A1, GSTA1-4, and GSTM1-4, were reduced by approximately 50% (p<0.05 in human obstructive cholestasis. The levels of membrane transporters, OSTβ and OCT1, were increased 10.4-fold and 1.8-fold, respectively, (p<0.05, whereas those of OSTα, ABCG2 and ABCG8 were all decreased by approximately 40%, (p<0.05 in human cholestatic livers. Hepatic nuclear receptors, VDR, HNF4α, RXRα and RARα, were induced (approximately 2.0-fold, (p<0.05 whereas FXR levels were markedly reduced to 44% of control, (p<0.05 in human obstructive cholestasis. There was a significantly positive correlation between the reduction in FXR mRNA and UGT2B4/7, SULT2A1, GSTA1, ABCG2/8 mRNA levels in livers of obstructive cholestatic patients (p<0.05.The levels of hepatic detoxification enzymes were significantly decreased in human obstructive cholestasis, and these decreases were positively associated with a marked reduction of FXR levels. These findings are consistent with impaired

  11. Genetic variability of glutathione S-transferase enzymes in human populations: functional inter-ethnic differences in detoxification systems.

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    Polimanti, Renato; Carboni, Cinzia; Baesso, Ilenia; Piacentini, Sara; Iorio, Andrea; De Stefano, Gian Franco; Fuciarelli, Maria

    2013-01-01

    Glutathione S-Transferase enzymes (GSTs) constitute the principal Phase II superfamily which plays a key role in cellular detoxification and in other biological processes. Studies of GSTs have revealed that genetic polymorphisms are present in these enzymes and that some of these are Loss-of-Function (LoF) variants, which affect enzymatic functions and are related to different aspects of human health. The aim of this study was to analyze functional genetic differences in GST enzymes among human populations. Attention was focused on LoF polymorphisms of GSTA1, GSTM1, GSTO1, GSTO2, GSTP1 and GSTT1 genes. These LoF variants were analyzed in 668 individuals belonging to six human groups with different ethnic backgrounds: Amhara and Oromo from Ethiopia; Colorado and Cayapa Amerindians and African Ecuadorians from Ecuador; and one sample from central Italy. The HapMap database was used to compare our data with reference populations and to analyze the haplotype and Linkage Disequilibrium diversity in different ethnic groups. Our results highlighted that ethnicity strongly affects the genetic variability of GST enzymes. In particular, GST haplotypes/variants with functional impact showed significant differences in human populations, according to their ethnic background. These data underline that human populations have different structures in detoxification genes, suggesting that these ethnic differences influence disease risk or response to drugs and therefore have implications for genetic association studies involving GST enzymes. In conclusion, our investigation provides data about the distribution of important LoF variants in GST genes in human populations. This information may be useful for designing and interpreting genetic association studies.

  12. Effects of dietary nickel on detoxification enzyme activities in the midgut of Spodoptera litura Fabricius larvae

    Institute of Scientific and Technical Information of China (English)

    SUN HongXia; ZHOU Qiang; TANG WenCheng; SHU YingHua; ZHANG GuRen

    2008-01-01

    Nickel accumulated in midugt of Spodoptera litura Fabricius could induce the expression of metal-Iothionein, one of the most important detoxification proteins in organisms. In the present study, the effects of dietary nickel on the activities of detoxification enzymes, such as carboxylesterase (CarE) and glutathione S-transferase (GST) in the midgut of S. litura larvae have been studied to get an un-derstanding of the detoxification mechanisms of S. litura larvae to excessive nickel. Results showed that CarE activities in the midgut of the 5th instar larvae decreased at lower levels of nickel (≤5 mg/kg), while increased with increasing nickel doses at higher levels of nickel (≥10 mg/kg) exposure in suc-cessive 3 generations. CarE activities of the 6th instar larvae were also characterized as inhibited at low levels of nickel exposure, and improved at higher levels in the 1st generation. CarE activities of 6th instar larvae in the 2rid and 3rd generations were all lower than that in control. However, GST activities in the midgut of the 5th and 6th instar larvae all increased with increasing nickel doses (1-20 mg/kg) in diets.

  13. Toxaphene detoxification and acclimation in Daphnia magna: do cytochrome P-450 enzymes play a role?

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    Kashian, Donna R

    2004-01-01

    Toxaphene is a persistent environmental contaminant that has been shown to alter male production in Daphnia magna and to induce P-450 activity in mammals. Cytochrome P-450-mediated metabolism may lead to xenobiotic detoxification resulting in acclimation. To determine if D. magna acclimate to toxaphene via P-450 pathways, chronic and acute toxicity tests were conducted with D. magna exposed to toxaphene in the presence and absence of piperonyl butoxide (PBO), an inhibitor of cytochrome P-450 enzymes. Toxaphene exposure increased male production in acute but not chronic assays, indicating that D. magna may acclimate to chronic toxaphene exposure. Upon co-administration of toxaphene and PBO in chronic tests, D. magna exhibited a decline in growth rate, fecundity and survival. The observed toxaphene acclimation in chronic tests, along with its increased toxicity in the presence of a P-450 suppressor, suggests that P-450 enzymes may contribute to detoxification and subsequent acclimation of D. magna to chronic toxaphene exposure. Additional chronic toxicity tests indicated that toxaphene acclimation occurs between 7 and 12 days following initial exposure, at which time sex determination is no longer affected. Thus, sublethal toxaphene toxicity effects such as reproductive impairments may be detectable with acute but not chronic tests, potentially due to the upregulation of P-450 isozymes.

  14. Forecasting Model of Gene Enzyme Polymorphism Detoxification in Patients Suffered from HFRS

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    G. M. Hasanova

    2016-01-01

    Full Text Available Aim: to study gene enzyme polymorphism of xenobiotic detoxification in patients suffered from HFRS influenced by disease severityProceedings : Molecular genetic checkup has been done in 292 patients suffered from HFRS and 426 seronegative donors.DNA samples isolated from lymphocytes of peripheral gene enzyme were used for molecular genetic checkup. Phenic-chloroform extraction method was applied to isolate DNA. The given DNA was used for polymerase chain reaction of DNA synthesis. Polymorphous CYP1A1 and GSTP1 gene locus analysis was performed on an automatic basis by polymerase chain reaction of DNA synthesis in a thermal cycle «Terzik» produced «DNK–techologiya» ( Moscow city with the use of locus specific and oligonucleotide primers.Outcomings: Glutathion-S-transferase class π with A313G locus of AG heterozygous genotype is typical for people of Bashkortostan due to underlying risk for HFRS. A combination of genotypes in the form of cytochrome P-450A1 with polymorphous locus A2455G and glutathione-S-transferase class π with A313G locus of AG can be found only in case of severe form of HFRS.

  15. Acute toxicity and sublethal effects of fipronil on detoxification enzymes in juvenile zebrafish (Danio rerio).

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    Wu, Haihua; Gao, Cuie; Guo, Yaping; Zhang, Yuping; Zhang, Jianzhen; Ma, Enbo

    2014-10-01

    The acute toxicity of fipronil and its sublethal effects on detoxification enzymes (carboxylesterases (CarEs), glutathione S-transferases (GSTs), and 7-ethoxycoumarin O-deethylase (ECOD)) in zebrafish (Danio rerio) were investigated. The results indicated that the 24-h LC50 of fipronil for zebrafish was 220.4 μg/L (95% CI: 173.7-272.4 μg/L). Sublethal concentrations of fipronil did not cause significant changes in CarEs activities. In the liver and muscle tissues, GST activities at the tested concentrations did not significantly differ from those in the control. In the brain and gill tissues, GST activities at a concentration of 4 μg/L were significantly lower than those at a concentration of 2 μg/L. The results suggest that CarEs and GSTs were not suitable biomarkers for fipronil effects in D. rerio. A significant induction in the ECOD activities in the brain, gill, liver, and muscle tissues was observed compared with the control. Moreover, the dose-dependent responses of the ECOD activity were observed after treatment with sublethal concentrations of fipronil in the range of 2-20 μg/L. The results suggested that ECOD could be a suitable biomarker of fipronil effects in D. rerio.

  16. The involvement of several enzymes in methanol detoxification in Drosophila melanogaster adults.

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    Wang, Shu-Ping; Hu, Xing-Xing; Meng, Qing-Wei; Muhammad, Shahid Arain; Chen, Rui-Rui; Li, Fei; Li, Guo-Qing

    2013-09-01

    Methanol is among the most common short-chain alcohols in fermenting fruits, the natural food and oviposition sites of the fruit fly Drosophila melanogaster. Our previous results showed that cytochrome P450 monooxygenases (CYPs) were associated with methanol detoxification in the larvae. Catalases, alcohol dehydrogenases (ADHs), esterases (ESTs) and glutathione S-transferases (GSTs) were specifically inhibited by 3-amino-1,2,4-triazole (3-AT), 4-methylpyrazole (4-MP), triphenyl phosphate (TPP) and diethylmeleate (DEM), respectively. CYPs were inhibited by piperonyl butoxide (PBO) and 1-aminobenzotriazole (1-ABT). In the present paper, the involvements of these enzymes in methanol metabolism were investigated in female and male adults by determining the combination indices of methanol and their corresponding inhibitors. When PBO, 1-ABT, 3-AT, 4-MP and TPP were individually mixed with methanol, they exhibited significant synergism to the mortality of the adults after 72h of dietary exposure. In contrast, the DEM and methanol mixture showed additive effects. Moreover, methanol exposure dramatically increased CYP activity and up-regulated mRNA expression levels of several Cyp genes. Bioassays using different strains revealed that the variation in ADH activity and RNAi-mediated knockdown of α-Est7 significantly changed LC50 values for methanol. These results suggest that CYPs, catalases, ADHs and ESTs are partially responsible for methanol elimination in adults. It seems that there are some differences in methanol metabolism between larvae and adults, but not between female and male adults.

  17. Lactobacillus casei stimulates phase-II detoxification system and rescues malathion-induced physiological impairments in Caenorhabditis elegans.

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    Kamaladevi, Arumugam; Ganguli, Abhijit; Balamurugan, Krishnaswamy

    2016-01-01

    Malathion, an organophosphorus insecticide, is renowned for its inhibitory action on acetylcholinesterase (AChE) enzyme that eventually leads to widespread disturbance in the normal physiological and behavioral activities of any organism. Lactic acid bacteria (LAB) are still an underexploited and inexhaustible source of significant pharmaceutical thrust. In the present study, Caenorhabditis elegans was employed to identify and characterize the indigenous LAB isolated from different traditional food against malathion-induced toxicity. The results demonstrated that malathion at its LD50 concentration decreased various C. elegans physiological parameters such as survival, feeding, and locomotion. Among the screened isolates, L. casei exhibited an excellent protective efficacy against malathion-induced toxicity by increasing the level of AChE and thereby rescued all physiological parameters of C. elegans. In addition, short-term exposure and food choice assay divulged that L. casei could serve as a better food to protect C. elegans from noxious environment. The expression analysis unveiled that L. casei gavage upregulated the phase-II detoxification enzymes coding genes metallothioneins (mtl-1 and mtl-2) and glutathione-S-transferase (gst-8) and thereby eliminated malathion from the host system. Furthermore, the upregulation of ace-3 along with down-regulation of cyp35a in the nematodes supplemented with L. casei could be attributed to attenuate the malathion-induced physiological defects in C. elegans. Thus, the present study reports that an indigenous LAB-L. casei could serve as a promising protective agent against the harmful effects of pesticide.

  18. Effect of benzo[a]pyrene on detoxification and the activity of antioxidant enzymes of marine microalgae

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    Shen, Chen; Miao, Jingjing; Li, Yun; Pan, Luqing

    2016-04-01

    The objective of this study was to examine the effect of benzo[a]pyrene (BaP) on the detoxification and antioxidant systems of two microalgae, Isochrysis zhanjiangensis and Platymonas subcordiformis. In our study, these two algae were exposed to BaP for 4 days at three different concentrations including 0.5 μg L-1 (low), 3 μg L-1 (mid) and 18 μg L-1 (high). The activity of detoxification enzymes, ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) increased in P. subcordiformis in all BaP-treated groups. In I. zhanjiangensis, the activity of these two enzymes increased at the beginning of exposure, and then decreased in the groups treated with mid- and high BaP. The activity of antioxidant enzyme superoxide dismutase (SOD) increased in I. zhanjiangensis in all BaP-treated groups, and then decreased in high BaP-treated group, while no significant change was observed in P. subcordiformis. The activity of antioxidant enzyme catalase (CAT) increased in I. zhanjiangensis and P. subcordiformis in all BaPtreated groups. The content of malondialdehyde (MDA) in Isochrysis zhanjiangensis increased first, and then decreased in high BaP-treated group, while no change occurred in P. subcordiformis. These results demonstrated that BaP significantly influenced the activity of detoxifying and antioxidant enzymes in microalgae. The metabolic related enzymes (EROD, GST and CAT) may serve as sensitive biomarkers of measuring the contamination level of BaP in marine water.

  19. Equilibrium sorption isotherm studies of Cd(II), Pb(II) and Zn(II) ions detoxification from waste water using unmodified and EDTA-modified maize husk

    OpenAIRE

    Igwe,Jude C; Abia,Augustin A

    2007-01-01

    The mobilization of heavy metals in the environment due to industrial activities is of serious concern due to the toxicity of these metals in humans and other forms of life. The equilibrium adsorption isotherms of Cd(II), Pb(II) and Zn(II) ions, detoxification from waste water using unmodified and EDTA-modified maize husk have been studied. Maize husk was found to be an excellent adsorbent for the removal of these metal ions. The amount of these metal ions adsorbed increased as the initial co...

  20. Chemopreventive effects of diverse dietary phytochemicals against DMBA-induced hamster buccal pouch carcinogenesis via the induction of Nrf2-mediated cytoprotective antioxidant, detoxification, and DNA repair enzymes.

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    Kavitha, K; Thiyagarajan, P; Rathna Nandhini, J; Mishra, Rajakishore; Nagini, S

    2013-08-01

    Identifying agents that activate nuclear factor erythroid-2 related factor-2 (Nrf2), a key regulator of various cytoprotective antioxidant, and detoxifying enzymes has evolved as a promising strategy for cancer chemoprevention. In the present study, we investigated the effect of dietary supplementation of structurally diverse phytochemicals- astaxanthin, blueberry, chlorophyllin, ellagic acid, and theaphenon-E on Nrf2 signaling, and xenobiotic-metabolizing and antioxidant enzymes in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model. We observed that these phytochemicals induce nuclear accumulation of Nrf2 while downregulating its negative regulator, Keap-1. This was associated with reduced expression of CYP1A1 and CYP1B1, the cytochrome P450 isoforms involved in the activation of DMBA, and the oxidative stress marker 8-hydroxy-2'-deoxyguanosine coupled with upregulation of the phase II detoxification enzymes glutathione S-transferases and NAD(P)H:quinone oxidoreductase 1 and the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase. In addition, these dietary phytochemicals also enhanced the DNA repair enzymes 8-oxoguanine glycosylase 1 (OGG1), xeroderma pigmentosum D (XPD), xeroderma pigmentosum G (XPG), and x-ray repair cross complementing group 1 (XRCC1). Our data provide substantial evidence that the dietary phytochemicals inhibit the development of HBP carcinomas through the activation of Nrf2/Keap-1 signaling and by upregulating cytoprotective enzymes. The extent of the chemopreventive effects of the phytochemicals was in the order: chlorophyllin > blueberry > ellagic acid > astaxanthin > theaphenon-E. Thus these dietary phytochemicals that function as potent activators of Nrf2 and its orchestrated response are novel candidates for cancer chemoprevention.

  1. Fermented wheat aleurone induces enzymes involved in detoxification of carcinogens and in antioxidative defence in human colon cells.

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    Stein, Katrin; Borowicki, Anke; Scharlau, Daniel; Glei, Michael

    2010-10-01

    Dietary fibre is fermented by the human gut flora resulting mainly in the formation of SCFA, for example, acetate, propionate and butyrate. SCFA, in particular butyrate, may be important for secondary cancer prevention by inducing apoptosis and inhibiting cell growth of cancer cells, thereby inhibiting the promotion and/or progression of cancer. Furthermore, SCFA could also act on primary cancer prevention by activation of detoxifying and antioxidative enzymes. We investigated the effects of fermented wheat aleurone on the expression of genes involved in stress response and toxicity, activity of drug-metabolising enzymes and anti-genotoxic potential. Aleurone was digested and fermented in vitro to obtain samples that reflect the content of the colon. HT29 cells and colon epithelial stripes were incubated with the resulting fermentation supernatant fractions (fs) and effects on mRNA expression of CAT, GSTP1 and SULT2B1 and enzyme activity of glutathione S-transferase (GST) and catalase (CAT) were measured. Fermented aleurone was also used to study the protection against H2O2-induced DNA damage in HT29 cells. The fs of aleurone significantly induced the mRNA expression of CAT, GSTP1 and SULT2B1 (HT29) and GSTP1 (epithelial stripes), respectively. The enzyme activities of GST (HT29) and CAT (HT29, epithelial stripes) were also unambiguously increased (1.4- to 3.7-fold) by the fs of aleurone. DNA damage induced by H2O2 was significantly reduced by the fs of aleurone after 48 h, whereupon no difference was observed compared with the faeces control. In conclusion, fermented aleurone is able to act on primary prevention by inducing mRNA expression and the activity of enzymes involved in detoxification of carcinogens and antioxidative defence.

  2. Targeted mutagenesis of mitochondrial carbonic anhydrases VA and VB implicates both enzymes in ammonia detoxification and glucose metabolism.

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    Shah, Gul N; Rubbelke, Timothy S; Hendin, Joshua; Nguyen, Hien; Waheed, Abdul; Shoemaker, James D; Sly, William S

    2013-04-30

    Prior studies with carbonic anhydrase (CA) inhibitors implicated mitochondrial CA in ureagenesis and gluconeogenesis. Subsequent studies identified two mitochondrial CAs. To distinguish the contribution of each enzyme, we studied the effects of targeted disruption of the murine CA genes, called Car5A and Car5B. The Car5A mutation had several deleterious consequences. Car5A null mice were smaller than wild-type littermates and bred poorly. However, on sodium-potassium citrate-supplemented water, they produced offspring in expected numbers. Their blood ammonia concentrations were markedly elevated, but their fasting blood sugars were normal. By contrast, Car5B null mice showed normal growth and normal blood ammonia levels. They too had normal fasting blood sugars. Car5A/B double-knockout (DKO) mice showed additional abnormalities. Impaired growth was more severe than for Car5A null mice. Hyperammonemia was even greater as well. Although fertile, DKO animals were produced in less-than-predicted numbers even when supplemented with sodium-potassium citrate in their drinking water. Survival after weaning was also reduced, especially for males. In addition, fasting blood glucose levels for DKO mice were significantly lower than for controls (153 ± 33 vs. 230 ± 24 mg/dL). The enhanced hyperammonemia and lower fasting blood sugar, which are both seen in the DKO mice, indicate that both Car5A and Car5B contribute to both ammonia detoxification (ureagenesis) and regulation of fasting blood sugar (gluconeogenesis). Car5A, which is expressed mainly in liver, clearly has the predominant role in ammonia detoxification. The contribution of Car5B to ureagenesis and gluconeogenesis was evident only on a Car5A null background.

  3. Trends in detoxification enzymes and heavy metal accumulation in ground beetles (Coleoptera: Carabidae) inhabiting a gradient of pollution.

    Science.gov (United States)

    Stone, David; Jepson, Paul; Laskowski, Ryszard

    2002-05-01

    Non-specfic carboxylesterase and glutathione S-transferase activity was measured in the ground beetle, Pterosthicus oblongopunctatus (Coleoptera: Carabidae), from five sites along a gradient of heavy metal pollution. A previous study determined that beetles from the two most polluted sites (site codes OLK2 and OLK3) were more susceptible to additional stressors compared with beetles from the reference site (Stone et al., Environ. Pollut. 113, 239-244 2001), suggesting the possibility of physiological impairment. Metal body burdens in ground beetles from five sites along the gradient ranged from 79 to 201 microg/g Zn, 0.174 to 8.66 microg/g Pb and 1.14 to 10.8 microg/g Cd, whereas Cu seemed to be efficiently regulated regardless of metal levels in the soil. Beetle mid- and hindguts were homogenized and the soluble fraction containing glutathione S-transferase (GST) and carboxylesterase (CaE) was assayed using kinetic analyses. Significantly higher levels of GST were found only in female beetles from the most polluted sites (OLK2 and OLK3; P=0.049, P<0.001, respectively) compared with the reference site (OLK7). In addition, OLK3 females had significantly higher levels of CaE compared with the reference beetles (P=0.01). Male beetles did not differ in enzyme activity along the metal gradient. Overall, obvious trends in detoxification enzymes were not detected in ground beetles in association with metal body burdens.

  4. Lactoylglutathione lyase, a critical enzyme in methylglyoxal detoxification, contributes to survival of Salmonella in the nutrient rich environment

    Science.gov (United States)

    Chakraborty, Sangeeta; Gogoi, Mayuri; Chakravortty, Dipshikha

    2015-01-01

    Glyoxalase I which is synonymously known as lactoylglutathione lyase is a critical enzyme in methylglyoxal (MG) detoxification. We assessed the STM3117 encoded lactoylglutathione lyase (Lgl) of Salmonella Typhimurium, which is known to function as a virulence factor, due in part to its ability to detoxify methylglyoxal. We found that STM3117 encoded Lgl isomerises the hemithioacetal adduct of MG and glutathione (GSH) into S-lactoylglutathione. Lgl was observed to be an outer membrane bound protein with maximum expression at the exponential growth phase. The deletion mutant of S. Typhimurium (Δlgl) exhibited a notable growth inhibition coupled with oxidative DNA damage and membrane disruptions, in accordance with the growth arrest phenomenon associated with typical glyoxalase I deletion. However, growth in glucose minimal medium did not result in any inhibition. Endogenous expression of recombinant Lgl in serovar Typhi led to an increased resistance and growth in presence of external MG. Being a metalloprotein, Lgl was found to get activated maximally by Co2+ ion followed by Ni2+, while Zn2+ did not activate the enzyme and this could be attributed to the geometry of the particular protein-metal complex attained in the catalytically active state. Our results offer an insight on the pivotal role of the virulence associated and horizontally acquired STM3117 gene in non-typhoidal serovars with direct correlation of its activity in lending survival advantage to Salmonella spp. PMID:25517857

  5. Polymorphic genes of detoxification and mitochondrial enzymes and risk for progressive supranuclear palsy: a case control study

    Directory of Open Access Journals (Sweden)

    Potts Lisa F

    2012-03-01

    Full Text Available Abstract Background There are no known causes for progressive supranuclear palsy (PSP. The microtubule associated protein tau (MAPT H1 haplotype is the major genetic factor associated with risk of PSP, with both oxidative stress and mitochondrial dysfunction also implicated. We investigated whether specific single nucleotide polymorphisms (SNPs in genes encoding enzymes of xenobiotic detoxification, mitochondrial functioning, or oxidative stress response, including debrisoquine 4-hydroxylase, paraoxonase 1 and 2, N-acetyltransferase 1 and 2 (NAT2, superoxide dismutase 1 and 2, and PTEN-induced putative kinase are associated with PSP. Methods DNA from 553 autopsy-confirmed Caucasian PSP cases (266 females, 279 males; age at onset 68 ± 8 years; age at death 75 ± 8 from the Society for PSP Brain Bank and 425 clinical control samples (197 females, 226 males; age at draw 72 ± 11 years from healthy volunteers were genotyped using Taqman PCR and the SequenomiPLEX Gold assay. Results The proportion of NAT2 rapid acetylators compared to intermediate and slow acetylators was larger in cases than in controls (OR = 1.82, p MAPT (p Conclusions Our results show that NAT2 rapid acetylator phenotype is associated with PSP, suggesting that NAT2 may be responsible for activation of a xenobiotic whose metabolite is neurotoxic. Although our results need to be further confirmed in an independent sample, NAT2 acetylation status should be considered in future genetic and epidemiological studies of PSP.

  6. In vivo phase II-enzymes inducers, as potential chemopreventive agents, based on the chalcone and furoxan skeletons.

    Science.gov (United States)

    Cabrera, Mauricio; Mastandrea, Ignacio; Otero, Gabriel; Cerecetto, Hugo; González, Mercedes

    2016-04-15

    Cancer chemoprevention involves prevention/delay/reverse of the carcinogenic process through administration of cancer chemopreventive agents (CCA). Compounds which are able to induce detoxification-enzymes, especially monofunctional phase II enzymes, have become in excellent approaches for new CCA. Herein, we report the synthesis of new furoxanyl chalcone-like hybrid compounds as CCA. In vitro studies showed that phenylfuroxanyl derivatives 6 and 9 displayed the best activities being 9 the greatest monofunctional-inducer. Additionally, compounds were non-mutagenic against TA98 Salmonella typhimurium strain (Ames test) and could be used in the prevention of the progression of pre-malignant lesions for their cytotoxic activity against tumoral cells. In vivo proof of concept showed increment on phase II-enzymes activities in liver, colon and mammary gland having derivative 9 the best induction profiles. We probed Nrf2 nuclear translocation is operative for both compounds allowing to exert protective effects via expression of downstream phase-II enzymes.

  7. Techniques for assaying detoxification enzyme activity inLocusta migratoria%飞蝗解毒酶系活力测定方法

    Institute of Scientific and Technical Information of China (English)

    董玮; 吴海花; 张建珍; 王泽世; 马恩波

    2016-01-01

    飞蝗Locusta migratoria是重要的农业害虫,代谢抗性是飞蝗主要的农药抗性机制之一。与代谢抗性相关的解毒酶系主要有:非专一性酯酶系( Non-specficesterases , ESTs )、谷胱甘肽 S-转移酶系(GlutathioneS-transferases,GSTs)和细胞色素P450单加氧酶系(Cytochrome P450 monooxygenases, P450s),解毒酶系活力的测定是研究飞蝗农药代谢机制的重要途径。本文详细介绍了飞蝗解毒酶系的测定方法,为蝗虫及其他昆虫解毒酶系的测定提供参考。%Locusta migratoria(L.) is a major agricultural pest and metabolic resistance is one of the most important mechanisms by which this species develops resistance to insecticides. The detoxification enzymes, which are associated with metabolic resistance, include non-specific esterase (ESTs), glutathioneS-transferases (GSTs) and cytochrome P450 monooxygenases (P450s). Assaying detoxification enzyme activity is an important way to study pesticide metabolism inL. migratoria. This paper describes in detail how to analyze the detoxification enzymes activity in L. migratoria, and provides a reference for this in other insects.

  8. Construction of chimeric enzymes out of maize endosperm branching enzymes I and II: activity and properties.

    Science.gov (United States)

    Kuriki, T; Stewart, D C; Preiss, J

    1997-11-14

    Branching enzyme I and II isoforms from maize endosperm (mBE I and mBE II, respectively) have quite different properties, and to elucidate the domain(s) that determines the differences, chimeric genes consisting of part mBE I and part mBE II were constructed. When expressed under the control of the T7 promoter in Escherichia coli, several of the chimeric enzymes were inactive. The only fully active chimeric enzyme was mBE II-I BspHI, in which the carboxyl-terminal part of mBE II was exchanged for that of mBE I at a BspHI restriction site and was purified to homogeneity and characterized. Another chimeric enzyme, mBE I-II HindIII, in which the amino-terminal end of mBE II was replaced with that of mBE I, had very little activity and was only partially characterized. The purified mBE II-I BspHI exhibited higher activity than wild-type mBE I and mBE II when assayed by the phosphorylase a stimulation assay. mBE II-I BspHI had substrate specificity (preference for amylose rather than amylopectin) and catalytic capacity similar to mBE I, despite the fact that only the carboxyl terminus was from mBE I, suggesting that the carboxyl terminus may be involved in determining substrate specificity and catalytic capacity. In chain transfer experiments, mBE II-I BspHI transferred more short chains (with a degree of polymerization of around 6) in a fashion similar to mBE II. In contrast, mBE I-II HindIII transferred more long chains (with a degree of polymerization of around 11-12), similar to mBE I, suggesting that the amino terminus of mBEs may play a role in the size of oligosaccharide chain transferred. This study challenges the notion that the catalytic centers for branching enzymes are exclusively located in the central portion of the enzyme; it suggests instead that the amino and carboxyl termini may also be involved in determining substrate preference, catalytic capacity, and chain length transfer.

  9. Biotransformation of albendazole and activities of selected detoxification enzymes in Haemonchus contortus strains susceptible and resistant to anthelmintics.

    Science.gov (United States)

    Vokřál, Ivan; Jirásko, Robert; Stuchlíková, Lucie; Bártíková, Hana; Szotáková, Barbora; Lamka, Jiří; Várady, Marián; Skálová, Lenka

    2013-09-23

    The increased activity of drug-metabolizing enzymes can protect helminths against the toxic effect of anthelmintics. The aim of this study was to compare the metabolism of the anthelmintic drug albendazole (ABZ) and the activities of selected biotransformation and antioxidant enzymes in three different strains of Haemonchus contortus: the ISE strain (susceptible to common anthelmintics), the BR strain (resistant to benzimidazole anthelmintics) and the WR strain (multi-resistant). H. contortus adults were collected from the abomasum of experimentally infected lambs. In vitro (subcellular fractions of H. contortus homogenate) as well as ex vivo (living nematodes cultivated in flasks with medium) experiments were performed. HPLC with spectrofluorimetric and mass-spectrometric detection was used in the analysis of ABZ metabolites. The in vitro activities of oxidation/antioxidation and conjugation enzymes toward model substrates were also assayed. The in vitro data showed significant differences between the susceptible (ISE) and resistant (BR, WR) strains regarding the activities of peroxidases, catalase and UDP-glucosyltransferases. S-oxidation of ABZ was significantly lower in BR than in the ISE strain. Ex vivo, four ABZ metabolites were identified: ABZ sulphoxide and three ABZ glucosides. In the resistant strains BR and WR, the ex vivo formation of all ABZ glucosides was significantly higher than in the susceptible ISE strain. The altered activities of certain detoxifying enzymes might partly protect the parasites against the toxic effect of the drugs as well as contribute to drug-resistance in these parasites.

  10. Targeted mutagenesis of mitochondrial carbonic anhydrases VA and VB implicates both enzymes in ammonia detoxification and glucose metabolism

    OpenAIRE

    Shah, Gul N.; Rubbelke, Timothy S.; Hendin, Joshua; Nguyen, Hien; Waheed, Abdul; Shoemaker, James D.; Sly, William S.

    2013-01-01

    Prior studies with carbonic anhydrase (CA) inhibitors implicated mitochondrial CA in ureagenesis and gluconeogenesis. Subsequent studies identified two mitochondrial CAs. To distinguish the contribution of each enzyme, we studied the effects of targeted disruption of the murine CA genes, called Car5A and Car5B. The Car5A mutation had several deleterious consequences. Car5A null mice were smaller than wild-type littermates and bred poorly. However, on sodium–potassium citrate-supplemented wate...

  11. New hits as phase II enzymes inducers from a focused library with heteroatom–heteroatom and Michael-acceptor motives

    Science.gov (United States)

    Cabrera, Mauricio; de Ovalle, Stefani; Bollati-Fogolín, Mariela; Nascimento, Fabiana; Corbelini, Patrícia; Janarelli, Fernanda; Kawano, Daniel; Eifler-Lima, Vera Lucia; González, Mercedes; Cerecetto, Hugo

    2015-01-01

    The increased activity of phase-II-detoxification enzymes, such as quinone reductase (QR) and glutation S-transferase (GST), correlates with protection against chemically induced carcinogenesis. Herein we studied 11 different chemotypes, pyrazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiazole, 1,3,4-oxathiazole, thienyl hydrazone, α,β-unsaturated-oxime, α,β-unsaturated-N-oxide, coumarin and α,β-unsaturated-carbonyl, as phase-II enzymes inducers in order to identify new pharmacophores with chemopreventive activity. Fifty-four compounds were analyzed on wild-type mouse-hepatoma Hepa-1c1c7 and on the aryl-hydrocarbon-nuclear-translocator (Arnt)-defective mutant BpRc1 cells. New monofunctional inducers of QR and GST were identified, the 1,2,5-oxadiazol-2-oxide (3), the 1,2,4-triazine-4-oxides (23) and (32) and the tetrahydropyrimidinones (28) and (49). It was confirmed that Nrf2 nuclear translocation is the operative molecular mechanism that allows compound (3) to exert protective effects via expression of downstream phase-II enzymes. PMID:28031894

  12. Crystal Structure of the Deglycating Enzyme Fructosamine Oxidase (Amadoriase II)

    Energy Technology Data Exchange (ETDEWEB)

    Collard, François; Zhang, Jianye; Nemet, Ina; Qanungo, Kaustubha R.; Monnier, Vincent M.; Yee, Vivien C. (Case Western)

    2009-01-12

    Fructosamine oxidases (FAOX) catalyze the oxidative deglycation of low molecular weight fructosamines (Amadori products). These proteins are of interest in developing an enzyme to deglycate proteins implicated in diabetic complications. We report here the crystal structures of FAOX-II from the fungi Aspergillus fumigatus, in free form and in complex with the inhibitor fructosyl-thioacetate, at 1.75 and 1.6{angstrom} resolution, respectively. FAOX-II is a two domain FAD-enzyme with an overall topology that is most similar to that of monomeric sarcosine oxidase. Active site residues Tyr-60, Arg-112 and Lys-368 bind the carboxylic portion of the fructosamine, whereas Glu-280 and Arg-411 bind the fructosyl portion. From structure-guided sequence comparison, Glu-280 was identified as a signature residue for FAOX activity. Two flexible surface loops become ordered upon binding of the inhibitor in a catalytic site that is about 12{angstrom} deep, providing an explanation for the very low activity of FAOX enzymes toward protein-bound fructosamines, which would have difficulty accessing the active site. Structure-based mutagenesis showed that substitution of Glu-280 and Arg-411 eliminates enzyme activity. In contrast, modification of other active site residues or of amino acids in the flexible active site loops has little effect, highlighting these regions as potential targets in designing an enzyme that will accept larger substrates.

  13. Crystal Structure of the Deglycating Enzyme Fructosamine Oxidase (Amadoriase II)*

    Science.gov (United States)

    Collard, François; Zhang, Jianye; Nemet, Ina; Qanungo, Kaustubha R.; Monnier, Vincent M.; Yee, Vivien C.

    2008-01-01

    Fructosamine oxidases (FAOX) catalyze the oxidative deglycation of low molecular weight fructosamines (Amadori products). These proteins are of interest in developing an enzyme to deglycate proteins implicated in diabetic complications. We report here the crystal structures of FAOX-II from the fungi Aspergillus fumigatus, in free form and in complex with the inhibitor fructosyl-thioacetate, at 1.75 and 1.6Å resolution, respectively. FAOX-II is a two domain FAD-enzyme with an overall topology that is most similar to that of monomeric sarcosine oxidase. Active site residues Tyr-60, Arg-112 and Lys-368 bind the carboxylic portion of the fructosamine, whereas Glu-280 and Arg-411 bind the fructosyl portion. From structure-guided sequence comparison, Glu-280 was identified as a signature residue for FAOX activity. Two flexible surface loops become ordered upon binding of the inhibitor in a catalytic site that is about 12Å deep, providing an explanation for the very low activity of FAOX enzymes toward protein-bound fructosamines, which would have difficulty accessing the active site. Structure-based mutagenesis showed that substitution of Glu-280 and Arg-411 eliminates enzyme activity. In contrast, modification of other active site residues or of amino acids in the flexible active site loops has little effect, highlighting these regions as potential targets in designing an enzyme that will accept larger substrates. PMID:18667417

  14. Crystal structure of the deglycating enzyme fructosamine oxidase (amadoriase II).

    Science.gov (United States)

    Collard, François; Zhang, Jianye; Nemet, Ina; Qanungo, Kaustubha R; Monnier, Vincent M; Yee, Vivien C

    2008-10-03

    Fructosamine oxidases (FAOX) catalyze the oxidative deglycation of low molecular weight fructosamines (Amadori products). These proteins are of interest in developing an enzyme to deglycate proteins implicated in diabetic complications. We report here the crystal structures of FAOX-II from the fungi Aspergillus fumigatus, in free form and in complex with the inhibitor fructosyl-thioacetate, at 1.75 and 1.6A resolution, respectively. FAOX-II is a two domain FAD-enzyme with an overall topology that is most similar to that of monomeric sarcosine oxidase. Active site residues Tyr-60, Arg-112 and Lys-368 bind the carboxylic portion of the fructosamine, whereas Glu-280 and Arg-411 bind the fructosyl portion. From structure-guided sequence comparison, Glu-280 was identified as a signature residue for FAOX activity. Two flexible surface loops become ordered upon binding of the inhibitor in a catalytic site that is about 12A deep, providing an explanation for the very low activity of FAOX enzymes toward protein-bound fructosamines, which would have difficulty accessing the active site. Structure-based mutagenesis showed that substitution of Glu-280 and Arg-411 eliminates enzyme activity. In contrast, modification of other active site residues or of amino acids in the flexible active site loops has little effect, highlighting these regions as potential targets in designing an enzyme that will accept larger substrates.

  15. Gene expression analysis and enzyme assay reveal a potential role of the carboxylesterase gene CpCE-1 from Cydia pomonella in detoxification of insecticides.

    Science.gov (United States)

    Yang, Xue-Qing

    2016-05-01

    Carboxylesterases (CarEs) are responsible for metabolism of xenobiotics including insecticides in insects. Understanding the expression patterns of a such detoxifying gene and effect of insecticides on its enzyme activity are important to clarify the function of this gene relevant to insecticides-detoxifying process, but little information is available in the codling moth Cydia pomonella (L.). In this study, we investigated the expression profiles of CarE gene CpCE-1 at different developmental stages and in different tissues of C. pomonella, as well as the larvae exposed to chlorpyrifos-ethyl and lambda-cyhalothrin by using absolute real-time quantitative PCR (absolute RT-qPCR). Results indicated that CpCE-1 expression was significantly altered during C. pomonella development stages, and this expression differed between sexes, with a higher transcript in females than males. Meanwhile, CpCE-1 is overexpressed in cuticle, midgut and head than silk gland, fat body and Malpighian tubules. Exposure of third instar larvae to a non-lethal dosage of chlorpyrifos-ethyl and lambda-cyhalothrin resulted in induction of CpCE-1 transcript. The total carboxylesterase enzyme activity was inhibited by chlorpyrifos-ethyl in vivo; in contrast, the activity of Escherichia coli produced recombinant CpCE-1 was significantly inhibited by both lambda-cyhalothrin and chlorpyrifos-ethyl in vitro. These results suggested that CpCE-1 in C. pomonella is potentially involved in the development and in detoxification of chlorpyrifos-ethyl and lambda-cyhalothrin.

  16. Chromate tolerance and accumulation in Chlorella vulgaris L.: role of antioxidant enzymes and biochemical changes in detoxification of metals.

    Science.gov (United States)

    Rai, U N; Singh, N K; Upadhyay, A K; Verma, S

    2013-05-01

    A concentration-dependent increase in activity of antioxidant enzymes (catalase, ascorbate peroxidase, glutathione, superoxide dismutase) and carotenoid, MDA level have been observed in the green alga Chlorella vulgaris following chromium exposure at different concentrations (0.01-100 μg ml(-1)). Simultaneously, decrease in growth rate, chlorophyll and protein contents was observed. In case of ascorbate peroxidase, glutathione peroxidase and superoxide dismutase a bell shaped dose response was evident, however, lipid peroxidation followed a linear relationship along with catalase activity, which could be used as biomarker of Cr toxicity and played important role in providing tolerance and subsequently, high accumulation potential of chromium in C. vulgaris. In present investigation, the green alga C. vulgaris respond better under chromium stress in terms of tolerance, growth and metal accumulating potential at higher concentration of Cr (VI) which could be employed in decontamination of chromium for environmental cleanup.

  17. Ensemble perspective for catalytic promiscuity: calorimetric analysis of the active site conformational landscape of a detoxification enzyme.

    Science.gov (United States)

    Honaker, Matthew T; Acchione, Mauro; Sumida, John P; Atkins, William M

    2011-12-09

    Enzymological paradigms have shifted recently to acknowledge the biological importance of catalytic promiscuity. However, catalytic promiscuity is a poorly understood property, and no thermodynamic treatment has described the conformational landscape of promiscuous versus substrate-specific enzymes. Here, two structurally similar glutathione transferase (GST, glutathione S-transferase) isoforms with high specificity or high promiscuity are compared. Differential scanning calorimetry (DSC) indicates a reversible low temperature transition for the promiscuous GSTA1-1 that is not observed with substrate-specific GSTA4-4. This transition is assigned to rearrangement of the C terminus at the active site of GSTA1-1 based on the effects of ligands and mutations. Near-UV and far-UV circular dichroism indicate that this transition is due to repacking of tertiary contacts with the remainder of the subunit, rather than "unfolding" of the C terminus per se. Analysis of the DSC data using a modified Landau theory indicates that the local conformational landscape of the active site of GSTA1-1 is smooth, with barrierless transitions between states. The partition function of the C-terminal states is a broad unimodal distribution at all temperatures within this DSC transition. In contrast, the remainder of the GSTA1-1 subunit and the GSTA4-4 protein exhibit folded and unfolded macrostates with a significant energy barrier separating them. Their partition function includes a sharp unimodal distribution of states only at temperatures that yield either folded or unfolded macrostates. At intermediate temperatures the partition function includes a bimodal distribution. The barrierless rearrangement of the GSTA1-1 active site within a local smooth energy landscape suggests a thermodynamic basis for catalytic promiscuity.

  18. Mechanistic Enzymology of the Radical SAM Enzyme DesII.

    Science.gov (United States)

    Ruszczycky, Mark W; Liu, Hung-Wen

    2015-04-01

    DesII is a member of the radical SAM family of enzymes that catalyzes radical-mediated transformations of TDP-4-amino-4,6-didexoy-D-glucose as well as other sugar nucleotide diphosphates. Like nearly all radical SAM enzymes, the reactions begin with the reductive homolysis of SAM to produce a 5'-deoxyadenosyl radical which is followed by regiospecific hydrogen atom abstraction from the substrate. What happens next, however, depends on the nature of the substrate radical so produced. In the case of the biosynthetically relevant substrate, a radical-mediated deamination ensues; however, when this amino group is replaced with a hydroxyl, one instead observes dehydrogenation. The factors that govern the fate of the initially generated substrate radical as well as the mechanistic details underlying these transformations have been a key focus of research into the chemistry of DesII. This review will discuss recent discoveries pertaining to the enzymology of DesII, how it may relate to understanding other radical-mediated lyases and dehydrogenases and the working hypotheses currently being investigated regarding the mechanism of DesII catalysis.

  19. The effect of Beauveria brongniartii and its secondary metabolites on the detoxification enzymes of the pine caterpillar, Dendrolimus tabulaeformis.

    Science.gov (United States)

    Fan, Jinhua; Xie, Yingping; Xue, Jiaoliang; Liu, Rui

    2013-01-01

    The mortality of pine caterpillar, Dendrolimus tabulaeformis Tsai et Liu (Lepidoptera: Lasiocampidae), larvae treated with Beauveria brongniartii (Saccardo) Petch (Hypocreales: Clavicipitaceae) conidia and cell-free culture supernatants enriched for the secondary metabolites of the fungus was investigated. In addition, the effects of the treatments on the activities of two insect-related defense response proteins, glutathione S-transferase (GST) and esterase (EST), were measured over time. Bioassays were performed using a range of fungal spore (6 × 10⁵ through 6 × 10⁷ spores/mL) and supernatant extract concentrations (5.5-550 µg/mL). The results showed that the mortalities of D. tabulaeformis larvae were closely related to the concentration of the conidia and the metabolites of B. brongniartii. The differences among the treatments all reached a significant level. The activities of the two detoxifying enzymes, GST and EST, in the larvae increased simultaneously post-treatment. After infection with the conidial suspensions, the highest GST activity appeared at 3 days, and the activities of the caterpillars infected with 6 × 10⁶ spores/mL and 6 × 10⁷ spores/mL were significantly higher than in the control. Using α-naphthyl, the highest activity of EST also appeared at 3 days, and the differences for the three different concentrations were significant. A similar trend of change in the EST activity was observed using β-naphthyl. After treatment with the secondary metabolite solution, the highest GST activity appeared at 6 hr, and significant differences were found both for the different durations (2, 4, 6, 12, 24, and 48 hr) and in the three concentration groups. When using α-naphthyl, the EST activity peak appeared at 24 hr, and the differences were significant among the durations of 2, 4, 6, 12, 24, and 48 hr. The effect of the concentration of the secondary metabolite solution notably induced the EST activity in the insects, and a similar result was

  20. Effect of the combined probiotics with aflatoxin B₁-degrading enzyme on aflatoxin detoxification, broiler production performance and hepatic enzyme gene expression.

    Science.gov (United States)

    Zuo, Rui-yu; Chang, Juan; Yin, Qing-qiang; Wang, Ping; Yang, Yu-rong; Wang, Xiao; Wang, Guo-qiang; Zheng, Qiu-hong

    2013-09-01

    In order to degrade aflatoxin B₁ (AFB₁), AFB₁-degrading microbes (probiotics) such as Lactobacillus casei, Bacillus subtilis and Pichia anomala, and the AFB₁-degrading enzyme from Aspergillus oryzae were selected and combined to make feed additive. Seventy-five 43-day-old male Arbor Acres broilers were randomly divided into 5 groups, 15 broilers for each group. The broilers were given with 5 kinds of diets such as the basal diet, 400 μg/kg AFB₁ supplement without feed additive, and 200, 400, 800 μg/kg AFB₁ supplement with 0.15% feed additive. The feeding experimental period was 30 d, which was used to determine production performance of broilers. In addition, serum, liver and chest muscle were selected for measuring AFB₁ residues, gene expressions, microscopic and antioxidant analyses. The results showed that adding 0.15% feed additive in broiler diets could significantly relieve the negative effect of AFB₁ on chicken's production performance and nutrient metabolic rates (P<0.05). It could also improve AFB₁ metabolism, hepatic cell structure, antioxidant activity, and many hepatic enzyme gene expressions involved in oxidoreductase, apoptosis, cell growth, immune system and metabolic process (P<0.05). It could be concluded that the feed additive was able to degrade AFB₁ and improve animal production.

  1. Action of Halowax 1051 on Enzymes of Phase I (CYP1A1 and Phase II (SULT1A and COMT Metabolism in the Pig Ovary

    Directory of Open Access Journals (Sweden)

    Justyna Barć

    2013-01-01

    Full Text Available Polychlorinated naphthalenes (PCNs are a group of organochlorinated compounds exhibiting dioxin-like properties. Previously published data showed the direct action of PCN-rich Halowax 1051 on ovarian follicular steroidogenesis. Taking into consideration that the observed biological effects of PCNs may be frequently side effects of metabolites generated by their detoxification, the aim of this study was to determine the activity and expression of enzymes involved in phase I (cytochrome P450, family 1 (CYP1A1 and phase II (sulfotransferase (SULT1A and catechol-O-methyltransferase (COMT detoxification metabolism. Cocultures of granulosa and theca interna cells collected from sexually mature pigs were exposed to 1 pg/mL to 10 ng/mL of Halowax 1051 for 1 to 48 hours, after which levels and activities of CYP1A1, SULT1A, and COMT were measured. Dose-dependent increases of CYP1A1 activity and expression were observed. High doses of Halowax 1051 were inhibitory to COMT and SULT1A activity and reduced their protein levels. In conclusion, fast activation of phase I enzymes with simultaneous inhibition of phase II enzymes indicates that the previously observed effect of Halowax 1051 on follicular steroidogenesis may partially result from metabolite action occurring locally in ovarian follicles.

  2. II-Q restriction endonucleases--new class of type II enzymes.

    Science.gov (United States)

    Degtyarev, S K; Rechkunova, N I; Kolyhalov, A A; Dedkov, V S; Zhilkin, P A

    1990-10-11

    Unique restriction endonucleases Bpu 10l and Bsil have been isolated from Bacillus pumilas and Bacillus sphaericus, respectively. The recognition sequences and cleavage points of these enzymes have been determinated as 5'-CC1TNAGC-3'/3'-GGANT1CG-5' for Bpu 10l and 5'-C1TCGTG-3'/3'-GAGCA1C-5' for Bsil. Restriction endonucleases Bpu 10l and Bsil represent a new class of enzymes which recognize non-palindromic nucleotide sequences and hydrolize DNA within the recognition sequence. Bpu 10l and Bsil recognition sequences may be regarded as quasipalindromic and the enzymes may be designated as type II-Q restriction endonucleases.

  3. Photolithographically patterned enzyme membranes for the detection of pesticides and copper(II) based on enzyme inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Zuern, A. (Inst. fuer Analytik und Umweltchemie, Univ. Halle, FB Chemie, Merseburg (Germany)); Mueller, H. (Inst. fuer Analytik und Umweltchemie, Univ. Halle, FB Chemie, Merseburg (Germany))

    A non-aqueous and an aqueous photopolymer system with an enzyme are used to prepare photolithographically patterned enzyme membranes for amperometric (thinfilm platinum electrode) and potentiometric (ISFET) sensors based on enzyme inhibition. Flow methods for enzyme inhibition tests are described. The decrease in enzyme (AChE) activity after incubation in a solution of dichlorvos as inhibitor is detected amperometrically. The enzyme urease is immobilized onto the pH-sensitive gate area of an ISFET. Such a biosensor is able to detect copper(II) in water in the ppm-range without preconcentration. (orig.)

  4. Restriction enzyme body doubles and PCR cloning: on the general use of type IIs restriction enzymes for cloning.

    Directory of Open Access Journals (Sweden)

    Eszter Tóth

    Full Text Available The procedure described here allows the cloning of PCR fragments containing a recognition site of the restriction endonuclease (Type IIP used for cloning in the sequence of the insert. A Type IIS endonuclease--a Body Double of the Type IIP enzyme--is used to generate the same protruding palindrome. Thus, the insert can be cloned to the Type IIP site of the vector without digesting the PCR product with the same Type IIP enzyme. We achieve this by incorporating the recognition site of a Type IIS restriction enzyme that cleaves the DNA outside of its recognition site in the PCR primer in such a way that the cutting positions straddle the desired overhang sequence. Digestion of the PCR product by the Body Double generates the required overhang. Hitherto the use of Type IIS restriction enzymes in cloning reactions has only been used for special applications, the approach presented here makes Type IIS enzymes as useful as Type IIP enzymes for general cloning purposes. To assist in finding Body Double enzymes, we summarised the available Type IIS enzymes which are potentially useful for Body Double cloning and created an online program (http://group.szbk.u-szeged.hu/welkergr/body_double/index.html for the selection of suitable Body Double enzymes and the design of the appropriate primers.

  5. Restriction enzyme body doubles and PCR cloning: on the general use of type IIs restriction enzymes for cloning.

    Science.gov (United States)

    Tóth, Eszter; Huszár, Krisztina; Bencsura, Petra; Kulcsár, Péter István; Vodicska, Barbara; Nyeste, Antal; Welker, Zsombor; Tóth, Szilvia; Welker, Ervin

    2014-01-01

    The procedure described here allows the cloning of PCR fragments containing a recognition site of the restriction endonuclease (Type IIP) used for cloning in the sequence of the insert. A Type IIS endonuclease--a Body Double of the Type IIP enzyme--is used to generate the same protruding palindrome. Thus, the insert can be cloned to the Type IIP site of the vector without digesting the PCR product with the same Type IIP enzyme. We achieve this by incorporating the recognition site of a Type IIS restriction enzyme that cleaves the DNA outside of its recognition site in the PCR primer in such a way that the cutting positions straddle the desired overhang sequence. Digestion of the PCR product by the Body Double generates the required overhang. Hitherto the use of Type IIS restriction enzymes in cloning reactions has only been used for special applications, the approach presented here makes Type IIS enzymes as useful as Type IIP enzymes for general cloning purposes. To assist in finding Body Double enzymes, we summarised the available Type IIS enzymes which are potentially useful for Body Double cloning and created an online program (http://group.szbk.u-szeged.hu/welkergr/body_double/index.html) for the selection of suitable Body Double enzymes and the design of the appropriate primers.

  6. Structural basis of Zn(II) induced metal detoxification and antibiotic resistance by histidine kinase CzcS in Pseudomonas aeruginosa.

    Science.gov (United States)

    Wang, Dan; Chen, Weizhong; Huang, Shanqing; He, Yafeng; Liu, Xichun; Hu, Qingyuan; Wei, Tianbiao; Sang, Hong; Gan, Jianhua; Chen, Hao

    2017-07-01

    Pseudomonas aeruginosa (P. aeruginosa) is a major opportunistic human pathogen, causing serious nosocomial infections among immunocompromised patients by multi-determinant virulence and high antibiotic resistance. The CzcR-CzcS signal transduction system in P. aeruginosa is primarily involved in metal detoxification and antibiotic resistance through co-regulating cross-resistance between Zn(II) and carbapenem antibiotics. Although the intracellular regulatory pathway is well-established, the mechanism by which extracellular sensor domain of histidine kinase (HK) CzcS responds to Zn(II) stimulus to trigger downstream signal transduction remains unclear. Here we determined the crystal structure of the CzcS sensor domain (CzcS SD) in complex with Zn(II) at 1.7 Å resolution. This is the first three-dimensional structural view of Zn(II)-sensor domain of the two-component system (TCS). The CzcS SD is of α/β-fold in nature, and it senses the Zn(II) stimulus at micromole level in a tetrahedral geometry through its symmetry-related residues (His55 and Asp60) on the dimer interface. Though the CzcS SD resembles the PhoQ-DcuS-CitA (PDC) superfamily member, it interacts with the effector in a novel domain with the N-terminal α-helices rather than the conserved β-sheets pocket. The dimerization of the N-terminal H1 and H1' α-helices is of primary importance for the activity of HK CzcS. This study provides preliminary insight into the molecular mechanism of Zn(II) sensing and signaling transduction by the HK CzcS, which will be beneficial to understand how the pathogen P. aeruginosa resists to high levels of heavy metals and antimicrobial agents.

  7. Structural basis of Zn(II induced metal detoxification and antibiotic resistance by histidine kinase CzcS in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2017-07-01

    Full Text Available Pseudomonas aeruginosa (P. aeruginosa is a major opportunistic human pathogen, causing serious nosocomial infections among immunocompromised patients by multi-determinant virulence and high antibiotic resistance. The CzcR-CzcS signal transduction system in P. aeruginosa is primarily involved in metal detoxification and antibiotic resistance through co-regulating cross-resistance between Zn(II and carbapenem antibiotics. Although the intracellular regulatory pathway is well-established, the mechanism by which extracellular sensor domain of histidine kinase (HK CzcS responds to Zn(II stimulus to trigger downstream signal transduction remains unclear. Here we determined the crystal structure of the CzcS sensor domain (CzcS SD in complex with Zn(II at 1.7 Å resolution. This is the first three-dimensional structural view of Zn(II-sensor domain of the two-component system (TCS. The CzcS SD is of α/β-fold in nature, and it senses the Zn(II stimulus at micromole level in a tetrahedral geometry through its symmetry-related residues (His55 and Asp60 on the dimer interface. Though the CzcS SD resembles the PhoQ-DcuS-CitA (PDC superfamily member, it interacts with the effector in a novel domain with the N-terminal α-helices rather than the conserved β-sheets pocket. The dimerization of the N-terminal H1 and H1' α-helices is of primary importance for the activity of HK CzcS. This study provides preliminary insight into the molecular mechanism of Zn(II sensing and signaling transduction by the HK CzcS, which will be beneficial to understand how the pathogen P. aeruginosa resists to high levels of heavy metals and antimicrobial agents.

  8. Enzyme replacement therapy (ERT) procedure for mucopolysaccharidosis type II (MPS II) by intraventricular administration (IVA) in murine MPS II.

    Science.gov (United States)

    Higuchi, Takashi; Shimizu, Hiromi; Fukuda, Takahiro; Kawagoe, Shiho; Matsumoto, Juri; Shimada, Yohta; Kobayashi, Hiroshi; Ida, Hiroyuki; Ohashi, Toya; Morimoto, Hideto; Hirato, Tohru; Nishino, Katsuya; Eto, Yoshikatsu

    2012-09-01

    Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS) and is characterized by the accumulation of glycosaminoglycans (GAGs). MPS II has been treated by hematopoietic stem cell therapy (HSCT)/enzyme replacement therapy (ERT), but its effectiveness in the central nervous system (CNS) is limited because of poor enzyme uptake across the blood-brain barrier (BBB). To increase the efficacy of ERT in the brain, we tested an intraventricular ERT procedure consisting of repeated administrations of IDS (20 μg/mouse/3 weeks) in IDS-knockout, MPS II model mice. The IDS enzyme activity and the accumulation of total GAGs were measured in mouse brains. The IDS activity was significantly increased, and the accumulation of total GAGs was decreased in the MPS II mouse brains treated with multiple administrations of IDS via intraventricular ERT. Additionally, a high level of IDS enzyme activity was appreciated in other MPS II mouse tissues, such as the liver, spleen, testis and others. A Y-maze was used to test learning and memory after repeated intraventricular ERT with IDS. The IDS-treated mouse groups recovered the capacity for short-term memory and activity. Although large and small vacuoles were found at the margin of the cerebellar Purkinje cells in the disease-control mice, these vacuoles disappeared upon treated with IDS. Loss of vacuoles was also observed in other tissues (liver, kidney and testis). These results demonstrate the possible efficacy of an ERT procedure with intraventricular administration of IDS for the treatment of MPS II. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  9. Sulfide detoxification in plant mitochondria.

    Science.gov (United States)

    Birke, Hannah; Hildebrandt, Tatjana M; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    In contrast to animals, which release the signal molecule sulfide in small amounts from cysteine and its derivates, phototrophic eukaryotes generate sulfide as an essential intermediate of the sulfur assimilation pathway. Additionally, iron-sulfur cluster turnover and cyanide detoxification might contribute to the release of sulfide in mitochondria. However, sulfide is a potent inhibitor of cytochrome c oxidase in mitochondria. Thus, efficient sulfide detoxification mechanisms are required in mitochondria to ensure adequate energy production and consequently survival of the plant cell. Two enzymes have been recently described to catalyze sulfide detoxification in mitochondria of Arabidopsis thaliana, O-acetylserine(thiol)lyase C (OAS-TL C), and the sulfur dioxygenase (SDO) ethylmalonic encephalopathy protein 1 (ETHE1). Biochemical characterization of sulfide producing and consuming enzymes in mitochondria of plants is fundamental to understand the regulatory network that enables mitochondrial sulfide homeostasis under nonstressed and stressed conditions. In this chapter, we provide established protocols to determine the activity of the sulfide releasing enzyme β-cyanoalanine synthase as well as sulfide-consuming enzymes OAS-TL and SDO. Additionally, we describe a reliable and efficient method to purify OAS-TL proteins from plant material.

  10. Long-term effects of a novel phosphorothionate (RPR-II) on detoxifying enzymes in brain, lung, and kidney rats.

    Science.gov (United States)

    Mahboob, M; Siddiqui, M K J

    2002-11-01

    The effects of a phosphorothionate, 2-butenoic acid-3-(diethoxyphosphinothioyl) methyl ester (RPR-II), on the activities of glutathione S-transferase (GST) and UDP-glucuronyltransferase (UDPGT) and the level of glutathione (GSH) were evaluated in rats after administration of RPR-II at 0.014 (low), 0.028 (medium), and 0.042 (high) mgkg(-1)day(-1) for 90 days and also at 28 days (withdrawal) after stopping treatment. Brain GST activity and GSH level decreased significantly at the high dose on the 45th and 90th days of treatment. Dose- and time-dependent decreases in GST activity and GSH was level were observed in lung at medium and high doses and in kidneys at all three doses on both the 45th and 90th days. UDPGT activity increased significantly in kidneys at the medium and high doses at 45 and 90 days. Brain and lung did not display any significant variations in UDPGT activity when compared with the control. Interestingly, the withdrawal study revealed that the effect was reversible within 28 days of cessation of treatment, when enzyme activity reverted to levels close to those of controls. The study revealed that RPR-II affected the GSH- and GST-dependent detoxification system of the treated tissues of rat and its potential to modulate the enzymes is in the order kidneys>lung>brain. The present subacute study suggests that RPR-II may bring about physiological upsets by altering GSH- and GST-dependent events in different tissues of exposed organisms.

  11. Protein film photoelectrochemistry of the water oxidation enzyme photosystem II.

    Science.gov (United States)

    Kato, Masaru; Zhang, Jenny Z; Paul, Nicholas; Reisner, Erwin

    2014-09-21

    Photosynthesis is responsible for the sunlight-powered conversion of carbon dioxide and water into chemical energy in the form of carbohydrates and the release of O2 as a by-product. Although many proteins are involved in photosynthesis, the fascinating machinery of Photosystem II (PSII) is at the heart of this process. This tutorial review describes an emerging technique named protein film photoelectrochemistry (PF-PEC), which allows for the light-dependent activity of PSII adsorbed onto an electrode surface to be studied. The technique is straightforward to use, does not require highly specialised and/or expensive equipment, is highly selective for the active fractions of the adsorbed enzyme, and requires a small amount of enzyme sample. The use of PF-PEC to study PSII can yield insights into its activity, stability, quantum yields, redox behaviour, and interfacial electron transfer pathways. It can also be used in PSII inhibition studies and chemical screening, which may prove useful in the development of biosensors. PSII PF-PEC cells also serve as proof-of-principle solar water oxidation systems; here, a comparison is made against PSII-inspired synthetic photocatalysts and materials for artificial photosynthesis.

  12. Modulatory Effect of Taurine on 7,12-Dimethylbenz(a)Anthracene-Induced Alterations in Detoxification Enzyme System, Membrane Bound Enzymes, Glycoprotein Profile and Proliferative Cell Nuclear Antigen in Rat Breast Tissue.

    Science.gov (United States)

    Vanitha, Manickam Kalappan; Baskaran, Kuppusamy; Periyasamy, Kuppusamy; Selvaraj, Sundaramoorthy; Ilakkia, Aruldoss; Saravanan, Dhiravidamani; Venkateswari, Ramachandran; Revathi Mani, Balasundaram; Anandakumar, Pandi; Sakthisekaran, Dhanapal

    2016-08-01

    The modulatory effect of taurine on 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer in rats was studied. DMBA (25 mg/kg body weight) was administered to induce breast cancer in rats. Protein carbonyl levels, activities of membrane bound enzymes (Na(+) /K(+) ATPase, Ca(2+) ATPase, and Mg(2+) ATPase), phase I drug metabolizing enzymes (cytochrome P450, cytochrome b5, NADPH cytochrome c reductase), phase II drug metabolizing enzymes (glutathione-S-transferase and UDP-glucuronyl transferase), glycoprotein levels, and proliferative cell nuclear antigen (PCNA) were studied. DMBA-induced breast tumor bearing rats showed abnormal alterations in the levels of protein carbonyls, activities of membrane bound enzymes, drug metabolizing enzymes, glycoprotein levels, and PCNA protein expression levels. Taurine treatment (100 mg/kg body weight) appreciably counteracted all the above changes induced by DMBA. Histological examination of breast tissue further supported our biochemical findings. The results of the present study clearly demonstrated the chemotherapeutic effect of taurine in DMBA-induced breast cancer.

  13. Effect of graded Nrf2 activation on phase-I and -II drug metabolizing enzymes and transporters in mouse liver.

    Directory of Open Access Journals (Sweden)

    Kai Connie Wu

    Full Text Available Nuclear factor erythroid 2-related factor 2 (Nrf2 is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1 sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S-transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification.

  14. Overexpression of multiple detoxification genes in deltamethrin resistant Laodelphax striatellus (Hemiptera: Delphacidae in China.

    Directory of Open Access Journals (Sweden)

    Lu Xu

    Full Text Available BACKGROUND: The small brown planthopper (SBPH, Laodelphax striatellus (Fallén, is one of the major rice pests in Asia and has developed resistance to multiple classes of insecticides. Understanding resistance mechanisms is essential to the management of this pest. Biochemical and molecular assays were performed in this study to systematically characterize deltamethrin resistance mechanisms with laboratory-selected resistant and susceptible strains of SBPH. METHODOLOGY/PRINCIPAL FINDINGS: Deltamethrin resistant strains of SBPH (JH-del were derived from a field population by continuously selections (up to 30 generations in the laboratory, while a susceptible strain (JHS was obtained from the same population by removing insecticide pressure for 30 generations. The role of detoxification enzymes in the resistance was investigated using synergism and enzyme activity assays with strains of different resistant levels. Furthermore, 71 cytochrome P450, 93 esterases and 12 glutathione-S-transferases cDNAs were cloned based on transcriptome data of a field collected population. Semi-quantitative RT-PCR screening analysis of 176 identified detoxification genes demonstrated that multiple P450 and esterase genes were overexpressed (>2-fold in JH-del strains (G4 and G30 when compared to that in JHS, and the results of quantitative PCR coincided with the semi-quantitative RT-PCR results. Target mutation at IIS3-IIS6 regions encoded by the voltage-gated sodium channel gene was ruled out for conferring the observed resistance. CONCLUSION/SIGNIFICANCE: As the first attempt to discover genes potentially involved in SBPH pyrethroid resistance, this study putatively identified several candidate genes of detoxification enzymes that were significantly overexpressed in the resistant strain, which matched the synergism and enzyme activity testing. The biochemical and molecular evidences suggest that the high level pyrethroid resistance in L. striatellus could be due to

  15. Potential applications of the oxidoreductive enzymes in the decolorization and detoxification of textile and other synthetic dyes from polluted water: a review.

    Science.gov (United States)

    Husain, Qayyum

    2006-01-01

    Recently, the enzymatic approach has attracted much interest in the decolorization/degradation of textile and other industrially important dyes from wastewater as an alternative strategy to conventional chemical, physical and biological treatments, which pose serious limitations. Enzymatic treatment is very useful due to the action of enzymes on pollutants even when they are present in very dilute solutions and recalcitrant to the action of various microbes participating in the degradation of dyes. The potential of the enzymes (peroxidases, manganese peroxidases, lignin peroxidases, laccases, microperoxidase-11, polyphenol oxidases, and azoreductases) has been exploited in the decolorization and degradation of dyes. Some of the recalcitrant dyes were not degraded/decolorized in the presence of such enzymes. The addition of certain redox mediators enhanced the range of substrates and efficiency of degradation of the recalcitrant compounds. Several redox mediators have been reported in the literature, but very few of them are frequently used (e.g., 1-hydroxybenzotriazole, veratryl alcohol, violuric acid, 2-methoxy-phenothiazone). Soluble enzymes cannot be exploited at the large scale due to limitations such as stability and reusability. Therefore, the use of immobilized enzymes has significant advantages over soluble enzymes. In the near future, technology based on the enzymatic treatment of dyes present in the industrial effluents/wastewater will play a vital role. Treatment of wastewater on a large scale will also be possible by using reactors containing immobilized enzymes.

  16. New modified β-cyclodextrin derivatives as detoxifying agents of chemical warfare agents (II). In vitro detoxification of cyclosarin (GF): general screening and toxicokinetic aspects of OP scavengers.

    Science.gov (United States)

    Müller, Susanne; Estour, François; Kalakuntla, Raman Kumar; Le Provost, Romain; Lafont, Olivier; Worek, Franz; Thiermann, Horst; Reiter, Georg

    2013-02-04

    As standard therapy of intoxication with organophosphorus (OP) compounds is still insufficient, developing new treatment strategies is urgently required. For evaluating potential of OP detoxification of several compounds correctly, different toxicodynamic impact of OP enantiomers has to be considered thoroughly. It has already been demonstrated that β-cyclodextrin (β-CD) derivatives with attached nucleophilic substituent iodosobenzoic acid (IBA) can be regarded as potent OP scavengers due to an accelerating effect on decay of different OP. Herein, six CD derivatives permethylated or not on CD torus as well as differently attached nucleophilic substituent IBA derivative were investigated regarding detoxification of GF as an OP model substance. Acceleration of GF detoxification could be detected for all compounds with highest rate constants for propylene chain linked nucleophilic substituents on CD derivative. In addition, fast initial binding of GF on CD could be observed and is ascribed to formation of CD complexes. Furthermore, terminal plateau phase was detected of about 1% of each enantiomer reflecting the necessity of a quantitative determination at low concentrations. Moreover, this molecular depot formation may represent an additional detoxification pathway for OP. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Endonuclease specificity and sequence dependence of type IIS restriction enzymes.

    Directory of Open Access Journals (Sweden)

    Sverker Lundin

    Full Text Available Restriction enzymes that recognize specific sequences but cleave unknown sequence outside the recognition site are extensively utilized tools in molecular biology. Despite this, systematic functional categorization of cleavage performance has largely been lacking. We established a simple and automatable model system to assay cleavage distance variation (termed slippage and the sequence dependence thereof. We coupled this to massively parallel sequencing in order to provide sensitive and accurate measurement. With this system 14 enzymes were assayed (AcuI, BbvI, BpmI, BpuEI, BseRI, BsgI, Eco57I, Eco57MI, EcoP15I, FauI, FokI, GsuI, MmeI and SmuI. We report significant variation of slippage ranging from 1-54%, variations in sequence context dependence, as well as variation between isoschizomers. We believe this largely overlooked property of enzymes with shifted cleavage would benefit from further large scale classification and engineering efforts seeking to improve performance. The gained insights of in-vitro performance may also aid the in-vivo understanding of these enzymes.

  18. Endonuclease specificity and sequence dependence of type IIS restriction enzymes.

    Science.gov (United States)

    Lundin, Sverker; Jemt, Anders; Terje-Hegge, Finn; Foam, Napoleon; Pettersson, Erik; Käller, Max; Wirta, Valtteri; Lexow, Preben; Lundeberg, Joakim

    2015-01-01

    Restriction enzymes that recognize specific sequences but cleave unknown sequence outside the recognition site are extensively utilized tools in molecular biology. Despite this, systematic functional categorization of cleavage performance has largely been lacking. We established a simple and automatable model system to assay cleavage distance variation (termed slippage) and the sequence dependence thereof. We coupled this to massively parallel sequencing in order to provide sensitive and accurate measurement. With this system 14 enzymes were assayed (AcuI, BbvI, BpmI, BpuEI, BseRI, BsgI, Eco57I, Eco57MI, EcoP15I, FauI, FokI, GsuI, MmeI and SmuI). We report significant variation of slippage ranging from 1-54%, variations in sequence context dependence, as well as variation between isoschizomers. We believe this largely overlooked property of enzymes with shifted cleavage would benefit from further large scale classification and engineering efforts seeking to improve performance. The gained insights of in-vitro performance may also aid the in-vivo understanding of these enzymes.

  19. Bioefficacy of Alpinia galanga (Zingiberaceae) rhizome extracts, (E)-p-acetoxycinnamyl alcohol, and (E)-p-coumaryl alcohol ethyl ether against Bactrocera dorsalis (Diptera: Tephritidae) and the impact on detoxification enzyme activities.

    Science.gov (United States)

    Sukhirun, N; Pluempanupat, W; Bullangpoti, V; Koul, O

    2011-10-01

    The application of insecticides to control oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), is a principal component of the current management of these fruit flies. However, we evaluated four extracts of Alpinia galanga Wild Linn (Zingiberaceae) rhizomes against adult flies and found hexane and ethanol extracts to be most effective (LC50 = 4,866 and 6,337 ppm, respectively, after 24 h). This suggested that both nonpolar and polar compounds could be active in the candidate plant. Accordingly, the hexane extract was further processed to isolate nonpolar active compounds from this plant source. Two compounds, (E)-p-acetoxycinnamyl alcohol and (E)-p-coumaryl alcohol ethyl ether, were identified as active ingredients and found to be more active than total hexane extract (LC50 = 3,654 and 4,044 ppm, respectively, after 24 h). The data suggested that the compounds were not synergistic but may have some additive effect in a mixture. The activity of the hexane extract against detoxification enzymes, carboxylesterase (CE) and glutathione transferase (GST) also was determined in vitro. CE was inhibited by 70%, whereas GST was not significantly inhibited. Insect CEs mediate insecticide resistance via their induction; therefore, inhibition of these enzymes by plant allelochemicals could be a useful alternative approach for the management of the pest in the field.

  20. Complete Detoxification of Short Chain Chlorinated Aliphatic Compounds: Isolation of Halorespiring Organisms and Biochemical Studies of the Dehalogenating Enzyme Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tiedje, J.M.

    1999-10-01

    Work focused on the isolation and characterization of halorespiring populations, and the initial investigation of the dechlorinating enzyme systems. In addition, tools to evaluate the presence/activity to halorespiring populations in the environment were developed. The tools developed in this work (measurements of hydrogen consumption thresholds, molecular probes) are relevant for regulatory agencies in order to facilitate decisions on which bioremediation technology (biostimulation or bioaugmentation) is most promising at a particular site. In addition, a better understanding of the physiology of the halorespiring organisms as well as the biochemistry of the dehalogenating enzyme systems enhances our knowledge of how these organisms can successfully be employed in the bioremediation of contaminated sites.

  1. 杀虫剂处理对水稻负泥虫体内解毒酶的影响%Effects of Pesticides Treatment on the Activity of Detoxification Enzymes in the Larvae of O. oryzae

    Institute of Scientific and Technical Information of China (English)

    于磊; 王丽艳; 张海燕

    2011-01-01

    [目的]研究不同杀虫剂对水稻负泥虫(Oulema onzae)体内解毒酶的影响.[方法]以水稻负泥虫为研究对象,分析幼虫在高效氯氰菊酯、阿维菌素和吡虫啉3种杀虫剂处理1、4、9和15 d后,幼虫体内羧酸酯酶及谷胱甘肽转移酶活性变化.[结果]随着取食时间的延长,3种药剂处理的幼虫体内羧酸酯酶活性均较对照增高,且差异明显;而3种药剂处理的谷胱甘肤转移酶活性均低于对照,但差异不明显.[结论]解毒酶的变化在害虫抵抗杀虫剂处理过程中起到指示作用,该研究可为水稻负泥虫抗药性研究奠定基础.%[ Objective ] The aim was to study the effects of different pesticides on the activity of detoxification enzymes in the larvae of O.oryzae. [ Method ] As the model of the larvae of O. oryzae, the change of carboxylesterase and glutathione transferase in larvaes fed with rice leaves treated 1, 4, 9 and 15 days by 3 insecticides, beta-cypermethrin, abamectin and imidacloprid, were analyzed. [ Result ] The results showed that carboxylesterase activity of 3 insecticides treatments in the larvae was higher than the control with the time increased, and the difference among 3 insecticides treatments was significant. While glutathione transferase activity of 3 insecticides treatments in the larvae was lower than the control with the time increased, but the difference among 3 insecticides treatments was no significant. [ Conclusion ] Detoxification enzymes can acted as markers in the process of insecticide pest control. The study can lay a basis for researching of the resistance mechanisms to insecticides of O. oryzae.

  2. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  3. Detoxification enzyme activities (CYP1A1 and GST) in the skin of humpback whales as a function of organochlorine burdens and migration status.

    Science.gov (United States)

    Bengtson Nash, S; Dawson, A; Burkhard, M; Waugh, C; Huston, W

    2014-10-01

    The activities of glutathione-s-transferase (GST) and cytochrome P-450 1A1 (CYP1A1) enzymes were measured in freshly extracted epidermis of live-biopsied, migrating, southern hemisphere humpback whales (Megaptera novaeangliae). The two quantified enzyme activities did not correlate strongly with each other. Similarly, neither correlated strongly with any of the organochlorine compound groups previously measured in the superficial blubber of the sample biopsy core, likely reflecting the anticipated low levels of typical aryl-hydrocarbon receptor ligands. GST activity did not differ significantly between genders or between northward (early migration) or southward (late migration) migrating cohorts. Indeed, the inter-individual variability in GST measurements was relatively low. This observation raises the possibility that measured activities were basal activities and that GST function was inherently impacted by the fasting state of the sampled animals, as seen in other species. These results do not support the implementation of CYP1A1 or GST as effective biomarkers of organochlorine contaminant burdens in southern hemisphere populations of humpback whales as advocated for other cetacean species. Further investigation of GST activity in feeding versus fasting cohorts may, however, provide some insight into the fasting metabolism of these behaviourally adapted populations.

  4. Angiotensin converting enzyme gene polymorphism in type II diabetics with nephropathy

    OpenAIRE

    Naresh, V. V. S.; Reddy, A. L. K.; Sivaramakrishna, G.; Sharma, P. V. G. K.; Vardhan, R. V.; Kumar, V. Siva

    2009-01-01

    Nephropathy is an important and a frequent complication of long-term type II diabetic nephropathy. Strong evidence exists that genetic predisposition plays a major role in the development of diabetic nephropathy. Recent studies have implicated association between angiotensin converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and nephropathy. The deletion gene polymorphism of ACE gene has been shown to be associated with increased activity of this enzyme. This study examines th...

  5. Toxicity of cycloxaprid toAphis craccivora (Koch) and its effects on detoxification enzymes%环氧虫啶对苜蓿蚜的毒力及对其体内解毒酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    吴勇超; 须志平; 邵旭升; 程家高; 李忠

    2016-01-01

    为研究桥环新烟碱类化合物对苜蓿蚜的影响,以吡虫啉为对照药剂,采用带虫浸叶法测定了环氧虫啶等桥环新烟碱类化合物对苜蓿蚜的毒力及对其体内解毒酶活性的影响。结果表明:以环氧虫啶为代表的七元桥环新烟碱类化合物对苜蓿蚜具有较好的杀虫活性,其中,环氧虫啶的 LC50值为3.454 mg/L,高于八元桥环新烟碱化合物。酶抑制剂顺丁烯二乙酯(DEM)和胡椒基丁醚(PBO)对环氧虫啶均具有显著的增效作用,增效比分别为4.02和3.22;而对照药剂吡虫啉仅 PBO对其具有明显增效作用。与空白对照组相比,经 LC50浓度环氧虫啶和吡虫啉处理后,存活苜蓿蚜体内谷胱甘肽S-转移酶(GSTs)和细胞色素 P450s活力均显著升高(P <0.05),其中,环氧虫啶处理组 GSTs和 P450s活力分别达到(2.730±0.012)和(0.239±0.009)μmol/(mg pro.·min),诱导能力弱于吡虫啉;而苜蓿蚜体内羧酸酯酶(CarE)活性则无明显变化。研究显示,在苜蓿蚜对环氧虫啶的解毒代谢过程中,GSTs和细胞色素 P450s可能发挥着主要作用。%To investigate the effects of bridged-neonicotinoid compounds onAphis craccivora (Koch), the toxicity of cycloxaprid and the other three bridged-neonicotinoid compounds onA. craccivora and its effects on detoxification enzymes were determined by leaf dipping method using imidacloprid as the control. The results showed that cycloxaprid and other seven-membered bridged neonicotinoid compounds displayed high insecticidal activities againstA. craccivora. The LC50 of cycloxaprid was 3.454 mg/L, which is higher than that of the eight-membered bridged neonicotinoid compounds. The synergistic ratios of enzyme inhibitors DEM and PBO were 4.02 and 3.22, respectively. Both compounds showed remarkable synergistic effects on the toxicity of cycloxaprid, whereas only PBO could significantly enhance the toxicity of imidacloprid. Further enzyme activity

  6. The phylogeny and evolution of deoxyribonuclease II: An enzyme essential for lysosomal DNA degradation

    OpenAIRE

    Shpak, Max; Kugelman, Jeffrey R.; Varela-Ramirez, Armando; Aguilera, Renato J.

    2007-01-01

    Deoxyribonuclease II (DNase II) is an endonuclease with optimal activity at low pH, localized within the lysosomes of higher eukaryotes. The origin of this enzyme remains in dispute, and its phylogenetic distribution leaves many questions about its subsequent evolutionary history open. Earlier studies have documented its presence in various metazoans, as well as in Dictyostelium, Trichomonas and, anomalously, a single genus of bacteria (Burkholderia). This study makes use of searches of the g...

  7. Complete detoxification of short chain chlorinated aliphatic compounds: Isolation of halorespiring organisms and biochemical studies of the dehalogenating enzyme systems. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Tiedje, J.M.

    1998-06-01

    'Widespread use and careless handling, storage and disposal practices, have lead to the dissemination of chlorinated short chain aliphatics into groundwater systems. These compounds are toxic and the presence of chlorinated ethenes and chlorinated propanes in the environment is of public concern. Halorespiration is a newly recognized anaerobic process by which certain bacteria use chlorinated compounds as terminal electron acceptors in their energy metabolism. In contrast to co-metabolic dechlorination, which is fortuitous, slow, and without benefit to the organisms, halorespiration, characterized by high dechlorination rates, is a specific metabolic process beneficial to the organism. The goals are to isolate and characterize organisms which use chlorinated ethenes (including tetrachloroethene [PCE], trichloroethene [TCE], cis-dichloroethene [cis-DCE], and vinyl chloride [VC], or 1,2-dichloropropane [1,2-D]) as electron acceptors in their energy metabolism. Better understanding of the physiology and phylogeny of the halorespiring organisms as well as the biochemistry of the dehalogenating enzyme systems, will greatly enhance the authors knowledge of how these organisms can successfully be employed in the bioremediation of contaminated sites. This report summarizes the results of 1.5 years of a 2-year project. Anaerobic microcosms were established using a variety of geographically distinct sediments. In several microcosms complete dechlorination of PCE to ethene (ETH), and 1,2-D to propene was observed. Upon subsequent transfers to anaerobic medium, four sediment-free, methanogenic enrichment cultures were obtained that dechlorinated PCE to ETH, and two cultures that dechlorinated 1,2-D to propene. 2-Bromoethanesulfonate (BES), a well known inhibitor of methanogens, did not inhibit the dechlorination of 1,2-D to propene or the dechlorination of PCE to cis-DCE. However, the complete dechlorination of PCE to VC and ETH was severely inhibited. They could also

  8. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in patients with abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Kristensen, Karl Emil; Torp-Pedersen, Christian; Gislason, Gunnar Hilmar;

    2015-01-01

    OBJECTIVE: The renin-angiotensin system is thought to play a pivotal role in the pathogenesis of abdominal aortic aneurysms (AAAs). However, effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs) on human AAAs remain unclear. We therefore ex...

  9. Regulation of phase II enzymes by genistein and daidzein in male and female Swiss Webster mice.

    Science.gov (United States)

    Froyen, Erik B; Reeves, Jaime L Rudolf; Mitchell, Alyson E; Steinberg, Francene M

    2009-12-01

    The consumption of soy and soy isoflavones has been associated with a decreased risk of certain cancers. A factor contributing to this dietary chemoprevention is the activity of phase I and II biotransformation enzymes. This study evaluated the hypothesis that dietary soy isoflavones will increase hepatic and extrahepatic quinone reductase (QR), UDP-glucuronosyltransferase (UGT), and glutathione S-transferase (GST) phase II enzyme activities, under short-term feeding and basal (non-pharmacologic-induced) conditions. Male and female Swiss Webster mice were fed for 1, 3, 5, or 7 days of one of four treatments: control (casein AIN-93G) or control supplemented with flavone (positive control), genistein, or daidzein aglycones at 1,500 mg/kg of diet. QR activity was increased by daidzein in the liver, by both isoflavones in the kidney and small intestine, and by genistein in the heart. Genistein and daidzein slightly decreased UGT activities in some tissues. Liver GST activity was decreased by genistein in females. In contrast, genistein and daidzein increased kidney GST activity. In general, the greatest effects of isoflavones on phase II enzymes were observed in liver and kidney tissues, occurring at day 3, and peaking at day 5. Sex effects in the liver and kidney included females exhibiting higher QR activities and males exhibiting higher UGT and GST activities. In conclusion, individual soy isoflavones modulate phase II enzymes in mice under short-term feeding and basal conditions. This study provides insights into the actions of isolated isoflavones in mice.

  10. Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity.

    Science.gov (United States)

    Huang, Yen-Hua; Huang, Cheng-Yang

    2015-01-01

    Dihydroorotase (DHOase) is the third enzyme in the de novo biosynthesis pathway of pyrimidine nucleotides. DHOase is divided into two types (I and II). Type II DHOase generally contains a binuclear metal center in its active site. Recently, the crystal structure of DHOase domain in human CAD protein (huDHOase) has revealed three metal ions in the protein's active site. However, whether type II DHOase can have the critical third metal ion, as observed in huDHOase, remains unknown. In the present study, the putative third metal binding site in type II enzymes, such as the prokaryotic Salmonella enterica serovar Typhimurium LT2 DHOase (StDHOase) and the eukaryotic Saccharomyces cerevisiae DHOase (ScDHOase), was created and identified. StDHOase T198E and ScDHOase T208E mutants had higher activities compared with their wild-type enzymes. The need for a higher DHOase stability and activity may drive creation of the third metal ion binding site in huDHOase, which can be achieved by mutating a highly conserved position T in type II dihydroorotases to E, similar to that in huDHOase.

  11. Complete detoxification of short chain chlorinated aliphatics: Isolation of halorespiring organisms and biochemical studies of the dehalogenating enzyme systems. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Loeffler, F.E.; Tiedje, J.M.

    1997-01-01

    'The objectives of the research within this grant are: (1) Isolation and characterization of chlororespiring organisms responsible for the complete dehalogenation of chlorinated ethenes and propanes. (2) Development of conditions that yield high cell densities and induce dechlorinating activity. (3) Development of assay systems to detect the dechlorinating activity in cell-free extracts. (4) Purification and characterization of the dehalogenating enzymes. Anaerobic microcosms were obtained from a variety of geographically different sediment samples. In several microcosms complete dechlorination of tetrachloroethene (PCE) to ethene (ETH), and 1,2-dichloropropane ( 1,2-D) and/or 1,2,3-trichloropropane to propene was observed. Upon subsequent transfers to anaerobic medium, sediment-free, methanogenic enrichment cultures were obtained that dechlorinated PCE to ETH, and 1,2-D to propene, respectively. 2-Bromoethanesulfonate (BES), a well known inhibitor of methanogens, did not inhibit the dechlorination of 1,2-D to propene and the dechlorination of PCE to cis-dichloroethene (cis-DCE). However,-the complete dechlorination of PCE to vinyl chloride (VC) and ETH was severely inhibited. The authors could show that BES inhibited the dechlorination of chloroethenes in cultures not containing methanogens. Previous to this study, BES was believed to be aspecific inhibitor of methanogens and the inhibitory effect of BES on declorination was explained by the involvement of methanogens in the dechlorination process. The non-methanogenic cultures obtained after the BES treatment were subsequently transferred to medium riot containing BES and complete dechlorination of PCE to ETH was observed as was in the original microcosms. Subcultures were further enriched with PCE, cis-DCE, VC, or 1,2-D as the only available electron acceptor and acetate, or acetate plus hydrogen as the only available electron donor(s). To date these cultures have undergone up to 45 transfers. Interestingly

  12. Deltamethrin resistance, metabolic detoxification enzyme and kdr mutation in Anopheles sinensis in region along Huaihe River in Anhui Province%安徽省沿淮地区中华按蚊溴氰菊酯抗性及代谢解毒酶活性kdr突变频率调查

    Institute of Scientific and Technical Information of China (English)

    常雪莲; 薛玉芹; 张安冬; 朱国鼎; 方强

    2013-01-01

    Objective To understand the deltamethrin resistance level,GTS and P450 metabolic detoxification enzyme activities,and mutations in the para-type sodium channel gene that confers knockdown resistance (kdr) in Anopheles sinensis mosquitoes from malaria endemic areas along the Huaihe River in Anhui Province,China.Methods An.sinensis adult mosquitoes were collected in Lilou,Mohekou and Tuohu townships of Bengbu City,Anhui Province from August to September,2011.The insecticide resistance bioassays were performed on adult mosquitoes by using the standard WHO susceptibility test with diagnostic concentrations of deltamethrin 0.05%,and the mosquito resistance status was classified based on the WHO resistance classification criteria.The metabolic detoxification enzyme activities were measured in randomly selected mosquitoes,and the IIS6 region of the para-type sodium channel gene was amplified by PCR and sequenced to detect mutations at the codon 1014.Results The knockdown rates within 60 min exposure to deltamethrin test paper were 4.1%,7.0% and 8.2%,and the mortality rates were 8.2%,12.0% and 12.8% for mosquitoes collected from Lilou,Mohekou and Tuohu townships,respectively.These three populations were classified as highly resistant populations based on the WHO resistance classification criteria.The GST and P450 enzyme activities of the three populations were significantly higher than those of the susceptible laboratory population (P < 0.001).L1014C and L1014F mutations were detected,and the wild type homozygote kdr genotype was not found.These three populations exhibited a small but insignificant difference in kdr allele frequencies.No mutation was found in the laboratory susceptible mosquitos.Conclusions The An.sinensis mosquito populations from the regions along the Huaihe River in Anhui Province are strongly resistant to pyrethroid insecticides,and exhibit significantly higher metabolic detoxification enzyme activities than the laboratory susceptible

  13. Asparaginase II of Saccharomyces cerevisiae: selection of four mutations that cause derepressed enzyme synthesis.

    Science.gov (United States)

    Kamerud, J Q; Roon, R J

    1986-01-01

    A positive selection method was used to isolate four Saccharomyces cerevisiae mutations that cause derepressed synthesis of asparaginase II. The four mutations (and1, and2, and3, and4) were neither closely linked to each other nor linked to previously characterized mutations (asp3, asp6) which cause the complete loss of asparaginase II activity. One of the new mutations (and4) was shown to be allelic to gdh-CR, a pleiotropic mutation which causes derepressed synthesis of a number of enzymes of nitrogen catabolism.

  14. Polymorphisms of phase I and phase II enzymes and breast cancer risk

    Directory of Open Access Journals (Sweden)

    Christina eJustenhoven

    2012-11-01

    Full Text Available Breast cancer is a complex disease which is provoked by a multitude of exogenous and endogenous factors including genetic variations. Recent genome-wide association studies identified a set of more than 18 novel low penetrant susceptibility loci, however, a limitation of this powerful approach is the hampered analysis of polymorphisms in DNA sequences with a high degree of similarity to other genes or pseudo genes. Since this common feature affects the majority of the highly polymorphic genes encoding phase I and II enzyme the retrieval of specific genotype data requires adapted amplification methods. With regard to breast cancer these genes are of certain interest due to their involvement in the metabolism of carcinogens like exogenous genotoxic compounds or steroid hormones. The present review summarizes the observed effects of functional genetic variants of phase I and II enzymes in well designed case control studies to shed light on their contribution to breast cancer risk.

  15. Glutathione-Dependent Detoxification Processes in Astrocytes

    DEFF Research Database (Denmark)

    Dringen, Ralf; Brandmann, Maria; Hohnholt, Michaela C

    2015-01-01

    component in many of the astrocytic detoxification processes is the tripeptide glutathione (GSH) which serves as electron donor in the GSH peroxidase-catalyzed reduction of peroxides. In addition, GSH is substrate in the detoxification of xenobiotics and endogenous compounds by GSH-S-transferases which......Astrocytes have a pivotal role in brain as partners of neurons in homeostatic and metabolic processes. Astrocytes also protect other types of brain cells against the toxicity of reactive oxygen species and are considered as first line of defence against the toxic potential of xenobiotics. A key...... generate GSH conjugates that are efficiently exported from the cells by multidrug resistance proteins. Moreover, GSH reacts with the reactive endogenous carbonyls methylglyoxal and formaldehyde to intermediates which are substrates of detoxifying enzymes. In this article we will review the current...

  16. Phytochelatins: peptides involved in heavy metal detoxification.

    Science.gov (United States)

    Pal, Rama; Rai, J P N

    2010-03-01

    Phytochelatins (PCs) are enzymatically synthesized peptides known to involve in heavy metal detoxification and accumulation, which have been measured in plants grown at high heavy metal concentrations, but few studies have examined the response of plants even at lower environmentally relevant metal concentrations. Recently, genes encoding the enzyme PC synthase have been identified in plants and other species enabling molecular biological studies to untangle the mechanisms underlying PC synthesis and its regulation. The present paper embodies review on recent advances in structure of PCs, their biosynthetic regulation, roles in heavy metal detoxification and/or accumulation, and PC synthase gene expression for better understanding of mechanism involved and to improve phytoremediation efficiency of plants for wider application.

  17. 昆虫对Bt毒素的抗性与中肠蛋白酶、解毒酶及保护酶系活性的关系%Relationship between midgut proteinases, detoxification enzymes,protective enzymes in insect and the resistance to Bt

    Institute of Scientific and Technical Information of China (English)

    蒋晴; 苏宏华; 杨益众

    2013-01-01

    There are many mechanisms of insect resistance to Bacillus thuringiensis toxin. Binding site modification and altered proteolytic processing are involved in most cases of resistance. This paper reviews the changes of midgut proteinases, detoxification enzymes and protective enzymes when insects were fed with Bt and the relationship between the three kinds of enzymes and the resistance to Bt. All the studies indicate that the altered enzymes may be related with the resistance to Bt. Studying the mechanisms of insect resistance to Bt toxin will help to build early monitoring technology of resistance, carry out integrated pest management programs and finally realize the sustainable utilization of Bt toxin and Bt crops.%昆虫对苏云金杆菌(Bacillus thuringiensis,Bt)毒素产生抗性的机理很多,其中Bt毒素与中肠细胞膜上受体结合能力的变化、Bt毒蛋白在中肠中水解作用的变化是抗性产生的两个主要环节.本文综述了昆虫取食Bt毒素后其体内中肠蛋白酶、解毒酶及保护酶活性的变化及这些变化与抗性之间的关系.结果表明,室内及田间对Bt毒素产生抗性的昆虫品系,可能与这三大酶系存在—定的关系.研究分析昆虫对Bt毒素的抗性机理,将有助于建立早期的抗性监测技术、实施抗性治理方案,实现Bt农药与转Bt基因作物的可持续利用.

  18. Targeting kynurenine aminotransferase II in psychiatric diseases: promising effects of an orally active enzyme inhibitor.

    Science.gov (United States)

    Wu, Hui-Qiu; Okuyama, Masahiro; Kajii, Yasushi; Pocivavsek, Ana; Bruno, John P; Schwarcz, Robert

    2014-03-01

    Increased brain levels of the tryptophan metabolite kynurenic acid (KYNA) have been linked to cognitive dysfunctions in schizophrenia and other psychiatric diseases. In the rat, local inhibition of kynurenine aminotransferase II (KAT II), the enzyme responsible for the neosynthesis of readily mobilizable KYNA in the brain, leads to a prompt reduction in extracellular KYNA levels, and secondarily induces an increase in extracellular glutamate, dopamine, and acetylcholine levels in several brain areas. Using microdialysis in unanesthetized, adult rats, we now show that the novel, systemically active KAT II inhibitor BFF-816, applied orally at 30 mg/kg in all experiments, mimics the effects of local enzyme inhibition. No tolerance was seen when animals were treated daily for 5 consecutive days. Behaviorally, daily injections of BFF-816 significantly decreased escape latency in the Morris water maze, indicating improved performance in spatial and contextual memory. Thus, systemically applied BFF-816 constitutes an excellent tool for studying the neurobiology of KYNA and, in particular, for investigating the mechanisms linking KAT II inhibition to changes in glutamatergic, dopaminergic, and cholinergic function in brain physiology and pathology.

  19. Current knowledge of detoxification mechanisms of xenobiotic in honey bees.

    Science.gov (United States)

    Gong, Youhui; Diao, Qingyun

    2017-01-01

    The western honey bee Apis mellifera is the most important managed pollinator species in the world. Multiple factors have been implicated as potential causes or factors contributing to colony collapse disorder, including honey bee pathogens and nutritional deficiencies as well as exposure to pesticides. Honey bees' genome is characterized by a paucity of genes associated with detoxification, which makes them vulnerable to specific pesticides, especially to combinations of pesticides in real field environments. Many studies have investigated the mechanisms involved in detoxification of xenobiotics/pesticides in honey bees, from primal enzyme assays or toxicity bioassays to characterization of transcript gene expression and protein expression in response to xenobiotics/insecticides by using a global transcriptomic or proteomic approach, and even to functional characterizations. The global transcriptomic and proteomic approach allowed us to learn that detoxification mechanisms in honey bees involve multiple genes and pathways along with changes in energy metabolism and cellular stress response. P450 genes, is highly implicated in the direct detoxification of xenobiotics/insecticides in honey bees and their expression can be regulated by honey/pollen constitutes, resulting in the tolerance of honey bees to other xenobiotics or insecticides. P450s is also a key detoxification enzyme that mediate synergism interaction between acaricides/insecticides and fungicides through inhibition P450 activity by fungicides or competition for detoxification enzymes between acaricides. With the wide use of insecticides in agriculture, understanding the detoxification mechanism of insecticides in honey bees and how honeybees fight with the xenobiotis or insecticides to survive in the changing environment will finally benefit honeybees' management.

  20. The Mercury Resistance Operon: From an Origin in a Geothermal Environment to an Efficient Detoxification Machine

    Directory of Open Access Journals (Sweden)

    Eric eBoyd

    2012-10-01

    Full Text Available Mercuric mercury (Hg[II] is a highly toxic and mobile element that is likely to have had a pronounced and adverse effect on biology since Earth’s oxygenation ~2.4 Gy ago due to its high affinity for protein sulfhydryl groups, which upon binding destabilizes protein structure and decreases enzyme activity, resulting in a decreased organismal fitness. The central enzyme in the microbial mercury detoxification system is the mercuric reductase (MerA protein, which catalyzes the reduction of Hg2+ to volatile Hg0. In addition to MerA, mer operons encode for proteins involved in regulation, Hg binding, and organomercury degradation. Here, we examine the composition of 272 individual mer operons and quantitatively map the distribution of mer-encoded functions on both taxonomic SSU rRNA gene and MerA protein phylogenies. The results indicate an origin and early evolution of MerA among thermophilic bacteria and an overall increase in the complexity of mer operons and in the sophistication of transcriptional regulation through evolutionary time, suggesting continual gene recruitment and evolution leading to an improved efficiency and functionality of the Mer detoxification system. Consistent with a positive relationship between the evolutionary history and topology of MerA and SSU rRNA gene phylogeneties (Mantel R = 0.81, p < 0.01, the distribution of the majority of mer functions, when mapped on these phylograms, indicates an overall tendency to inherit mer-encoded functions through vertical descent. However, individual mer functions display evidence of a variable degree of vertical inheritance, with several genes exhibiting strong evidence for acquisition via lateral gene transfer and/or gene loss. These data suggest that (i mer has evolved from a simple system in geothermal environments to a widely distributed and more complex and efficient detoxification system, and (ii MerA is a suitable taxonomic marker for examining the functional diversity of mer.

  1. Wheat bran feruloyl oligosaccharides modulate the phase II detoxifying/antioxidant enzymes via Nrf2 signaling.

    Science.gov (United States)

    Zhang, Huijuan; Wang, Jing; Liu, Yingli; Sun, Baoguo

    2015-03-01

    The antioxidant activities of wheat bran feruloyl oligosaccharides (FOs) were determined in rats by determining the activities and mRNA expression levels of phase II detoxifying/antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and heme oxygenase-1 (HO-1) in rat organs. FOs was given by gavage at doses of 0.25, 0.5, and 0.75 mmol/kg body weight every day for 15 days. Compared with the control group, the activities of SOD, CAT, and GSH-Px in FOs treatment groups significantly (Plevels of SOD, CAT, and HO-1 in organs. Moreover, the immunoblot analysis revealed increased nuclear factor-E2-related factor (Nrf2) protein expression levels in organs and there were positive correlations between the mRNA expression of phase II detoxifying/antioxidant enzymes and the expressions of Nrf2 protein, which demonstrated FOs treatment could modulate the detoxifying/antioxidant enzymes via Nrf2 signaling. Copyright © 2014. Published by Elsevier B.V.

  2. In vivo induction of phase II detoxifying enzymes, glutathione transferase and quinone reductase by citrus triterpenoids

    Directory of Open Access Journals (Sweden)

    Ahmad Hassan

    2010-09-01

    Full Text Available Abstract Background Several cell culture and animal studies demonstrated that citrus bioactive compounds have protective effects against certain types of cancer. Among several classes of citrus bioactive compounds, limonoids were reported to prevent different types of cancer. Furthermore, the structures of citrus limonoids were reported to influence the activity of phase II detoxifying enzymes. The purpose of the study was to evaluate how variations in the structures of citrus limonoids (namely nomilin, deacetyl nomilin, and isoobacunoic acid and a mixture of limonoids would influence phase II enzyme activity in excised tissues from a mouse model. Methods In the current study, defatted sour orange seed powder was extracted with ethyl acetate and subjected to silica gel chromatography. The HPLC, NMR and mass spectra were used to elucidate the purity and structure of compounds. Female A/J mice were treated with three limonoids and a mixture in order to evaluate their effect on phase II enzymes in four different tissues. Assays for glutathione S-transferase and NAD(PH: quinone reductase (QR were used to evaluate induction of phase II enzymatic activity. Results The highest induction of GST against 1-chloro-2,4-dinitrobenzene (CDNB was observed in stomach (whole, 58% by nomilin, followed by 25% isoobacunoic acid and 19% deacetyl nomilin. Deacetyl nomilin in intestine (small as well as liver significantly reduced GST activity against CDNB. Additionally isoobacunoic acid and the limonoid mixture in liver demonstrated a significant reduction of GST activity against CDNB. Nomilin significantly induced GST activity against 4-nitroquinoline 1-oxide (4NQO, intestine (280% and stomach (75% while deacetyl nomilin showed significant induction only in intestine (73%. Induction of GST activity was also observed in intestine (93% and stomach (45% treated with the limonoid mixture. Finally, a significant induction of NAD(PH: quinone reductase (QR activity was

  3. Newer approaches to opioid detoxification

    Directory of Open Access Journals (Sweden)

    Siddharth Sarkar

    2012-01-01

    Full Text Available Opioid use disorders present with distressing withdrawal symptoms at the time of detoxification. The pharmacological agents and methods currently in use for detoxification mainly include buprenorphine, methadone, and clonidine. Many other pharmacological agents have been tried for opioid detoxification. This review takes a look at the newer pharmacological options, both opioid agonists and non-agonist medications that have been utilized for detoxification. Peer reviewed articles were identified using PubMed and PsychInfo databases. The keywords included for the search were a combination of ′opioid′ and ′detoxification′ and their synonyms. All the articles published in the last 10 years were screened for. Relevant data was extracted from identified studies. Many newer pharmacological agents have been tried in detoxification of opioids. However, the quest for a safe, efficacious, cost-effective pharmacological option which requires minimal monitoring still continues. The role of non-pharmacological measures and alternative medicine needs further evaluation.

  4. In Vivo Exposure of Kaempferol Is Driven by Phase II Metabolic Enzymes and Efflux Transporters.

    Science.gov (United States)

    Zheng, Liang; Zhu, Lijun; Zhao, Min; Shi, Jian; Li, Yuhuan; Yu, Jia; Jiang, Huangyu; Wu, Jinjun; Tong, Yunli; Liu, Yuting; Hu, Ming; Lu, Linlin; Liu, Zhongqiu

    2016-09-01

    Kaempferol is a well-known flavonoid; however, it lacks extensive pharmacokinetic studies. Phase II metabolic enzymes and efflux transporters play an important role in the disposition of flavonoids. This study aimed to investigate the mechanism by which phase II metabolic enzymes and efflux transporters determine the in vivo exposure of kaempferol. Pharmacokinetic analysis in Sprague-Dawley rats revealed that kaempferol was mostly biotransformed to conjugates, namely, kaempferol-3-glucuronide (K-3-G), kaempferol-7-glucuronide (K-7-G), and kaempferol-7-sulfate, in plasma. K-3-G represented the major metabolite. Compared with that in wild-type mice, pharmacokinetics in knockout FVB mice demonstrated that the absence of multidrug resistance protein 2 (MRP2) and breast cancer resistance protein (BCRP) significantly increased the area under the curve (AUC) of the conjugates. The lack of MRP1 resulted in a much lower AUC of the conjugates. Intestinal perfusion in rats revealed that the glucuronide conjugates were mainly excreted in the small intestine, but 7-sulfate was mainly excreted in the colon. In Caco-2 monolayers, K-7-G efflux toward the apical (AP) side was significantly higher than K-3-G efflux. In contrast, K-3-G efflux toward the basolateral (BL) side was significantly higher than K-7-G efflux. The BL-to-AP efflux was significantly reduced in the presence of the MRP2 inhibitor LTC4. The AP-to-BL efflux was significantly decreased in the presence of the BL-side MRPs inhibitor MK571. The BCRP inhibitor Ko143 decreased the glucuronide conjugate efflux. Therefore, kaempferol is mainly exposed as K-3-G in vivo, which is driven by phase II metabolic enzymes and efflux transporters (i.e., BCRP and MRPs).

  5. Proteinuria, a modifiable risk factor: angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs).

    Science.gov (United States)

    Dykeman-Sharpe, Jennifer

    2003-01-01

    Microalbuminuria and proteinuria have been determined to be modifiable risk factors for the progression of chronic kidney disease as well as risk factors for cardiovascular events. Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers have been demonstrated to decrease proteinuria at all stages and slow the progression of renal disease. Proteinuria can be used as a marker of successful treatment in patients with chronic kidney disease in combination with other established targets. This article discusses the various diagnostic tests used for the detection of microalbuminuria and proteinuria and appropriate pharmaceutical treatment.

  6. Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) and lactation: an update.

    Science.gov (United States)

    Shannon, M E; Malecha, S E; Cha, A J

    2000-05-01

    Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are commonly used for the treatment of hypertension. ACEIs have been promoted as first-line therapy for selected patients with chronic hypertension and for the prevention of diabetic nephropathy, thus creating the potential for frequent ACEI exposure among women of childbearing age. ARBs are the most recent addition to the available options for antihypertensive agents. This review specifically focuses on the most up-to-date information regarding these newer antihypertensives with regard to lactation.

  7. Stochastic ensembles, conformationally adaptive teamwork, and enzymatic detoxification.

    Science.gov (United States)

    Atkins, William M; Qian, Hong

    2011-05-17

    It has been appreciated for a long time that enzymes exist as conformational ensembles throughout multiple stages of the reactions they catalyze, but there is renewed interest in the functional implications. The energy landscape that results from conformationlly diverse poteins is a complex surface with an energetic topography in multiple dimensions, even at the transition state(s) leading to product formation, and this represents a new paradigm. At the same time there has been renewed interest in conformational ensembles, a new paradigm concerning enzyme function has emerged, wherein catalytic promiscuity has clear biological advantages in some cases. "Useful", or biologically functional, promiscuity or the related behavior of "multifunctionality" can be found in the immune system, enzymatic detoxification, signal transduction, and the evolution of new function from an existing pool of folded protein scaffolds. Experimental evidence supports the widely held assumption that conformational heterogeneity promotes functional promiscuity. The common link between these coevolving paradigms is the inherent structural plasticity and conformational dynamics of proteins that, on one hand, lead to complex but evolutionarily selected energy landscapes and, on the other hand, promote functional promiscuity. Here we consider a logical extension of the overlap between these two nascent paradigms: functionally promiscuous and multifunctional enzymes such as detoxification enzymes are expected to have an ensemble landscape with more states accessible on multiple time scales than substrate specific enzymes. Two attributes of detoxification enzymes become important in the context of conformational ensembles: these enzymes metabolize multiple substrates, often in substrate mixtures, and they can form multiple products from a single substrate. These properties, combined with complex conformational landscapes, lead to the possibility of interesting time-dependent, or emergent

  8. Interplay of drug metabolizing enzymes with cellular transporters.

    Science.gov (United States)

    Böhmdorfer, Michaela; Maier-Salamon, Alexandra; Riha, Juliane; Brenner, Stefan; Höferl, Martina; Jäger, Walter

    2014-11-01

    Many endogenous and xenobiotic substances and their metabolites are substrates for drug metabolizing enzymes and cellular transporters. These proteins may not only contribute to bioavailability of molecules but also to uptake into organs and, consequently, to overall elimination. The coordinated action of uptake transporters, metabolizing enzymes, and efflux pumps, therefore, is a precondition for detoxification and elimination of drugs. As the understanding of the underlying mechanisms is important to predict alterations in drug disposal, adverse drug reactions and, finally, drug-drug interactions, this review illustrates the interplay between selected uptake/efflux transporters and phase I/II metabolizing enzymes.

  9. Phenotype prediction of nonsynonymous single nucleotide polymorphisms in human phase II drug/xenobiotic metabolizing enzymes: perspectives on molecular evolution

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Nonsynonymous single nucleotide polymorphisms (nsSNPs) in coding regions can lead to amino acid changes that might alter the protein’s function and account for susceptibility to disease and altered drug/xenobiotic response. Many nsSNPs have been found in genes encoding human phase II metabolizing enzymes; however, there is little known about the relationship between the genotype and phenotype of nsSNPs in these enzymes. We have identified 923 validated nsSNPs in 104 human phase II enzyme genes from the Ensembl genome database and the NCBI SNP database. Using PolyPhen, Panther, and SNAP algorithms, 44%?59% of nsSNPs in phase II enzyme genes were predicted to have functional impacts on protein function. Predictions largely agree with the available experimental annotations. 68% of deleterious nsSNPs were correctly predicted as damaging. This study also identified many amino acids that are likely to be functionally critical, but have not yet been studied experimentally. There was significant concordance between the predicted results of Panther and PolyPhen, and between SNAP non-neutral predictions and PolyPhen scores. Evolutionarily non-neutral (destabilizing) amino acid substitutions are thought to be the pathogenetic basis for the alteration of phase II enzyme activity and to be associated with disease susceptibility and drug/xenobiotic toxicity. Furthermore, the molecular evolutionary patterns of phase II enzymes were characterized with regards to the predicted deleterious nsSNPs.

  10. Phase II enzyme induction by a carotenoid, lutein, in a PC12D neuronal cell line

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Seiji [Laboratory of Retinal Cell Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Wakasa Seikatsu Co., Ltd., 134 Chudoujiminami-cho, Shimogyo-ku, Kyoto 600-8813 (Japan); Kobayashi, Saori [Wakasa Seikatsu Co., Ltd., 134 Chudoujiminami-cho, Shimogyo-ku, Kyoto 600-8813 (Japan); Tsubota, Kazuo [Laboratory of Retinal Cell Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Ozawa, Yoko, E-mail: ozawa@a5.keio.jp [Laboratory of Retinal Cell Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan)

    2014-04-04

    Highlights: • Lutein reduced ROS levels in a PC12D neuronal cell line. • Lutein induced mRNAs of phase II antioxidative enzymes in PC12D neuronal cells. • Lutein increased protein levels of HO-1, SOD2, and NQO-1 in PC12D neuronal cells. • Lutein had no effect on intranuclear Nrf2 levels in PC12D neuronal cells. • Lutein did not activate potential upstream Nrf2 nuclear translocation pathways. - Abstract: The mechanism by which lutein, a carotenoid, acts as an antioxidant in retinal cells is still not fully understood. Here, lutein treatment of a neuronal cell line (PC12D) immediately resulted in reduced intracellular ROS levels, implying that it has a direct role in ROS scavenging. Significantly, lutein treatment also induced phase II antioxidative enzyme expression, probably via a nuclear factor-like 2 (Nrf2) independent pathway. This latter mechanism could explain why lutein acts diversely to protect against oxidative/cytotoxic stress, and why it is physiologically involved in the human neural tissue, such as the retina.

  11. 'Photosystem II: the water splitting enzyme of photosynthesis and the origin of oxygen in our atmosphere'.

    Science.gov (United States)

    Barber, James

    2016-01-01

    About 3 billion years ago an enzyme emerged which would dramatically change the chemical composition of our planet and set in motion an unprecedented explosion in biological activity. This enzyme used solar energy to power the thermodynamically and chemically demanding reaction of water splitting. In so doing it provided biology with an unlimited supply of reducing equivalents needed to convert carbon dioxide into the organic molecules of life while at the same time produced oxygen to transform our planetary atmosphere from an anaerobic to an aerobic state. The enzyme which facilitates this reaction and therefore underpins virtually all life on our planet is known as Photosystem II (PSII). It is a pigment-binding, multisubunit protein complex embedded in the lipid environment of the thylakoid membranes of plants, algae and cyanobacteria. Today we have detailed understanding of the structure and functioning of this key and unique enzyme. The journey to this level of knowledge can be traced back to the discovery of oxygen itself in the 18th-century. Since then there has been a sequence of mile stone discoveries which makes a fascinating story, stretching over 200 years. But it is the last few years that have provided the level of detail necessary to reveal the chemistry of water oxidation and O-O bond formation. In particular, the crystal structure of the isolated PSII enzyme has been reported with ever increasing improvement in resolution. Thus the organisational and structural details of its many subunits and cofactors are now well understood. The water splitting site was revealed as a cluster of four Mn ions and a Ca ion surrounded by amino-acid side chains, of which seven provide direct ligands to the metals. The metal cluster is organised as a cubane structure composed of three Mn ions and a Ca2+ linked by oxo-bonds with the fourth Mn ion attached to the cubane. This structure has now been synthesised in a non-protein environment suggesting that it is a totally

  12. Enzymic synthesis of lacto-N-triose II and its positional analogues.

    Science.gov (United States)

    Matahira, Y; Tashiro, A; Sato, T; Kawagishi, H; Usui, T

    1995-10-01

    N-acetylhexosaminidase from Nocardia orientalis catalysed the synthesis of lacto-N-triose II glycoside (beta-D-GlcNAc-(1-3)-beta-D-Gal-(1-4)-beta-D-Glc-OMe, 3) with its isomers beta-D-GlcNAc-(1-6)-beta-D-Gal-(1-4)-beta-d-Glc-OMe (4) and beta-D-Gal-(1-4)-[beta-D-GlcNAc-(1-6)]-beta-D-Glc-OMe (5) through N-acetylglucosaminyl transfer from N,N'-diacetylchitobiose (GlcNAc2) to methyl beta-lactoside. The enzyme formed the mixture of trisaccharides 3, 4 and 5 in 17% overall yield based on GlcNAc2, in a ratio of 20:21:59. With p-nitrophenyl beta-lactoside as an acceptor, the enzyme also produced p-nitrophenyl beta-lacto-N-trioside II (beta-D-GlcNAc-(1-3)-beta-D-Gal-(1-4)-beta-D-Glc-OC6H4NO2-p, 6) with its isomers beta-D-GlcNAc-(1-6)-beta-D-Gal-(1-4)-beta-D-Glc-OC6H4NO2-p (7) and beta-D-Gal-(1-4)-[beta-D-GlcNAc-(1-6)]-beta-D-Glc-OC6H4NO2-p (8). In this case, when an inclusion complex of p-nitrophenyl lactoside acceptor with beta-cyclodextrin was used the regioselectivity of glycosidase-catalysed formation of trisaccharide glycoside was substantially changed. It resulted not only in a significant increase of the overall yield of transfer products, but also in the proportion of the desired compound 6.

  13. Enzymic synthesis of indole-3-acetyl-1-O-beta-d-glucose. II. Metabolic characteristics of the enzyme

    Science.gov (United States)

    Leznicki, A. J.; Bandurski, R. S.

    1988-01-01

    The synthesis of indole-3-acetyl-1-O-beta-D-glucose from indole-3-acetic acid (IAA) and uridine diphosphoglucose (UDPG) has been shown to be a reversible reaction with the equilibrium away from ester formation and toward formation of IAA. The enzyme occurs primarily in the liquid endosperm of the corn kernel but some activity occurs in the embryo. It is relatively specific showing no glucose ester formation with oxindole-3-acetic acid or 7-hydroxy-oxindole-3-acetic acid, and low activity with phenylpropene acids, such as rho-coumaric acid. The enzyme is also specific for the nucleotide sugar showing no activity with UDPGalactose or UDPXylose. The enzyme is inhibited by inorganic pyrophosphate, by phosphate esters and by phospholipids, particularly phosphatidyl ethanolamine. The enzyme is inhibited by zeatin, by 2,4-dichlorophenoxy-acetic acid, by IAA-myo-inositol and IAA-glucan, but not by zeatin riboside, and only weakly by gibberellic acid, abscisic acid and kinetin. The reaction is slightly stimulated by both calcium and calmodulin and, in some cases, by thiol compounds. The role of this enzyme in the homeostatic control of indole-3-acetic acid levels in Zea mays is discussed.

  14. THE COORDINATION COMPOUNDS OF COBALT (II, III WITH DITHIOCARBAMIC ACID DERIVATIVES — MODIFICATORS OF HYDROLYTIC ENZYMES ACTIVITY

    Directory of Open Access Journals (Sweden)

    L. D. Varbanets

    2013-02-01

    Full Text Available Chloride, bromide and isothiocyanate complexes of cobalt(II with N-substituted thiocarbamoyl-N?-pentamethylenesulfenamides (1–(12, and also complexes of cobalt(II, Ш with derivatives of morpholine-4-carbodithioic acid (13–(18 have been used as modificators of enzymes of hydrolytic action — Bacillus thurin-giensis ІМВ В-7324 peptidases, Bacillus subtilis 147 and Aspergillus flavus var. oryzae 80428 amylases, Eupenicillium erubescens 248 and Cryptococcus albidus 1001 rhamnosidases. It was shown that cobalt (II, Ш compounds influence differently on the activity of enzymes tested, exerted both inhibitory and stimulatory action. It gives a possibility to expect that manifestation of activity by complex molecule depends on ligand and anion presence — Cl–, Br– or NCS–. The high activating action of cobalt(II complexes with N-substituted thiocarbamoyl-N?-pentamethylenesulphenamides (1–(12 on elastase and fibrinolytic activity of peptidases compared to tris(4-morpholinecarbodithioatocobalt(ІІІ (14 and products of its interaction with halogens (15–(17, causes inhibitory effect that is probably due to presence of a weekly S–N link, which is easy subjected to homolytic breaking. The studies of influences of cobalt(II complexes on activity of C. аlbidus and E. еrubescens ?-Lrhamnosidases showed, that majority of compounds inhibits of its activity, at that the most inhibitory effect exerts to C. аlbidus enzyme.To sum up, it is possible to state that character of influence of cobalt(II complexes with N-substituted thiocarbamoyl-N?-pentamethylenesulphenamides, and also cobalt(II, Ш complexes with derivatives of morpholine-4-carbodithioic acid varies depending on both strain producer and enzyme tested. The difference in complex effects on enzymes tested are due to peculiarities of building and functional groups of their active centers, which are also responsible for binding with modificators.

  15. Effects of ethylene on photosystem II and antioxidant enzyme activity in Bermuda grass under low temperature.

    Science.gov (United States)

    Hu, Zhengrong; Fan, Jibiao; Chen, Ke; Amombo, Erick; Chen, Liang; Fu, Jinmin

    2016-04-01

    The phytohormone ethylene has been reported to mediate plant response to cold stress. However, it is still debated whether the effect of ethylene on plant response to cold stress is negative or positive. The objective of the present study was to explore the role of ethylene in the cold resistance of Bermuda grass (Cynodon dactylon (L).Pers.). Under control (warm) condition, there was no obvious effect of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) or the antagonist Ag(+) of ethylene signaling on electrolyte leakage (EL) and malondialdehyde (MDA) content. Under cold stress conditions, ACC-treated plant leaves had a greater level of EL and MDA than the untreated leaves. However, the EL and MDA values were lower in the Ag(+) regime versus the untreated. In addition, after 3 days of cold treatment, ACC remarkably reduced the content of soluble protein and also altered antioxidant enzyme activity. Under control (warm) condition, there was no significant effect of ACC on the performance of photosystem II (PS II) as monitored by chlorophyll α fluorescence transients. However, under cold stress, ACC inhibited the performance of PS II. Under cold condition, ACC remarkably reduced the performance index for energy conservation from excitation to the reduction of intersystem electron acceptors (PI(ABS)), the maximum quantum yield of primary photochemistry (φP0), the quantum yield of electron transport flux from Q(A) to Q(B) (φE0), and the efficiency/probability of electron transport (ΨE0). Simultaneously, ACC increased the values of specific energy fluxes for absorption (ABS/RC) and dissipation (DI0/RC) after 3 days of cold treatment. Additionally, under cold condition, exogenous ACC altered the expressions of several related genes implicated in the induction of cold tolerance (LEA, SOD, POD-1 and CBF1, EIN3-1, and EIN3-2). The present study thus suggests that ethylene affects the cold tolerance of Bermuda grass by impacting the antioxidant system

  16. The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II.

    Science.gov (United States)

    Sivaraman, Sharada; Kirsch, Jack F

    2006-05-01

    Human tyrosine aminotransferase (hTATase) is the pyridoxal phosphate-dependent enzyme that catalyzes the reversible transamination of tyrosine to p-hydrophenylpyruvate, an important step in tyrosine metabolism. hTATase deficiency is implicated in the rare metabolic disorder, tyrosinemia type II. This enzyme is a member of the poorly characterized Igamma subfamily of the family I aminotransferases. The full length and truncated forms of recombinant hTATase were expressed in Escherichia coli, and purified to homogeneity. The pH-dependent titration of wild-type reveals a spectrum characteristic of family I aminotransferases with an aldimine pK(a) of 7.22. I249A mutant hTATase exhibits an unusual spectrum with a similar aldimine pK(a) (6.85). hTATase has very narrow substrate specificity with the highest enzymatic activity for the Tyr/alpha-ketoglutarate substrate pair, which gives a steady state k(cat) value of 83 s(-1). In contrast there is no detectable transamination of aspartate or other cosubstrates. The present findings show that hTATase is the only known aminotransferase that discriminates significantly between Tyr and Phe: the k(cat)/K(m) value for Tyr is about four orders of magnitude greater than that for Phe. A comparison of substrate specificities of representative Ialpha and Igamma aminotransferases is described along with the physiological significance of the discrimination between Tyr and Phe by hTATase as applied to the understanding of the molecular basis of phenylketonuria.

  17. Renal graft failure after addition of an angiotensin II receptor antagonist to an angiotensin-converting enzyme inhibitor

    DEFF Research Database (Denmark)

    Kamper, Anne-Lise; Nielsen, Arne Høj; Baekgaard, Niels

    2002-01-01

    Combined treatment with an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II (Ang II) receptor blocker (ARB) has been suggested in order to achieve a more complete blockade of the renin-angiotensin-aldosterone system in cardiovascular and renal disease. The present report...... describes a case of acute renal graft dysfunction following the addition of an ARB to existing ACE inhibition. This unmasked an unknown iliac artery stenosis. The case indicates a possible important role of Ang II generated by non-ACE pathways in this situation....

  18. Combined effect of genetic polymorphisms in phase I and II biotransformation enzymes on head and neck cancer risk

    NARCIS (Netherlands)

    Lacko, M.; Voogd, A.C.; Roelofs, H.M.J.; Morsche, R.H.M. te; Ophuis, M.B.; Peters, W.H.M.; Manni, J.J.

    2013-01-01

    BACKGROUND: Combinations of genetic polymorphisms in biotransformation enzymes might modify the individual risk for head and neck cancer. METHODS: Blood from 432 patients with head and neck cancer and 437 controls was investigated for genetic polymorphisms in 9 different phase I and II biotransforma

  19. CYANIDE HEAP BIOLOGICAL DETOXIFICATION - PHASE II

    Science.gov (United States)

    Many active mine sites, mines in the closure stage and some abandoned mines are and have utilized cyanidation to remove and recover precious metals. Discharges from these sites normally contain significant amounts of metal cyanide complexes and concentrations of thiocyanate, solu...

  20. CYANIDE HEAP BILOGICAL DETOXIFICATION - PHASE II

    Science.gov (United States)

    Many active mine sites, mines in closure stage and some abandoned mines are and have utilized cyanidation to remove and recover precious metals. Discharges from these sites normally contain significant amounts of metal cyanide complexes and concentrations of thiocyanate, soluble...

  1. [Glucuronidation of antitumour therapeutics--detoxification, mechanism of resistance or prodrug formation?].

    Science.gov (United States)

    Mróz, Anna; Mazerska, Zofia

    2015-12-31

    The physiological role of phase I and II of xenobiotic biotransformations is their detoxification and better excretion outside the organism. UDP-glucuronosyltransferases (UGTs) being the enzymes of phase II metabolism catalyse the conjugation of glucuronic acid to the lipophilic substrate by its specific nucleophilic group. UGT isoenzymes of various substrate specificities and different expression profiles in selected tissues belong to the large UGT superfamily. Usually, glucuronidation is the detoxification process, but sometimes (morphine, tamoxifen) glucuronides express biological activity higher than or comparable to the native compound. The level of UGT gene expression is individual for patients, because of their genetic status as well as epigenetic conditions. Also, xenobiotics are able to modulate UGT level and gene expression by the interaction with nuclear receptors. Moreover, one can find a lower level of UGT in the tumour compared to normal tissue, which results in the protection against deactivation of the drug and in the promotion of its selective activity in tumor tissue. On the other hand, UGT activity is considered as the possible cause of resistance to chemotherapy. Metabolism by hepatic and intestinal UGT isoenzymes is responsible for the "first-pass effect", whereas acquired resistance consists in the induction of UGT gene expression by the chemotherapeutic or its metabolite. Moreover, UGT induction can be associated with the induction of membrane transporters, particularly proteins of the ABC family, responsible for drug excretion outside the cell. The above resistance effects can be fortified by the overexpression of selected UGT isoenzymes sometimes observed in specific types of tumours. It is also considered that many advanced tumours are characterized by a higher level of β-glucuronidase. This enzyme has a chance to be the molecular target of directed antitumour therapy, as it catalyses β-glucuronide hydrolysis, leading to active aglycones.

  2. Optimality in the zonation of ammonia detoxification in rodent liver.

    Science.gov (United States)

    Bartl, Martin; Pfaff, Michael; Ghallab, Ahmed; Driesch, Dominik; Henkel, Sebastian G; Hengstler, Jan G; Schuster, Stefan; Kaleta, Christoph; Gebhardt, Rolf; Zellmer, Sebastian; Li, Pu

    2015-11-01

    The rodent liver eliminates toxic ammonia. In mammals, three enzymes (or enzyme systems) are involved in this process: glutaminase, glutamine synthetase and the urea cycle enzymes, represented by carbamoyl phosphate synthetase. The distribution of these enzymes for optimal ammonia detoxification was determined by numerical optimization. This in silico approach predicted that the enzymes have to be zonated in order to achieve maximal removal of toxic ammonia and minimal changes in glutamine concentration. Using 13 compartments, representing hepatocytes, the following predictions were generated: glutamine synthetase is active only within a narrow pericentral zone. Glutaminase and carbamoyl phosphate synthetase are located in the periportal zone in a non-homogeneous distribution. This correlates well with the paradoxical observation that in a first step glutamine-bound ammonia is released (by glutaminase) although one of the functions of the liver is detoxification by ammonia fixation. The in silico approach correctly predicted the in vivo enzyme distributions also for non-physiological conditions (e.g. starvation) and during regeneration after tetrachloromethane (CCl4) intoxication. Metabolite concentrations of glutamine, ammonia and urea in each compartment, representing individual hepatocytes, were predicted. Finally, a sensitivity analysis showed a striking robustness of the results. These bioinformatics predictions were validated experimentally by immunohistochemistry and are supported by the literature. In summary, optimization approaches like the one applied can provide valuable explanations and high-quality predictions for in vivo enzyme and metabolite distributions in tissues and can reveal unknown metabolic functions.

  3. Xanthohumol induces phase II enzymes via Nrf2 in human hepatocytes in vitro.

    Science.gov (United States)

    Krajka-Kuźniak, Violetta; Paluszczak, Jarosław; Baer-Dubowska, Wanda

    2013-02-01

    The aim of this study was to investigate whether xanthohumol may exert chemoprotective activity through the modulation of the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway in immortalized normal THLE-2 hepatocytes and a hepatocellular carcinoma HepG2 cell line. Cells were incubated in the presence of xanthohumol and the activation of Nrf2 and expression of genes controlled by this transcription factor were evaluated. Additionally, p53 level was assessed. Xanthohumol increased the expression and led to the activation of Nrf2 in both cell lines. However, in contrast to normal cells the expression of genes controlled by this transcription factor was not affected in HepG2 cells, except for GSTA and GSTP. Xanthohumol, beside the induction of GSTs and HO-1, significantly elevated NQO1 expression in concert with p53 level in normal hepatocytes. The activation of Nrf2 pathway and subsequently phase II enzymes in concert with p53 induction in normal hepatocytes may account for the molecular mechanism of the chemopreventive activity of xanthohumol. On the other hand its cytotoxicity towards HCC cells shown in this study indicates that it may also be considered as potentially chemotherapeutic.

  4. Golden gate shuffling: a one-pot DNA shuffling method based on type IIs restriction enzymes.

    Directory of Open Access Journals (Sweden)

    Carola Engler

    Full Text Available We have developed a protocol to assemble in one step and one tube at least nine separate DNA fragments together into an acceptor vector, with 90% of recombinant clones obtained containing the desired construct. This protocol is based on the use of type IIs restriction enzymes and is performed by simply subjecting a mix of 10 undigested input plasmids (nine insert plasmids and the acceptor vector to a restriction-ligation and transforming the resulting mix in competent cells. The efficiency of this protocol allows generating libraries of recombinant genes by combining in one reaction several fragment sets prepared from different parental templates. As an example, we have applied this strategy for shuffling of trypsinogen from three parental templates (bovine cationic trypsinogen, bovine anionic trypsinogen and human cationic trypsinogen each divided in 9 separate modules. We show that one round of shuffling using the 27 trypsinogen entry plasmids can easily produce the 19,683 different possible combinations in one single restriction-ligation and that expression screening of a subset of the library allows identification of variants that can lead to higher expression levels of trypsin activity. This protocol, that we call 'Golden Gate shuffling', is robust, simple and efficient, can be performed with templates that have no homology, and can be combined with other shuffling protocols in order to introduce any variation in any part of a given gene.

  5. Fast conversion of scFv to Fab antibodies using type IIs restriction enzymes.

    Science.gov (United States)

    Sanmark, Hanna; Huovinen, Tuomas; Matikka, Tero; Pettersson, Tiina; Lahti, Maria; Lamminmäki, Urpo

    2015-11-01

    Single chain variable fragment (scFv) antibody libraries are widely used for developing novel bioaffinity reagents, although Fab or IgG molecules are the preferred antibody formats in many final applications. Therefore, rapid conversion methods for combining multiple DNA fragments are needed to attach constant domains to the scFv derived variable domains. In this study we describe a fast and easy cloning method for the conversion of single framework scFv fragments to Fab fragments using type IIS restriction enzymes. All cloning steps excluding plating of the Fab transformants can be done in 96 well plates and the procedure can be completed in one working day. The concept was tested by converting 69 scFv clones into Fab format on 96 well plates, which resulted in 93% success rate. The method is particularly useful as a high-throughput tool for the conversion of the chosen scFv clones into Fab molecules in order to analyze them as early as possible, as the conversion can significantly affect the binding properties of the chosen clones.

  6. The Fetal Safety of Angiotensin Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers

    Directory of Open Access Journals (Sweden)

    Myla E. Moretti

    2012-01-01

    Full Text Available Angiotensin converting enzyme (ACE inhibitors and angiotensin II receptor blockers (ARBs are known to cause fetal renal damage in pregnancy. Due to conflicting reports in the literature, their safety after first trimester exposure has been debated. Our aim was to determine whether the use of ACE inhibitors or ARBs in the first trimester of pregnancy is associated with an increased risk for major malformations or other adverse outcomes. All subjects were prospectively enrolled from among women contacting a teratogen information service. At initial contact, details of maternal medical history and exposures were collected and follow-up interviews were conducted to ascertain pregnancy outcomes. Two comparator groups, women with hypertension treated with other antihypertensives, and healthy controls were also recruited. Baseline maternal characteristics were not different among the three groups. There were no differences in rates of major malformations. Both the ACE-ARBs and disease-matched groups exhibited significantly lower birth weight and gestational ages than the healthy controls (P<0.001 for both variables. There was a significantly higher rate of miscarriage noted in the ACE/ARB group (P<0.001. These results suggest that ACE inhibitors/ARBs are not major human teratogens; however, they may be associated with an increased risk for miscarriage.

  7. Synthesis, characterization, antimicrobial activity and carbonic anhydrase enzyme inhibitor effects of salicilaldehyde-N-methyl p-toluenesulfonylhydrazone and its Palladium(II), Cobalt(II) complexes

    Science.gov (United States)

    Alyar, Saliha; Adem, Şevki

    2014-10-01

    We report the synthesis of the ligand, salicilaldehyde-N-methyl p-toluenesulfonylhydrazone (salptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Pd(II) and Co(II) metal complexes were synthesized for the first time. The structure of the ligand and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, NMR and LC-MS) measurements. Salptsmh has also been characterized by single crystal X-ray diffraction. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The complexes were found to have general composition [ML2]. The results of elemental analysis showed 1:2 (metal/ligand) stoichiometry for all the complex. Magnetic and spectral data indicate a square planar geometry for Pd(II) complex and a distorted tetrahedral geometry for Co(II) complexes. The ligand and its metal chelates have been screened for their antimicrobial activities using the disk diffusion method against the selected Gram positive bacteria: Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Gram negative bacteria: Eschericha coli, Pseudomonas aeruginosa, Klebsiella pneumonia. The inhibition activities of these compounds on carbonic anhydrase II (CA II) and carbonic anhydrase I (CA I) have been investigated by comparing IC50 and Ki values and it has been found that Pd(II) complex have more enzyme inhibition efficiency than salptsmh and Co(II) complex.

  8. STEADY-STATE KINETICS OF MANNITOL PHOSPHORYLATION CATALYZED BY ENZYME-II(MTL) OF THE ESCHERICHIA-COLI PHOSPHOENOLPYRUVATE-DEPENDENT PHOSPHOTRANSFERASE SYSTEM

    NARCIS (Netherlands)

    LOLKEMA, JS; TENHOEVEDUURKENS, RH; ROBILLARD, GT

    1993-01-01

    The kinetics of mannitol phosphorylation catalyzed by enzyme II(mtl) of the bacterial P-enolpyruvate-dependent phosphotransferase system are described for three different physical conditions of the enzyme, (i) embedded in the membrane of inside-out (ISO) oriented vesicles, (ii) solubilized and

  9. Detection of possible restriction sites for type II restriction enzymes in DNA sequences.

    Science.gov (United States)

    Gagniuc, P; Cimponeriu, D; Ionescu-Tîrgovişte, C; Mihai, Andrada; Stavarachi, Monica; Mihai, T; Gavrilă, L

    2011-01-01

    In order to make a step forward in the knowledge of the mechanism operating in complex polygenic disorders such as diabetes and obesity, this paper proposes a new algorithm (PRSD -possible restriction site detection) and its implementation in Applied Genetics software. This software can be used for in silico detection of potential (hidden) recognition sites for endonucleases and for nucleotide repeats identification. The recognition sites for endonucleases may result from hidden sequences through deletion or insertion of a specific number of nucleotides. Tests were conducted on DNA sequences downloaded from NCBI servers using specific recognition sites for common type II restriction enzymes introduced in the software database (n = 126). Each possible recognition site indicated by the PRSD algorithm implemented in Applied Genetics was checked and confirmed by NEBcutter V2.0 and Webcutter 2.0 software. In the sequence NG_008724.1 (which includes 63632 nucleotides) we found a high number of potential restriction sites for ECO R1 that may be produced by deletion (n = 43 sites) or insertion (n = 591 sites) of one nucleotide. The second module of Applied Genetics has been designed to find simple repeats sizes with a real future in understanding the role of SNPs (Single Nucleotide Polymorphisms) in the pathogenesis of the complex metabolic disorders. We have tested the presence of simple repetitive sequences in five DNA sequence. The software indicated exact position of each repeats detected in the tested sequences. Future development of Applied Genetics can provide an alternative for powerful tools used to search for restriction sites or repetitive sequences or to improve genotyping methods.

  10. Effects of Curcuma xanthorrhiza Extracts and Their Constituents on Phase II Drug-metabolizing Enzymes Activity

    Science.gov (United States)

    Salleh, Nurul Afifah Mohd; Ismail, Sabariah; Ab Halim, Mohd Rohaimi

    2016-01-01

    Background: Curcuma xanthorrhiza is a native Indonesian plant and traditionally utilized for a range of illness including liver damage, hypertension, diabetes, and cancer. Objective: The study determined the effects of C. xanthorrhiza extracts (ethanol and aqueous) and their constituents (curcumene and xanthorrhizol) on UDP-glucuronosyltransferase (UGT) and glutathione transferase (GST) activities. Materials and Methods: The inhibition studies were evaluated both in rat liver microsomes and in human recombinant UGT1A1 and UGT2B7 enzymes. p-nitrophenol and beetle luciferin were used as the probe substrates for UGT assay while 1-chloro-2,4-dinitrobenzene as the probe for GST assay. The concentrations of extracts studied ranged from 0.1 to 1000 μg/mL while for constituents ranged from 0.01 to 500 μM. Results: In rat liver microsomes, UGT activity was inhibited by the ethanol extract (IC50 =279.74 ± 16.33 μg/mL). Both UGT1A1 and UGT2B7 were inhibited by the ethanol and aqueous extracts with IC50 values ranging between 9.59–22.76 μg/mL and 110.71–526.65 μg/Ml, respectively. Rat liver GST and human GST Pi-1 were inhibited by ethanol and aqueous extracts, respectively (IC50 =255.00 ± 13.06 μg/mL and 580.80 ± 18.56 μg/mL). Xanthorrhizol was the better inhibitor of UGT1A1 (IC50 11.30 ± 0.27 μM) as compared to UGT2B7 while curcumene did not show any inhibition. For GST, both constituents did not show any inhibition. Conclusion: These findings suggest that C. xanthorrhiza have the potential to cause herb-drug interaction with drugs that are primarily metabolized by UGT and GST enzymes. SUMMARY Findings from this study would suggest which of Curcuma xanthorrhiza extracts and constituents that would have potential interactions with drugs which are highly metabolized by UGT and GST enzymes. Further clinical studies can then be designed if needed to evaluate the in vivo pharmacokinetic relevance of these interactions Abbreviations Used: BSA: Bovine serum albumin

  11. The relationship between the bioactivation and detoxification of diazinon and chlorpyrifos, and the inhibition of acetylcholinesterase activity in Chirostoma jordani from three lakes with low to high organophosphate pesticides contamination.

    Science.gov (United States)

    Dzul-Caamal, Ricardo; Domínguez-Lòpez, M Lilia; Olivares-Rubio, Hugo F; García-Latorre, Ethel; Vega-López, Armando

    2014-07-01

    In fish, a number of studies have linked acetylcholinesterase (AChE) inhibition with exposure to organophosphate pesticides (OPs); however, evidence suggests the need to study aspects related to the bioactivation and detoxification of OPs, since their neurotoxicity is dependent on these processes. Thus, the study aim was to examine the relations between chlorpyrifos (CPF) and diazinon (DZN) bioactivation by hepatic CYP450 izoenzymes (CYP 2B6, CYP 2C19, CYP 3A4) and detoxification by aryl esterases and oxonases with brain and muscle AChE activity in Chirostoma jordani from three lakes with low to high OPs contamination in water and sediments. We found two patterns of bioactivation in vitro: (i) in fish from a lake with high CPF pollution, the main isoenzymes involved in this process were CYP 2C19>CYP 2B6>CYP 3A4, and (ii) in fish captured in a lake with a high concentration of DZN, the isoenzymes were CYP 3A4>CYP 2C19>CYP 2B6. Bioactivation is shown in this study to be fundamental in brain and muscle AChE inhibition in vivo. The rate of bioactivation of CPF was lower than for DZN. CPF bioactivation was accompanied by reduced detoxification and higher neurotoxicity, which was inversely dependent on the environmental contamination of CPF. Detoxification was also inversely correlated with environmental contamination by CPF, and was higher with diazoxon than chlorpyrifos-oxon. Oxonases were the most relevant enzymes involved in detoxification. The current findings suggest a series of strategies between the bioactivation and detoxification of OPs that allowed the survival of C. jordani despite of OPs pollution levels.

  12. Growth of Bacillus methanolicus in 2 M methanol at 50 °C: the effect of high methanol concentration on gene regulation of enzymes involved in formaldehyde detoxification by the ribulose monophosphate pathway.

    Science.gov (United States)

    Bozdag, Ahmet; Komives, Claire; Flickinger, Michael C

    2015-07-01

    Bacillus methanolicus MGA3 is a Gram-positive aerobic methylotroph growing optimally at 50-53°C. Methylotrophy in B. methanolicus is encoded on pBM19 and by two chromosomal copies of the methanol dehydrogenase (mdh), hexulose phosphate synthase (hps) and phosphohexuloisomerase (phi) genes. However, there are no published studies on the regulation of methylotrophy or the dominant mechanism of detoxification of intracellular formaldehyde in response to high methanol concentration. The µ max of B. methanolicus MGA3 was assessed on methanol, mannitol and glucose. B. methanolicus achieved a µ max at 25 mM initial methanol of 0.65 ± 0.007 h(-1), which decreased to 0.231 ± 0.004 h(-1) at 2 M initial methanol. Slow growth was also observed with initial methanol concentrations of >2 M. The µ max on mannitol and glucose are 0.532 ± 0.002 and 0.336 ± 0.003 h(-1), respectively. Spiking cultures with additional methanol (100 mM) did not disturb the growth rate of methanol-grown cells, whereas, a 50 mM methanol spike halted the growth in mannitol. Surprisingly, growth in methanol was inhibited by 1 mM formaldehyde, while mannitol-grown cells tolerated 2 mM. Moreover, mannitol-grown cells removed formaldehyde faster than methanol-grown cells. Further, we show that methanol oxidation in B. methanolicus MGA3 is mainly carried out by the pBM19-encoded mdh. Formaldehyde and formate addition down-regulate the mdh and hps genes in methanol-grown cells. Similarly, they down-regulate mdh genes in mannitol-grown cells, but up-regulate hps. Phosphofructokinase (pfk) is up-regulated in both methanol and mannitol-grown cells, which suggests that pfk may be a possible synthetic methylotrophy target to reduce formaldehyde growth toxicity at high methanol concentrations.

  13. Evolutionary diversification and characterization of the eubacterial gene family encoding DXR type II, an alternative isoprenoid biosynthetic enzyme.

    Science.gov (United States)

    Carretero-Paulet, Lorenzo; Lipska, Agnieszka; Pérez-Gil, Jordi; Sangari, Félix J; Albert, Victor A; Rodríguez-Concepción, Manuel

    2013-09-03

    Isoprenoids constitute a vast family of natural compounds performing diverse and essential functions in all domains of life. In most eubacteria, isoprenoids are synthesized through the methylerythritol 4-phosphate (MEP) pathway. The production of MEP is usually catalyzed by deoxyxylulose 5-phosphate reductoisomerase (DXR-I) but a few organisms use an alternative DXR-like enzyme (DXR-II). Searches through 1498 bacterial complete proteomes detected 130 sequences with similarity to DXR-II. Phylogenetic analysis identified three well-resolved clades: the DXR-II family (clustering 53 sequences including eleven experimentally verified as functional enzymes able to produce MEP), and two previously uncharacterized NAD(P)-dependent oxidoreductase families (designated DLO1 and DLO2 for DXR-II-like oxidoreductases 1 and 2). Our analyses identified amino acid changes critical for the acquisition of DXR-II biochemical function through type-I functional divergence, two of them mapping onto key residues for DXR-II activity. DXR-II showed a markedly discontinuous distribution, which was verified at several levels: taxonomic (being predominantly found in Alphaproteobacteria and Firmicutes), metabolic (being mostly found in bacteria with complete functional MEP pathways with or without DXR-I), and phenotypic (as no biological/phenotypic property was found to be preferentially distributed among DXR-II-containing strains, apart from pathogenicity in animals). By performing a thorough comparative sequence analysis of GC content, 3:1 dinucleotide frequencies, codon usage and codon adaptation indexes (CAI) between DXR-II sequences and their corresponding genomes, we examined the role of horizontal gene transfer (HGT), as opposed to an scenario of massive gene loss, in the evolutionary origin and diversification of the DXR-II subfamily in bacteria. Our analyses support a single origin of the DXR-II family through functional divergence, in which constitutes an exceptional model of

  14. Studies on dimethylamine in food - II: concerning the enzymic formation of dimethylamine

    National Research Council Canada - National Science Library

    Tomioka, K; Ogushi, J; Endo, K

    1975-01-01

    Enzymic formation of dimethylamine and formaldehyde from trimethylamine oxide by an extract of the acetone powder prepared from the pyloric caeca of Theragra chalcogramma was examined under various...

  15. Impact of food processing and detoxification treatments on mycotoxin contamination.

    Science.gov (United States)

    Karlovsky, Petr; Suman, Michele; Berthiller, Franz; De Meester, Johan; Eisenbrand, Gerhard; Perrin, Irène; Oswald, Isabelle P; Speijers, Gerrit; Chiodini, Alessandro; Recker, Tobias; Dussort, Pierre

    2016-11-01

    Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

  16. Detoxification of arsenic by phytochelatins in plants.

    Science.gov (United States)

    Schmöger, M E; Oven, M; Grill, E

    2000-03-01

    As is a ubiquitous element present in the atmosphere as well as in the aquatic and terrestrial environments. Arsenite and arsenate are the major forms of As intoxication, and these anions are readily taken up by plants. Both anions efficiently induce the biosynthesis of phytochelatins (PCs) ([gamma-glutamate-cysteine](n)-glycine) in vivo and in vitro. The rapid induction of the metal-binding PCs has been observed in cell suspension cultures of Rauvolfia serpentina, in seedlings of Arabidopsis, and in enzyme preparations of Silene vulgaris upon challenge to arsenicals. The rate of PC formation in enzyme preparations was lower compared with Cd-induced biosynthesis, but was accompanied by a prolonged induction phase that resulted finally in higher peptide levels. An approximately 3:1 ratio of the sulfhydryl groups from PCs to As is compatible with reported As-glutathione complexes. The identity of the As-induced PCs and of reconstituted metal-peptide complexes has unequivocally been demonstrated by electrospray ionization mass spectroscopy. Gel filtration experiments and inhibitor studies also indicate a complexation and detoxification of As by the induced PCs.

  17. Mucopolysaccharidosis: cardiologic features and effects of enzyme-replacement therapy in 24 children with MPS I, II and VI.

    Science.gov (United States)

    Brands, Marion M M G; Frohn-Mulder, Ingrid M; Hagemans, Marloes L C; Hop, Wim C J; Oussoren, Esmee; Helbing, Wim A; van der Ploeg, Ans T

    2013-03-01

    We determined the cardiologic features of children with MPS I, II and VI, and evaluated the effect of enzyme-replacement therapy (ERT) on cardiac disease. Twenty-four children aged 1-18 years with MPS I, II or VI were prospectively evaluated with echocardiogram and electrocardiogram from the start of enzyme-replacement therapy up to 6 years of treatment. At start of therapy, 66% had abnormal cardiac geometric features. Left-ventricular mass index (LVMI) was increased in half of the patients, due mainly to concentric hypertrophy in MPS I and II and to eccentric hypertrophy in MPS VI. Regurgitation was most severe in a subgroup of young MPS VI patients ( 2. LVMI Z-scores decreased significantly in patients with MPS I and MPS II (p = 0.04 and p = 0.032). Despite ERT, valve regurgitation increased in 60% of the patients. We conclude that all our MPS patients have cardiac abnormalities. The most severe cardiac disease was observed in a subgroup of young MPS VI patients. While ERT had an effect on LVMI and IVSd, it apparently had little or none on valve regurgitation.

  18. Elastase-2, an angiotensin II-generating enzyme, contributes to increased Ang II in resistance arteries of mice with myocardial infarction.

    Science.gov (United States)

    Becari, Christiane; Silva, Marcondes A B; Durand, Marina T; Prado, Cibele M; Oliveira, Eduardo B; Ribeiro, Mauricio S; Salgado, Helio C; Salgado, Maria Cristina O; Tostes, Rita C

    2017-02-21

    Angiotensin II (Ang II), whose generation largely depends on angiotensin-converting enzyme activity, mediates most of the renin-angiotensin-system effects. Elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, alternatively generates Ang II in rat arteries. Myocardial infarction (MI) leads to intense RAS activation, but mechanisms involved on Ang II-generation in resistance arteries are unknown. We hypothesized that ELA-2 contributes to vascular Ang II generation and to cardiac damage in mice submitted to MI. Concentration-effect curves to Ang I and Ang II were performed in mesenteric resistance arteries from male wild type (WT) and ELA-2 knockout (ELA-2KO) mice submitted to left anterior descending coronary artery ligation (myocardial infarction, MI). MI size was similar in WT (29.5 ± 9 %) and ELA-2KO (32 ± 4%) mice. Ejection fraction and fractional shortening after MI similarly decreased in both strains. However, MI decreased stroke volume and cardiac output in WT, but not in ELA-2KO mice. Ang I-induced contractions increased in WT mice submitted to MI (MI-WT) compared to Sham-WT mice. No differences were observed in Ang I reactivity between arteries from Sham-ELA-2KO and ELA-2KO submitted to MI (MI-ELA-2KO). Ang I contractions increased in arteries from MI-WT vs. MI-ELA-2KO mice. Chymostatin attenuated Ang I-induced vascular contractions in WT mice (P ELA-2KO arteries. These results provide the first evidence that ELA-2 contributes to increased Ang II formation in resistance arteries and modulates cardiac function after MI, implicating ELA-2 as a key player in ACE-independent dysregulation of the RAS.

  19. Biocatalytic nerve agent detoxification in fire fighting foams.

    Science.gov (United States)

    LeJeune, K E; Russell, A J

    1999-03-20

    Current events across the globe necessitate rapid technological advances to combat the epidemic of nerve agent chemical weapons. Biocatalysis has emerged as a viable tool in the detoxification of organophosphorus neurotoxins, such as the chemical weapons VX and sarin. Efficient detoxification of contaminated equipment, machinery, and soils are of principal concern. This study describes the incorporation of a biocatalyst (organophosphorus hydrolase, E.C. 3.1.8.1) into conventional formulations of fire fighting foam. The capacity of fire fighting foams to decrease volatilization of contained contaminants, increase surface wettability, and control the rate of enzyme delivery to large areas makes them useful vehicles for enzyme application at surfaces. The performance of enzyme containing foams has been shown to be not only reproducible but also predictable. An empirical model provides reasonable estimations for the amounts of achievable surface decontamination as a function of the important parameters of the system. Theoretical modeling illustrates that the enzyme-containing foam is capable of extracting agent from the surface and is catalytically active at the foam-surface interface and throughout the foam itself. Biocatalytic foam has proven to be an effective, "environmentally friendly" means of surface and soil decontamination.

  20. Synthesis, characterization, antibacterial activities and carbonic anhydrase enzyme inhibitor effects of new arylsulfonylhydrazone and their Ni(II), Co(II) complexes

    Science.gov (United States)

    Özdemir, Ümmühan Özmen; Arslan, Fatma; Hamurcu, Fatma

    2010-01-01

    Ethane sulfonic acide hydrazide ( esh: CH 3CH 2SO 2NHNH 2) derivatives as 5-methylsalicyl-aldehydeethanesulfonylhydrazone ( 5msalesh), 5-methyl-2-hydroxyacetophenoneethane sulfonylhydrazone ( 5mafesh) and their Ni(II), Co(II) complexes have been synthesized for the first time. The structure of these compounds has been investigated by elemental analysis, FT-IR, 1H NMR, 13C NMR, LC/MS, UV-vis spectrophotometric method, magnetic susceptibility, thermal studies and conductivity measurements. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus, Bacillus subtilis, Bacillus magaterium and Gram negative bacteria; Salmonella enteritidis, Escherichia coli by using the microdilution broth method. The biological activity screening showed that ligands have more activity than complexes against the tested bacteria. The inhibition activities of these compounds on carbonic anhydrase II (CA II) have been investigated by comparing IC 50 and Ki values and it has been found that 5msalesh and its complexes have more enzyme inhibition efficiency than other compounds.

  1. Prediction of withdrawal symptoms during opioid detoxification

    NARCIS (Netherlands)

    Dijkstra, Boukje A G; Krabbe, Paul F M; De Jong, Cor A J; van der Staak, Cees P F

    2008-01-01

    OBJECTIVE: The severity of self-reported withdrawal symptoms varies during detoxification of opioid-dependent patients. The aim of this study is to identify subgroups of withdrawal symptoms within the detoxification trajectory and to predict the severity of withdrawal symptoms on the basis of

  2. Bifidobacterium longum subsp. longum Exo-β-1,3-Galactanase, an enzyme for the degradation of type II arabinogalactan.

    Science.gov (United States)

    Fujita, Kiyotaka; Sakaguchi, Takenori; Sakamoto, Ayami; Shimokawa, Michiko; Kitahara, Kanefumi

    2014-08-01

    Type II arabinogalactan (AG-II) is a suitable carbohydrate source for Bifidobacterium longum subsp. longum, but the degradative enzymes have never been characterized. In this study, we characterized an exo-β-1,3-galactanase, BLLJ_1840, belonging to glycoside hydrolase family 43 from B. longum subsp. longum JCM1217. The recombinant BLLJ_1840 expressed in Escherichia coli hydrolyzed β-1,3-linked galactooligosaccharides but not β-1,4- and β-1,6-linked galactooligosaccharides. The enzyme also hydrolyzed larch wood arabinogalactan (LWAG), which comprises a β-1,3-linked galactan backbone with β-1,6-linked galactan side chains. The kcat/Km ratio of dearabinosylated LWAG was 24-fold higher than that of β-1,3-galactan. BLLJ_1840 is a novel type of exo-β-1,3-galactanase with a higher affinity for the β-1,6-substituted β-1,3-galactan than for nonsubstituted β-1,3-galactan. BLLJ_1840 has 27% to 28% identities with other characterized exo--1,3-galactanases from bacteria and fungi. The homologous genes are conserved in several strains of B. longum subsp. longum and B. longum subsp. infantis but not in other bifidobacteria. Transcriptional analysis revealed that BLLJ_1840 is intensively induced with BLLJ_1841, an endo-β-1,6-galactanase candidate, in the presence of LWAG. This is the first report of exo-β-1,3-galactanase in bifidobacteria, which is an enzyme used for the acquisition of AG-II in B. longum subsp. longum.

  3. The role of copper(II) and zinc(II) in the degradation of human and murine IAPP by insulin-degrading enzyme.

    Science.gov (United States)

    Bellia, Francesco; Grasso, Giuseppe

    2014-04-01

    Amylin or islet amyloid polypeptide (IAPP) is a 37-residue peptide hormone secreted from the pancreatic islets into the blood circulation and is cleared by peptidases in the kidney. IAPP aggregates are strongly associated with β-cell degeneration in type 2 diabetes, as demonstrated by the fact that more than 95% of patients exhibit IAPP amyloid upon autopsy. Recently, it has been reported that metal ions such as copper(II) and zinc(II) are implicated in the aggregation of IAPP as well as able to modulate the proteolytic activity of IAPP degrading enzymes. For this reason, in this work, the role of the latter metal ions in the degradation of IAPP by insulin-degrading enzyme (IDE) has been investigated by a chromatographic and mass spectrometric combined method. The latter experimental approach allowed not only to assess the overall metal ion inhibition of the human and murine IAPP degradation by IDE but also to have information on copper- and zinc-induced changes in IAPP aggregation. In addition, IDE cleavage site preferences in the presence of metal ions are rationalized as metal ion-induced changes in substrate accessibility.

  4. 3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Pseudomonas aeruginosa: An Fe(II)-containing enzyme with fast turnover

    Science.gov (United States)

    Kamutira, Philaiwarong; Watthaisong, Pratchaya; Thotsaporn, Kittisak; Tongsook, Chanakan; Juttulapa, Maneerat; Nijvipakul, Sarayut; Chaiyen, Pimchai

    2017-01-01

    3,4-dihydroxyphenylacetate (DHPA) dioxygenase (DHPAO) from Pseudomonas aeruginosa (PaDHPAO) was overexpressed in Escherichia coli and purified to homogeneity. As the enzyme lost activity over time, a protocol to reactivate and conserve PaDHPAO activity has been developed. Addition of Fe(II), DTT and ascorbic acid or ROS scavenging enzymes (catalase or superoxide dismutase) was required to preserve enzyme stability. Metal content and activity analyses indicated that PaDHPAO uses Fe(II) as a metal cofactor. NMR analysis of the reaction product indicated that PaDHPAO catalyzes the 2,3-extradiol ring-cleavage of DHPA to form 5-carboxymethyl-2-hydroxymuconate semialdehyde (CHMS) which has a molar absorptivity of 32.23 mM-1cm-1 at 380 nm and pH 7.5. Steady-state kinetics under air-saturated conditions at 25°C and pH 7.5 showed a Km for DHPA of 58 ± 8 μM and a kcat of 64 s-1, indicating that the turnover of PaDHPAO is relatively fast compared to other DHPAOs. The pH-rate profile of the PaDHPAO reaction shows a bell-shaped plot that exhibits a maximum activity at pH 7.5 with two pKa values of 6.5 ± 0.1 and 8.9 ± 0.1. Study of the effect of temperature on PaDHPAO activity indicated that the enzyme activity increases as temperature increases up to 55°C. The Arrhenius plot of ln(k’cat) versus the reciprocal of the absolute temperature shows two correlations with a transition temperature at 35°C. Two activation energy values (Ea) above and below the transition temperature were calculated as 42 and 14 kJ/mol, respectively. The data imply that the rate determining steps of the PaDHPAO reaction at temperatures above and below 35°C may be different. Sequence similarity network analysis indicated that PaDHPAO belongs to the enzyme clusters that are largely unexplored. As PaDHPAO has a high turnover number compared to most of the enzymes previously reported, understanding its biochemical and biophysical properties should be useful for future applications in biotechnology

  5. Cysteine biosynthesis, in concert with a novel mechanism, contributes to sulfide detoxification in mitochondria of Arabidopsis thaliana.

    Science.gov (United States)

    Birke, Hannah; Haas, Florian H; De Kok, Luit J; Balk, Janneke; Wirtz, Markus; Hell, Rüdiger

    2012-07-15

    In higher plants, biosynthesis of cysteine is catalysed by OAS-TL [O-acetylserine(thiol)lyase], which replaces the activated acetyl group of O-acetylserine with sulfide. The enzyme is present in cytosol, plastids and mitochondria of plant cells. The sole knockout of mitochondrial OAS-TL activity (oastlC) leads to significant reduction of growth in Arabidopsis thaliana. The reason for this phenotype is still enigmatic, since mitochondrial OAS-TL accounts only for approximately 5% of total OAS-TL activity. In the present study we demonstrate that sulfide specifically intoxicates Complex IV activity, but not electron transport through Complexes II and III in isolated mitochondria of oastlC plants. Loss of mitochondrial OAS-TL activity resulted in significant inhibition of dark respiration under certain developmental conditions. The abundance of mitochondrially encoded proteins and Fe-S cluster-containing proteins was not affected in oastlC. Furthermore, oastlC seedlings were insensitive to cyanide, which is detoxified by β-cyano-alanine synthase in mitochondria at the expense of cysteine. These results indicate that in situ biosynthesis of cysteine in mitochondria is not mandatory for translation, Fe-S cluster assembly and cyanide detoxification. Finally, we uncover an OAS-TL-independent detoxification system for sulfide in mitochondria of Arabidopsis that allows oastlC plants to cope with high sulfide levels caused by abiotic stresses.

  6. Effect of low dose spinetoram on detoxification enzymes inPlutella xylostella%低剂量乙基多杀菌素对小菜蛾解毒酶的影响

    Institute of Scientific and Technical Information of China (English)

    田雪莲; 尹显慧; 龙友华; 李明; 蔡滔; 李荣玉; 朱流红

    2016-01-01

    为探讨低剂量乙基多杀菌素对小菜蛾Plutella xylostella (L.)解毒酶的影响,采用叶片浸渍法,测定了乙基多杀菌素和多杀菌素对小菜蛾敏感种群的毒力,并比较了低剂量(LC25和LC50)处理6、12、24、48和72 h时小菜蛾体内羧酸酯酶(CarE)、谷胱甘肽S-转移酶(GST)和多功能氧化酶系(MFOs)活性的变化动态。结果表明:乙基多杀菌素对小菜蛾的杀虫活性优于多杀菌素,处理48 h后其 LC25和 LC50浓度分别为0.018和0.048 mg/L,经此低剂量浓度处理后,小菜蛾 CarE活性波动较大,6~24 h,处理组 CarE活性高于对照组,且均呈先升后降趋势,24~72 h,处理组 CarE活性均低于对照组,并且具有一定的时间效应;对 GST具有明显的诱导作用,GST活性均高于对照组;对 MFOs具有明显的抑制作用,除在48 h时相差不大外,其他时间 MFOs活性均显著低于对照组。结果表明,GST可能参与了乙基多杀菌素在小菜蛾体内的代谢。%To clarify the effects of low dose spinetoram on the activitiy of detoxifying enzymes in Plutella xylostella (L.), the toxicities of spinetoram and spinosad to susceptible population ofP. xylostella were assayed using leaf dipping method. And the changing dynamics of detoxifying enzymes of carboxylesterase, glutathioneS-transferase and mixed-functional oxidase were measured after exposure to LC25 and LC50 doses of spinetoram at 6, 12, 24, 48 and 72 h, respectively. The results showed that the spinetoram had higher toxicity toP. xylostella than that of spinosad. The 48 h LC25 and LC50 of spinetoram were 0.018 and 0.048 mg/L, respectively. After treatment with low concentrations spinetoram, a large fluctuation of the CarE was observed. CarE activity in the treatment strain were higher than those in the untreated control strain after treatment 6-24 h, and showed tendency of first increasing and then decreasing. Whereas, from 24 h to 72 h, CarE activity was lower

  7. Association of angiotensin-converting enzyme and angiotensin II type I receptor gene polymorphisms with extreme obesity in Polish individuals.

    Science.gov (United States)

    Pacholczyk, Marta; Ferenc, Tomasz; Kowalski, Jan; Adamczyk, Przemysław; Chojnowski, Jacek; Ponikowska, Irena

    2013-08-01

    There is strong evidence for the presence of a functional renin-angiotensin system in human adipose tissue. The aim of our study was to investigate the association of polymorphic variants of angiotensin-converting enzyme gene (ACE I/D) and angiotensin II type I receptor gene (AGTR1 A1166C) with extreme obesity and obesity-associated type 2 diabetes mellitus (T2DM) and to examine their combined effect on extremely obese patients. Overall, no significant associations were detected between ACE and AGTR1 gene polymorphisms and extreme obesity. However, extremely obese patients with T2DM showed an increased frequency of ACE II genotype compared with controls (pAGTR1 gene, regardless of the presence of T2DM. Moreover, the analysis of genetic polymorphisms demonstrated that ACE II and AGTR1 AC genotypes were most frequently observed in patients with extreme obesity and T2DM. On the basis of our results, we suggest that ACE II homozygosity may be a significant predictor of extreme obesity and T2DM and that the interaction between ACE and AGTR1 genes may be considered a predisposing factor for extreme obesity and extreme obesity-associated T2DM development.

  8. Cryptic indole hydroxylation by a non-canonical terpenoid cyclase parallels bacterial xenobiotic detoxification

    Science.gov (United States)

    Kugel, Susann; Baunach, Martin; Baer, Philipp; Ishida-Ito, Mie; Sundaram, Srividhya; Xu, Zhongli; Groll, Michael; Hertweck, Christian

    2017-06-01

    Terpenoid natural products comprise a wide range of molecular architectures that typically result from C-C bond formations catalysed by classical type I/II terpene cyclases. However, the molecular diversity of biologically active terpenoids is substantially increased by fully unrelated, non-canonical terpenoid cyclases. Their evolutionary origin has remained enigmatic. Here we report the in vitro reconstitution of an unusual flavin-dependent bacterial indoloterpenoid cyclase, XiaF, together with a designated flavoenzyme-reductase (XiaP) that mediates a key step in xiamycin biosynthesis. The crystal structure of XiaF with bound FADH2 (at 2.4 Å resolution) and phylogenetic analyses reveal that XiaF is, surprisingly, most closely related to xenobiotic-degrading enzymes. Biotransformation assays show that XiaF is a designated indole hydroxylase that can be used for the production of indigo and indirubin. We unveil a cryptic hydroxylation step that sets the basis for terpenoid cyclization and suggest that the cyclase has evolved from xenobiotics detoxification enzymes.

  9. Solar detoxification of waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, J. M.

    2000-07-01

    Heterogeneous photocatalysis is a discipline which includes a large variety of reactions: mild or total oxidations, dehydrogenation, hydrogen transfer. oxygen-18 and deuterium isotopic exchange, metal deposition, water detoxification, gaseous pollutant removal, etc. In line with the latter point, it can be considered as one of the new Advanced Oxidation Technologies (AOT) for air and water purification treatment. Several books and reviews have been recently devoted to this problem (1-6). A recent review has reported more than 1200 references on the subject (7). Heterogeneous photocatalysis can be carried out in various media: gas phase, pure organic liquid phases or aqueous solutions. As for classical heterogeneous catalysis, the overall process can be decomposed into five independent steps: 1. Transfer of the reactants in the fluid to the surface. 2. Adsorption of a least one of the reactants. 3. Reaction in the adsorbed phase 4. Desorption of the product (s) 5. Removal of the products from the interface region. (Author) 11 refs.

  10. Solar Detoxification of Waste Waters

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, J.M.

    2002-07-01

    Heterogeneous photocatalysis is a discipline which includes a large variety of reactions: mild or total oxidations, dehydrogenation, hydrogen transfer, oxygen-18 and deuterium isotopic exchange, metal deposition, water detoxification, gaseous pollutant removal, etc. In line with the latter point, it can be considered as one of the new. Advanced Oxidation Technologies (AOT) for air and water purification treatment. Several books and reviews have been recently devoted to this problem (1-6). A recent review has reported more than 1200 references on the subject. Heterogeneous photocatalysis can be carried out in various media: gas phase, pure organic liquid phases or aqueous solutions. As for classical heterogeneous catalysis, the overall process can be decomposed into five independent steps: 1. Transfer of the reactants in the fluid phase to the surface 2. Adsorption of a least one of the reactants 3. Reaction in the adsorbed phase 4. Desorption of the products 5. Removal of the products from the interface region. (Author)

  11. Abstinence phenomena of chronic cannabis-addicts prospectively monitored during controlled inpatient detoxification (Part II): Psychiatric complaints and their relation to delta-9-tetrahydrocannabinol and its metabolites in serum.

    Science.gov (United States)

    Bonnet, Udo; Borda, Thorsten; Scherbaum, Norbert; Specka, Michael

    2015-10-01

    To investigate the impact of inpatient detoxification treatment on psychiatric symptoms of chronic cannabis addicts and to analyze the influence of serum cannabinoid levels on the severity of these symptoms. Thirty five treatment-seeking, not active co-morbid chronic cannabis dependents (ICD-10) were studied on admission and on abstinence days 8 and 16, using several observational and self-report scales, such as Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), Young Mania Rating Scale (YMRS) and Brief Psychiatric Rating Scale (BPRS), and the Symptom Checklist-90-Revised (SCL-90-R). Simultaneously obtained serum was analyzed with regard to levels of delta-9-tetrahydrocannabinol (THC) and its main metabolites 11-hydroxy-delta-9-tetrahydrocannabinol (THC-OH) and 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). At admission, nearly 90% of the patients were not, or only mildly, affected by depression, anxiety or manic symptoms. In contrast, patients' self-description indicated a strong psychiatric burden in approximately 60% of the cases. All patients improved significantly within 16 days of the treatment. Effect sizes ranged from 0.7 to 1.4. (Cohen's d) for the respective scales. Serum THC-levels were positively associated with impairment of cognition in HAMA and motor retardation in BPRS. All other test results were not significantly related to the serum levels of the measured cannabinoids. Effects of the cannabis withdrawal syndrome and executive dysfunctions might explain the discrepancy between the observer ratings and self-reported psychiatric burden. Inpatient cannabis detoxification treatment significantly improved psychiatric symptoms. Serum THC-levels were not associated with affective symptoms and anxiety but predicted cognitive impairment and motor retardation. Copyright © 2015. Published by Elsevier Ireland Ltd.

  12. Triesterase and promiscuous diesterase activities of a di-Co(II)-containing organophosphate degrading enzyme reaction mechanisms.

    Science.gov (United States)

    Alberto, Marta E; Pinto, Gaspar; Russo, Nino; Toscano, Marirosa

    2015-02-23

    The reaction mechanism for the hydrolysis of trimethyl phosphate and of the obtained phosphodiester by the di-Co(II) derivative of organophosphate degrading enzyme from Agrobacterium radiobacter P230(OpdA), have been investigated at density functional level of theory in the framework of the cluster model approach. Both mechanisms proceed by a multistep sequence and each catalytic cycle begins with the nucleophilic attack by a metal-bound hydroxide on the phosphorus atom of the substrate, leading to the cleavage of the phosphate-ester bond. Four exchange-correlation functionals were used to derive the potential energy profiles in protein environments. Although the enzyme is confirmed to work better as triesterase, as revealed by the barrier heights in the rate-limiting steps of the catalytic processes, its promiscuous ability to hydrolyze also the product of the reaction has been confirmed. The important role played by water molecules and some residues in the outer coordination sphere has been elucidated, while the binuclear Co(II) center accomplishes both structural and catalytic functions. To correctly describe the electronic configuration of the d shell of the metal ions, high- and low-spin arrangement jointly with the occurrence of antiferromagnetic coupling, have been herein considered.

  13. Genetic Polymorphisms of Phase II Metabolic Enzymes and Lung Cancer Susceptibility in a Population of Central South China

    Directory of Open Access Journals (Sweden)

    Han-chun Chen

    2006-01-01

    Full Text Available A case-control study was conducted for analyzing the genetic polymorphisms of phase II metabolic enzymes in 97 patients with lung cancer and 197 healthy subjects from Han ethnic group of Hunan Province located in Central South China. The results showed that the frequencies of glutathione S-transferase (GST M1-null (GSTM1- or GSTT1-null (GSTT1- genotype alone, or combined form of both in lung cancer patients were significantly higher than those of the controls. Genotypes of combining GSTP1 mutant/GSTM1(- or GSTP1 mutant/GSTT1(- led to high risk of lung cancer. Individuals carrying any two or all three of GSTM1(-, GSTT1(- and GSTP1 mutant genotypes have a distinctly increased risk of lung cancer when compared to those with GSTM1 present (GSTM1+: GSTM1+/+ or GSTM1+/−, GSTT1 present (GSTT1+: GSTT1+/+ or GSTT1+/− and GSTP1 wild genotypes. Furthermore, individuals possessing combined genotypes of N-acetyltransferase 2 (NAT2 rapid acetylator, GSTP1 mutant and both GSTT1(- and GSTM1(- have a remarkably higher lung cancer risk than those carrying combined NAT2 slow acetylator genotype, GSTP1 wild genotype and both GSTT1(+ and GSTM1(+ genotypes. All these findings suggest that the genetic polymorphisms of phase II metabolic enzymes affect the susceptibility of lung cancer in the Han ethnic group of Central South China.

  14. Gene expression in the DpnI and DpnII restriction enzyme systems of Streptococcus pneumoniae

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.; Sabelnikov, A.G.; Chen, Jau-Der; Greenberg, B.

    1992-12-31

    Although a number of bacterial species are naturally transformable, that is, their cells are able to take up external DNA in substantial amounts and integrate it into the chromosome without artificial manipulation of the cell surface, Streptococcus pneumoniae, the first species in which this phenomenon was detected, remains a prototype of such transformation. Cells of S. pneumonias also contain potent restriction endonucleases able to severely restrict DNA introduced during viral infection. Our current understanding of the genetic basis of the complementary DpnI and DpnII restriction systems and of the biochemistry of their component enzymes are briefly reviewed. The manner in which these enzymes impinge on the transfer of chromosomal genes and of plasmeds will be examined in detail. It will be seen that far from acting against foreign DNA in general, the restriction systems seem to be designed to exclude only infecting viral DNA The presence of complementary restriction systems in different cells of S. pneumonias enhances their effectiveness in blocking viral infection and promoting species survival. This enhanced effectiveness requires the expression of alternative restriction systems. Therefore, the ability of the cells to transfer the restriction enzyme genes and to regulate their expression are important for survival of the species.

  15. Preparation of a Cu(II-PVA/PA6 Composite Nanofibrous Membrane for Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Dayin Hou

    2012-10-01

    Full Text Available PVA/PA6 composite nanofibers were formed by electrospinning. Cu(II-PVA/PA6 metal chelated nanofibers, prepared by the reaction between PVA/PA6 composite nanofibers and Cu2+ solution, were used as the support for catalase immobilization. The result of the experiments showed that PVA/PA6 composite nanofibers had an excellent chelation capacity for Cu2+ ions, and the structures of nanofibers were stable during the reaction with Cu2+ solution. The adsorption of Cu(II onto PVA/PA6 composite nanofibers was studied by the Langmuir isothermal adsorption model. The maximum amount of coordinated Cu(II (qm was 3.731 mmol/g (dry fiber, and the binding constant (Kl was 0.0593 L/mmol. Kinetic parameters were analyzed for both immobilized and free catalases. The value of Vmax (3774 μmol/mg·min for the immobilized catalases was smaller than that of the free catalases (4878 μmol/mg·min, while the Km for the immobilized catalases was larger. The immobilized catalases showed better resistance to pH and temperature than that of free form, and the storage stabilities, reusability of immobilized catalases were significantly improved. The half-lives of free and immobilized catalases were 8 days and 24 days, respectively.

  16. Preparation of a Cu(II)-PVA/PA6 composite nanofibrous membrane for enzyme immobilization.

    Science.gov (United States)

    Feng, Quan; Tang, Bin; Wei, Qufu; Hou, Dayin; Bi, Songmei; Wei, Anfang

    2012-10-05

    PVA/PA6 composite nanofibers were formed by electrospinning. Cu(II)-PVA/PA6 metal chelated nanofibers, prepared by the reaction between PVA/PA6 composite nanofibers and Cu2+ solution, were used as the support for catalase immobilization. The result of the experiments showed that PVA/PA6 composite nanofibers had an excellent chelation capacity for Cu2+ ions, and the structures of nanofibers were stable during the reaction with Cu2+ solution. The adsorption of Cu(II) onto PVA/PA6 composite nanofibers was studied by the Langmuir isothermal adsorption model. The maximum amount of coordinated Cu(II) (q(m)) was 3.731 mmol/g (dry fiber), and the binding constant (K(l)) was 0.0593 L/mmol. Kinetic parameters were analyzed for both immobilized and free catalases. The value of V(max) (3774 μmol/mg·min) for the immobilized catalases was smaller than that of the free catalases (4878 μmol/mg·min), while the K(m) for the immobilized catalases was larger. The immobilized catalases showed better resistance to pH and temperature than that of free form, and the storage stabilities, reusability of immobilized catalases were significantly improved. The half-lives of free and immobilized catalases were 8 days and 24 days, respectively.

  17. Multiple roles for plant glutathione transferases in xenobiotic detoxification.

    Science.gov (United States)

    Cummins, Ian; Dixon, David P; Freitag-Pohl, Stefanie; Skipsey, Mark; Edwards, Robert

    2011-05-01

    Discovered 40 years ago, plant glutathione transferases (GSTs) now have a well-established role in determining herbicide metabolism and selectivity in crops and weeds. Within the GST superfamily, the numerous and plant-specific phi (F) and tau (U) classes are largely responsible for catalyzing glutathione-dependent reactions with xenobiotics, notably conjugation leading to detoxification and, more rarely, bioactivating isomerizations. In total, the crystal structures of 10 plant GSTs have been solved and a highly conserved N-terminal glutathione binding domain and structurally diverse C-terminal hydrophobic domain identified, along with key coordinating residues. Unlike drug-detoxifying mammalian GSTs, plant enzymes utlilize a catalytic serine in place of a tyrosine residue. Both GSTFs and GSTUs undergo changes in structure during catalysis indicative of an induced fit mechanism on substrate binding, with an understanding of plant GST structure/function allowing these proteins to be engineered for novel functions in detoxification and ligand recognition. Several major crops produce alternative thiols, with GSTUs shown to use homoglutathione in preference to glutathione, in herbicide detoxification reactions in soybeans. Similarly, hydroxymethylglutathione is used, in addition to glutathione in detoxifying the herbicide fenoxaprop in wheat. Following GST action, plants are able to rapidly process glutathione conjugates by at least two distinct pathways, with the available evidence suggesting these function in an organ- and species-specific manner. Roles for GSTs in endogenous metabolism are less well defined, with the enzymes linked to a diverse range of functions, including signaling, counteracting oxidative stress, and detoxifying and transporting secondary metabolites.

  18. 细辛精油对2种农业害虫保护酶和解毒酶活性的影响%Effects of Asarum Essential Oils on Protection/Detoxification Enzyme Activities of Two Agricultural Pest Insects

    Institute of Scientific and Technical Information of China (English)

    姬兰柱; 王桂清; 刘艳; 王远遐; 张悦; 易雪梅

    2013-01-01

    To evaluate the insecticidal potential and mechanism of asarum essential oils ,the effects of three kinds of asarum essential oils extracted by different methods on protection/detoxification enzyme activities of Asian corn borer[Ostrinia furnacalis(Guenee)] and army worm[Mythimna seperata(Walker)] were studied .The three asarum essential oils were as follows :essential oil X1 was extracted by steam distillation method ,essential oil X3 was extracted by supercritical CO2 ex-traction method ,and essential oil X5 was a product obtained by refining X3 through a silica gel column chromatography .X1 was sprayed on the corn sprout ,according to a dose of 1 000 mg/L . X3 and X5 were separately added to the corn borer artificial feed ,according to a dose of 0 .5 mg/g . The experiment tested the response of Asian corn borer larvae fed on artificial diet containing X 3 or X5 ,and response of army worm larvae fed on tender corn shoots containing X 1 .In control group ,asarum essential oil was not added .The results showed that ,under the set experimental concentrations ,essential oils X1 and X3 inhibited the activities of three protective enzymes (su-peroxide dismutase ,SOD ;catalase ,CAT ;peroxidase ,POD) of the test insects ;X5 showed cer-tain inhibitory effect on POD activity of the test insects ,but exhibited an activation effect on SOD and CAT .Asarum essential oils showed some activation effect on carboxylesterase (CarE) ,acid phosphatase (ApE) and glutathione S-transferase (GST ) ,but the degree of activation effect re-duced over time ,meanwhile alkaline phosphatase(ALP) activity significantly increased early ,then significantly reduced ,w hich demonstrated that insects firstly increased their detoxification ability under excessive exogenous compound ,and then the detoxification capacity would decrease with the accumulation of toxic substances .The insecticidal effect of asarum essential oils may be achieved by inhibiting the insects’ protective enzymes .%为评价

  19. ETS: DEVELOPMENT OF A PHOTOTHERMAL DETOXIFICATION UNIT

    Science.gov (United States)

    There has long been interest in utilizing photochemical methods for destroying hazardous organic materials. Unfortunately, the direct application of classic, low temperature photochemical processes to hazardous waste detoxification is often too slow to be practical for wide spre...

  20. ETS: DEVELOPMENT OF A PHOTOTHERMAL DETOXIFICATION UNIT

    Science.gov (United States)

    There has long been interest in utilizing photochemical methods for destroying hazardous organic materials. Unfortunately, the direct application of classic, low temperature photochemical processes to hazardous waste detoxification is often too slow to be practical for wide spre...

  1. Shotgun proteomic analysis unveils survival and detoxification strategies by Caulobacter crescentus during exposure to uranium, chromium, and cadmium.

    Science.gov (United States)

    Yung, Mimi C; Ma, Jincai; Salemi, Michelle R; Phinney, Brett S; Bowman, Grant R; Jiao, Yongqin

    2014-04-01

    The ubiquitous bacterium Caulobacter crescentus holds promise to be used in bioremediation applications due to its ability to mineralize U(VI) under aerobic conditions. Here, cell free extracts of C. crescentus grown in the presence of uranyl nitrate [U(VI)], potassium chromate [Cr(VI)], or cadmium sulfate [Cd(II)] were used for label-free proteomic analysis. Proteins involved in two-component signaling and amino acid metabolism were up-regulated in response to all three metals, and proteins involved in aerobic oxidative phosphorylation and chemotaxis were down-regulated under these conditions. Clustering analysis of proteomic enrichment revealed that the three metals also induce distinct patterns of up- or down-regulated expression among different functional classes of proteins. Under U(VI) exposure, a phytase enzyme and an ABC transporter were up-regulated. Heat shock and outer membrane responses were found associated with Cr(VI), while efflux pumps and oxidative stress proteins were up-regulated with Cd(II). Experimental validations were performed on select proteins. We found that a phytase plays a role in U(VI) and Cr(VI) resistance and detoxification and that a Cd(II)-specific transporter confers Cd(II) resistance. Interestingly, analysis of promoter regions in genes associated with differentially expressed proteins suggests that U(VI) exposure affects cell cycle progression.

  2. Detoxification of Abrus precatorius L. seeds by Ayurvedic Shodhana process and anti-inflammatory potential of the detoxified extract

    OpenAIRE

    Dhoble, Sagar B.; Majumdar, Anuradha S.

    2014-01-01

    Background: Abrus precatorius seeds traditionally used for the treatment of sciatica and alopecia contains the toxic protein, abrin, a Type II Ribosome Inactivating Protein. Ayurveda recommends the use of Abrus seeds after the Shodhana process (detoxification). Objective: The current study was aimed at performing the Shodhana process, swedana (boiling) of Abrus precatorius seeds using water as a medium and to evaluate the anti-inflammatory potential of seed extract post detoxification. Materi...

  3. Gene expression of transporters and phase I/II metabolic enzymes in murine small intestine during fasting

    Directory of Open Access Journals (Sweden)

    van der Meijde Jolanda

    2007-08-01

    Full Text Available Abstract Background Fasting has dramatic effects on small intestinal transport function. However, little is known on expression of intestinal transport and phase I/II metabolism genes during fasting and the role the fatty acid-activated transcription factor PPARα may play herein. We therefore investigated the effects of fasting on expression of these genes using Affymetrix GeneChip MOE430A arrays and quantitative RT-PCR. Results After 24 hours of fasting, expression levels of 33 of the 253 analyzed transporter and phase I/II metabolism genes were changed. Upregulated genes were involved in transport of energy-yielding molecules in processes such as glycogenolysis (G6pt1 and mitochondrial and peroxisomal oxidation of fatty acids (Cact, Mrs3/4, Fatp2, Cyp4a10, Cyp4b1. Other induced genes were responsible for the inactivation of the neurotransmitter serotonin (Sert, Sult1d1, Dtd, Papst2, formation of eicosanoids (Cyp2j6, Cyp4a10, Cyp4b1, or for secretion of cholesterol (Abca1 and Abcg8. Cyp3a11, typically known because of its drug metabolizing capacity, was also increased. Fasting had no pronounced effect on expression of phase II metabolic enzymes, except for glutathione S-transferases which were down-regulated. Time course studies revealed that some genes were acutely regulated, whereas expression of other genes was only affected after prolonged fasting. Finally, we identified 8 genes that were PPARα-dependently upregulated upon fasting. Conclusion We have characterized the response to fasting on expression of transporters and phase I/II metabolic enzymes in murine small intestine. Differentially expressed genes are involved in a variety of processes, which functionally can be summarized as a increased oxidation of fat and xenobiotics, b increased cholesterol secretion, c increased susceptibility to electrophilic stressors, and d reduced intestinal motility. This knowledge increases our understanding of gut physiology, and may be of relevance

  4. Aflatoxin detoxification by manganese peroxidase purified from Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Ramy Sayed Yehia

    2014-01-01

    Full Text Available Manganese peroxidase (MnP was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH42SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81UmL-1, specific activity 78 U mg-1 with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 ºC. The pure MnP activity was enhanced by Mn2+,Cu2+,Ca2+ and K+ and inhibited by Hg+2 and Cd+2.H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined (GenBank accession no. AB698450.1. The MnP-cDNA was found to consist of 497 bp in an Open Reading Frame (ORF encoding 165 amino acids. MnP from P. ostreatus could detoxify aflatoxin B1 (AFB1 depending on enzyme concentration and incubation period. The highest detoxification power (90% was observed after 48 h incubation at 1.5 U mL-1 enzyme activities.

  5. Aflatoxin detoxification by manganese peroxidase purified from Pleurotus ostreatus.

    Science.gov (United States)

    Yehia, Ramy Sayed

    2014-01-01

    Manganese peroxidase (MnP) was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH4)2SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81 U mL(-1), specific activity 78 U mg(-1) with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 °C. The pure MnP activity was enhanced by Mn(2+), Cu(2+), Ca(2+) and K(+) and inhibited by Hg(+2) and Cd(+2). H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined (GenBank accession no. AB698450.1). The MnP-cDNA was found to consist of 497 bp in an Open Reading Frame (ORF) encoding 165 amino acids. MnP from P. ostreatus could detoxify aflatoxin B1 (AFB1) depending on enzyme concentration and incubation period. The highest detoxification power (90%) was observed after 48 h incubation at 1.5 U mL(-1) enzyme activities.

  6. A novel whole genome amplification method using type IIS restriction enzymes to create overhangs with random sequences.

    Science.gov (United States)

    Pan, Xiaoming; Wan, Baihui; Li, Chunchuan; Liu, Yu; Wang, Jing; Mou, Haijin; Liang, Xingguo

    2014-08-20

    Ligation-mediated polymerase chain reaction (LM-PCR) is a whole genome amplification (WGA) method, for which genomic DNA is cleaved into numerous fragments and then all of the fragments are amplified by PCR after attaching a universal end sequence. However, the self-ligation of these fragments could happen and may cause biased amplification and restriction of its application. To decrease the self-ligation probability, here we use type IIS restriction enzymes to digest genomic DNA into fragments with 4-5nt long overhangs with random sequences. After ligation to an adapter with random end sequences to above fragments, PCR is carried out and almost all present DNA sequences are amplified. In this study, whole genome of Vibrio parahaemolyticus was amplified and the amplification efficiency was evaluated by quantitative PCR. The results suggested that our approach could provide sufficient genomic DNA with good quality to meet requirements of various genetic analyses.

  7. Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, E.

    1998-02-01

    The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds produced during hydrolysis. Evaluation of the effect of various biological, physical and chemical detoxification treatments by fermentation assays using Saccharomyces cerevisiae was used to characterise inhibitors. Inhibition of fermentation was decreased after removal of the non-volatile compounds, pre-fermentation by the filamentous fungus Trichoderma reesei, treatment with the lignolytic enzyme laccase, extraction with ether, and treatment with alkali. Yeast growth in lignocellulosic hydrolysates was inhibited below a certain fermentation pH, most likely due to high concentrations of undissociated weak acids. The effect of individual compounds were studied in model fermentations. Furfural is reduced to furfuryl alcohol by yeast dehydrogenases, thereby affecting the intracellular redox balance. As a result, acetaldehyde accumulated during furfural reduction, which most likely contributed to inhibition of growth. Acetic acid (10 g 1{sup -1}) and furfural (3 g 1{sup -1}) interacted antagonistically causing decreased specific growth rate, whereas no significant individual or interaction effects were detected by the lignin-derived compound 4-hydroxybenzoic acid (2 g 1{sup -1}). By maintaining a high cell mass density in the fermentor, the process was less sensitive to inhibitors affecting growth and to fluctuations in fermentation pH, and in addition the depletion rate of bioconvertible inhibitors was increased. A theoretical ethanol yield and high productivity was obtained in continuous fermentation of spruce hydrolysate when the cell mass concentration was maintained at a high level by applying cell recirculation 164 refs, 16 figs, 5 tabs

  8. Detoxification Mechanisms of Mercury Toxicity in Plants: A Review

    Directory of Open Access Journals (Sweden)

    Shilpa Shrivastava

    2015-12-01

    Full Text Available Mercury is one of the most toxic heavy metals present in the earth’s crust. It has been considered as environmental pollutant because of its potent toxicity to plants and humans. In this review, we discuss mercury toxicity responses on plant metabolism and its detoxification mechanism by phytochelatins and antioxidant enzymes. Some light is also shed on selenium antagonistic study with mercury. Due to its potential toxicity, it has attracted attention in fields of soil science and plant nutrition. Mercury has harmful toxic effects on the molecular and physiobiochemical behavior of plants. Mostly research work has been done on seed germination, and shoot, root, and leaf morphology. Enzyme responses with respect to mercury as a result Hg accumulated in food chain is also reviewed here. Hence, this review may provide a compiled data for other researches in this direction, to provide a better mechanism or details about mercury’s noxious effect in the ecosystem.

  9. Comparative study on the impact of copper sulphate and copper nitrate on the detoxification mechanisms in Typha latifolia.

    Science.gov (United States)

    Lyubenova, Lyudmila; Bipuah, Hanif; Belford, Ebenezer; Michalke, Bernhard; Winkler, Barbro; Schröder, Peter

    2015-01-01

    The present study focused on cupric sulphate and cupric nitrate uptake in Typha latifolia and the impact of these copper species on the plant's detoxification capacity. When the plants were exposed to 10, 50 and 100 μM cupric sulphate or cupric nitrate, copper accumulation in T. latifolia roots and shoots increased with rising concentration of the salts. Shoot to root ratios differed significantly depending on the form of copper supplementation, e.g. if it was added as cupric (II) sulphate or cupric (II) nitrate. After incubation with 100 μM of cupric sulphate, up to 450 mg Cu/kg fresh weight (FW) was accumulated, whereas the same concentration of cupric nitrate resulted in accumulation of 580 mg/kg FW. Furthermore, significant differences in the activity of some antioxidative enzymes in Typha roots compared to the shoots, which are essential in the plant's reaction to cope with metal stress, were observed. The activity of peroxidase (POX) in roots was increased at intermediate concentrations (10 and 50 μM) of CuSO4, whereas it was inhibited at the same Cu(NO3)2 concentrations. Ascorbate peroxidase (APOX) and dehydroascorbate reductase (DHAR) increased their enzyme activity intensely, which may be an indication for copper toxicity in T. latifolia plants. Besides, fluorodifen conjugation by glutathione S-transferases (GSTs) was increased up to sixfold, especially in roots.

  10. Effect of anthocyanin fractions from selected cultivars of Georgia-grown blueberries on apoptosis and phase II enzymes.

    Science.gov (United States)

    Srivastava, Anita; Akoh, Casimir C; Fischer, Joan; Krewer, Gerard

    2007-04-18

    In recent years, considerable attention has been paid to anthocyanins due to their abilities to inhibit oxidative stress and cell proliferation. The regulations of apoptosis and the phase II enzymes glutathione-S-transferase (GST) and quinone reductase (QR) are other potential mechanisms through which flavonoids such as anthocyanins may prevent cancer. Our study confirmed that anthocyanin fractions from high bush blueberry cultivars increased apoptosis using two different methods: DNA fragmentation and caspase-3 activity. The effect of anthocyanins on the activity of the detoxifying enzymes GST and QR was also determined. Major anthocyanins identified were delphinidin, cyanidin, peonidin, petunidin, and malvidin. In Tifblue and Powderblue cultivars, DNA fragmentation increased at anthocyanin concentrations from 50 to 150 microg/mL, but cells treated with the anthocyanin fraction of Brightblue and Brightwell showed a prominent ladder at 50-100 microg/mL when compared to cells treated with 150 microg/mL. There was a significant difference in the caspase-3 activity (P cultivars. The response correlated positively with dose. The QR activity was lower in all cells treated with an anthocyanin fraction from Tifblue, Powderblue, Brightblue, and Brightwell cultivars than in control cells (P cultivars. The GST activity was lower (P cultivars and at all concentrations. These results indicated that apoptosis was confirmed in HT-29 cells when treated with anthocyanins from blueberry cultivars at 50-150 microg/mL concentrations, but these same concentrations decrease QR and GST activities rather than induce them.

  11. Bioactive compounds extracted from Indian wild legume seeds: antioxidant and type II diabetes-related enzyme inhibition properties.

    Science.gov (United States)

    Gautam, Basanta; Vadivel, Vellingiri; Stuetz, Wolfgang; Biesalski, Hans K

    2012-03-01

    Seven different wild legume seeds (Acacia leucophloea, Bauhinia variegata, Canavalia gladiata, Entada scandens, Mucuna pruriens, Sesbania bispinosa and Tamarindus indica) from various parts of India were analyzed for total free phenolics, l-Dopa (l-3,4 dihydroxyphenylalanine), phytic acid and their antioxidant capacity (ferric-reducing antioxidant power [FRAP] and 2,2-diphenyl-1-picrylhydrazyl [DPPH] assay) and type II diabetes-related enzyme inhibition activitiy (α-amylase). S. bispinosa had the highest content in both total free phenolics and l-Dopa, and relatively low phytic acid when compared with other seeds. Phytic acid content, being highest in E. scandens, M. pruriens and T. indica, was highly predictive for FRAP (r = 0.47, p < 0.05) and DPPH (r = 0.66, p < 0.001) assays. The phenolic extract from T. indica and l-Dopa extract from E. scandens showed significantly higher FRAP values among others. All seed extracts demonstrated a remarkable reducing power (7-145 mM FeSO4 per mg extract), DPPH radical scavenging activity (16-95%) and α-amylase enzyme inhibition activity (28-40%).

  12. Novel Platinum(II) compounds modulate insulin-degrading enzyme activity and induce cell death in neuroblastoma cells.

    Science.gov (United States)

    Tundo, Grazia R; Sbardella, Diego; De Pascali, Sandra A; Ciaccio, Chiara; Coletta, Massimo; Fanizzi, Francesco P; Marini, Stefano

    2015-01-01

    The properties of three novel Platinum(II) compounds toward the insulin-degrading enzyme (IDE) enzymatic activity have been investigated under physiological conditions. The rationale of this study resides on previous observations that these compounds, specifically designed and synthesized by some of us, induce apoptosis in various cancer cell lines, whereas IDE has been proposed as a putative oncogene involved in neuroblastoma onset and progression. Two of these compounds, namely [PtCl(O,O'-acac)(DMSO)] and [Pt(O,O'-acac)(γ-acac)(DMS)], display a modulatory behavior, wherefore activation or inhibition of IDE activity occurs over different concentration ranges (suggesting the existence of two binding sites on the enzyme). On the other hand, [Pt(O,O'-acac)(γ-acac)(DMSO)] shows a typical competitive inhibitory pattern, characterized by a meaningful affinity constant (K i  = 0.95 ± 0.21 μM). Although all three compounds induce cell death in neuroblastoma SHSY5Y cells at concentrations exceeding 2 μM, the two modulators facilitate cells' proliferation at concentrations ≤ 1.5 μM, whereas the competitive inhibitor [Pt(O,O'-acac)(γ-acac)(DMSO)] only shows a pro-apoptotic activity at all investigated concentrations. These features render the [Pt(O,O'-acac)(γ-acac)(DMSO)] a promising "lead compound" for the synthesis of IDE-specific inhibitors (not characterized yet) with therapeutic potentiality.

  13. Identification of Chromobacterium violaceum genes with potential biotechnological application in environmental detoxification.

    Science.gov (United States)

    Carepo, Marta S P; Azevedo, Juliana S Nina de; Porto, Jorge I R; Bentes-Sousa, Alexandra R; Batista, Jacqueline da Silva; Silva, Artur L C da; Schneider, Maria P C

    2004-01-01

    Chromobacterium violaceum is a Gram-negative bacterium found in a wide variety of tropical and subtropical ecosystems. The complete genome sequence of C. violaceum ATCC 12472 is now available, and it has considerable biotechnological potential for various applications, such as environmental detoxification, as well as medical and agricultural use. We examined the biotechnological potential of C. violaceum for environmental detoxification. Three operons, comprising the ars operon, involved in arsenic resistance, the cyn operon, involved in cyanate detoxification, and the hcn operon, encoding a cyanase, responsible for biogenic production of cyanide, as well as an open reading frame, encoding an acid dehalogenase, were analyzed in detail. Probable catalytic mechanisms for the enzymes were determined, based on amino acid sequence comparisons and on published structural information for these types of proteins.

  14. Functions, Evolution, and Application of the Supramolecular Machines of Hg Detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Susan M.

    2009-11-27

    The bacterial mercury resistance (mer) operon functions in Hg biogeochemistry and bioremediation by converting reactive inorganic [Hg(II)] and organic [RHg(I)] mercurials to relatively inert monoatomic mercury vapor, Hg(0). Its genes regulate expression (MerR, MerD, MerOP), import Hg(II) (MerT, MerP, and MerC), and demethylate (MerB) and reduce (MerA) mercurials. We focus on how these components interact with each other and with the host cell to allow cells to survive and detoxify Hg compounds. Understanding how this ubiquitous detoxification system fits into the biology and ecology of its bacterial host is essential to guide interventions that support and enhance Hg remediation. At a more basic level, studies of interactions between the metal ion trafficking proteins in this pathway provide insights into general mechanisms used by proteins in pathways involved in trafficking of other metal ions in cells of all types of organisms, including pathways for essential metal ions such as Cu and Zn and other toxic metal ions such as Cd. In this project we focused on investigations of proteins from mer operons found in gamma-proteobacteria with specific objectives to use biophysical and biochemical approaches to detect and define (1) interactions between the structural components of the key detoxifying mer operon enzyme, mercuric ion reductase (MerA), (2) interactions between the components of MerA and the other mer operon enzyme, organomercurial lyase (MerB), and (3) to investigate the structure and interactions of integral membrane transport proteins, MerT and MerC, with MerA.

  15. Enzymes approved for human therapy: indications, mechanisms and adverse effects.

    Science.gov (United States)

    Baldo, Brian A

    2015-02-01

    Research and drug developments fostered under orphan drug product development programs have greatly assisted the introduction of efficient and safe enzyme-based therapies for a range of rare disorders. The introduction and regulatory approval of 20 different recombinant enzymes has enabled, often for the first time, effective enzyme-replacement therapy for some lysosomal storage disorders, including Gaucher (imiglucerase, taliglucerase, and velaglucerase), Fabry (agalsidase alfa and beta), and Pompe (alglucosidase alfa) diseases and mucopolysaccharidoses I (laronidase), II (idursulfase), IVA (elosulfase), and VI (galsulfase). Approved recombinant enzymes are also now used as therapy for myocardial infarction (alteplase, reteplase, and tenecteplase), cystic fibrosis (dornase alfa), chronic gout (pegloticase), tumor lysis syndrome (rasburicase), leukemia (L-asparaginase), some collagen-based disorders such as Dupuytren's contracture (collagenase), severe combined immunodeficiency disease (pegademase bovine), detoxification of methotrexate (glucarpidase), and vitreomacular adhesion (ocriplasmin). The development of these efficacious and safe enzyme-based therapies has occurred hand in hand with some remarkable advances in the preparation of the often specifically designed recombinant enzymes; the manufacturing expertise necessary for commercial production; our understanding of underlying mechanisms operative in the different diseases; and the mechanisms of action of the relevant recombinant enzymes. Together with information on these mechanisms, safety findings recorded so far on the various adverse events and problems of immunogenicity of the recombinant enzymes used for therapy are presented.

  16. Polybacterial Periodontal Pathogens Alter Vascular and Gut BH4/nNOS/NRF2-Phase II Enzyme Expression.

    Directory of Open Access Journals (Sweden)

    Pandu Gangula

    Full Text Available Periodontal disease is a highly prevalent chronic inflammatory disease and is associated with complex microbial infection in the subgingival cavity. Recently, American Heart Association supported a century old association between periodontal disease and atherosclerotic vascular disease. We have recently shown that polybacterial periodontal infection led to aortic atherosclerosis and modulation of lipid profiles; however the underlying mechanism(s has not been yet demonstrated. Altered nitric oxide (NO synthesis and tetrahydrobiopterin (BH4, a cofactor for nitric oxide synthases (NOS has long been shown to be associated with vascular dysfunction and gastrointestinal motility disorders. We sought to examine the mechanism of periodontal infection leading to altered vascular and gastrointestinal smooth muscle relaxation, focusing on the BH4/nNOS pathways. In addition, we also have investigated how the antioxidant system (NRF2-Phase II enzyme expression in vascular and GI specimens is altered by oral infection. Eight week old male ApoEnull mice were either sham-infected or infected orally for 16 weeks with a mixture of major periodontal bacteria Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia to induce experimental periodontitis. Serum, vascular (mesenteric, stomach, and colon specimens were collected at the end of periodontal pathogen infection. Bacterial infection induced significant (p<0.05 reductions in the levels of BH4,in ratio of BH4:BH2+B and also in nitric oxide levels compared to sham-infected controls. In addition, we identified a significant (p<0.05 reduction in eNOS dimerization, nNOS dimerization and protein expression of BH4 biosynthesis enzymes; GCH-1, DHFR and NRF2 & Phase II enzymes in infected mice versus controls in both mesenteric artery and colon tissues. However, we found no differences in nNOS/BH4 protein expression in stomach tissues of infected and sham-infected mice. This suggests that a polybacterial

  17. 2-Octadecynoic acid as a dual life stage inhibitor of Plasmodium infections and plasmodial FAS-II enzymes.

    Science.gov (United States)

    Carballeira, Néstor M; Bwalya, Angela Gono; Itoe, Maurice Ayamba; Andricopulo, Adriano D; Cordero-Maldonado, María Lorena; Kaiser, Marcel; Mota, Maria M; Crawford, Alexander D; Guido, Rafael V C; Tasdemir, Deniz

    2014-09-01

    The malaria parasite Plasmodium goes through two life stages in the human host, a non-symptomatic liver stage (LS) followed by a blood stage with all clinical manifestation of the disease. In this study, we investigated a series of 2-alkynoic fatty acids (2-AFAs) with chain lengths between 14 and 18 carbon atoms for dual in vitro activity against both life stages. 2-Octadecynoic acid (2-ODA) was identified as the best inhibitor of Plasmodium berghei parasites with ten times higher potency (IC50=0.34 μg/ml) than the control drug. In target determination studies, the same compound inhibited three Plasmodium falciparum FAS-II (PfFAS-II) elongation enzymes PfFabI, PfFabZ, and PfFabG with the lowest IC50 values (0.28-0.80 μg/ml, respectively). Molecular modeling studies provided insights into the molecular aspects underlying the inhibitory activity of this series of 2-AFAs and a likely explanation for the considerably different inhibition potentials. Blood stages of P. falciparum followed a similar trend where 2-ODA emerged as the most active compound, with 20 times less potency. The general toxicity and hepatotoxicity of 2-AFAs were evaluated by in vitro and in vivo methods in mammalian cell lines and zebrafish models, respectively. This study identifies 2-ODA as the most promising antiparasitic 2-AFA, particularly towards P. berghei parasites.

  18. Urinary angiotensin-converting enzyme 2 increases in diabetic nephropathy by angiotensin II type 1 receptor blocker olmesartan.

    Science.gov (United States)

    Abe, Masanori; Oikawa, Osamu; Okada, Kazuyoshi; Soma, Masayoshi

    2015-03-01

    Angiotensin-converting enzyme 2 (ACE2) is a member of the renin-angiotensin system that degrades angiotensin (Ang) II to the seven-amino acid peptide fragment Ang-(1-7). We evaluated the changes in urinary ACE2 levels in response to treatment with the angiotensin II type 1 receptor blocker olmesartan in diabetes patients with nephropathy. This prospective, open-label, interventional study was conducted with 31 type 2 diabetes patients with nephropathy. After initial evaluation, patients received 20 mg/day olmesartan, which was increased to 40 mg/day over a 24-week period. In diabetes patients with chronic kidney disease, olmesartan significantly increased urinary ACE2 levels independently of blood pressure and plasma aldosterone levels and reduced albuminuria, urinary liver-type fatty acid binding protein (L-FABP), and plasma aldosterone levels. Multivariable regression analysis revealed that the change in urinary L-FABP levels was an independent predictor of increased urinary ACE2 levels. Olmesartan may have the unique effect of increasing urinary ACE2 levels. However, whether this contributes to olmesartan's renoprotective effect must be examined further. © The Author(s) 2014.

  19. Formation of insulin fragments by insulin-degrading enzyme: the role of zinc(II) and cystine bridges.

    Science.gov (United States)

    Bellia, Francesco; Pietropaolo, Adriana; Grasso, Giuseppe

    2013-02-01

    Insulin is the hormone mainly involved in widespread diseases such as diabetes mellitus. It is widely recognized that metal ions such as zinc(II) as well as insulin degradation and insulin fragments are inexplicably linked to the hormone action. Insulin-degrading enzyme (IDE) has been identified as the main factor of insulin degradation, but it is still unknown the exact way and location at which IDE action toward insulin occurs and how metal ions can modulate this interaction. Interestingly, some insulin fragments have different biological activity from the intact hormone, and it is not clear how they can be generated from insulin. In this work, the role of zinc(II) and cystine bridges in the degradation of insulin by IDE are investigated by high-performance liquid chromatography-mass spectrometry (HPLC-MS), and the experimental conditions at which peculiar insulin fragments having biological activity are formed by the action of IDE are found and discussed. Docking simulations of IDE/insulin A and B chains are in good accordance with the insulin fragments detected by HPLC-MS.

  20. 泥鳅生长及抗氧化-解毒酶系统对水体中转Cry1Ab/Ac基因水稻残遗物的响应%Responses of growth and activities of antioxidant and detoxification enzymes ofMisgurnus anguillicaudatus to transgenicCry1Ab/Acrice residues in water

    Institute of Scientific and Technical Information of China (English)

    孙远东; 戈峰; 刘雨芳; 李菲; 肖璐; 谭树华; 桂芳艳; 莫书银; 孙丽川; 刘文海

    2015-01-01

    在泥鳅养殖水体中添加稻秆粉模拟水稻残遗物生境,研究了泥鳅生长和肝胰脏抗氧化酶(SOD、CAT)与解毒酶(GST)活性对转Cry1Ab/Ac基因水稻‘华恢1号’(HH1)的响应。设计以HH1稻秆粉10 mg·L−1、50 mg·L−1、100 mg·L−1和200 mg·L−14个梯度浓度处理泥鳅为试验组,以非转Bt基因水稻‘明恢63’(MH63)稻秆粉处理组为阴性对照,不加稻秆粉的基础饲养组为空白对照。结果显示:在4种稻秆粉浓度下, HH1组与MH63对照组泥鳅的特定生长率、肥满度、内脏系数及SOD、CAT和GST酶活性均无显著差异(P>0.05);与空白对照比较,稻秆粉浓度升高对泥鳅生长的抑制逐渐增强,当浓度达到200 mg·L−1时, HH1组和MH63对照组泥鳅的特定生长率、内脏系数与CAT活性降低。研究结果表明,水体中低含量的转融合基因Cry1Ab/Ac水稻HH1稻秆粉对泥鳅的生长与生理酶活性没有明显影响,高浓度HH1和MH63稻秆粉均使泥鳅的生长和生理酶活性显著降低,这可能与养殖水体中浓度较高的悬浮稻秆粉妨碍了泥鳅的呼吸和滤食,及稻秆粉的分解降低了水体 pH 和溶氧量有关。%A loach (Misgurnus anguillicaudatus) aquaculture experiment was conducted in phytotron with aquatic water added with straw power in different concentrations (10 mg·L−1, 50 mg·L−1, 100 mg·L−1, 200 mg·L−1) of different rice varieties, which were transgenicCry1Ab/Acrice variety of ‘Huahui 1’ (HH1) and non-Bt control rice variety of ‘Minghui 63’ (MH63). In the experiment, the loach basal fed without rice straw powder was set as the blank control. The specific growth rate, condition factor, and viscera somatic index as well as activities of antioxidant enzymes of superoxide dismutase (SOD) and catalase (CAT), and detoxification enzyme of glutathione-s-transferase (GST) of loach were investigated after culture for 100 days. The aim of the study was to explore

  1. In vitro detoxification of cyclosarin (GF) by modified cyclodextrins.

    Science.gov (United States)

    Müller, Susanne; Koller, Marianne; Le Provost, Romain; Lafont, Olivier; Estour, François; Wille, Timo; Thiermann, Horst; Worek, Franz; Reiter, Georg

    2011-01-15

    Developing potent detoxification strategies for prophylaxis and therapy against organophosphate (OP) intoxication still represents a challenging task. Clinical application of numerous investigated substances including enzymes and low molecular scavengers like metal ions or nucleophiles could not yet be realised due to profound disadvantages. Presenting a promising attempt, cyclodextrins (CDs) efficiently enhance the degradation of some organophosphorus compounds. The present study examined the in vitro GF degradation mediated by three CDs and a nucleophilic precursor performed by mass spectrometric detection with ammonia chemical ionisation. All four compounds caused a notable enhancement of GF detoxification that was synergistically accelerated in the case of 2-O-(3-carboxy-4-iodosobenzyl)-β-cyclodextrin (IBA-β-CD) with the alpha-nucleophile 2-iodosobenzoic acid (IBA) grafted on the secondary face of β-cyclodextrin (β-CD). In vitro toxicokinetic investigations of CD derivatives are needed to evaluate the effect of slow terminal elimination phase of the more toxic (-)-GF shown for two CD-derivatives underlining the necessity of detecting the complete kinetic course of inactivation. The observed effect of fast high affinity binding (20-30%) represents an additional therapeutic option of an extremely rapid reduction of GF concentration in vivo. Distinctive differences in the course of reaction are detected depending on β-CD-derivatives, allowing a first inference of possible mechanisms and relevance of attached substituents. However, further profound investigation needs to be done to evaluate the basis of a clinical application of substituted CDs as potential detoxification agents. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Insight into the interactive residues between two domains of human somatic Angiotensin-converting enzyme and Angiotensin II by MM-PBSA calculation and steered molecular dynamics simulation.

    Science.gov (United States)

    Guan, Shan-shan; Han, Wei-wei; Zhang, Hao; Wang, Song; Shan, Ya-ming

    2016-01-01

    Angiotensin-converting enzyme (ACE), a membrane-bound zinc metallopeptidase, catalyzes the formation of Angiotensin-II (AngII) and the deactivation of bradykinin in the renin-angiotensin-aldosterone and kallikrein-kinin systems. As a hydrolysis product of ACE, AngII is regarded as an inhibitor and displays stronger competitive inhibition in the C-domain than the N-domain of ACE. However, the AngII binding differences between the two domains and the mechanisms behind AngII dissociation from the C-domain are rarely explored. In this work, molecular docking, Molecular Mechanics/Poisson-Boltzmann Surface Area calculation, and steered molecular dynamics (SMD) are applied to explore the structures and interactions in the binding or unbinding of AngII with the two domains of human somatic ACE. Calculated free energy values suggest that the C-domain-AngII complex is more stable than the N-domain-AngII complex, consistent with available experimental data. SMD simulation results imply that electrostatic interaction is dominant in the dissociation of AngII from the C-domain. Moreover, Gln106, Asp121, Glu123, and Tyr213 may be the key residues in the unbinding pathway of AngII. The simulation results in our work provide insights into the interactions between the two domains of ACE and its natural peptide inhibitor AngII at a molecular level. Moreover, the results provide theoretical clues for the design of new inhibitors.

  3. Lipoamide Acts as an Indirect Antioxidant by Simultaneously Stimulating Mitochondrial Biogenesis and Phase II Antioxidant Enzyme Systems in ARPE-19 Cells.

    Science.gov (United States)

    Zhao, Lin; Liu, Zhongbo; Jia, Haiqun; Feng, Zhihui; Liu, Jiankang; Li, Xuesen

    2015-01-01

    In our previous study, we found that pretreatment with lipoamide (LM) more effectively than alpha-lipoic acid (LA) protected retinal pigment epithelial (RPE) cells from the acrolein-induced damage. However, the reasons and mechanisms for the greater effect of LM than LA are unclear. We hypothesize that LM, rather than the more direct antioxidant LA, may act more as an indirect antioxidant. In the present study, we treated ARPE-19 cells with LA and LM and compared their effects on activation of mitochondrial biogenesis and induction of phase II enzyme systems. It is found that LM is more effective than LA on increasing mitochondrial biogenesis and inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation to the nucleus, leading to an increase in expression or activity of phase II antioxidant enzymes (NQO-1, GST, GCL, catalase and Cu/Zn SOD). Further study demonstrated that mitochondrial biogenesis and phase II enzyme induction are closely coupled via energy requirements. These results suggest that LM, compared with the direct antioxidant LA, plays its protective effect on oxidative damage more as an indirect antioxidant to simultaneously stimulate mitochondrial biogenesis and induction of phase II antioxidant enzymes.

  4. Proteomic Identification of Nrf2-Mediated Phase II Enzymes Critical for Protection of Tao Hong Si Wu Decoction against Oxygen Glucose Deprivation Injury in PC12 Cells

    Directory of Open Access Journals (Sweden)

    Hong-yi Qi

    2014-01-01

    Full Text Available Chinese herbal medicine formula Tao Hong Si Wu decoction (THSWD is traditionally used in China for cerebrovascular diseases. However, the molecular mechanisms of THSWD associated with the cerebral ischemia reperfusion injury are largely unknown. The current study applied the two-dimensional gel electrophoresis-based proteomics to investigate the different protein profiles in PC12 cells with and without the treatment of THSWD. Twenty-six proteins affected by THSWD were identified by MALDI-TOF mass spectrometry. Gene ontology analysis showed that those proteins participated in several important biological processes and exhibited diverse molecular functions. In particular, six of them were found to be phase II antioxidant enzymes, which were regulated by NF-E2-related factor-2 (Nrf2. Quantitative PCR further confirmed a dose-dependent induction of the six phase II enzymes by THSWD at the transcription level. Moreover, the individual ingredients of THSWD were discovered to synergistically contribute to the induction of phase II enzymes. Importantly, THSWD’s protection against oxygen-glucose deprivation-reperfusion (OGD-Rep induced cell death was significantly attenuated by antioxidant response element (ARE decoy oligonucleotides, suggesting the protection of THSWD may be likely regulated at least in part by Nrf2-mediated phase II enzymes. Thus, our data will help to elucidate the molecular mechanisms underlying the neuroprotective effect of THSWD.

  5. Moxonidine for tramadol withdrawal symptoms during detoxification.

    Science.gov (United States)

    Talih, Farid; Ghossoub, Elias

    2015-07-08

    It is well documented in the literature that noradrenergic pathways are key in the manifestation of opioid withdrawal symptoms, which is why clonidine is used as an off-label agent in opioid detoxification regimens given its anti-sympathetic properties. Moxonidine is a selective I1-imidazoline receptor agonist, similar to clonidine but with no α2-adrenergic agonist activity and subsequently fewer side effects. We report the case of a 33-year-old woman with a 15-year history of tramadol use who was admitted voluntarily for detoxification. She was started on moxonidine and had an uneventful detoxification. Two months after discharge, the patient maintained tramadol abstinence with good tolerability to moxonidine. To the best of our knowledge, this has not been previously reported in the medical literature.

  6. Roles of vertebrate aquaglyceroporins in arsenic transport and detoxification.

    Science.gov (United States)

    Liu, Zijuan

    2010-01-01

    Aquaporins are important channel proteins that are responsible for the balance of cellular osmolarity and nutrient transport in vertebrates. Recently, new functions of these ancient channels have been found in the conduction of metalloid arsenic (As). Chronic As exposure through contaminated water and food sources is associated with multiple human diseases and endangers millions of people's health worldwide. Therefore, identification of the As transport pathways is necessary to elucidate the mechanisms of As carcinogenesis. Arsenic detoxification systems have been studied in multiple vertebrates such as mammalian mouse, rat, humans and nonmammalian vertebrates. Multiple transporters and enzymes have been shown to be involved in As translocation and cellular transformation. In these vertebrates, members ofaquaglyceroporins, which include AQP7 in kidney and AQP9 in liver, catalyze uptake of inorganic trivalent arsenite [As(III)]. AQP9, the major liver aquaglyceroporin, conducts both inorganic As(III) and organic monomethylarsonous acid [MMA(III)], an intermediate that is generated during the cellular methylation. As a channel that facilitates a downhill movement of substances dependent on the concentration gradient, AQP9 may play an important role in the simultaneous influx of inorganic As(III) from blood to liver and efflux of As metabolite MMA(III) from liver to blood. In this chapter, we will discuss the function ofaquaglyceroporins ofvertebrates in uptake and detoxification of the metalloid As.

  7. Urinary angiotensin-converting enzyme 2 in hypertensive patients may be increased by olmesartan, an angiotensin II receptor blocker.

    Science.gov (United States)

    Furuhashi, Masato; Moniwa, Norihito; Mita, Tomohiro; Fuseya, Takahiro; Ishimura, Shutaro; Ohno, Kohei; Shibata, Satoru; Tanaka, Marenao; Watanabe, Yuki; Akasaka, Hiroshi; Ohnishi, Hirofumi; Yoshida, Hideaki; Takizawa, Hideki; Saitoh, Shigeyuki; Ura, Nobuyuki; Shimamoto, Kazuaki; Miura, Tetsuji

    2015-01-01

    Angiotensin-converting enzyme 2 (ACE2) is highly expressed in the kidney and converts angiotensin (Ang) II to Ang-(1-7), a renoprotective peptide. Urinary ACE2 has been shown to be elevated in patients with chronic kidney disease. However, the effects of antihypertensive agents on urinary ACE2 remain unclear. Of participants in the Tanno-Sobetsu cohort study in 2011 (n = 617), subjects on no medication (n = 101) and hypertensive patients treated with antihypertensive agents, including the calcium channel blockers amlodipine and long-acting nifedipine; the ACE inhibitor enalapril; and the Ang II receptor blockers losartan, candesartan, valsartan, telmisartan, and olmesartan, for more than 1 year (n = 100) were enrolled, and urinary ACE2 level was measured. Glucose and hemoglobin A1c were significantly higher in patients treated with enalapril, telmisartan or olmesartan than in the control subjects. Urinary albumin-to-creatinine ratio (UACR) was significantly higher in patients treated with enalapril than in the control subjects. Urinary ACE2 level was higher in the olmesartan-treated group, but not the other treatment groups, than in the control group. Urinary ACE2 level was positively correlated with systolic blood pressure (r = 0.211; P = 0.003), UACR (r = 0.367; P olmesartan was an independent predictor of urinary ACE2 level. In contrast with other antihypertensive drugs, olmesartan may uniquely increase urinary ACE2 level, which could potentially offer additional renoprotective effects. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Complexation and toxicity of copper in higher plants. II. Different mechanisms for copper versus cadmium detoxification in the copper-sensitive cadmium/zinc hyperaccumulator Thlaspi caerulescens (Ganges Ecotype).

    Science.gov (United States)

    Mijovilovich, Ana; Leitenmaier, Barbara; Meyer-Klaucke, Wolfram; Kroneck, Peter M H; Götz, Birgit; Küpper, Hendrik

    2009-10-01

    The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 microm Cu(2+) remained in the nonaccumulator range (hyperaccumulation and metal resistance are highly metal specific. Cu-induced inhibition of photosynthesis followed the "sun reaction" type of damage, with inhibition of the photosystem II reaction center charge separation and the water-splitting complex. A few individuals of T. caerulescens were more Cu resistant. Compared with Cu-sensitive individuals, they recovered faster from inhibition, at least partially by enhanced repair of chlorophyll-protein complexes but not by exclusion, since the content of Cu in their shoots was increased by about 25%. Extended x-ray absorption fine structure (EXAFS) measurements on frozen-hydrated leaf samples revealed that a large proportion of Cu in T. caerulescens is bound by sulfur ligands. This is in contrast to the known binding environment of cadmium and zinc in the same species, which is dominated by oxygen ligands. Clearly, hyperaccumulators detoxify hyperaccumulated metals differently compared with nonaccumulated metals. Furthermore, strong features in the Cu-EXAFS spectra ascribed to metal-metal contributions were found, in particular in the Cu-resistant specimens. Some of these features may be due to Cu binding to metallothioneins, but a larger proportion seems to result from biomineralization, most likely Cu(II) oxalate and Cu(II) oxides. Additional contributions in the EXAFS spectra indicate complexation of Cu(II) by the nonproteogenic amino acid nicotianamine, which has a very high affinity for Cu(II) as further characterized here.

  9. Induced mutations in the starch branching enzyme II (SBEII) genes increase amylose and resistant starch content in durum wheat.

    Science.gov (United States)

    Hazard, Brittany; Zhang, Xiaoqin; Colasuonno, Pasqualina; Uauy, Cristobal; Beckles, Diane M; Dubcovsky, Jorge

    2012-01-01

    Starch is the largest component of the wheat (Triticum aestivum L.) grain and consists of approximately 70-80% amylopectin and 20-30% amylose. Amylopectin is a highly-branched, readily digested polysaccharide, whereas amylose has few branches and forms complexes that resist digestion and mimic dietary fiber (resistant starch). Down-regulation of the starch branching enzyme II (SBEII) gene by RNA interference (RNAi) was previously shown to increase amylose content in both hexaploid and tetraploid wheat. We generated ethyl methane sulphonate (EMS) mutants for the SBEIIa-A and SBEIIa-B homoeologs in the tetraploid durum wheat variety Kronos (T. turgidum ssp. durum L.). Single-gene mutants showed non-significant increases in amylose and resistant starch content, but a double mutant combining a SBEIIa-A knock-out mutation with a SBEIIa-B splice-site mutation showed a 22% increase in amylose content (P<0.0001) and a 115% increase in resistant starch content (P<0.0001). In addition, we obtained mutants for the A and B genome copies of the paralogous SBEIIb gene, mapped them 1-2 cM from SBEIIa, and generated double SBEIIa-SBEIIb mutants to study the effect of the SBEIIb gene in the absence of SBEIIa. These mutants are available to those interested in increasing amylose content and resistant starch in durum wheat.

  10. Renoprotective Effect of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Diabetic Patients with Proteinuria

    Directory of Open Access Journals (Sweden)

    Feng-Yi Hsu

    2017-06-01

    Full Text Available Background/Aims: Limited evidence exists on the choice of angiotensin-converting enzyme inhibitors (ACEIs and angiotensin II receptor blockers (ARBs in diabetic patients with nephropathy. We aim to assess the renal effectiveness and safety of these drugs among diabetic nephropathy patients. Methods: This retrospective cohort study was conducted with diabetic nephropathy patients who initiated ACEI or ARB monotherapy. The primary outcome was a composite of end stage of renal disease and renal transplantation, and the secondary outcome was all-cause mortality. The safety endpoint was hyperkalemia. Results: Three thousand seven hundred and thirty-nine ACEI users and 3,316 ARB users were identified. ARBs seemed to be inferior to ACEIs given their poorer renal outcome (HR 1.31; 95% CI, 1.15-1.50 and higher risk of hyperkalemia (HR 1.17; 95% CI, 1.04-1.32. Among the four ACEIs compared, captopril was an inferior treatment choice given its poorer renal outcomes (HR 1.42; 95% CI, 1.05-1.93 and higher mortality rate (HR 1.25; 95% CI, 1.01-1.55. Irbesartan appeared to be a poorer treatment choice among the three ARBs compared, given its inferior renal protective effect (HR 1.35; 95% CI, 1.03-1.78. Conclusions: Our findings suggest ACEIs as a relatively more renoprotective and safer treatment as compared to ARBs. Captopril and irbesartan may be inferior to the other ACEIs and ARBs respectively.

  11. Transdermal delivery of angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs) and others for management of hypertension.

    Science.gov (United States)

    Ahad, Abdul; Al-Mohizea, Abdullah Mohammed; Al-Jenoobi, Fahad Ibrahim; Aqil, Mohd

    2016-01-01

    Angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs) are some of the most commonly prescribed medications for hypertension. Most of all conventional dosage forms of ARBs and ACEIs undergo extensive first-pass metabolism, which significantly reduces bioavailability. Majority of ARBs and ACEIs are inherently short acting due to a rapid elimination half-life. In addition, oral dosage forms of ARBs and ACEIs have many high incidences of adverse effects due to variable absorption profiles, higher frequency of administration and poor patient compliance. Many attempts have been made globally at the laboratory level to investigate the skin permeation and to develop transdermal therapeutic systems of various ARBs, ACEIs and other anti-hypertensives, to circumvent the drawbacks associated with their conventional dosage form. This manuscript presents an outline of the transdermal research specifically in the area of ARBs, ACEIs and other anti-hypertensives reported in various pharmaceutical journals. The transdermal delivery has gained a significant importance for systemic treatment as it is able to avoid first-pass metabolism and major fluctuations of plasma levels typical of repeated oral administration. As we can experience from this review article that transdermal delivery of different ARBs and ACEIs improves bioavailability as well as patient compliance by many folds. In fact, the rationale development of some newer ARBs, ACEIs and other anti-hypertensives transdermal systems will provide new ways of treatment, circumventing current limitations for conventional dosage forms.

  12. Renoprotective Effect of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Diabetic Patients with Proteinuria.

    Science.gov (United States)

    Hsu, Feng-Yi; Lin, Fang-Ju; Ou, Huang-Tz; Huang, Shih-Hui; Wang, Chi-Chuan

    2017-01-01

    Limited evidence exists on the choice of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in diabetic patients with nephropathy. We aim to assess the renal effectiveness and safety of these drugs among diabetic nephropathy patients. This retrospective cohort study was conducted with diabetic nephropathy patients who initiated ACEI or ARB monotherapy. The primary outcome was a composite of end stage of renal disease and renal transplantation, and the secondary outcome was all-cause mortality. The safety endpoint was hyperkalemia. Three thousand seven hundred and thirty-nine ACEI users and 3,316 ARB users were identified. ARBs seemed to be inferior to ACEIs given their poorer renal outcome (HR 1.31; 95% CI, 1.15-1.50) and higher risk of hyperkalemia (HR 1.17; 95% CI, 1.04-1.32). Among the four ACEIs compared, captopril was an inferior treatment choice given its poorer renal outcomes (HR 1.42; 95% CI, 1.05-1.93) and higher mortality rate (HR 1.25; 95% CI, 1.01-1.55). Irbesartan appeared to be a poorer treatment choice among the three ARBs compared, given its inferior renal protective effect (HR 1.35; 95% CI, 1.03-1.78). Our findings suggest ACEIs as a relatively more renoprotective and safer treatment as compared to ARBs. Captopril and irbesartan may be inferior to the other ACEIs and ARBs respectively. © 2017 The Author(s). Published by S. Karger AG, Basel.

  13. Residue Phe112 of the Human-Type Corrinoid Adenosyltransferase (PduO) Enzyme of Lactobacillus reuteri Is Critical to the Formation of the Four-Coordinate Co(II) Corrinoid Substrate and to the Activity of the Enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Mera, Paola E.; St. Maurice, Martin; Rayment, Ivan; Escalante-Semerena, Jorge C.; UW

    2009-06-08

    ATP:Corrinoid adenosyltransferases (ACAs) catalyze the transfer of the adenosyl moiety from ATP to cob(I)alamin via a four-coordinate cob(II)alamin intermediate. At present, it is unknown how ACAs promote the formation of the four-coordinate corrinoid species needed for activity. The published high-resolution crystal structure of the ACA from Lactobacillus reuteri (LrPduO) in complex with ATP and cob(II)alamin shows that the environment around the alpha face of the corrin ring consists of bulky hydrophobic residues. To understand how these residues promote the generation of the four-coordinate cob(II)alamin, variants of the human-type ACA enzyme from L. reuteri (LrPduO) were kinetically and structurally characterized. These studies revealed that residue Phe112 is critical in the displacement of 5,6-dimethylbenzimidazole (DMB) from its coordination bond with the Co ion of the ring, resulting in the formation of the four-coordinate species. An F112A substitution resulted in a 80% drop in the catalytic efficiency of the enzyme. The explanation for this loss of activity was obtained from the crystal structure of the mutant protein, which showed cob(II)alamin bound in the active site with DMB coordinated to the cobalt ion. The crystal structure of an LrPduO(F112H) variant showed a DMB-off/His-on interaction between the corrinoid and the enzyme, whose catalytic efficiency was 4 orders of magnitude lower than that of the wild-type protein. The analysis of the kinetic parameters of LrPduO(F112H) suggests that the F112H substitution negatively impacts product release. Substitutions of other hydrophobic residues in the Cbl binding pocket did not result in significant defects in catalytic efficiency in vitro; however, none of the variant enzymes analyzed in this work supported AdoCbl biosynthesis in vivo.

  14. Glutathione transferase mimics : Micellar catalysis of an enzymic reaction

    NARCIS (Netherlands)

    Lindkvist, Björn; Weinander, Rolf; Engman, Lars; Koetse, Marc; Engberts, Jan B.F.N.; Morgenstern, Ralf

    1997-01-01

    Substances that mimic the enzyme action of glutathione transferases (which serve in detoxification) are described. These micellar catalysts enhance the reaction rate between thiols and activated halogenated nitroarenes as well as alpha,beta-unsaturated carbonyls. The nucleophilic aromatic substituti

  15. Fisetin inhibits osteoclastogenesis through prevention of RANKL-induced ROS production by Nrf2-mediated up-regulation of phase II antioxidant enzymes.

    Science.gov (United States)

    Sakai, Eiko; Shimada-Sugawara, Megumi; Yamaguchi, Yu; Sakamoto, Hiroshi; Fumimoto, Reiko; Fukuma, Yutaka; Nishishita, Kazuhisa; Okamoto, Kuniaki; Tsukuba, Takayuki

    2013-01-01

    Osteoclasts (OCLs) are multinucleated bone-resorbing cells that are differentiated by stimulation with receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colony-stimulating factor. We recently demonstrated that regulation of heme-oxygenase 1 (HO-1), a stress-induced cytoprotective enzyme, also functions in OCL differentiation. In this study, we investigated effects of fisetin, a natural bioactive flavonoid that has been reported to induce HO-1 expression, on the differentiation of macrophages into OCLs. Fisetin inhibited the formation of OCLs in a dose-dependent manner and suppressed the bone-resorbing activity of OCLs. Moreover, fisetin-treated OCLs showed markedly decreased phosphorylation of extracellular signal-regulated kinase, Akt, and Jun N-terminal kinase, but fisetin did not inhibit p38 phosphorylation. Fisetin up-regulated mRNA expression of phase II antioxidant enzymes including HO-1 and interfered with RANKL-mediated reactive oxygen species (ROS) production. Studies with RNA interference showed that suppression of NF-E2-related factor 2 (Nrf2), a key transcription factor for phase II antioxidant enzymes, rescued fisetin-mediated inhibition of OCL differentiation. Furthermore, fisetin significantly decreased RANKL-induced nuclear translocation of cFos and nuclear factor of activated T cells cytoplasmic-1 (NFATc1), which is a transcription factor critical for osteoclastogenic gene regulation. Therefore, fisetin inhibits OCL differentiation through blocking RANKL-mediated ROS production by Nrf2-mediated up-regulation of phase II antioxidant enzymes.

  16. Different contributions of the angiotensin-converting enzyme C-domain and N-domain in subjects with the angiotensin-converting enzyme II and DD genotype.

    NARCIS (Netherlands)

    Esch, JH van; Gool, JM van; Bruin, R.J. de; Payne, J.R.; Montgomery, Henry; Hectors, M.; Deinum, J.; Dive, V.; Danser, A.H.

    2008-01-01

    BACKGROUND: Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism-related differences in ACE concentration do not result in differences in angiotensin levels. METHODS AND RESULTS: To investigate whether this relates to differences in the contribution of the ACE C-domain and

  17. The biotechnological potential of subtilisin-like fibrinolytic enzyme from a newly isolated Lactobacillus plantarum KSK-II in blood destaining and antimicrobials.

    Science.gov (United States)

    Kotb, Essam

    2015-01-01

    An antimicrobial oxidative- and SDS-stable fibrinolytic alkaline protease designated as KSK-II was produced by Lactobacillus plantarum KSK-II isolated from kishk, a traditional Egyptian food. Maximum enzyme productivity was obtained in medium containing 1% lactose and 0.5% soybean flour as carbon and nitrogen sources, respectively. Purification of enzyme increased its specific activity to 1,140-fold with a recovery of 33% and molecular weight of 43.6 kDa. Enzyme activity was totally lost in the presence of ethylenediaminetetraacetic acid and was restored after addition of Fe(2+) suggesting that KSK-II is a metalloprotease and Fe(2+) acts as cofactor. Enzyme hydrolyzed not only the natural proteins but also synthetic substrates, particularly Suc-Ala-Ala-Pro-Phe-pNA. KSK-II can hydrolyze the Lys-X easier than Arg-X; thus, it was considered as a subtilisin-family protease. Its apparent Km , Vmax , and Kcat were 0.41 mM, 6.4 µmol mg(-1) min(-1) , and 28.0 s(-1) , respectively. KSK-II is industrially important from the perspectives of its maximal activity at 50°C (stable up to 70°C), ability to function at alkaline pH (10.0), stability at broad pH ranges (7.5-12.0) in addition to its stability toward SDS, H2 O2 , organic solvents, and detergents. We emphasize for the first time the potential of fibrinolytic activity for alkaline proteases used in detergents especially in blood destaining. © 2014 American Institute of Chemical Engineers.

  18. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers reduced dementia risk in patients with diabetes mellitus and hypertension.

    Science.gov (United States)

    Kuan, Yi-Chun; Huang, Kuang-Wei; Yen, Der-Jen; Hu, Chaur-Jong; Lin, Cheng-Li; Kao, Chia-Hung

    2016-10-01

    The effects of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) on dementia risk in patients with type 2 diabetes mellitus (DM) and hypertension remain unknown. We investigated the effects of ACEIs and ARBs on dementia risk in patients with type 2 DM and hypertension. We conducted a cohort study by using the Taiwan National Health Insurance Research Database. We included 2377 patients receiving ACEIs and 1780 patients receiving ARBs in the ACEI and ARB cohorts, respectively. We included a comparable number of patients not receiving ACEIs and ARBs as controls in the non-ACEI and non-ARB cohorts through propensity score matching. The effect of ACEIs and ARBs on dementia risk was estimated through multivariate Cox proportional hazard regression after adjustment for several confounding factors. During the 12-year follow-up period, compared with the non-ACEI cohort, all-cause dementia risk decreased by 26% in the ACEI cohort [hazard ratio (HR)=0.74, 95% confidence interval (CI)=0.56-0.96]. The all-cause dementia risk was nearly 40% lower in the ARB cohort than in the non-ARB cohort (HR=0.60, 95% CI=0.37-0.97). These drugs prevented the occurrence of vascular dementia (VD), however, this effect was nonsignificant for Alzheimer's dementia (AD). Treatment duration- and dosage-related protection effects on dementia occurrence were observed. ACEIs and ARBs may effectively prevent all-cause dementia, particularly VD, in patients with type 2 DM and hypertension. Moreover, compared with ACEIs, ARBs appear to be more advantageous in dementia prevention. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Assessing functional diversity in the soybean β-substituted alanine synthase enzyme family.

    Science.gov (United States)

    Yi, Hankuil; Jez, Joseph M

    2012-11-01

    In plants, proteins of the β-substituted alanine synthase (BSAS) enzyme family perform a diverse range of reactions, including formation of cysteine from O-acetylserine and sulfide, detoxification of cyanide by its addition to cysteine, the breakdown of cysteine into pyruvate, ammonia, and sulfide, and the synthesis of S-sulfocysteine. With the completed genome sequence of soybean (Glycine max (L.) Merr. cv. Williams 82), the functional diversity of the BSAS in this highly duplicated plant species was examined to determine whether soybean BSAS enzymes catalyze the various reactions connected to cysteine metabolism. The 16 soybean BSAS can be grouped into clades that are similar to those observed in Arabidopsis. Biochemical analysis of soybean BSAS proteins demonstrate that enzymes of clades I and III function as O-acetylserine sulfhydrylases for cysteine synthesis, clade II encodes cysteine desulfhydrase activity, and that clade V proteins function as β-cyanoalanine synthase for cyanide detoxification. Although clade IV is similar to Arabidopsis S-sulfocysteine synthase, this activity was not detected in the soybean homolog. Overall, our results show that bioinformatics approach provides a useful method to assess the biochemical properties of BSAS enzymes in plant species.

  20. Decreased skin-mediated detoxification contributes to oxidative stress and insulin resistance.

    Science.gov (United States)

    Liu, Xing-Xing; Sun, Chang-Bin; Yang, Ting-Tong; Li, Da; Li, Chun-Yan; Tian, Yan-Jie; Guo, Ming; Cao, Yu; Zhou, Shi-Sheng

    2012-01-01

    The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Rats received an intraperitoneal glucose injection (2 g/kg) with (sham-nicotinamide and burn-nicotinamide groups) or without (sham-operated and burn groups) coadministration of nicotinamide (100 mg/kg). The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin. The clearance of nicotinamide and N(1)-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats. After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups. More profound changes in plasma H(2)O(2) and insulin levels were observed in burn-nicotinamide group. It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.

  1. Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Xing-Xing Liu

    2012-01-01

    Full Text Available The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Rats received an intraperitoneal glucose injection (2 g/kg with (sham-nicotinamide and burn-nicotinamide groups or without (sham-operated and burn groups coadministration of nicotinamide (100 mg/kg. The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin. The clearance of nicotinamide and N1-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats. After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups. More profound changes in plasma H2O2 and insulin levels were observed in burn-nicotinamide group. It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.

  2. Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD.

    Science.gov (United States)

    Bóka, Beáta; Myari, Alexandra; Sóvágó, Imre; Hadjiliadis, Nick

    2004-01-01

    Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD were studied by potentiometric and spectroscopic (UV-Vis, CD and EPR) techniques. The results reveal that both ligands have effective metal binding sites, but the tripeptide is a much stronger complexing agent than the tetrapeptide. The formation of a macrochelate via the coordination of the imidazolyl residues is suggested in the copper(II)-Ac-HisValHis-NH2 system in the acidic pH range, while a 4N complex predominates at physiological pH. The interaction of Ac-HisValHis-NH2 with zinc(II) results in the formation of a precipitate indicating polynuclear complex formation. Both copper(II)-Ac-HisValHis-NH2 and copper(II)-HisValHis systems exhibit catalytic activity toward the dismutation of superoxide anion at physiological pH, but the saturated coordination sphere of the metal ions in both systems results in low reactivity as compared to the native enzyme.

  3. Flavonoid inhibitors as novel antimycobacterial agents targeting Rv0636, a putative dehydratase enzyme involved in Mycobacterium tuberculosis fatty acid synthase II.

    Science.gov (United States)

    Brown, Alistair K; Papaemmanouil, Athina; Bhowruth, Veemal; Bhatt, Apoorva; Dover, Lynn G; Besra, Gurdyal S

    2007-10-01

    Flavonoids comprise a large group of bioactive polyphenolic plant secondary metabolites. Several of these possess potent in vivo activity against Escherichia coli and Plasmodium falciparum, targeting enzymes involved in fatty acid biosynthesis, such as enoyl-ACP-reductase, beta-ketoacyl-ACP reductase and beta-hydroxyacyl-ACP dehydratase. Herein, we report that butein, isoliquirtigenin, 2,2',4'-trihydroxychalcone and fisetin inhibit the growth of Mycobacterium bovis BCG. Furthermore, in vitro inhibition of the mycolic-acid-producing fatty acid synthase II (FAS-II) of Mycobacterium smegmatis suggests a mode of action related to those observed in E. coli and P. falciparum. Through a bioinformatic approach, we have established the product of Rv0636 as a candidate for the unknown mycobacterial dehydratase, and its overexpression in M. bovis BCG conferred resistance to growth inhibition by butein and isoliquirtigenin, and relieved inhibition of fatty acid and mycolic acid biosynthesis in vivo. Furthermore, after overexpression of Rv0636 in M. smegmatis, FAS-II was less sensitive to these inhibitors in vitro. Overall, the data suggest that these flavonoids are inhibitors of mycobacterial FAS-II and in particular Rv0636, which represents a strong candidate for the beta-hydroxyacyl-ACP dehydratase enzyme of M. tuberculosis FAS-II.

  4. An mRNA Capping Enzyme Targets FACT to the Active Gene To Enhance the Engagement of RNA Polymerase II into Transcriptional Elongation.

    Science.gov (United States)

    Sen, Rwik; Kaja, Amala; Ferdoush, Jannatul; Lahudkar, Shweta; Barman, Priyanka; Bhaumik, Sukesh R

    2017-07-01

    We have recently demonstrated that an mRNA capping enzyme, Cet1, impairs promoter-proximal accumulation/pausing of RNA polymerase II (Pol II) independently of its capping activity in Saccharomyces cerevisiae to control transcription. However, it is still unknown how Pol II pausing is regulated by Cet1. Here, we show that Cet1's N-terminal domain (NTD) promotes the recruitment of FACT (facilitates chromatin transcription that enhances the engagement of Pol II into transcriptional elongation) to the coding sequence of an active gene, ADH1, independently of mRNA-capping activity. Absence of Cet1's NTD decreases FACT targeting to ADH1 and consequently reduces the engagement of Pol II in transcriptional elongation, leading to promoter-proximal accumulation of Pol II. Similar results were also observed at other genes. Consistently, Cet1 interacts with FACT. Collectively, our results support the notion that Cet1's NTD promotes FACT targeting to the active gene independently of mRNA-capping activity in facilitating Pol II's engagement in transcriptional elongation, thus deciphering a novel regulatory pathway of gene expression. Copyright © 2017 American Society for Microbiology.

  5. Liquiritigenin, a flavonoid aglycone from licorice, has a choleretic effect and the ability to induce hepatic transporters and phase-II enzymes.

    Science.gov (United States)

    Kim, Young Woo; Kang, Hee Eun; Lee, Myung Gull; Hwang, Se Jin; Kim, Sang Chan; Lee, Chang Ho; Kim, Sang Geon

    2009-02-01

    Liquiritigenin (LQ), an active component of licorice, has an inhibitory effect on LPS-induced inhibitory nitric oxide synthase expression. This study investigated the effects of LQ on choleresis, the expression of hepatic transporters and phase-II enzymes, and fulminant hepatitis. The choleretic effect and the pharmacokinetics of LQ and its glucuronides were monitored in rats. After intravenous administration of LQ, the total area under the plasma concentration-time curve of glucuronyl metabolites was greater than that of LQ in plasma, which accompanied elevations in bile flow rate and biliary excretion of bile acid, glutathione, and bilirubin. The expressions of hepatocellular transporters and phase-II enzymes were assessed by immunoblots, real-time PCR, and immunohistochemistry. In the livers of rats treated with LQ, the protein and mRNA levels of multidrug resistance protein 2 and bile salt export pump were increased in the liver, which was verified by their increased localizations in canalicular membrane. In addition, LQ treatment enhanced the expression levels of major hepatic phase-II enzymes. Consistent with these results, LQ treatments attenuated galactosamine/LPS-induced hepatitis in rats, as supported by decreases in the plasma alanine aminotransferase, liver necrosis, and plasma TNF-alpha. These results demonstrate that LQ has a choleretic effect and the ability to induce transporters and phase-II enzymes in the liver, which may be associated with a hepatoprotective effect against galactosamine/LPS. Our findings may provide insight into understanding the action of LQ and its therapeutic use for liver disease.

  6. The activation of the Nrf2/ARE pathway in HepG2 hepatoma cells by phytochemicals and subsequent modulation of phase II and antioxidant enzyme expression.

    Science.gov (United States)

    Krajka-Kuźniak, Violetta; Paluszczak, Jarosław; Szaefer, Hanna; Baer-Dubowska, Wanda

    2015-06-01

    Previous studies have shown that naturally occurring phytochemicals, indole-3-carbinol, phenethyl isothiocyanate, protocatechuic acid, and tannic acid increased the activity and protein level of hepatic phase II enzymes in animal models. In order to further explore the mechanism of this activity, we investigated the effect of these compounds on the activation of nuclear factor erythroid-2-related factor 2 (Nrf2)-regulated transcription in human hepatocellular carcinoma HepG2 cells. Treatment with all the tested compounds resulted in the translocation from the cytosol and nuclear accumulation of active phosphorylated Nrf2. Furthermore, phenethyl isothiocyanate and indole-3-carbinol increased the transcript and protein levels of GSTA, GSTP, GSTM, GSTT, and NQO1. On the other hand, protocatechuic and tannic acids enhanced only the expression of GSTA, GSTM, and GSTT. The expression of genes encoding antioxidant enzymes CAT, SOD, GR, and GPx was increased after the treatment with all the tested phytochemicals. These results indicate that isothiocyanates/indoles and protocatechuic and tannic acids induce phase II and antioxidant gene expression in HepG2 cells through the Nrf2-Keap1-ARE signaling pathway. Moreover, the results of this study confirmed that the degradation products of glucosinolates are more effective inducers of phase II and antioxidant enzymes than protocatechuic and tannic acids.

  7. The Cyt P450 enzyme CYP716A47 catalyzes the formation of protopanaxadiol from dammarenediol-II during ginsenoside biosynthesis in Panax ginseng.

    Science.gov (United States)

    Han, Jung-Yeon; Kim, Hyun-Jung; Kwon, Yong-Soo; Choi, Yong-Eui

    2011-12-01

    Ginseng (Panax ginseng C.A. Meyer) is one of the most popular medicinal herbs and contains pharmacologically active components, ginsenosides, in its roots. Ginsenosides, a class of tetracyclic triterpene saponins, are thought to be synthesized from dammarenediol-II after hydroxylation by the Cyt P450 (CYP) enzyme and then glycosylation by glycosyltransferase (GT). However, no genes encoding the hydroxylation and glycosylation in ginsenoside biosynthesis have been identified. Here, we identify protopanaxadiol synthase, which is a CYP enzyme (CYP716A47), to be involved in the hydroxylation of dammarenediol-II at the C-12 position to yield protopanaxadiol. Nine putative full CYP sequences were isolated from the expressed sequence tags (ESTs) of methyl jasmonate (MeJA)-treated adventitious ginseng roots. The CYP716A47 gene product was selected as the putative protopanaxadiol synthase because this gene was transcriptionally activated not only by MeJA treatment but also in transgenic ginseng that overexpresses squalene synthase and overproduces ginsenosides. In vitro enzymatic activity assays revealed that CYP716A47 catalyzed the oxidation of dammarenediol-II to produce protopanaxadiol. Ectopic expression of CYP716A47 in recombinant WAT21 yeasts that were fed dammarenediol-II yielded protopanaxadiol. Furthermore, co-expression of the dammarenediol synthase gene (PgDDS) and CYP716A47 in yeast yielded protopanaxadiol without adding dammarenediol-II. The chemical structures of the protopanaxadiol products from dammarenediol-II were confirmed using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC/APCIMS). Thus, CYP716A47 is a dammarenediol 12-hydroxylase that produces protopanaxadiol from dammarenediol-II.

  8. Effect of angiotensin II type 1 receptor blocker and angiotensin converting enzyme inhibitor on the intraocular growth factors and their receptors in streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Ik Soo Byon

    2017-06-01

    Full Text Available AIM: To investigate the effect of angiotensin II type 1 receptor blocker (ARB and angiotensin converting enzyme inhibitor (ACEI on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS: Forty Sprague-Dawley rats were divided into 4 groups: control, diabetes mellitus (DM, candesartan-treated DM, and enalapril-treated DM (each group, n=10. After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/(kg·d] and enalapril [ACEI, 10 mg/(kg·d] were administered to rats orally for 4wk. Vascular endothelial growth factor (VEGF and angiotensin II (Ang II concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor (AT1R levels were assessed at week 4 by Western blotting. RESULTS: Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control (P=0.04 and 0.005, respectively. Vitreous AT1R increased significantly in DM compared to the other three groups (P<0.007. Candesartan-treated DM rats showed higher vitreal AT1R concentration than the enalapril-treated DM group and control (P<0.001 and P=0.005, respectively. No difference in vitreous Ang II and AT1R concentration was found between the enalapril-treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION: Increased Ang II and AT1R in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.

  9. Immobilization of catalase on electrospun PVA/PA6-Cu(II) nanofibrous membrane for the development of efficient and reusable enzyme membrane reactor.

    Science.gov (United States)

    Feng, Quan; Zhao, Yong; Wei, Anfang; Li, Changlong; Wei, Qufu; Fong, Hao

    2014-09-02

    In this study, a mat/membrane consisting of overlaid PVA/PA6-Cu(II) composite nanofibers was prepared via the electrospinning technique followed by coordination/chelation with Cu(II) ions; an enzyme of catalase (CAT) was then immobilized onto the PVA/PA6-Cu(II) nanofibrous membrane. The amount of immobilized catalase reached a high value of 64 ± 4.6 mg/g, while the kinetic parameters (Vmax and Km) of enzyme were 3774 μmol/mg·min and 41.13 mM, respectively. Furthermore, the thermal stability and storage stability of immobilized catalase were improved significantly. Thereafter, a plug-flow type of immobilized enzyme membrane reactor (IEMR) was assembled from the PVA/PA6-Cu(II)-CAT membrane. With the increase of operational pressure from 0.02 to 0.2 MPa, the flux value of IEMR increased from 0.20 ± 0.02 to 0.76 ± 0.04 L/m(2)·min, whereas the conversion ratio of H2O2 decreased slightly from 92 ± 2.5% to 87 ± 2.1%. After 5 repeating cycles, the production capacity of IEMR was merely decreased from 0.144 ± 0.006 to 0.102 ± 0.004 mol/m(2)·min. These results indicated that the assembled IEMR possessed high productivity and excellent reusability, suggesting that the IEMR based on electrospun PVA/PA6-Cu(II) nanofibrous membrane might have great potential for various applications, particularly those related to environmental protection.

  10. Enzymatic degradation of finely divided wood meal. II. Rollmilling and the subsequent enzymic degradation of Pinus densiflora wood

    Energy Technology Data Exchange (ETDEWEB)

    Muraki, E.; Yaku, F.; Tanaka, R.; Koshijima, T.

    1982-01-01

    The roll-milling of wood (P. densiflora) gave products with particle size less than 10 mu and high rate of saccharification under enzymic hydrolysis. About 90% of the available polysaccharides in wood could be converted into reducing sugars when roll-milled wood was subjected to enzymic hydrolysis using cellulase.

  11. Heavy metal detoxification in eukaryotic microalgae.

    Science.gov (United States)

    Perales-Vela, Hugo Virgilio; Peña-Castro, Julián Mario; Cañizares-Villanueva, Rosa Olivia

    2006-06-01

    Microalgae are aquatic organisms possessing molecular mechanisms that allow them to discriminate non-essential heavy metals from those essential ones for their growth. The different detoxification processes executed by algae are reviewed with special emphasis on those involving the peptides metallothioneins, mainly the post transcriptionally synthesized class III metallothioneins or phytochelatins. Also, the features that make microalgae suitable organisms technologies specially to treat water that is heavily polluted with metals is discussed.

  12. Overdose after detoxification: a prospective study.

    Science.gov (United States)

    Wines, James D; Saitz, Richard; Horton, Nicholas J; Lloyd-Travaglini, Christine; Samet, Jeffrey H

    2007-07-10

    The aim of this study was to determine predictors of non-fatal overdose (OD) among a cohort of 470 adults after detoxification from heroin, cocaine or alcohol. We examined factors associated with time to OD during 2 years after discharge from an urban detoxification unit in Boston, MA, USA using multivariable regression analyses. Separate analyses were performed for both the total sample and a subgroup with problem opioid use. Lifetime prevalence for any OD was 30.9% (145/470) in the total sample and 42.3% (85/201) in patients with opioid problems. During the 2-year follow-up, OD was estimated to occur in 16.9% of the total sample and 26.7% of the opioid problem subgroup, with new-onset (incidence) OD estimated at 5.7% and 11.0%, respectively. Factors associated with an increased hazard of OD in both samples included white race, more depressive symptoms, and prior OD regardless of intent. Prior suicidal ideation or attempt was not associated with future OD. Findings underscore both the high prevalence of non-fatal OD among detoxification patients especially opioid users, and the potency of prior OD as a risk factor for future OD. Depressive symptoms, a modifiable risk factor, may represent a potential intervention target to prevent OD, including some "unintentional" ODs.

  13. Spatial learning in men undergoing alcohol detoxification.

    Science.gov (United States)

    Ceccanti, Mauro; Hamilton, Derek; Coriale, Giovanna; Carito, Valentina; Aloe, Luigi; Chaldakov, George; Romeo, Marina; Ceccanti, Marco; Iannitelli, Angela; Fiore, Marco

    2015-10-01

    Alcohol dependence is a major public health problem worldwide. Brain and behavioral disruptions including changes in cognitive abilities are common features of alcohol addiction. Thus, the present study was aimed to investigate spatial learning and memory in 29 alcoholic men undergoing alcohol detoxification by using a virtual Morris maze task. As age-matched controls we recruited 29 men among occasional drinkers without history of alcohol dependence and/or alcohol related diseases and with a negative blood alcohol level at the time of testing. We found that the responses to the virtual Morris maze are impaired in men undergoing alcohol detoxification. Notably they showed increased latencies in the first movement during the trials, increased latencies in retrieving the hidden platform and increased latencies in reaching the visible platform. These findings were associated with reduced swimming time in the target quadrant of the pool where the platform had been during the 4 hidden platform trials of the learning phase compared to controls. Such increasing latency responses may suggest motor control, attentional and motivational deficits due to alcohol detoxification.

  14. Host-Pathogen Interactions: II. Parameters Affecting Polysaccharide-degrading Enzyme Secretion by Colletotrichum lindemuthianum Grown in Culture.

    Science.gov (United States)

    English, P D; Jurale, J B; Albersheim, P

    1971-01-01

    The effect of a number of physiological variables on the secretion of polysaccharide-degrading enzymes by culture-grown Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner was determined. The number of spores used to inoculate cultures grown on isolated bean hypocotyl cell walls affects the time after inoculation at which enzyme secretion occurs, but has no significant effect on the maximal amount of enzyme ultimately secreted. Cell walls isolated from bean leaves, first internodes, or hypocotyls (susceptible to C. lindemuthianum infection), when used as carbon source for C. lindemuthianum growth, stimulate the fungus to secrete more alpha-galactosidase than do cell walls isolated from roots (resistant to infection). The concentration of carbon source used for fungal growth determines the final level of enzyme activity in the culture fluid. The level of enzyme secretion is not proportional to fungal growth; rather, enzyme secretion is induced. Maximal alpha-galactosidase activity in the culture medium is found when the concentration of cell walls used as carbon source is 1% or greater. A higher concentration of cell walls is necessary for maximal alpha-arabinosidase activity. Galactose, when used as the carbon source, stimulates alpha-galactosidase secretion but, at comparable concentrations, is less effective in doing so than are cell walls. Polysaccharide-degrading enzymes are secreted by C. lindemuthianum at different times during growth of the pathogen on isolated cell walls. Pectinase and alpha-arabinosidase are secreted first, followed by beta-xylosidase and cellulase, then beta-glucosidase, and, finally, alpha-galactosidase.

  15. Purification and characterisation of trypsin-like enzyme from the pyloric caeca of cod (Gadus morhua) II

    OpenAIRE

    Luiz Henrique Beirão; Ian Mckintoch Mackie; Evanilda Teixeira; César Damian

    2001-01-01

    A trypsin -like enzyme from the pyloric caeca of cod (Gadus morhua) was purified by affinity chromatography on CHOM Sepharose 4B. Some characteristics were established by its catalytic activity on T.A.M.E., typical enzyme substrate, and serine protease inhibitors. The enzyme had an isoelectric point of 5.30 and 5.89 and was very similar in amino acid composition to bovine trypsin, but differed in having a higher relative amount of acidic amino acids and a lower amount of basic amino acids. Th...

  16. Severe hepatic encephalopathy in a patient with liver cirrhosis after administration of angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker combination therapy: a case report

    Directory of Open Access Journals (Sweden)

    Podda Mauro

    2010-05-01

    Full Text Available Abstract Introduction A combination therapy of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers has been used to control proteinuria, following initial demonstration of its efficacy. However, recently concerns about the safety of this therapy have emerged, prompting several authors to urge for caution in its use. In the following case report, we describe the occurrence of a serious and unexpected adverse drug reaction after administration of a combination of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers to a patient with nephrotic syndrome and liver cirrhosis with severe portal hypertension. Case presentation We administered this combination therapy to a 40-year-old Caucasian man with liver cirrhosis in our Hepatology Clinic, given the concomitant presence of glomerulopathy associated with severe proteinuria. While the administration of one single drug appeared to be well-tolerated, our patient developed severe acute encephalopathy after the addition of the second one. Discontinuation of the therapy led to the disappearance of the side-effect. A tentative rechallenge with the same drug combination led to a second episode of acute severe encephalopathy. Conclusion We speculate that this adverse reaction may be directly related to the effect of angiotensin II on the excretion of blood ammonia. Therefore, we suggest that patients with liver cirrhosis and portal hypertension are at risk of developing clinically relevant encephalopathy when angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker combination therapy is administered, thus indicating the need for a careful clinical follow-up. In addition, the incidence of this serious side-effect should be rigorously evaluated in all patients with liver cirrhosis administered with this common treatment combination.

  17. Tandem Mass Spectrometry Has a Larger Analytical Range than Fluorescence Assays of Lysosomal Enzymes: Application to Newborn Screening and Diagnosis of Mucopolysaccharidoses Types II, IVA, and VI.

    Science.gov (United States)

    Kumar, Arun Babu; Masi, Sophia; Ghomashchi, Farideh; Chennamaneni, Naveen Kumar; Ito, Makoto; Scott, C Ronald; Turecek, Frantisek; Gelb, Michael H; Spacil, Zdenek

    2015-11-01

    There is interest in newborn screening and diagnosis of lysosomal storage diseases because of the development of treatment options that improve clinical outcome. Assays of lysosomal enzymes with high analytical range (ratio of assay response from the enzymatic reaction divided by the assay response due to nonenzymatic processes) are desirable because they are predicted to lead to a lower rate of false positives in population screening and to more accurate diagnoses. We designed new tandem mass spectrometry (MS/MS) assays that give the largest analytical ranges reported to date for the use of dried blood spots (DBS) for detection of mucopolysaccharidoses type II (MPS-II), MPS-IVA, and MPS-VI. For comparison, we carried out fluorometric assays of 6 lysosomal enzymes using 4-methylumbelliferyl (4MU)-substrate conjugates. The MS/MS assays for MPS-II, -IVA, and -VI displayed analytical ranges that are 1-2 orders of magnitude higher than those for the corresponding fluorometric assays. The relatively small analytical ranges of the 4MU assays are due to the intrinsic fluorescence of the 4MU substrates, which cause high background in the assay response. These highly reproducible MS/MS assays for MPS-II, -IVA, and -VI can support multiplex newborn screening of these lysosomal storage diseases. MS/MS assays of lysosomal enzymes outperform 4MU fluorometric assays in terms of analytical range. Ongoing pilot studies will allow us to gauge the impact of the increased analytical range on newborn screening performance. © 2015 American Association for Clinical Chemistry.

  18. Enzymatic detoxification of jojoba meal and effect of the resulting meal on food intake in rats.

    Science.gov (United States)

    Bouali, Abderrahime; Bellirou, Ahmed; Boukhatem, Noureddin; Hamal, Abdellah; Bouammali, Boufelja

    2008-05-10

    When defatted jojoba meal is used as animal food, it causes food-intake reduction and growth retardation. Detoxification procedures by chemical, microbiological, and solvent extraction methods are reported by several authors. Here we report a successful detoxification of jojoba meal using enzymes. We establish reaction conditions that yield new meal which has the same nutritional qualities in proteins as the original meal. The enzymatic reaction gives rise to one major compound to which the structure of an amide is assigned on the basis of IR, 1H and 13C NMR spectra. The effect of the resulting jojoba meal on the food intake in rats is checked. In contrast, the detoxified meal containing the amide derivatives shows no toxicological activity since rats receiving oral administration of the obtained meal show normal growth. Thus, it is expected that this meal could be used as an animal feed ingredient.

  19. Rational proteomics II: electrostatic nature of cofactor preference in the short-chain oxidoreductase (SCOR) enzyme family.

    Science.gov (United States)

    Pletnev, Vladimir Z; Weeks, Charles M; Duax, William L

    2004-11-01

    The dominant role of long-range electrostatic interatomic interactions in nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NAD/NADP) cofactor recognition has been shown for enzymes of the short-chain oxidoreductase (SCOR) family. An estimation of cofactor preference based only on the contribution of the electrostatic energy term to the total energy of enzyme-cofactor interaction has been tested for approximately 40 known three-dimensional (3D) crystal complexes and approximately 330 SCOR enzymes, with cofactor preference predicted by the presence of Asp or Arg recognition residues at specific 3D positions in the beta2alpha3 loop (Duax et al., Proteins 2003;53:931-943). The results obtained were found to be consistent with approximately 90% reliable cofactor assignments for those subsets. The procedure was then applied to approximately 170 SCOR enzymes with completely uncertain NAD/NADP dependence, due to the lack of Asp and Arg marker residues. The proposed 3D electrostatic approach for cofactor assignment ("3D_DeltaE(el)") has been implemented in an automatic screening procedure, and together with the use of marker residues proposed earlier (Duax et al., Proteins 2003;53:931-943), increases the level of reliable predictions for the putative SCORs from approximately 70% to approximately 90%. It is expected to be applicable for any NAD/NADP-dependent enzyme subset having at least 25-30% sequence identity, with at least one enzyme of known 3D crystal structure.

  20. Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

    Science.gov (United States)

    Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

    2016-10-01

    Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

  1. Cytotoxicity of TiO{sub 2} nanoparticles and their detoxification in a freshwater system

    Energy Technology Data Exchange (ETDEWEB)

    Dalai, Swayamprava; Pakrashi, Sunandan; Joyce Nirmala, M.; Chaudhri, Apoorvi; Chandrasekaran, N. [Centre for Nanobiotechnology, VIT University, Vellore (India); Mandal, A.B. [Chemical Laboratory, Central Leather Research Institute, Chennai (India); Mukherjee, Amitava, E-mail: amitav@vit.ac.in [Centre for Nanobiotechnology, VIT University, Vellore (India)

    2013-08-15

    Highlights: •TiO{sub 2} NPs cytotoxicity at low exposure levels (≤1 μg/mL) to freshwater algae. •ROS generation, NP adsorption and internalization contributors to toxicity. •Observational evidence of genotoxicity by nanoparticles in an algal cell. •Reduced bioavailability thus detoxification of NPs by microalgae. •Possible role of EPS in detoxification. -- Abstract: In the current study, two aspects concerning (i) the cytotoxicity potential of TiO{sub 2} nanoparticles (NPs) toward freshwater algal isolate Scenedesmus obliquus and (ii) the potential detoxification of NPs by the microalgae were assessed under light (UV-illumination) and dark conditions at low exposure levels (≤1 μg/mL), using sterile freshwater as the test medium. The statistically significant reduction in cell viability, increase in reactive oxygen species production and membrane permeability (light vs. dark) suggested photo-induced toxicity of TiO{sub 2} NPs. The electron micrographs demonstrated adsorption of the NPs onto the cell surface and substantiated their internalization/uptake. The fluorescence micrographs and the confocal laser scanning (CLSM) images suggested the absence of a definite/intact nucleus in the light treated cells pointing toward the probable genotoxic effects of NPs. In a separate three cycle experiment, a continuous decrease in the cytotoxicity was observed, whereas, at the end of each cycle only fresh algae were added to the supernatant containing NPs from the previous cycle. The decreasing concentrations of the NPs in the subsequent cycles owing to agglomeration–sedimentation processes exacerbated by the algal interactions played a crucial role in the detoxification. In addition, the exo-polymeric substances produced by the cells could have rendered the available NPs less reactive, thereby, enhancing the detoxification effects.

  2. Effects of cow ghee (clarified butter oil) & soybean oil on carcinogen-metabolizing enzymes in rats.

    Science.gov (United States)

    Rani, Rita; Kansal, Vinod K

    2012-09-01

    Our previous study showed that cow ghee relative to soybean oil had a protective effect against carcinogen induced mammary cancer in rats. The objective of this study was to elucidate its biochemical mechanism. Two groups of 21 day old rats (20 each) were fed for 44 wk diet containing cow ghee or soybean oil (10%). Five animals from each group were sacrificed at 0 day and at 5, 21 and 44 wk for analysis of phase I and phase II pathways enzymes of carcinogen metabolism. Dietary cow ghee relative to soybean oil decreased the activities of cytochrome P450 (CYP) enzymes, CYP1A1, CYP1A2, CYP1B1 and CYP2B1, responsible for activation of carcinogen in liver. Carcinogen detoxification activities of uridinediphospho-glucuronosyl transferase (UDPGT) and quinone reductase (QR) in liver, and γ-glutamyltranspeptidase (GGTP) and QR in mammary tissue were significantly higher in cow ghee fed rats than in soybean oil fed rats. The hepatic GGTP activity decreased on soybean oil diet; while in cow ghee group it remained unaffected. Our findings show that dietary cow ghee compared to soybean oil downregulates the enzyme activities responsible for carcinogen activation in liver and upregulates carcinogen detoxification activities in liver and mammary tissues.

  3. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen

    Energy Technology Data Exchange (ETDEWEB)

    Phung, Thu-Ha; Jung, Sunyo, E-mail: sjung@knu.ac.kr

    2015-04-03

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, F{sub v}/F{sub m}, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H{sub 2}O{sub 2} production and greater increases in H{sub 2}O{sub 2}-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. - Highlights: • We employ two different types of photodynamic stress, white and brown necrosis. • We examine molecular mechanisms of antioxidative and detoxification systems. • ALA and OF develop differential actions of antioxidant and detoxification systems. • Coordinated mechanism of antioxidants and detoxification works against toxic ROS. • Detoxification system plays critical roles in protection against photodynamic stress.

  4. Synthesis and biological evaluation of NAS-21 and NAS-91 analogues as potential inhibitors of the mycobacterial FAS-II dehydratase enzyme Rv0636.

    Science.gov (United States)

    Bhowruth, Veemal; Brown, Alistair K; Besra, Gurdyal S

    2008-07-01

    The identification of potential new anti-tubercular chemotherapeutics is paramount due to the recent emergence of extensively drug-resistant strains of Mycobacterium tuberculosis (XDR-TB). Libraries of NAS-21 and NAS-91 analogues were synthesized and evaluated for their whole-cell activity against Mycobacterium bovis BCG. NAS-21 analogues 1 and 2 demonstrated enhanced whole-cell activity in comparison to the parental compound, and an M. bovis BCG strain overexpressing the dehydratase enzyme Rv0636 was resistant to these analogues. NAS-91 analogues with ortho-modifications gave enhanced whole-cell activity. However, extension with biphenyl modifications compromised the whole-cell activities of both NAS-21 and NAS-91 analogues. Interestingly, both libraries demonstrated in vitro activity against fatty acid synthase II (FAS-II) but not FAS-I in cell-free extracts. In in vitro assays of FAS-II inhibition, NAS-21 analogues 4 and 5 had IC(50) values of 28 and 19 mug ml(-1), respectively, for the control M. bovis strain, and the M. bovis BCG strain overexpressing Rv0636 showed a marked increase in resistance. In contrast, NAS-91 analogues demonstrated moderate in vitro activity, although increased resistance was again observed in FAS-II activity assays with the Rv0636-overexpressing strain. Fatty acid methyl ester (FAME) and mycolic acid methyl ester (MAME) analysis of M. bovis BCG and the Rv0636-overexpressing strain revealed that the effect of the drug was relieved in the overexpressing strain, further implicating and potentially identifying Rv0636 as the target for these known FabZ dehydratase inhibitors. This study has identified candidates for further development as drug therapeutics against the mycobacterial FAS-II dehydratase enzyme.

  5. Identification and in vitro analysis of the GatD/MurT enzyme-complex catalyzing lipid II amidation in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Daniela Münch

    2012-01-01

    Full Text Available The peptidoglycan of Staphylococcus aureus is characterized by a high degree of crosslinking and almost completely lacks free carboxyl groups, due to amidation of the D-glutamic acid in the stem peptide. Amidation of peptidoglycan has been proposed to play a decisive role in polymerization of cell wall building blocks, correlating with the crosslinking of neighboring peptidoglycan stem peptides. Mutants with a reduced degree of amidation are less viable and show increased susceptibility to methicillin. We identified the enzymes catalyzing the formation of D-glutamine in position 2 of the stem peptide. We provide biochemical evidence that the reaction is catalyzed by a glutamine amidotransferase-like protein and a Mur ligase homologue, encoded by SA1707 and SA1708, respectively. Both proteins, for which we propose the designation GatD and MurT, are required for amidation and appear to form a physically stable bi-enzyme complex. To investigate the reaction in vitro we purified recombinant GatD and MurT His-tag fusion proteins and their potential substrates, i.e. UDP-MurNAc-pentapeptide, as well as the membrane-bound cell wall precursors lipid I, lipid II and lipid II-Gly₅. In vitro amidation occurred with all bactoprenol-bound intermediates, suggesting that in vivo lipid II and/or lipid II-Gly₅ may be substrates for GatD/MurT. Inactivation of the GatD active site abolished lipid II amidation. Both, murT and gatD are organized in an operon and are essential genes of S. aureus. BLAST analysis revealed the presence of homologous transcriptional units in a number of gram-positive pathogens, e.g. Mycobacterium tuberculosis, Streptococcus pneumonia and Clostridium perfringens, all known to have a D-iso-glutamine containing PG. A less negatively charged PG reduces susceptibility towards defensins and may play a general role in innate immune signaling.

  6. Probing fundamental film parameters of immobilized enzymes--towards enhanced biosensor performance. Part II-Electroanalytical estimation of immobilized enzyme performance.

    Science.gov (United States)

    Fogel, R; Limson, J L

    2011-07-10

    The method of immobilization of a protein has a great influence on the overall conformation, and hence, functioning of the protein. Thus, a greater understanding of the events undergone by the protein during immobilization is key to manipulating the immobilization method to produce a strategy that influences the advantages of immobilization while minimizing their disadvantages in biosensor design. In this, the second paper of a two-part series, we have assessed the kinetic parameters of thin-film laccase monolayers, covalently attached to SAMs differing in spacer-arm length and lateral density of spacer arms. This was achieved using chronoamperometry and an electroactive product (p-benzoquinone), which was modeled in a non-linear regressional fashion to extract the relevant parameters. Finally, comparisons between the kinetic parameters presented in this paper and the rheological parameters of laccase monolayers immobilized in the same manner (Part I of this two paper series) were performed. Improvements in the maximal enzyme-catalysed current, i(max), the apparent Michaelis-Menten constant, K(m) and the apparent biosensor sensitivity were noted for most of the surfaces with increasing linker length. Decreasing the lateral density of the spacer-arms brought about a general improvement in these parameters, which is attributed to the decrease in multiple points of immobilization undergone by functional proteins. Finally, comparisons between rheological data and kinetics data showed that the degree of viscosity exhibited by protein films has a negative influence on attached protein layers, while enhanced protein hydration levels (assessed piezoelectrically from data obtained in Paper 1) has a positive effect on those surfaces comprising rigidly bound protein layers.

  7. Analysis of mucolipidosis II/III GNPTAB missense mutations identifies domains of UDP-GlcNAc:lysosomal enzyme GlcNAc-1-phosphotransferase involved in catalytic function and lysosomal enzyme recognition.

    Science.gov (United States)

    Qian, Yi; van Meel, Eline; Flanagan-Steet, Heather; Yox, Alex; Steet, Richard; Kornfeld, Stuart

    2015-01-30

    UDP-GlcNAc:lysosomal enzyme GlcNAc-1-phosphotransferase tags newly synthesized lysosomal enzymes with mannose 6-phosphate recognition markers, which are required for their targeting to the endolysosomal system. GNPTAB encodes the α and β subunits of GlcNAc-1-phosphotransferase, and mutations in this gene cause the lysosomal storage disorders mucolipidosis II and III αβ. Prior investigation of missense mutations in GNPTAB uncovered amino acids in the N-terminal region and within the DMAP domain involved in Golgi retention of GlcNAc-1-phosphotransferase and its ability to specifically recognize lysosomal hydrolases, respectively. Here, we undertook a comprehensive analysis of the remaining missense mutations in GNPTAB reported in mucolipidosis II and III αβ patients using cell- and zebrafish-based approaches. We show that the Stealth domain harbors the catalytic site, as some mutations in these regions greatly impaired the activity of the enzyme without affecting its Golgi localization and proteolytic processing. We also demonstrate a role for the Notch repeat 1 in lysosomal hydrolase recognition, as missense mutations in conserved cysteine residues in this domain do not affect the catalytic activity but impair mannose phosphorylation of certain lysosomal hydrolases. Rescue experiments using mRNA bearing Notch repeat 1 mutations in GNPTAB-deficient zebrafish revealed selective effects on hydrolase recognition that differ from the DMAP mutation. Finally, the mutant R587P, located in the spacer between Notch 2 and DMAP, was partially rescued by overexpression of the γ subunit, suggesting a role for this region in γ subunit binding. These studies provide new insight into the functions of the different domains of the α and β subunits.

  8. Dietary sodium deprivation evokes activation of brain regional neurons and down-regulation of angiotensin II type 1 receptor and angiotensin-convertion enzyme mRNA expression.

    Science.gov (United States)

    Lu, B; Yang, X J; Chen, K; Yang, D J; Yan, J Q

    2009-12-15

    Previous studies have indicated that the renin-angiotensin-aldosterone system (RAAS) is implicated in the induction of sodium appetite in rats and that different dietary sodium intakes influence the mRNA expression of central and peripheral RAAS components. To determine whether dietary sodium deprivation activates regional brain neurons related to sodium appetite, and changes their gene expression of RAAS components of rats, the present study examined the c-Fos expression after chronic exposure to low sodium diet, and determined the relationship between plasma and brain angiotensin I (ANG I), angiotensin II (ANG II) and aldosterone (ALD) levels and the sodium ingestive behavior variations, as well as the effects of prolonged dietary sodium deprivation on ANG II type 1 (AT1) and ANG II type 2 (AT2) receptors and angiotensin-convertion enzyme (ACE) mRNA levels in the involved brain regions using the method of real-time polymerase chain reaction (PCR). Results showed that the Fos immunoreactivity (Fos-ir) expression in forebrain areas such as subfornical organ (SFO), paraventricular hypothalamic nuclei (PVN), supraoptic nucleus (SON) and organum vasculosum laminae terminalis (OVLT) all increased significantly and that the levels of ANG I, ANG II and ALD also increased in plasma and forebrain in rats fed with low sodium diet. In contrast, AT1, ACE mRNA in PVN, SON and OVLT decreased significantly in dietary sodium depleted rats, while AT2 mRNA expression did not change in the examined areas. These results suggest that many brain areas are activated by increased levels of plasma and/or brain ANG II and ALD, which underlies the elevated preference for hypertonic salt solution after prolonged exposure to low sodium diet, and that the regional AT1 and ACE mRNA are down-regulated after dietary sodium deprivation, which may be mediated by increased ANG II in plasma and/or brain tissue.

  9. Sulfide intrusion and detoxification in Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2014-01-01

    nutrition in general. By a global review of sulfide intrusion, coupled with a series of field studies and in situ experiments we elucidate sulfide intrusion and different strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis...... indicating a possible role of sulfide in the sulfur nutrition beside the detoxification function. Our results suggest different adaptations of Z. marina to reduced sediments and sulfide intrusion ranging from bacterial and chemical reoxidation of sulfide to sulfate to incorporation of sulfide into organic...

  10. Biochemical and Spectroscopic Characterization of the Non-Heme Fe(II)- and 2-Oxoglutarate-Dependent Ethylene-Forming Enzyme from Pseudomonas syringae pv. phaseolicola PK2.

    Science.gov (United States)

    Martinez, Salette; Hausinger, Robert P

    2016-11-01

    The ethylene-forming enzyme (EFE) from Pseudomonas syringae pv. phaseolicola PK2 is a member of the mononuclear non-heme Fe(II)- and 2-oxoglutarate (2OG)-dependent oxygenase superfamily. This enzyme is reported to simultaneously catalyze the conversion of 2OG into ethylene and three CO2 molecules and the Cδ hydroxylation of l-arginine (l-Arg) while oxidatively decarboxylating 2OG to form succinate and carbon dioxide. A new plasmid construct for expression in recombinant Escherichia coli cells allowed for the purification of large amounts of EFE with activity greater than that previously recorded. A variety of assays were used to quantify and confirm the identity of the proposed products, including the first experimental demonstration of l-Δ(1)-pyrroline-5-carboxylate and guanidine derived from 5-hydroxyarginine. Selected l-Arg derivatives could induce ethylene formation without undergoing hydroxylation, demonstrating that ethylene production and l-Arg hydroxylation activities are not linked. Similarly, EFE utilizes the alternative α-keto acid 2-oxoadipate as a cosubstrate (forming glutaric acid) during the hydroxylation of l-Arg, with this reaction unlinked from ethylene formation. Kinetic constants were determined for both ethylene formation and l-Arg hydroxylation reactions. Anaerobic UV-visible difference spectra were used to monitor the binding of Fe(II) and substrates to the enzyme. On the basis of our results and what is generally known about EFE and Fe(II)- and 2OG-dependent oxygenases, an updated model for the reaction mechanism is presented.

  11. 2-Hexadecynoic Acid Inhibits Plasmodial FAS-II Enzymes and Arrest Erythrocytic and Liver Stage Plasmodium Infections

    OpenAIRE

    Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L.; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H.; Brun, Reto; Carballeira, Néstor M.

    2010-01-01

    Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of P. yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the in...

  12. Induction of phase 2 antioxidant enzymes by broccoli sulforaphane: Perspectives in maintaining the antioxidant activity of vitamins A, C, and E

    Directory of Open Access Journals (Sweden)

    Sekhar s Boddupalli

    2012-01-01

    Full Text Available Consumption of fruits and vegetables is recognized as an important part of a healthy diet. Increased consumption of cruciferous vegetables in particular has been associated with a decreased risk of several degenerative and chronic diseases, including cardiovascular disease and certain cancers. Members of the cruciferous vegetable family, which includes broccoli, Brussels sprouts, cauliflower, and cabbage, accumulate significant concentrations of glucosinolates, which are metabolized in vivo to biologically active isothiocyanates (ITCs. The ITC sulforaphane, which is derived from glucoraphanin, has garnered particular interest due to its extraordinary ability to induce expression of several enzymes via the Keap1/Nrf2/ARE pathway. Nrf2/ARE gene products are typically characterized as Phase II detoxification enzymes and/or antioxidant (AO enzymes. Over the last decade, human clinical studies have begun to provide in vivo evidence of both Phase II and AO enzyme induction by SF. Many AO enzymes are redox cycling enzymes that maintain redox homeostasis and activity of free radical scavengers such as such as vitamins A, C and E. In this review, we present the existing evidence for induction of PII and AO enzymes by SF, the interactions of SF-induced AO enzymes and proposed maintenance of the essential vitamins A, C and E, and, finally, the current view of genotypic effects on ITC metabolism and AO enzyme induction and function.

  13. Cell organelles from crassulacean acid metabolism (CAM) plants : II. Compartmentation of enzymes of the crassulacean acid metabolism.

    Science.gov (United States)

    Schnarrenberger, C; Groß, D; Burkhard, C; Herbert, M

    1980-02-01

    The intracellular distribution of enzymes involved in the Crassulacean acid metabolism (CAM) has been studied in Bryophyllum calycinum Salisb. and Crassula lycopodioides Lam. After separation of cell organelles by isopycnic centrifugation, enzymes of the Crassulacean acid metabolism were found in the following cell fractions: Phosphoenolpyruvate carboxylase in the chloroplasts; NAD-dependent malate dehydrogenase in the mitochondria and in the supernatant; NADP-dependent malate dehydrogenase and phosphoenolpyruvate carboxykinase in the chloroplasts; NADP-dependent malic enzyme in the supernatant and to a minor extent in the chloroplasts; NAD-dependent malic enzyme in the supernatant and to some degree in the mitochondria; and pyruvate; orthophosphate dikinase in the chloroplasts. The activity of the NAD-dependent malate dehydrogenase was due to three isoenzymes separated by (NH4)2SO4 gradient solubilization. These isoenzymes represented 17, 78, and 5% of the activity recovered, respectively, in the order of elution. The isoenzyme eluting first was associated with the mitochondria and the second isoenzyme was of cytosolic origin, while the intracellular location of the third isoenzyme was probably the peroxisome. Based on these findings, the metabolic path of Crassulacean acid metabolism within cells of CAM plants is discussed.

  14. General anaesthesia does not improve outcome in opioid antagonist detoxification treatment : a randomized controlled trial

    NARCIS (Netherlands)

    De Jong, Cor A J; Laheij, Robert J F; Krabbe, Paul F M

    AIM: Opioid detoxification by administering opioid-antagonists under general anaesthesia has caused considerable controversy. This study is conducted to determine whether rapid detoxification under general anaesthesia results in higher levels of opioid abstinence than rapid detoxification without

  15. General anaesthesia does not improve outcome in opioid antagonist detoxification treatment: a randomized controlled trial.

    NARCIS (Netherlands)

    Jong, C.A.J. de; Laheij, R.J.F.; Krabbe, P.F.M.

    2005-01-01

    AIM: Opioid detoxification by administering opioid-antagonists under general anaesthesia has caused considerable controversy. This study is conducted to determine whether rapid detoxification under general anaesthesia results in higher levels of opioid abstinence than rapid detoxification without

  16. Microbial detoxification of metalaxyl in aquatic system

    Institute of Scientific and Technical Information of China (English)

    Ahmed H.Massoud; Aly S.Derbalah; El-Sayed.B.Belal

    2008-01-01

    Four microorganisms,Pseudomonas sp.(ER2),Aspergillus niger (ER6),Cladosporium herbarum (ER4) and Penicilluim sp.(ER3),were isolated from cucumber leaves previously treated with metalaxyl using enrichment technique.These isolates were evaluated for detoxification of metalaxyl at the recommended dose level in aquatic system.The effect of pH and temperature on the growth ability of the tested isolates was also investigated by measuring the intracellular protein and mycelia dry weight for bacterial and fungal isolates,respectively.Moreover,the toxicity of metalaxyl after 28 d of treatment with the tested isolates was evaluated to confirm the complete removal of any toxic materials (metalaxyl and its metabolites).The results showed that the optimum degree pH for the growth of metalaxyl degrading isolates (bacterial and fungal isolates) was 7.The temperature 30℃ appeared to be the optimum degree for the growth of either fungal or bacterial isolates.The results showed that Pseudomonas sp.(ER2) was the most effective isolate in metalaxyl degradation followed by Aspergillus niger (ER6),Cladosporium herbarum (ER4) and PeniciUuim sp.(ER3),respectively.There is no toxicity of metalaxyl detected in the supernatant after 28 d of treannent with Pseudomonas sp.(ER2).The results suggest that bioremediation by Pseudomonas sp.(ER2) isolate was considered to be effective method for detoxification of metalaxyl in aqueous media.

  17. Occurrence, detection and detoxification of mycotoxins

    Indian Academy of Sciences (India)

    Visenuo Aiko; Alka Mehta

    2015-12-01

    Mycotoxins have been identified as important toxins affecting animal species and humans ever since the discovery of aHatoxin Bl in 1960. Mycotoxigenic fungi are ubiquitous in nature and are held responsible for economic loss as they decrease crop yield and quality of food. The presence of fungi and their mycotoxins are reported not only in food grains but also in medicinal herbs and processed foods. Since prevention is not always possible, detoxification of mycotoxins have been attempted using several means; however, only few have been accepted for practical use, e.g. ammonia in the com industry. Organizations such as the World Health Organization, US Food and Drug Adminis-tration and European Union have set regulations and safety limits of important mycotoxins, viz. aHatoxins, fusarium toxins, ochratoxin, patulin zearalenone, etc., to ensure the safety of the consumers. This review article is a brief and up-to-date account of the occurrence, detection and detoxification of mycotoxins for those interested in and considering research in this area.

  18. Microbial detoxification of metalaxyl in aquatic system.

    Science.gov (United States)

    Massoud, Ahmed H; Derbalah, Aly S; Belal, El-Sayed B

    2008-01-01

    Four microorganisms, Pseudomonas sp. (ER2), Aspergillus niger (ER6), Cladosporium herbarum (ER4) and Penicilluim sp. (ER3), were isolated from cucumber leaves previously treated with metalaxyl using enrichment technique. These isolates were evaluated for detoxification of metalaxyl at the recommended dose level in aquatic system. The effect of pH and temperature on the growth ability of the tested isolates was also investigated by measuring the intracellular protein and mycelia dry weight for bacterial and fungal isolates, respectively. Moreover, the toxicity of metalaxyl after 28 d of treatment with the tested isolates was evaluated to confirm the complete removal of any toxic materials (metalaxyl and its metabolites). The results showed that the optimum degree pH for the growth of metalaxyl degrading isolates (bacterial and fungal isolates) was 7. The temperature 30 degrees C appeared to be the optimum degree for the growth of either fungal or bacterial isolates. The results showed that Pseudomonas sp. (ER2) was the most effective isolate in metalaxyl degradation followed by Aspergillus niger (ER6), Cladosporium herbarum (ER4) and Penicilluim sp. (ER3), respectively. There is no toxicity of metalaxyl detected in the supernatant after 28 d of treatment with Pseudomonas sp. (ER2). The results suggest that bioremediation by Pseudomonas sp. (ER2) isolate was considered to be effective method for detoxification of metalaxyl in aqueous media.

  19. [Blood detoxification using superparamagnetic nanoparticles (magnetic hemodialysis)].

    Science.gov (United States)

    Ciochină, Al D; Untu, Alina; Iacob, Gh

    2010-01-01

    The authors present an experimental study realized in order to simulate blood detoxification with the help of supermagnetic nanoparticles. The particles used are red oxide nanoparticles which are considered to be equivalent from a magnetic susceptibility and dynamic diameter point of view to the complex structures of magnetite nanoparticles. Two types of custom HGMS matrices have been used--a threaded one and a micro-spheres one. For testing red oxide particles have been purposefully created to have a lower magnetic susceptibility than magnetite or iron-carbon particles used in other experimental studies. Different concentrations of iron oxide, glycerine and water have been prepared, creating a 3.5 cP viscosity (equivalent to the one of the blood); the concentrations of the prepared solutions varied between 0.16 mg/mL and 2 mg/mL, with the background magnetic field value ranging from 0.25 T to 0.9 T, in order to observer the effectiveness of filtering at different intensities. The efficiency of HGMS filtering in experimental conditions was almost completely successful (99.99%) in all experimental conditions, both with the threaded and micro-spheres matrices. The high gradient magnetic separation system of nanoparticles has maximum efficiency and has the potential of being implemented in a medical blood detoxification device.

  20. Occurrence, detection and detoxification of mycotoxins.

    Science.gov (United States)

    Aiko, Visenuo; Mehta, Alka

    2015-12-01

    Mycotoxins have been identified as important toxins affecting animal species and humans ever since the discovery of aflatoxin B1 in 1960. Mycotoxigenic fungi are ubiquitous in nature and are held responsible for economic loss as they decrease crop yield and quality of food. The presence of fungi and their mycotoxins are reported not only in food grains but also in medicinal herbs and processed foods. Since prevention is not always possible, detoxification of mycotoxins have been attempted using several means; however, only few have been accepted for practical use, e.g. ammonia in the corn industry. Organizations such as the World Health Organization, US Food and Drug Administration and European Union have set regulations and safety limits of important mycotoxins, viz. aflatoxins, fusarium toxins, ochratoxin, patulin zearalenone, etc., to ensure the safety of the consumers. This review article is a brief and up-to-date account of the occurrence, detection and detoxification of mycotoxins for those interested in and considering research in this area.

  1. Rheumatoid arthritis and its association with HLA-DR antigens. II. Antibodies to native connective tissue antigens detected by enzyme linked immunosorbent assay.

    Science.gov (United States)

    Pesoa, S A; Vullo, C M; Onetti, C M; Riera, C M

    1989-01-01

    The distribution of frequencies of HLA-DR alloantigens in HLA-DR4 negative subjects was determined in patients with Rheumatoid arthritis (RA) and normal individuals. An increased incidence of HLA-DR1 alloantigen in DR4 negative RA patients (45.9%) compared with DR4 negative healthy controls (23.6%) was found. The difference became significant when the incidence of DR1 was compared between patients with severe disease stages (III-IV) (75%) in contrast to 32% of incidence in patients of the milder stages (I-II) (p less than 0.05). Using Enzyme Linked Immunosorbent Assay we have determined the incidence of serum antibodies to native bovine type I and type II collagens and proteoglycans in patients with RA. Presence of serum antibodies to native type I collagen was detected in 59% of patients with RA, 60% of sera exhibited reactivity to type II collagen and 12% had antibodies to proteoglycans. There was no correlation between the presence of antibodies to type I and II collagens and disease stages, however, the incidence of serum antibodies to proteoglycans was increased in severe disease stages. On the other hand, the presence of high levels of antibodies to type I collagen was associated to HLA-DR1 antigen, (p less than 0.05).

  2. Different reactivity to angiotensin II of peripheral and renal arteries in spontaneously hypertensive rats: effect of acute and chronic angiotensin converting enzyme inhibition

    Science.gov (United States)

    Guidi, E.; Hollenberg, N. K.

    1986-01-01

    We assessed renal blood flow and pressor responses to graded angiotensin II doses in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats ingesting a diet containing 1.6% sodium basally and after acute and chronic angiotensin converting enzyme (ACE) inhibition with captopril. In the basal state the pressor response to angiotensin II was enhanced (Prenal vascular response was blunted (Pacute captopril administration the pressor response was enhanced in both strains, and the difference between them was maintained, while the renal vascular response was enhanced in both, but more in SHR, so that the renal vascular response in the SHR became larger than in WKY (Prenal responses in WKY rats, but only the pressor response in SHR. The renal vessels of SHR seem to be different from those of WKY rats in reaction to exogenous angiotensin II, and in response to both acute administration of captopril (probably acting through blockade of angiotensin II production) and chronic administration of captopril (probably acting mainly through accumulation of kinin or production of prostaglandins).

  3. Natural variations in xenobiotic-metabolizing enzymes: developing tools for coral monitoring

    Science.gov (United States)

    Rougée, L. R. A.; Richmond, R. H.; Collier, A. C.

    2014-06-01

    The continued deterioration of coral reefs worldwide demonstrates the need to develop diagnostic tools for corals that go beyond general ecological monitoring and can identify specific stressors at sublethal levels. Cellular diagnostics present an approach to defining indicators (biomarkers) that have the potential to reflect the impact of stress at the cellular level, allowing for the detection of intracellular changes in corals prior to outright mortality. Detoxification enzymes, which may be readily induced or inhibited by environmental stressors, present such a set of indicators. However, in order to apply these diagnostic tools for the detection of stress, a detailed understanding of their normal, homeostatic levels within healthy corals must first be established. Herein, we present molecular and biochemical evidence for the expression and activity of major Phase I detoxification enzymes cytochrome P450 (CYP450), CYP2E1, and CYP450 reductase, as well as the Phase II enzymes UDP, glucuronosyltransferase (UGT), β-glucuronidase, glutathione- S-transferase (GST), and arylsulfatase C (ASC) in the coral Pocillopora damicornis. Additionally, we characterized enzyme expression and activity variations over a reproductive cycle within a coral's life history to determine natural endogenous changes devoid of stress exposure. Significant changes in enzyme activity over the coral's natural lunar reproductive cycle were observed for CYP2E1 and CYP450 reductase as well as UGT and GST, while β-glucuronidase and ASC did not fluctuate significantly. The data represent a baseline description of `health' for the expression and activity of these enzymes that can be used toward understanding the impact of environmental stressors on corals. Such knowledge can be applied to address causes of coral reef ecosystem decline and to monitor effectiveness of mitigation strategies. Achieving a better understanding of cause-and-effect relationships between putative stressors and biological

  4. Colorectal cancer and detoxification enzymes : with emphasis on enzyme modulation and genetic polymorphisms

    NARCIS (Netherlands)

    Logt, E.M.J. van der

    2005-01-01

    The aetiology of sporadic colorectal cancer (CRC) is complex and involves genetic and lifestyle factors. To deal with the daily load of carcinogens, present in food, tobacco smoke etc., humans possess an efficient system of defence against such compounds and an important role is reserved for the det

  5. Perioperative angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers for preventing mortality and morbidity in adults.

    Science.gov (United States)

    Zou, Zui; Yuan, Hong B; Yang, Bo; Xu, Fengying; Chen, Xiao Y; Liu, Guan J; Shi, Xue Y

    2016-01-27

    Perioperative hypertension requires careful management. Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) have shown efficacy in treating hypertension associated with surgery. However, there is lack of consensus about whether they can prevent mortality and morbidity. To systematically assess the benefits and harms of administration of ACEIs or ARBs perioperatively for the prevention of mortality and morbidity in adults (aged 18 years and above) undergoing any type of surgery under general anaesthesia. We searched the current issue of the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 12), Ovid MEDLINE (1966 to 8 December 2014), EMBASE (1980 to 8 December 2014), and references of the retrieved randomized trials, meta-analyses, and systematic reviews. We included randomized controlled trials (RCTs) comparing perioperative administration of ACEIs or ARBs with placebo in adults (aged 18 years and above) undergoing any type of surgery under general anaesthesia. We excluded studies in which participants underwent procedures that required local anaesthesia only, or participants who had already been on ACEIs or ARBs. Two review authors independently performed study selection, assessed the risk of bias, and extracted data. We used standard methodological procedures expected by Cochrane. We included seven RCTs with a total of 571 participants in the review. Two of the seven trials involved 36 participants undergoing non-cardiac vascular surgery (infrarenal aortic surgery), and five involved 535 participants undergoing cardiac surgery, including valvular surgery, coronary artery bypass surgery, and cardiopulmonary bypass surgery. The intervention was started from 11 days to 25 minutes before surgery in six trials and during surgery in one trial. We considered all seven RCTs to carry a high risk of bias. The effects of ACEIs or ARBs on perioperative mortality and acute myocardial infarction were uncertain

  6. Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes

    Science.gov (United States)

    Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J. Shawn; Okoro, Emmanuel U.; Guo, ZhongMao

    2016-01-01

    We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of NAD(P)H: quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites

  7. Biological detoxification of the mycotoxin deoxynivalenol and its use in genetically engineered crops and feed additives.

    Science.gov (United States)

    Karlovsky, Petr

    2011-08-01

    Deoxynivalenol (DON) is the major mycotoxin produced by Fusarium fungi in grains. Food and feed contaminated with DON pose a health risk to humans and livestock. The risk can be reduced by enzymatic detoxification. Complete mineralization of DON by microbial cultures has rarely been observed and the activities turned out to be unstable. The detoxification of DON by reactions targeting its epoxide group or hydroxyl on carbon 3 is more feasible. Microbial strains that de-epoxidize DON under anaerobic conditions have been isolated from animal digestive system. Feed additives claimed to de-epoxidize trichothecenes enzymatically are on the market but their efficacy has been disputed. A new detoxification pathway leading to 3-oxo-DON and 3-epi-DON was discovered in taxonomically unrelated soil bacteria from three continents; the enzymes involved remain to be identified. Arabidopsis, tobacco, wheat, barley, and rice were engineered to acetylate DON on carbon 3. In wheat expressing DON acetylation activity, the increase in resistance against Fusarium head blight was only moderate. The Tri101 gene from Fusarium sporotrichioides was used; Fusarium graminearum enzyme which possesses higher activity towards DON would presumably be a better choice. Glycosylation of trichothecenes occurs in plants, contributing to the resistance of wheat to F. graminearum infection. Marker-assisted selection based on the trichothecene-3-O-glucosyltransferase gene can be used in breeding for resistance. Fungal acetyltransferases and plant glucosyltransferases targeting carbon 3 of trichothecenes remain promising candidates for engineering resistance against Fusarium head blight. Bacterial enzymes catalyzing oxidation, epimerization, and less likely de-epoxidation of DON may extend this list in future.

  8. Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation.

    Science.gov (United States)

    Marowsky, Anne; Haenel, Karen; Bockamp, Ernesto; Heck, Rosario; Rutishauser, Sibylle; Mule, Nandkishor; Kindler, Diana; Rudin, Markus; Arand, Michael

    2016-12-01

    Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.

  9. Studies on NADPH-cytochrome c reductase. II. Steady-state kinetic properties of the crystalline enzyme from ale yeast.

    Science.gov (United States)

    Tryon, E; Kuby, S A

    1984-01-01

    From a study of the steady-state kinetics (at pH 7.6, 30 degrees C) of the reduction of cytochrome c, a 'ping-pong' mechanism may be postulated for the crystalline NADPH-cytochrome c reductase from ale yeast, Saccharomyces cerevisiae [1], a result derivable from a three-substrate ordered system with a rapid equilibrium random sequence in substrates, NADPH and FAD, followed by reactions of the third substrate, Cyt C3+. On this basis, estimates for the kinetic parameters were made together with the inhibitor dissociation constants for NADP+ (competitive with respect to NADPH as variable substrate, but noncompetitive with respect to cytochrome c3+ as the variable substrate). A noncompetitive type of inhibition was also found for cytochrome c2+ with NADPH as variable substrate, in confirmation of the proposed mechanism. With 2,6-dichloroindophenol as the acceptor, in place of cytochrome c3+, a value for KNADPH could be estimated which agreed with that estimated above, with cytochrome c3+ as the acceptor, again, in confirmation of the postulated mechanism. The reactions with molecular O2 catalyzed by the enzyme with NADPH as the reductant have been studied polarographically, and its Km for O2 estimated to be about 0.15 mmol/l at pH 7.6, 25 degrees C. The product of the reaction appears to be H2O2, which acts as a noncompetitive inhibitor for NADPH (Ki = 0.5 mmol/l), and tentatively an enzyme ternary complex containing oxygen and FADoh (semiquinone of FAD) may be assumed to be the kinetically important intermediate, which may be postulated to be in quasi-equilibrium with an enzyme ternary complex containing Oo2 (superoxide) and FAD.

  10. The evaluation and validation of copper (II) force field parameters of the Auxiliary Activity family 9 enzymes

    Science.gov (United States)

    Moses, Vuyani; Tastan Bishop, Özlem; Lobb, Kevin A.

    2017-06-01

    The Auxiliary Activity family 9 (AA9) proteins are Cu2+ coordinating enzymes which are crucial for the early stages of cellulose degradation. In this study, the force field parameters for copper-containing bonds in the Type 1 AA9 protein active site were established and used in a molecular dynamics simulation on a solvated, neutralized system containing an AA9 protein, Cu2+ and a β-cellulose surface. The copper to cellulose interaction was evident during the dynamics, which could also be accelerated by the use of high Cusbnd O van der Waals parameters. The interaction of AA9, Cu2+ and cellulose is described in detail.

  11. Zearalenone detoxification by zearalenone hydrolase is important for the antagonistic ability of Clonostachys rosea against mycotoxigenic Fusarium graminearum

    DEFF Research Database (Denmark)

    Kosawang, Chatchai; Karlsson, Magnus; Vélëz, Heriberto

    2014-01-01

    The fungus Clonostachys rosea is antagonistic against plant pathogens, including Fusarium graminearum, which produces the oestrogenic mycotoxin zearalenone (ZEA). ZEA inhibits other fungi, and C. rosea can detoxify ZEA through the enzyme zearalenone lactonohydrolase (ZHD101). As the relevance...... wheat seedlings against foot rot caused by the ZEA-producing F. graminearum. These data show that ZEA detoxification by ZHD101 is important for the biocontrol ability of C. rosea against F. graminearum....

  12. Modification of carbonic anhydrase II with acetaldehyde, the first metabolite of ethanol, leads to decreased enzyme activity.

    OpenAIRE

    2008-01-01

    Abstract Background Acetaldehyde, the first metabolite of ethanol, can generate covalent modifications of proteins and cellular constituents. However, functional consequences of such modification remain poorly defined. In the present study, we examined acetaldehyde reaction with human carbonic anhydrase (CA) isozyme II, which has several features that make it a suitable target protein: It is widely expressed, its enzymatic activity can be monitored, its structural and catalytic properties are...

  13. Phenobarbital induction and chemical synergism demonstrate the role of UDP-glucuronosyltransferases in detoxification of naphthalophos by Haemonchus contortus larvae.

    Science.gov (United States)

    Kotze, Andrew C; Ruffell, Angela P; Ingham, Aaron B

    2014-12-01

    We used an enzyme induction approach to study the role of detoxification enzymes in the interaction of the anthelmintic compound naphthalophos with Haemonchus contortus larvae. Larvae were treated with the barbiturate phenobarbital, which is known to induce the activity of a number of detoxification enzymes in mammals and insects, including cytochromes P450 (CYPs), UDP-glucuronosyltransferases (UDPGTs), and glutathione (GSH) S-transferases (GSTs). Cotreatment of larvae with phenobarbital and naphthalophos resulted in a significant increase in the naphthalophos 50% inhibitory concentration (IC50) compared to treatment of larvae with the anthelmintic alone (up to a 28-fold increase). The phenobarbital-induced drug tolerance was reversed by cotreatment with the UDPGT inhibitors 5-nitrouracil, 4,6-dihydroxy-5-nitropyrimidine, probenecid, and sulfinpyrazone. Isobologram analysis of the interaction of 5-nitrouracil with naphthalophos in phenobarbital-treated larvae clearly showed the presence of strong synergism. The UDPGT inhibitors 5-nitrouracil, 4,6-dihydroxy-5-nitropyrimidine, and probenecid also showed synergistic effects with non-phenobarbital-treated worms (synergism ratio up to 3.2-fold). This study indicates that H. contortus larvae possess one or more UDPGT enzymes able to detoxify naphthalophos. In highlighting the protective role of this enzyme group, this study reveals the potential for UDPGT enzymes to act as a resistance mechanism that may develop under drug selection pressure in field isolates of this species. In addition, the data indicate the potential for a chemotherapeutic approach utilizing inhibitors of UDPGT enzymes as synergists to increase the activity of naphthalophos against parasitic worms and to combat detoxification-mediated drug resistance if it arises in the field. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  14. Sulforaphane induces phase II detoxication enzymes in mouse skin and prevents mutagenesis induced by a mustard gas analog

    Energy Technology Data Exchange (ETDEWEB)

    Abel, E.L. [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957 (United States); Boulware, S. [Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723 (United States); Fields, T.; McIvor, E.; Powell, K.L. [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957 (United States); DiGiovanni, J.; Vasquez, K.M. [Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723 (United States); MacLeod, M.C., E-mail: mcmacleod@mdanderson.org [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957 (United States)

    2013-02-01

    Mustard gas, used in chemical warfare since 1917, is a mutagenic and carcinogenic agent that produces severe dermal lesions for which there are no effective therapeutics; it is currently seen as a potential terrorist threat to civilian populations. Sulforaphane, found in cruciferous vegetables, is known to induce enzymes that detoxify compounds such as the sulfur mustards that react through electrophilic intermediates. Here, we observe that a single topical treatment with sulforaphane induces mouse epidermal levels of the regulatory subunit of glutamate-cysteine ligase, the rate-limiting enzyme in glutathione biosynthesis, and also increases epidermal levels of reduced glutathione. Furthermore, a glutathione S-transferase, GSTA4, is also induced in mouse skin by sulforaphane. In an in vivo model in which mice are given a single mutagenic application of the sulfur mustard analog 2-(chloroethyl) ethyl sulfide (CEES), we now show that therapeutic treatment with sulforaphane abolishes the CEES-induced increase in mutation frequency in the skin, measured four days after exposure. Sulforaphane, a natural product currently in clinical trials, shows promise as an effective therapeutic against mustard gas. -- Highlights: ► Sulforaphane induces increased levels of glutathione in mouse skin. ► Sulforaphane induces increased levels of GSTA4 in mouse skin. ► Sulforaphane, applied after CEES-treatment, completely abolishes CEES-mutagenesis. ► The therapeutic effect may suggest a long biological half-life for CEES in vivo.

  15. Characteristics of opiate users leaving detoxification treatment against medical advice.

    Science.gov (United States)

    Kenne, Deric R; Boros, Alec P; Fischbein, Rebecca L

    2010-07-01

    Substance-dependent patients leaving against medical advice (AMA) pose a unique challenge to detoxification programs. Most notably, AMA patients fail to access residential or outpatient treatment needed after detoxification and often return to detoxification treatment multiple times which has deleterious results for the patient and is taxing to the healthcare system. Using retrospective data from 89 daily opiate-using detoxification patients completing detoxification and 95 patients leaving AMA, we sought to identify patient characteristics useful in predicting AMA discharges from detoxification. Bivariate analyses indicated that AMA patients reported drug use did not impair their health, were injection drug users, younger and had fewer previous treatment admissions. Binomial logistic regression indicated that AMA patients were more likely to be unemployed and report that drug use did not impair their health. Patients completing detoxification were less likely to be injection drug users and less likely to be self-referred to treatment. Identifying patients at risk of leaving AMA provides an opportunity for clinicians to intervene in an effort to increase treatment engagement for these patients.

  16. Functional Class I and II Amino Acid-activating Enzymes Can Be Coded by Opposite Strands of the Same Gene.

    Science.gov (United States)

    Martinez-Rodriguez, Luis; Erdogan, Ozgün; Jimenez-Rodriguez, Mariel; Gonzalez-Rivera, Katiria; Williams, Tishan; Li, Li; Weinreb, Violetta; Collier, Martha; Chandrasekaran, Srinivas Niranj; Ambroggio, Xavier; Kuhlman, Brian; Carter, Charles W

    2015-08-07

    Aminoacyl-tRNA synthetases (aaRS) catalyze both chemical steps that translate the universal genetic code. Rodin and Ohno offered an explanation for the existence of two aaRS classes, observing that codons for the most highly conserved Class I active-site residues are anticodons for corresponding Class II active-site residues. They proposed that the two classes arose simultaneously, by translation of opposite strands from the same gene. We have characterized wild-type 46-residue peptides containing ATP-binding sites of Class I and II synthetases and those coded by a gene designed by Rosetta to encode the corresponding peptides on opposite strands. Catalysis by WT and designed peptides is saturable, and the designed peptides are sensitive to active-site residue mutation. All have comparable apparent second-order rate constants 2.9-7.0E-3 M(-1) s(-1) or ∼750,000-1,300,000 times the uncatalyzed rate. The activities of the two complementary peptides demonstrate that the unique information in a gene can have two functional interpretations, one from each complementary strand. The peptides contain phylogenetic signatures of longer, more sophisticated catalysts we call Urzymes and are short enough to bridge the gap between them and simpler uncoded peptides. Thus, they directly substantiate the sense/antisense coding ancestry of Class I and II aaRS. Furthermore, designed 46-mers achieve similar catalytic proficiency to wild-type 46-mers by significant increases in both kcat and Km values, supporting suggestions that the earliest peptide catalysts activated ATP for biosynthetic purposes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Spectral studies of dimeric copper(II) complexes of acid amide derivatives as models for type III copper enzymes

    Science.gov (United States)

    Garg, Bhagwan S.; Nandan Kumar, Deo; Sarbhai, Meenu; Reddy, Malladi J.

    2003-10-01

    Dimeric (hydrated and anhydrated) complexes of Cu(II) with N, N'-bis(3-carboxy-1-oxo-2-prop-2-enyl)ethylenediamine(BCOPENH 2, A) and N, N'-bis(2-carboxy-1-oxo-phenylenyl)ethylenediamine(BCOPHENH 2, B) have been prepared and characterised by elemental analysis, magnetic susceptibility measurements, EPR, thermal and spectral (IR, UV/Vis) studies. EPR parameters and magnetic behaviour indicates that the complexes are antiferromagnetic in nature and most likely adopt the typical carboxylate cage structure. Interesting amide bonding patterns have been observed and various EPR parameters have been evaluated on the basis of these studies, tentative probable structures of the complexes have been proposed.

  18. Maternal Gestational Hypertension-Induced Sensitization of Angiotensin II Hypertension Is Reversed by Renal Denervation or Angiotensin-Converting Enzyme Inhibition in Rat Offspring.

    Science.gov (United States)

    Xue, Baojian; Yin, Haifeng; Guo, Fang; Beltz, Terry G; Thunhorst, Robert L; Johnson, Alan Kim

    2017-04-01

    Numerous findings demonstrate that there is a strong association between maternal health during pregnancy and cardiovascular disease in adult offspring. The purpose of the present study was to test whether maternal gestational hypertension modulates brain renin-angiotensin-aldosterone system (RAAS) and proinflammatory cytokines that sensitizes angiotensin II-elicited hypertensive response in adult offspring. In addition, the role of renal nerves and the RAAS in the sensitization process was investigated. Reverse transcription polymerase chain reaction analyses of structures of the lamina terminalis and paraventricular nucleus indicated upregulation of mRNA expression of several RAAS components and proinflammatory cytokines in 10-week-old male offspring of hypertensive dams. Most of these increases were significantly inhibited by either renal denervation performed at 8 weeks of age or treatment with an angiotensin-converting enzyme inhibitor, captopril, in drinking water starting at weaning. When tested beginning at 10 weeks of age, a pressor dose of angiotensin II resulted in enhanced upregulation of mRNA expression of RAAS components and proinflammatory cytokines in the lamina terminalis and paraventricular nucleus and an augmented pressor response in male offspring of hypertensive dams. The augmented blood pressure change and most of the increases in gene expression in the offspring were abolished by either renal denervation or captopril. The results suggest that maternal hypertension during pregnancy enhances pressor responses to angiotensin II through overactivity of renal nerves and the RAAS in male offspring and that upregulation of the brain RAAS and proinflammatory cytokines in these offspring may contribute to maternal gestational hypertension-induced sensitization of the hypertensive response to angiotensin II. © 2017 American Heart Association, Inc.

  19. New aromatic/heteroaromatic propanesulfonylhydrazone compounds: Synthesis, physical properties and inhibition studies against carbonic anhydrase II (CAII) enzyme

    Science.gov (United States)

    Özmen Özdemir, Ümmühan; Altuntaş, Ayşegül; Gündüzalp, Ayla Balaban; Arslan, Fatma; Hamurcu, Fatma

    2014-07-01

    Some new aromatic/heteroaromatic propanesulfonylhydrazone derivatives (1-8) were synthesized and characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR, LC/MS techniques. The geometry optimizations and spectral calculations were performed by using DFT/B3LYP/6-311G(d,p) basis set in Gaussian 09 program. The inhibition activities of the synthesized compounds on carbonic anhydrase II (CAII) isoenzyme have been investigated by comparing IC50 values. Acetazolamide (5-acetamido-1,3,4-thiadiazole-2-sulfonamide) AAZ, a clinically used in CAII inhibition has also been investigated as standard inhibitor. The best aromatic/heteroaromatic propanesulfonylhydrazone inhibitors of this isoform were o-aminobenzaldehydepropanesulfonylhydrazone (1) and thiophenecarboxyaldehyde propanesulfonylhydrazone (5) having the same IC50 (0.55 mM) value. The molecular descriptors for propanesulfonylhydrazones were obtained to develop structure activity relationship (SAR) model between experimental IC50 values and the molecular descriptors calculated by PM3-based SAR models in Hyperchem 8, respectively. The obtained models confirm the good carbonic anhydrase II (CAII) inhibition activity of the propanesulfonylhydrazone derivatives. The selected descriptors are sensitive both to the imine (CHdbnd N) and NH2 groups that are responsible from higher activities of (1) and (5) in their series.

  20. Caricain: A basis for enzyme therapy for coeliac disease

    Directory of Open Access Journals (Sweden)

    Hugh J. Cornell

    2011-09-01

    Full Text Available Gliadin, a glycoprotein present in wheat and other grass cereals, is a causative agent in coeliac disease. It is therefore important to find methods for the detoxification of gliadin. Lysosomal integrity is lost in patients with active coeliac disease but restored when gliadin is removed from the diet. We employed a rat liver lysosome assay to monitor the extent of detoxification of a gliadin digest by caricain, a protein enzyme found in papaya. Pre-incubating the gliadin digest for different durations with caricain allowed the kinetics of the detoxification process to be studied. A significant degree of protection (80% of the lysosomes was achieved with 1.7% w/w of caricain on substrate after incubation for 2 h at 37 °C. The detoxification followed first-order kinetics with a rate constant of 1.7 x 10-4/s. The enzyme was strongly inhibited by imidazole, but weakly by phenylmethyl sulphonyl fluoride, as was also a caricain-enriched fraction from ion-exchange chromatography of papaya oleo-resin. The value of caricain in the detoxification of gliadin was confirmed in the present studies and this enzyme shows promise for enzyme therapy in coeliac disease.

  1. Mannitol-Specific Enzyme II of the Phosphoenolpyruvate-Dependent Phosphotransferase System of Escherichia coli : Physical Size of Enzyme IImtl and Its Domains IIBA and IIC in the Active State

    NARCIS (Netherlands)

    Lolkema, Juke S.; Kuiper, Harald; Hoeve-Duurkens, Ria H. ten; Robillard, George T.

    1993-01-01

    The size of enzyme IImtl solubilized in the active state has been determined by size-exclusion chromatography under conditions that favor the association of the enzyme. The contribution of the detergent bound to the enzyme was determined by solubilizing the enzyme and running the TSK250 column in a

  2. Hypoxia diminishes the detoxification of the environmental mutagen benzo[a]pyrene.

    Science.gov (United States)

    Schults, Marten A; Sanen, Kathleen; Godschalk, Roger W; Theys, Jan; van Schooten, Frederik J; Chiu, Roland K

    2014-11-01

    Hypoxia promotes genetic instability and is therefore an important factor in carcinogenesis. We have previously shown that activation of the hypoxia responsive transcription factor HIFα can enhance the mutagenic phenotype induced by the environmental mutagen benzo[a]pyrene (BaP). To further elucidate the mechanism behind the ability of hypoxia to increase mutagenicity of carcinogens, we examined the activation and detoxification of BaP under hypoxic conditions. To this end, the human lung carcinoma cell line A549 was treated with BaP under 20%, 5% or 0.2% oxygen for 18h and alterations in BaP metabolism were assayed. First, BaP-induced expression of key metabolic enzymes was analysed; expression levels of the activating CYP1A1 and CYP1B1 were increased, while the detoxifying enzymes UGT1A6 and UGT2B7 were significantly reduced by hypoxia. To evaluate whether these changes had an effect on metabolism, levels of BaP and several of its metabolites were determined. Cells under hypoxia have a reduced capacity to metabolise BaP leaving more of the parent molecule intact. Additionally, BaP-7,8-dihydrodiol, the pre-cursor metabolite of the reactive metabolite BaP-7,8-dihydroxy-9,10-epoxide (BPDE), was formed in higher concentrations. Finally, under hypoxia, DNA adducts accumulated over a period of 168 h, whereas adducts were efficiently removed in 20% oxygen conditions. The delayed detoxification kinetics resulted in a 1.5-fold increase in DNA adducts. These data indicate that the metabolism under hypoxic conditions has shifted towards increased activation of BaP instead of detoxification and support the idea that modulation of carcinogen metabolism is an important additional mechanism for the observed HIF1 mediated genetic instability.

  3. Thiol metabolism and antioxidant systems complement each other during arsenate detoxification in Ceratophyllum demersum L.

    Science.gov (United States)

    Mishra, Seema; Srivastava, Sudhakar; Tripathi, Rudra D; Trivedi, Prabodh K

    2008-01-31

    Ceratophyllum demersum L. is known to be a potential accumulator of arsenic (As), but mechanisms of As detoxification have not been investigated so far. In the present study, we analyzed the biochemical responses of Ceratophyllum plants to arsenate (As(V); 0-250 microM) exposure to explore the underlying mechanisms of As detoxification. Plants efficiently tolerated As toxicity up to concentrations of 50 microM As(V) and durations of 4 d with no significant effect on growth by modulating various pathways in a coordinated and complementary manner and accumulated about 76 microg As g(-1)dw. Significant increases were observed in the levels of various thiols including phytochelatins (PCs), the activities of enzymes of thiolic metabolism as well as arsenate reductase (AR). These primary responses probably enabled plants to detoxify at least some part of As(V) through its reduction and subsequent complexation. The maximum proportion of As chelated by PCs was found to be about 30% (at 50 microM As(V) after 2 d). Simultaneously, a significant increase in the activities of antioxidant enzymes was observed and hence plants did not experience oxidative stress when exposed to 50 microM As(V) for 4 d. Exposure of plants to higher concentrations (250 microM As(V)) and/or for longer durations (7 d) resulted in a significant increase in the level of As (maximum 525 microgg(-1)dw at 250 microM after 7 d) and an inverse relationship between As accumulation and various detoxification strategies was observed that lead to enhanced oxidative stress and hampered growth.

  4. Antiproliferative effects of palladium(II) complexes of 5-nitrosopyrimidines and interactions with the proteolytic regulatory enzymes of the renin-angiotensin system in tumoral brain cells.

    Science.gov (United States)

    Illán-Cabeza, Nuria A; García-García, Antonio R; Martínez-Martos, José M; Ramírez-Expósito, María J; Moreno-Carretero, Miguel N

    2013-09-01

    Seventeen new palladium(II) complexes of general formulaes PdCl2L, PdCl(LH-1)(solvent) and PdCl2(PPh3)2L containing pyrimidine ligands derived from 6-amino-5-nitrosouracil and violuric acid have been prepared and characterized by elemental analysis, IR and NMR ((1)H and (13)C) methods and, two of them, PdCl(DANUH-1)(CH3CN)]·½H2O and [PdCl(2MeOANUH-1)(CH3CN)] by X-ray single-crystal diffraction (DANU: 6-amino-1,3-dimethyl-5-nitrosouracil; 2MeOANU: 6-amino-2-methoxy-5-nitroso-3H-pyrimidin-4-one). The coordination environment around palladium is nearly square planar in the two compounds with different supramolecular arrangements. Crystallographic and spectral data are consistent with a bidentate coordination mode through N5 and O4 atoms when the ligands act in neutral form and N5 and N6 atoms in the monodeprotonated ones. The cytotoxicity of the complexes against human neuroblastoma (NB69) and human glioma (U373-MG) cell lines has been tested showing a considerable antiproliferative activity. Also, the study of the effects of palladium(II) complexes on the renin-angiotensin system (RAS) regulating proteolytic regulatory enzymes aminopeptidase A (APA), aminopeptidase N (APN) and insulin-regulated aminopeptidase (IRAP) shows a strong dependence on the compound tested and the tumoral cell type, also affecting different catalytic routes; the compounds affect in a different way the activities of enzymes of the RAS system, changing their functional roles as initiators of cell proliferation in tumors as autocrine/paracrine mediators.

  5. Garlic attenuates chrysotile-mediated pulmonary toxicity in rats by altering the phase I and phase II drug metabolizing enzyme system.

    Science.gov (United States)

    Ameen, Mohamed; Musthapa, M Syed; Abidi, Parveen; Ahmad, Iqbal; Rahman, Qamar

    2003-01-01

    Asbestos and its carcinogenic properties have been extensively documented. Asbestos exposure induces diverse cellular events associated with lung injury. Previously, we have shown that treatment with chrysotile shows significant alteration in phase I and phase II drug metabolizing enzyme system. In this study we have examined some potential mechanisms by which garlic treatment attenuates chrysotile-mediated pulmonary toxicity in rat. Female Wistar rats received an intratracheal instillation of 5 mg chrysotile (0.5 mL saline) as well as intragastric garlic treatment (1% body weight (v/w); 6 days per week). Effect of garlic treatment was evaluated after 1, 15, 30, 90, and 180 days by assaying aryl hydrocarbon hydroxylase (AHH), glutathione (GSH), glutathione S-transferase (GST), and production of thiobarbituric acid reactive substances (TBARS) in rat lung microsome. The results showed that AHH and TBARS formation were significantly reduced at day 90 and day 180 in chrysotile treated garlic cofed rats; GSH recovered 15 days later to the near normal level and GST elevated significantly after treatment of garlic as compared to chrysotile alone treated rat lung microsome. The data obtained shows that inhibition of AHH activity and induction of GST activity could be contributing factor in chrysotile-mediated pulmonary toxicity in garlic cofed rats. However, recovery of GSH and inhibition of TBARS formation by garlic and its constituent(s) showed that garlic may give protection by altering the drug metabolizing enzyme system.

  6. The role of angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists in the management of diabetic complications.

    Science.gov (United States)

    Podar, Toomas; Tuomilehto, Jaakko

    2002-01-01

    Evidence suggests that ACE inhibitors can be advantageous for prevention and halting progression of both micro- and macrovascular complications in patients with diabetes mellitus. ACE inhibitors are useful antihypertensive agents in both type 1 and type 2 diabetes; however, ACE inhibitor therapy often needs to be supplemented with calcium channel antagonists, beta-blockers or diuretics to achieve good blood pressure control. ACE inhibitors are also indicated in non-hypertensive patients with type 1 and type 2 diabetes who have micro- or macroalbuminuria. The effect of ACE inhibitors in halting the development and progression of retinopathy and, potentially, neuropathy needs further proof in large-scale studies. More recently, angiotensin II receptor antagonists are emerging as drugs with the potential to be successfully included in the management of diabetic complications, especially when ACE inhibitors are not suitable because of adverse effects.

  7. Detoxification of cyanides in cassava flour by linamarase of Bacillus ...

    African Journals Online (AJOL)

    enoh

    2012-04-05

    Apr 5, 2012 ... utilizing indigenous bacteria from cyanide rich cassava peel waste and exploited their potential for detoxification. ... lotaustralin), and low content of protein and free amino ... these toxic constituents is required to avoid chronic.

  8. EMERGING TECHNOLOGY REPORT: DEVELOPMENT OF A PHOTOTHERMAL DETOXIFICATION UNIT

    Science.gov (United States)

    There has long been interest in utilizing photochemical methods for destroying hazardous organic materials. Unfortunately, the direct application of classic, low temperature photochemical processes to hazardous waste detoxification are often too slow to be practical for wide spr...

  9. Detoxification of model phenolic compounds in lignocellulosic hydrolysates with peroxidase for butanol production from Clostridium beijerinckii.

    Science.gov (United States)

    Cho, Dae Haeng; Lee, Yun Jie; Um, Youngsoon; Sang, Byoung-In; Kim, Yong Hwan

    2009-07-01

    In the present study, we investigated the peroxidase-catalyzed detoxification of model phenolic compounds and evaluated the inhibitory effects of the detoxified solution on butanol production by Clostridium beijerinckii National Collection of Industrial and Marine Bacteria Ltd. 8052. The six phenolic compounds, p-coumaric acid, ferulic acid, 4-hydroxybenzoic acid, vanillic acid, syringaldehyde, and vanillin, were selected as model fermentation inhibitors generated during pretreatment and hydrolysis of lignocellulose. The enzyme reaction was optimized as a function of the reaction conditions of pH, peroxidase concentration, and hydrogen peroxide to substrate ratio. Most of the tested phenolics have a broad optimum pH range of 6.0 to 9. Removal efficiency increased with the molar ratio of H(2)O(2) to each compound up to 0.5-1.25. In the case of p-coumaric acid, ferulic acid, vanillic acid, and vanillin, the removal efficiency was almost 100% with only 0.01 microM of enzyme. The tested phenolic compounds (1 g/L) inhibited cell growth by 64-74%, while completely inhibiting the production of butanol. Although syringaldehyde and vanillin were less toxic on cell growth, the level of inhibition on the butanol production was quite different. The detoxified solution remarkably improved cell growth and surprisingly increased butanol production to the level of the control. Hence, our present study, using peroxidase for the removal of model phenolic compounds, could be applied towards the detoxification of lignocellulosic hydrolysates for butanol fermentation.

  10. Structural, EPR, and Mössbauer characterization of (μ-alkoxo)(μ-carboxylato)diiron(II,III) model complexes for the active sites of mixed-valent diiron enzymes.

    Science.gov (United States)

    Li, Feifei; Chakrabarti, Mrinmoy; Dong, Yanhong; Kauffmann, Karl; Bominaar, Emile L; Münck, Eckard; Que, Lawrence

    2012-03-05

    To obtain structural and spectroscopic models for the diiron(II,III) centers in the active sites of diiron enzymes, the (μ-alkoxo)(μ-carboxylato)diiron(II,III) complexes [Fe(II)Fe(III)(N-Et-HPTB)(O(2)CPh)(NCCH(3))(2)](ClO(4))(3) (1) and [Fe(II)Fe(III)(N-Et-HPTB)(O(2)CPh)(Cl)(HOCH(3))](ClO(4))(2) (2) (N-Et-HPTB = N,N,N',N'-tetrakis(2-(1-ethyl-benzimidazolylmethyl))-2-hydroxy-1,3-diaminopropane) have been prepared and characterized by X-ray crystallography, UV-visible absorption, EPR, and Mössbauer spectroscopies. Fe1-Fe2 separations are 3.60 and 3.63 Å, and Fe1-O1-Fe2 bond angles are 128.0° and 129.4° for 1 and 2, respectively. Mössbauer and EPR studies of 1 show that the Fe(III) (S(A) = 5/2) and Fe(II) (S(B) = 2) sites are antiferromagnetically coupled to yield a ground state with S = 1/2 (g= 1.75, 1.88, 1.96); Mössbauer analysis of solid 1 yields J = 22.5 ± 2 cm(-1) for the exchange coupling constant (H = JS(A)·S(B) convention). In addition to the S = 1/2 ground-state spectrum of 1, the EPR signal for the S = 3/2 excited state of the spin ladder can also be observed, the first time such a signal has been detected for an antiferromagnetically coupled diiron(II,III) complex. The anisotropy of the (57)Fe magnetic hyperfine interactions at the Fe(III) site is larger than normally observed in mononuclear complexes and arises from admixing S > 1/2 excited states into the S = 1/2 ground state by zero-field splittings at the two Fe sites. Analysis of the "D/J" mixing has allowed us to extract the zero-field splitting parameters, local g values, and magnetic hyperfine structural parameters for the individual Fe sites. The methodology developed and followed in this analysis is presented in detail. The spin Hamiltonian parameters of 1 are related to the molecular structure with the help of DFT calculations. Contrary to what was assumed in previous studies, our analysis demonstrates that the deviations of the g values from the free electron value (g = 2) for the

  11. Biological activities of Zn(II)-S-methyl-cysteine complex as antiradical, inhibitor of acid phosphatase enzyme and in vivo antidepressant effects.

    Science.gov (United States)

    Escudero, Graciela E; Martini, Nancy; Jori, Khalil; Jori, Nadir; Maresca, Nahuel R; Laino, Carlos H; Naso, Luciana G; Williams, Patricia A M; Ferrer, Evelina G

    2016-12-01

    The antidepressant effect of simple Zn(II) salts has been proved in several animal models of depression. In this study, a coordination metal complex of Zn(II) having a sulfur containing ligand is tested as antidepressant for the first time. Forced swimming test method on male Wistar rats shows a decrease in the immobility and an increase in the swimming behavior after treatment with [Zn(S-Met)2] (S-Met=S-methyl-l-cysteine) being more effective and remarkable than ZnCl2. The thiobarbituric acid and the pyranine consumption (hydroxyl and peroxyl radicals, respectively) methods were applied to evaluate the antioxidant activity of S-Met and [Zn(S-Met)2] showing evidence of attenuation of hydroxyl but not peroxyl radicals activities. UV-vis studies on the inhibition of acid phosphatase enzyme (AcP) demonstrated that S-methyl-l-cysteine did not produce any effect but, in contrast, [Zn(S-Met)2] complex behaved as a moderate inhibitor. Finally, bioavailability studies were performed by fluorescence spectroscopy denoting the ability of the albumin to transport the complex.

  12. Clinical Research on Detoxification with Acupuncture

    Institute of Scientific and Technical Information of China (English)

    HU Jun; XIN Yu-hu; ZONG Lei; IHAO Shan-xiang; LI Shen; XIAO Yuan-chun

    2003-01-01

    Purpose To confirm the effects of acupuncture, and Chinese medicines in controlling the withdrawal symptoms from the opium-like drugs. Method 96 heroin-dependent subjects were divided into four groups,which were treated respectively by western medicine (Agroup), acupuncture (B group), Chinese herbs (Cgroup), and acupuncture & Chinese herbs (D group).Before, during and after treatment, the concentration of serum testosterone and prolactin, and immune functions (serum CD3+ 、CD4+ 、CD8+ and CD4+/CD8+ ) were tested.Results After treatment, the concentration of serum testosterone in A and B group were higher than before and during treatment, and in C and D group, during treatment were higher. In the four groups, the concentration of serum prolactin before treatment was the highest. The levels of CD3+、CD4+、 CD8+ and CD4+/CD8+ were lowest before treatment and highest after treatment. Conclusion Acupuncture and Chinese medicines effective in relieving spasm and pain can control the opium-like drug withdrawal symptoms to different degrees, especially acupuncture. However, acupuncture cannot ease the withdrawal symptoms completely. Acupuncture does not strikingly cooperate with the Chinese medicines effective in relieving spasm and pain (including M-receptor antagonists). In detoxification, the Jiaji points are the primary ones and symptom-based points the secondary ones.

  13. Engineered photocatalysts for detoxification of waste water

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, S.A.; Prairie, M.R.; Shelnutt, J.A. [Sandia National Lab., Albuquerque, NM (United States); Khan, S.U.M. [Duquesne Univ., Pittsburgh, PA (United States). Dept. of Chemistry and Biochemistry] [and others

    1996-12-01

    This report describes progress on the development of engineered photocatalysts for the detoxification of water polluted with toxic organic compounds and heavy metals. We examined a range of different oxide supports (titania, alumina, magnesia and manganese dioxide) for tin uroporphyrin and investigated the efficacy of a few different porphyrins. A water-soluble octaacetic-acid-tetraphenylporphyrin and its derivatives have been synthesized and characterized in an attempt to design a porphyrin catalyst with a larger binding pocket. We have also investigated photocatalytic processes on both single crystal and powder forms of semiconducting SiC with an ultimate goal of developing a dual-semiconductor system combining TiO{sub 2} and SiC. Mathematical modeling was also performed to identify parameters that can improve the efficiency of SiC-based photocatalytic systems. Although the conceptual TiO{sub 2}/SiC photodiode shows some promises for photoreduction processes, SiC itself was found to be an inefficient photocatalyst when combined with TiO{sub 2}. Alternative semiconductors with bandgap and band potentials similar to SiC should be tested in the future for further development and a practical utilization of the dual photodiode concept.

  14. Potency of Semecarpus anacardium Linn. nut milk extract against aflatoxin B(1)-induced hepatocarcinogenesis: reflection on microsomal biotransformation enzymes.

    Science.gov (United States)

    Premalatha, B; Sachdanandam, P

    2000-08-01

    The effect of Semecarpus anacardium Linn. nut milk extract on host detoxification system in aflatoxin B(1) induced hepatocellular carcinoma, which is a vital mechanism in cancer treatment, was studied in male albino rats. Oral administration of nut extract (200 mg kg(-1)body weight per day for 14 days) is found to be highly effective in inducing phase I and phase II biotransformation enzymes. The obtained results have shown an overall decrease of liver microsomal cytochrome P450, cytochrome b5, NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase, and aniline hydroxylase with a subsequent decrease of phase II enzymes, glutathione-S-transferase and UDP-glucuronyl transferase in cancer-bearing animals. The Semecarpus anacardium nut extract affords anticancer activity by enhancing both phase I and phase II enzymes to near normal levels. We propose that, much of the anticarcinogenic potency of Semecarpus anacardium nut extract on aflatoxin B(1)-induced hepatocarcinogenesis is mediated through the induction of hepatic biotransformation enzymes. Copyright 2000 Academic Press.

  15. Flavin-dependent monooxygenases as a detoxification mechanism in insects: new insights from the arctiids (lepidoptera.

    Directory of Open Access Journals (Sweden)

    Sven Sehlmeyer

    Full Text Available Insects experience a wide array of chemical pressures from plant allelochemicals and pesticides and have developed several effective counterstrategies to cope with such toxins. Among these, cytochrome P450 monooxygenases are crucial in plant-insect interactions. Flavin-dependent monooxygenases (FMOs seem not to play a central role in xenobiotic detoxification in insects, in contrast to mammals. However, the previously identified senecionine N-oxygenase of the arctiid moth Tyria jacobaeae (Lepidoptera indicates that FMOs have been recruited during the adaptation of this insect to plants that accumulate toxic pyrrolizidine alkaloids. Identification of related FMO-like sequences of various arctiids and other Lepidoptera and their combination with expressed sequence tag (EST data and sequences emerging from the Bombyx mori genome project show that FMOs in Lepidoptera form a gene family with three members (FMO1 to FMO3. Phylogenetic analyses suggest that FMO3 is only distantly related to lepidopteran FMO1 and FMO2 that originated from a more recent gene duplication event. Within the FMO1 gene cluster, an additional gene duplication early in the arctiid lineage provided the basis for the evolution of the highly specific biochemical, physiological, and behavioral adaptations of these butterflies to pyrrolizidine-alkaloid-producing plants. The genes encoding pyrrolizidine-alkaloid-N-oxygenizing enzymes (PNOs are transcribed in the fat body and the head of the larvae. An N-terminal signal peptide mediates the transport of the soluble proteins into the hemolymph where PNOs efficiently convert pro-toxic pyrrolizidine alkaloids into their non-toxic N-oxide derivatives. Heterologous expression of a PNO of the generalist arctiid Grammia geneura produced an N-oxygenizing enzyme that shows noticeably expanded substrate specificity compared with the related enzyme of the specialist Tyria jacobaeae. The data about the evolution of FMOs within lepidopteran insects

  16. In silico multiple-targets identification for heme detoxification in the human malaria parasite Plasmodium falciparum.

    Science.gov (United States)

    Phaiphinit, Suthat; Pattaradilokrat, Sittiporn; Lursinsap, Chidchanok; Plaimas, Kitiporn

    2016-01-01

    Detoxification of hemoglobin byproducts or free heme is an essential step and considered potential targets for anti-malaria drug development. However, most of anti-malaria drugs are no longer effective due to the emergence and spread of the drug resistant malaria parasites. Therefore, it is an urgent need to identify potential new targets and even for target combinations for effective malaria drug design. In this work, we reconstructed the metabolic networks of Plasmodium falciparum and human red blood cells for the simulation of steady mass and flux flows of the parasite's metabolites under the blood environment by flux balance analysis (FBA). The integrated model, namely iPF-RBC-713, was then adjusted into two stage-specific metabolic models, which first was for the pathological stage metabolic model of the parasite when invaded the red blood cell without any treatment and second was for the treatment stage of the parasite when a drug acted by inhibiting the hemozoin formation and caused high production rate of heme toxicity. The process of identifying target combinations consisted of two main steps. Firstly, the optimal fluxes of reactions in both the pathological and treatment stages were computed and compared to determine the change of fluxes. Corresponding enzymes of the reactions with zero fluxes in the treatment stage but non-zero fluxes in the pathological stage were predicted as a preliminary list of potential targets in inhibiting heme detoxification. Secondly, the combinations of all possible targets listed in the first step were examined to search for the best promising target combinations resulting in more effective inhibition of the detoxification to kill the malaria parasites. Finally, twenty-three enzymes were identified as a preliminary list of candidate targets which mostly were in pyruvate metabolism and citrate cycle. The optimal set of multiple targets for blocking the detoxification was a set of heme ligase, adenosine transporter, myo

  17. Polymorphisms in angiotensin II type 1 receptor and angiotensin I-converting enzyme genes and breast cancer risk among Chinese women in Singapore.

    Science.gov (United States)

    Koh, Woon-Puay; Yuan, Jian-Min; Van Den Berg, David; Lee, Hin-Peng; Yu, Mimi C

    2005-02-01

    Angiotensin II is converted from its precursor by angiotensin I-converting enzyme (ACE) and has been shown to mediate growth in breast cancer cell lines via ligand-induced activity through the angiotensin II type 1 receptor (AGTR1). Earlier we showed that women with the low activity genotype of the ACE gene have a statistically significantly ( approximately 50%) reduced breast cancer risk compared with those possessing the high activity ACE genotype. To further test the hypothesis that angiotensin II participates in breast carcinogenesis through AGTR1, we examined genetic polymorphisms in the 5'-region of the AGTR1 gene (A-168G, C-535T and T-825A) in relation to risk of breast cancer in 258 breast cancer cases and 670 female controls within the Singapore Chinese Health Study. Relative to the homozygotes, individual genotypes with one or two copies of the respective allelic variants (putative low risk genotypes) were each associated with an approximately 30% reduction in risk of breast cancer. Risk of breast cancer decreased with increasing number of low risk AGTR1 genotypes after adjustment for potential confounders. Relative to those carrying no low risk genotypes (homozygous for A, C and T alleles for the three polymorphisms, respectively), the odds ratios (95% confidence intervals) were 0.84 (0.51-1.37) for women possessing one low risk genotype and 0.68 (0.46-1.01) for women possessing two or three low risk genotypes (P for trend = 0.05). When both AGTR1 and ACE gene polymorphisms were examined simultaneously, women possessing at least one AGTR1 low risk genotype in combination with the ACE low activity genotype had an odds ratio of 0.35 (95% confidence interval, 0.20-0.62) compared with those possessing the ACE high activity genotype and no AGTR1 low risk genotype. Our findings suggest that pharmacological inhibition of the angiotensin II effect by blockade of ACE and/or AGTR1 could be potential targets for the prevention and treatment of breast cancer.

  18. Biotransformation of endocrine disrupting compounds by selected phase I and phase II enzymes--formation of estrogenic and chemically reactive metabolites by cytochromes P450 and sulfotransferases.

    Science.gov (United States)

    Reinen, J; Vermeulen, N P E

    2015-01-01

    The endocrine system is a major communication system in the body and is involved in maintenance of the reproductive system, fetal development, growth, maturation, energy production, and metabolism,. The endocrine system responds to the needs of an organism by secreting a wide variety of hormones that enable the body to maintain homeostasis, to respond to external stimuli, and to follow various developmental programs. This occurs through complex signalling cascades,with multiple sites at which the signals can be regulated. Endocrine disrupting compounds (EDCs) affect the endocrine system by simulating the action of the naturally produced hormones, by inhibiting the action of natural hormones, by changing the function and synthesis of hormone receptors, or by altering the synthesis, transport, metabolism, and elimination of hormones. It has been established that exposure to environmental EDCs is a risk factor for disruption of reproductive development and oncogenesis in both humans and wildlife. For accurate risk assessment of EDCs, the possibility of bioactivation through biotransformation processes needs to be included since neglecting these mechanisms may lead to undervaluation of adverse effects on human health caused by EDCs and/or their metabolites. This accurate risk assessment should include: (1) possibility of EDCs to be bioactivated into metabolites with enhanced endocrine disruption (ED) effects, and (2) possibility of EDCs to be biotransformed into reactive metabolites that may cause DNA damage. Here, we present an overview of different metabolic enzymes that are involved in the biotransformation of EDCs. In addition, we describe how biotransformation by Cytochromes P450 (CYPs), human estrogen sulfotransferase 1E1 (SULT1E1) and selected other phase II enzymes, can lead to the formation of bioactive metabolites. This review mainly focuses on CYP- and SULT-mediated bioactivation of estrogenic EDCs and summarizes our views on this topic while also showing

  19. Ni l-edge soft x-ray spectroscopy of ni-fe hydrogenases and modelcompounds--evidence for high-spin ni(ii) in the active enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongxin; Ralston, C.Y.; Patil, D.S.; Jones, R.M.; Gu, M.; Verhagen, M.; Adams, M.; Ge, P.; Riordan, C.; Marganian, C.A.; Mascharak,P.; Kovacs, J.; Miller, C.G.; Collins, T.J.; Brooker, S.; Croucher, P.D.; Wang, Kun; Stiefel, E.I.; Cramer, S.P.

    2000-03-15

    L-edge X-ray absorption spectroscopy has been used to study, under a variety of conditions, the electronic structure of Ni in the Ni-Fe hydrogenases from Desulfovibrio gigas, Desulfovibrio baculatus, and Pyrococcus furiosus. The status of the enzyme films used for these measurements was monitored by FT-IR spectroscopy. The L-edge spectra were interpreted by ligand field multiplet simulations and by comparison with data for Ni model complexes. The spectrum for Ni in D. gigas enzyme ''form A'' is consistent with a covalent Ni(III) species. In contrast, all of the reduced enzyme samples exhibited high spin Ni(II) spectra. The significance of the Ni(II) spin state for the structure of the hydrogenase active site is discussed.

  20. Midgut Transcriptome of the Cockroach Periplaneta americana and Its Microbiota: Digestion, Detoxification and Oxidative Stress Response.

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    Full Text Available The cockroach, Periplaneta americana, is an obnoxious and notorious pest of the world, with a strong ability to adapt to a variety of complex environments. However, the molecular mechanism of this adaptability is mostly unknown. In this study, the genes and microbiota composition associated with the adaptation mechanism were studied by analyzing the transcriptome and 16S rDNA pyrosequencing of the P. americana midgut, respectively. Midgut transcriptome analysis identified 82,905 unigenes, among which 64 genes putatively involved in digestion (11 genes, detoxification (37 genes and oxidative stress response (16 genes were found. Evaluation of gene expression following treatment with cycloxaprid further revealed that the selected genes (CYP6J1, CYP4C1, CYP6K1, Delta GST, alpha-amylase, beta-glucosidase and aminopeptidase were upregulated at least 2.0-fold at the transcriptional level, and four genes were upregulated more than 10.0-fold. An interesting finding was that three digestive enzymes positively responded to cycloxaprid application. Tissue expression profiles further showed that most of the selected genes were midgut-biased, with the exception of CYP6K1. The midgut microbiota composition was obtained via 16S rDNA pyrosequencing and was found to be mainly dominated by organisms from the Firmicutes phylum, among which Clostridiales, Lactobacillales and Burkholderiales were the main orders which might assist the host in the food digestion or detoxification of noxious compounds. The preponderant species, Clostridium cellulovorans, was previously reported to degrade lignocellulose efficiently in insects. The abundance of genes involved in digestion, detoxification and response to oxidative stress, and the diversity of microbiota in the midgut might provide P. americana high capacity to adapt to complex environments.

  1. Shemamruthaa, herbal formulation modulates xenobiotic metabolizing enzymes and energy metabolism in 7,12-Dimethylbenz[a]anthracene-induced breast cancer in rats

    Directory of Open Access Journals (Sweden)

    Purushothaman Ayyakkannu

    2014-12-01

    Full Text Available There is an increasing interest in identifying naturally occurring potent preventive and therapeutic agents for cancer. Shemamruthaa, a phytochemical formulation was evaluated for the first time with a view to potentiate more intense anticancer property. Adult female Sprague-Dawley rats (8-week-old were used for the study and were divided into 4 Groups. Group I control animals received standard pellet diet and water ad libitum. Group II animals were induced for mammary carcinoma with a single oral dose of 25 mg of DMBA, whereas another set of DMBA-induced rats were treated with SM (400 mg/kg body weight/day orally by gastric intubation for 14 days after 3 months of induction period (Group III. Group IV animals served as SM-control. The status xenobiotic metabolizing enzymes, glycolytic and gluconeogenic enzymes were analysed in control and experimental rats. Our findings revealed that the SM formulation has potential to induce Phase-II enzyme activities, associated mainly with carcinogen detoxification and inhibit the Phase I enzyme activities. The activities of glycolytic and gluconeogenic enzymes were significantly brought back to near normal levels in SM treated animals. The results demonstrated unequivocally the effect of SM on inhibition of tumor progression by altering xenobiotic metabolizing enzymes and restoring energy metabolism. 

  2. Angiotensin II type 2 receptor expression after vascular injury: differing effects of angiotensin-converting enzyme inhibition and angiotensin receptor blockade.

    Science.gov (United States)

    Barker, Thomas A; Massett, Michael P; Korshunov, Vyacheslav A; Mohan, Amy M; Kennedy, Amy J; Berk, Bradford C

    2006-11-01

    It has been suggested that the effects of angiotensin II type 1 receptor (AT1R) blockers are in part because of angiotensin II type 2 receptor (AT2R) signaling. Interactions between the AT2R and kinins modulate cardiovascular function. Because AT2R expression increases after vascular injury, we hypothesized that the effects on vascular remodeling of the AT1R blocker valsartan and the ACE inhibitor benazepril require AT2R signaling through the bradykinin 1 and 2 receptors (B1R and B2R). To test this hypothesis, Brown Norway rats were assigned to 8 treatments (n=16): valsartan, valsartan+PD123319 (AT2R inhibitor), valsartan+des-arg9-[Leu8]-bradykinin (B1R inhibitor), valsartan+HOE140 (B2R inhibitor), benazepril, benazepril+HOE140, amlodipine, and vehicle. After 1 week of treatment, carotid balloon injury was performed. Two weeks later, carotids were harvested for morphometry and analysis of receptor expression by immunohistochemistry and Western blotting. Valsartan and benazepril significantly reduced the intima:media ratio compared with vehicle. Blockade of AT2R, B1R, or B2R in the presence of valsartan prevented the reduction seen with valsartan alone. B2R blockade inhibited the effect of benazepril. Injury increased AT1R, AT2R, B1R, and B2R expression. Treatment with valsartan but not benazepril significantly increased intima AT2R expression 2-fold compared with vehicle, which was not reversed by inhibition of AT2R, B1R, and B2R. Functionally, valsartan increased intimal cGMP levels compared with vehicle, and this increase was inhibited by blocking the AT2R, B1R, and B2R. Results suggest that AT2R expression and increased cGMP represent a molecular mechanism that differentiates AT1R blockers, such as valsartan, from angiotensin-converting enzyme inhibitors like benazepril.

  3. The effect of endurance training with cinnamon supplementation on plasma concentrations of liver enzymes (ALT, AST in women with type II diabetes

    Directory of Open Access Journals (Sweden)

    Shahla Torabi

    2016-09-01

    Full Text Available Background: Diabetes is associated with many pathological changes and one of the most important consequences of the diabetes is hepatic injury. The present study was performed to investigate the effect of eight weeks endurance training with consumption of cinnamon supplementation on plasma concentrations of liver enzymes, alanine aminotransferase (ALT and aspartate aminotransferase (AST in women with type II diabetes. Methods: In this quasi-experimental study, 36 female volunteers with type II diabetes (age 52.72±2.64 years and body mass index 29.28±2.94 Kg/m2 were participated. The subjects were homogenized regarding their body mass index and then were divided randomly into four groups (each group=9 patients: Training, training-cinnamon, cinnamon, and Control. Endurance training was performed for eight weeks (three sessions per week at the intensity of 60-75% of maximum heart rate for 40-60 minutes. The consumption of cinnamon supplementation was 1.5 gr per day. Plasma concentrations of ALT and AST were measured following 12 hours fasting, 48 hours before and after performing the experiment, by the enzymatic method. Data were analyzed by paired t-test and factorial ANOVA, using SPSS version 21 (Chicago, IL, USA and at the significant level of P0.05. There was no significant difference between groups in pre and posttests. Conclusion: The results confirm that cinnamon supplementation may be effective in improving the plasma levels of ALT but the intensity and duration of an effective exercise training especially with consumption of cinnamon supplementation simultaneously need more study in diabetic patients.

  4. Analysis of plant Pb tolerance at realistic submicromolar concentrations demonstrates the role of phytochelatin synthesis for Pb detoxification.

    Science.gov (United States)

    Fischer, Sina; Kühnlenz, Tanja; Thieme, Michael; Schmidt, Holger; Clemens, Stephan

    2014-07-01

    Lead (Pb) ranks first among metals with respect to tonnage produced and released into the environment. It is highly toxic and therefore an important pollutant of worldwide concern. Plant Pb uptake, accumulation, and detoxification mobilize Pb into food webs. Still, knowledge about the underlying mechanisms is very limited. This is largely due to serious experimental challenges with respect to Pb availability. In most studies, Pb(II) concentrations in the millimolar range have been used even though the toxicity threshold is in the nanomolar range. We therefore developed a low-phosphate, low-pH assay system that is more realistic with respect to soil solution conditions. In this system the growth of Arabidopsis thaliana seedlings was significantly affected by the addition of only 0.1 μM Pb(NO3)2. Involvement of phytochelatins in the detoxification of Pb(II) could be demonstrated by investigating phytochelatin synthase mutants. They showed a stronger inhibition of root growth and a lack of Pb-activated phytochelatin synthesis. In contrast, other putative Pb hypersensitive mutants were unaffected under these conditions, further supporting the essential role of phytochelatins for Pb detoxification. Our findings demonstrate the need to monitor plant Pb responses at realistic concentrations under controlled conditions and provide a strategy to achieve this.

  5. Induced thiacloprid insensitivity in honeybees (Apis mellifera L.) is associated with up-regulation of detoxification genes.

    Science.gov (United States)

    Alptekin, S; Bass, C; Nicholls, C; Paine, M J I; Clark, S J; Field, L; Moores, G D

    2016-04-01

    Honey bees, Apis mellifera, are markedly less sensitive to neonicotinoid insecticides containing a cyanoimino pharmacophore than to those with a nitroimino group. Although previous work has suggested that this results from enhanced metabolism of the former by detoxification enzymes, the specific enzyme(s) involved remain to be characterized. In this work, a pretreatment of honey bees with a sublethal dose of thiacloprid resulted in induced insensitivity to the same compound immediately following thiacloprid feeding. A longer pretreatment time resulted in no, or increased, sensitivity. Transcriptome profiling, using microarrays, identified a number of genes encoding detoxification enzymes that were over-expressed significantly in insecticide-treated bees compared with untreated controls. These included five P450s, CYP6BE1, CYP305D1, CYP6AS5, CYP315A1, CYP301A1, and a carboxyl/cholinesterase (CCE) CCE8. Four of these P450s were functionally expressed in Escherichia coli and their ability to metabolize thiacloprid examined by liquid chromatography-mass spectrometry (LC-MS) analysis.

  6. Biochemical strategies for the detection and detoxification of toxic chemicals in the environment.

    Science.gov (United States)

    Febbraio, Ferdinando

    2017-02-26

    Addressing the problems related to the widespread presence of an increasing number of chemicals released into the environment by human activities represents one of the most important challenges of this century. In the last few years, to replace the high cost, in terms of time and money, of conventional technologies, the scientific community has directed considerable research towards the development both of new detection systems for the measurement of the contamination levels of chemicals in people's body fluids and tissue, as well as in the environment, and of new remediation strategies for the removal of such chemicals from the environment, as a means of the prevention of human diseases. New emerging biosensors for the analysis of environmental chemicals have been proposed, including VHH antibodies, that combine the antibody performance with the affinity for small molecules, genetically engineered microorganisms, aptamers and new highly stable enzymes. However, the advances in the field of chemicals monitoring are still far from producing a continuous real-time and on-line system for their detection. Better results have been obtained in the development of strategies which use organisms (microorganisms, plants and animals) or metabolic pathway-based approaches (single enzymes or more complex enzymatic solutions) for the fixation, degradation and detoxification of chemicals in the environment. Systems for enzymatic detoxification and degradation of toxic agents in wastewater from chemical and manufacturing industries, such as ligninolytic enzymes for the treatment of wastewater from the textile industry, have been proposed. Considering the high value of these research studies, in terms of the protection of human health and of the ecosystem, science must play a major role in guiding policy changes in this field.

  7. Effects of stachyose on absorption and transportation of tea catechins in mice: possible role of Phase II metabolic enzymes and efflux transporters inhibition by stachyose

    Science.gov (United States)

    Li, Wenfeng; Lu, Yalong; Huang, Di; Han, Xiao; Yang, Xingbin

    2016-01-01

    Background Nutritional and absorption-promoting properties of stachyose combined with tea catechins (TC) have been revealed. However, the mechanism involved in non-digestible oligosaccharides-mediated enhancement of flavonoid absorption has largely remained elusive. Methods This study was designed to investigate the molecular mechanism of stachyose in enhancing absorption and transportation of TC in mice. Mice were orally pre-treated with stachyose (50, 250, and 500 mg/kg·bw) for 0–8 weeks, and 1 h before sacrifice, mice were treated with TC (250 mg/kg·bw). Results Gas chromatography-mass spectrometry analysis showed that serum concentrations of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were dose- and time-dependently elevated with stachyose pre-treatment in mice. Furthermore, pre-treatment with stachyose in mice reduced intestinal sulfotransferase and uridine diphosphate-glucuronosyltransferase levels by 3.3–43.2% and 23.9–30.4%, relative to control mice, respectively. Moreover, intestinal P-glycoprotein and multidrug resistance-associated protein-1 contents were decreased in mice by pre-administration of stachyose in dose- and time-dependent manner. Conclusions This is the first time to demonstrate that suppression of Phase II metabolic enzymes and efflux transporters of TC in the intestine can play a major role in increasing absorption of TC by stachyose feeding. PMID:27782875

  8. Effects of stachyose on absorption and transportation of tea catechins in mice: possible role of Phase II metabolic enzymes and efflux transporters inhibition by stachyose

    Directory of Open Access Journals (Sweden)

    Wenfeng Li

    2016-10-01

    Full Text Available Background: Nutritional and absorption-promoting properties of stachyose combined with tea catechins (TC have been revealed. However, the mechanism involved in non-digestible oligosaccharides-mediated enhancement of flavonoid absorption has largely remained elusive. Methods: This study was designed to investigate the molecular mechanism of stachyose in enhancing absorption and transportation of TC in mice. Mice were orally pre-treated with stachyose (50, 250, and 500 mg/kg·bw for 0–8 weeks, and 1 h before sacrifice, mice were treated with TC (250 mg/kg·bw. Results: Gas chromatography-mass spectrometry analysis showed that serum concentrations of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were dose- and time-dependently elevated with stachyose pre-treatment in mice. Furthermore, pre-treatment with stachyose in mice reduced intestinal sulfotransferase and uridine diphosphate-glucuronosyltransferase levels by 3.3–43.2% and 23.9–30.4%, relative to control mice, respectively. Moreover, intestinal P-glycoprotein and multidrug resistance-associated protein-1 contents were decreased in mice by pre-administration of stachyose in dose- and time-dependent manner. Conclusions: This is the first time to demonstrate that suppression of Phase II metabolic enzymes and efflux transporters of TC in the intestine can play a major role in increasing absorption of TC by stachyose feeding.

  9. Serum levels of renin, angiotensin-converting enzyme and angiotensin II in patients treated by surgical excision, propranolol and captopril for problematic proliferating infantile haemangioma.

    Science.gov (United States)

    Sulzberger, L; Baillie, R; Itinteang, T; de Jong, S; Marsh, R; Leadbitter, P; Tan, S T

    2016-03-01

    The role of the renin-angiotensin system (RAS) in the biology of infantile haemangioma (IH) and its accelerated involution induced by β-blockers was first proposed in 2010. This led to the first clinical trial in 2012 using low-dose captopril, an angiotensin-converting enzyme (ACE) inhibitor, demonstrating a similar response in these tumours. This study aimed to compare serial serum levels of the components of the RAS in patients before and after surgical excision, propranolol or captopril treatment for problematic proliferating IH. Patients with problematic proliferating IH underwent measurements of serum levels of plasma renin activity (PRA), ACE and angiotensin II (ATII) before, and 1-2 and 6 months following surgical excision, propranolol or captopril treatment. This study included 27 patients undergoing surgical excision (n = 8), propranolol (n = 11) and captopril (n = 8) treatment. Treatment with either surgical excision or propranolol resulted in significant decrease in the mean levels of PRA. Surgical excision or captopril treatment led to significant decline in the mean levels of ATII. All three treatment modalities had no significant effect on the mean levels of ACE. This study demonstrates the effect of surgical excision, propranolol and captopril treatment in lowering the levels of PRA and ATII, but not ACE, supporting a mechanistic role for the RAS in the biology of IH. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Impact of Angiotensin I-converting Enzyme Inhibitors and Angiotensin II Type-1 Receptor Blockers on Survival of Patients with NSCLC

    Science.gov (United States)

    Miao, Lili; Chen, Wei; Zhou, Ling; Wan, Huanying; Gao, Beili; Feng, Yun

    2016-01-01

    It has been shown that angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs) can decrease tumor growth and tumor-associated angiogenesis and inhibit metastasis. Epidermal growth factor receptor (EGFR) mutations are found in approximately 30% of patients with advanced non-small cell lung cancer (NSCLC) in East Asia and in 10–15% of such patients in Western countries. We retrospectively identified 228 patients with histologically confirmed advanced NSCLC and 73 patients with early stage disease; 103 of these patients took antihypertensive drugs, and 112 received treatment with EGFR tyrosine kinase inhibitors (TKIs). There was a significant difference in progression-free survival after first-line therapy (PFS1) between the ACEI/ARB group and the non-ACEI/ARB group. For the patients treated with TKIs, there was a significant difference in PFS but not in overall survival (OS) between the ACEI/ARB group and the non-ACEI/ARB group. For the patients with advanced NSCLC, there was a significant difference in PFS1 between the ACEI/ARB group and the non-ACEI/ARB group. ACEI/ARB in combination with standard chemotherapy or TKIs had a positive effect on PFS1 or OS, regardless of whether the lung cancer was in the early or advanced stage. PMID:26883083

  11. Comparative effectiveness of angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers for major renal outcomes in patients with diabetes: A 15-year cohort study.

    Science.gov (United States)

    Wu, Hon-Yen; Peng, Chiao-Ling; Chen, Pei-Chun; Chiang, Chih-Kang; Chang, Chee-Jen; Huang, Jenq-Wen; Peng, Yu-Sen; Tu, Yu-Kang; Chu, Tzong-Shinn; Hung, Kuan-Yu; Chien, Kuo-Liong

    2017-01-01

    Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are considered to have similar renoprotective effects; so far there has been no consensus about their priorities. This study aimed to compare ACEIs and ARBs for major renal outcomes and survival in a 15-year cohort of adults with diabetes. This study utilized Taiwan's medical and pharmacy claims data in the Longitudinal Cohort of Diabetes Patients. The primary outcome was long-term dialysis, and secondary outcomes were hospitalization for acute kidney injury, hospitalization for hyperkalemia, all-cause death, cardiovascular death, and non-cardiovascular death. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes comparing ACEIs with ARBs. We conducted subgroup analyses and interaction tests among patients with different age and comorbid diseases. A total of 34,043 patients received ACEIs and 23,772 patients received ARBs. No differences were found for primary or secondary outcomes in the main analyses. ACEIs showed significantly lower hazard than ARBs for long-term dialysis among patients with cardiovascular disease (HR 0.80, 95% CI 0.66-0.97, interaction P = 0.003) or chronic kidney disease (0.81, 0.71-0.93, interaction P = 0.001). Our analyses show similar effects of ACEIs and ARBs in patients with diabetes. However, ACEIs might provide additional renoprotective effects among patients who have cardiovascular disease or chronic kidney disease.

  12. Application of electrolysis for detoxification of an antineoplastic in urine.

    Science.gov (United States)

    Kobayashi, Toyohide; Hirose, Jun; Sano, Kouichi; Kato, Ryuji; Ijiri, Yoshio; Takiuchi, Hiroya; Tanaka, Kazuhiko; Goto, Emi; Tamai, Hiroshi; Nakano, Takashi

    2012-04-01

    Antineoplastics in excreta from patients have been considered to be one of the origins of cytotoxic, carcinogenic, teratogenic, and mutagenic contaminants in surface water. Recent studies have demonstrated that antineoplastics in clinical wastewater can be detoxified by electrolysis. In this study, to develop a method for the detoxification of antineoplastics in excreta, methotrexate solution in the presence of human urine was electrolyzed and evaluated. We found that urine inhibits detoxification by electrolysis; however, this inhibition decreased by diluting urine. In urine samples, the concentrations of active chlorine generated by anodic oxidation from 0.9% NaCl solution for inactivation of antineoplastics increased in dilution-dependent and time-dependent manner. These results indicate that electrolysis with platinum-based iridium oxide composite electrode is a possible method for the detoxification of a certain antineoplastic in urine.

  13. Current and Emerging Detoxification Therapies for Critical Care

    Directory of Open Access Journals (Sweden)

    Brett A. Howell

    2010-04-01

    Full Text Available Toxicity resulting from prescription drugs such as tricyclic antidepressants and cardioactive steroids, as well as drugs of abuse and exposure to environmental chemicals, represents a major need for detoxification treatments. Particles and colloids, antibody fragments (Fab, and indirect treatment methods such as macroemulsions, are currently being developed or employed as detoxification therapies. Colloids, particles, and protein fragments typically mitigate toxicity by binding to the toxin and reducing its concentration in vital organs. Indirect methods such as macroemulsions and sodium bicarbonate act directly on the affected organs, rather than the toxin. In this review, key design parameters (i.e. binding affinity, biocompatibility, pharmacokinetics are discussed for each type of detoxification treatment. In addition, some of the latest research in each area is reviewed.

  14. The Oxidative Stress Network of Mycobacterium tuberculosis Reveals Coordination between Radical Detoxification Systems.

    Science.gov (United States)

    Nambi, Subhalaxmi; Long, Jarukit E; Mishra, Bibhuti B; Baker, Richard; Murphy, Kenan C; Olive, Andrew J; Nguyen, Hien P; Shaffer, Scott A; Sassetti, Christopher M

    2015-06-10

    M. tuberculosis (Mtb) survives a hostile environment within the host that is shaped in part by oxidative stress. The mechanisms used by Mtb to resist these stresses remain ill-defined because the complex combination of oxidants generated by host immunity is difficult to accurately recapitulate in vitro. We performed a genome-wide genetic interaction screen to comprehensively delineate oxidative stress resistance pathways necessary for Mtb to resist oxidation during infection. Our analysis predicted functional relationships between the superoxide-detoxifying enzyme (SodA), an integral membrane protein (DoxX), and a predicted thiol-oxidoreductase (SseA). Consistent with that, SodA, DoxX, and SseA form a membrane-associated oxidoreductase complex (MRC) that physically links radical detoxification with cytosolic thiol homeostasis. Loss of any MRC component correlated with defective recycling of mycothiol and accumulation of cellular oxidative damage. This previously uncharacterized coordination between oxygen radical detoxification and thiol homeostasis is required to overcome the oxidative environment Mtb encounters in the host.

  15. Coordinating Role of RXRα in Downregulating Hepatic Detoxification during Inflammation Revealed by Fuzzy-Logic Modeling.

    Science.gov (United States)

    Keller, Roland; Klein, Marcus; Thomas, Maria; Dräger, Andreas; Metzger, Ute; Templin, Markus F; Joos, Thomas O; Thasler, Wolfgang E; Zell, Andreas; Zanger, Ulrich M

    2016-01-01

    During various inflammatory processes circulating cytokines including IL-6, IL-1β, and TNFα elicit a broad and clinically relevant impairment of hepatic detoxification that is based on the simultaneous downregulation of many drug metabolizing enzymes and transporter genes. To address the question whether a common mechanism is involved we treated human primary hepatocytes with IL-6, the major mediator of the acute phase response in liver, and characterized acute phase and detoxification responses in quantitative gene expression and (phospho-)proteomics data sets. Selective inhibitors were used to disentangle the roles of JAK/STAT, MAPK, and PI3K signaling pathways. A prior knowledge-based fuzzy logic model comprising signal transduction and gene regulation was established and trained with perturbation-derived gene expression data from five hepatocyte donors. Our model suggests a greater role of MAPK/PI3K compared to JAK/STAT with the orphan nuclear receptor RXRα playing a central role in mediating transcriptional downregulation. Validation experiments revealed a striking similarity of RXRα gene silencing versus IL-6 induced negative gene regulation (rs = 0.79; P<0.0001). These results concur with RXRα functioning as obligatory heterodimerization partner for several nuclear receptors that regulate drug and lipid metabolism.

  16. The detoxification of lead in Sedum alfredii H. is not related to phytochelatins but the glutathione.

    Science.gov (United States)

    Gupta, D K; Huang, H G; Yang, X E; Razafindrabe, B H N; Inouhe, M

    2010-05-15

    Two ecotypes of S. alfredii [Pb accumulating (AE) and Pb non-accumulating (NAE)] differing in their ability in accumulating Pb were exposed to different Pb levels to evaluate the effects on plant length, photosynthetic pigments, antioxidant enzymes (SOD and APX), cysteine, non-protein thiols (NP-SH), phytochelatins (PCs) and glutathione (GSH) vis-à-vis Pb accumulation. Both ecotypes showed significant Pb accumulation in roots, however only the AE showed significant Pb accumulation in shoots. We found that both AE and NAE of S. alfredii-induced biosynthesis of GSH rather than phytochelatins in their tissue upon addition of even high Pb levels (200 microM). Root and shoot length were mostly affected in both ecotypes after addition of higher Pb concentrations and on longer durations, however photosynthetic pigments did not alter upon addition of any Pb treatment. Both superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities of AE were higher than NAE. The levels of cysteine and NP-SH were also higher in AE than in NAE. Hence, the characteristic Pb accumulation of ecotypes differed presumably in relation to their capacity for detoxification of Pb. These results suggest that enzymatic and non-enzymatic antioxidants play a key role in the detoxification of Pb-induced toxic effects in Sedum alfredii. This plant can be used as an indicator species for Pb contamination.

  17. Detoxification of furfural in Corynebacterium glutamicum under aerobic and anaerobic conditions.

    Science.gov (United States)

    Tsuge, Yota; Hori, Yoshimi; Kudou, Motonori; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-10-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates raise serious problems for the microbial production of fuels and chemicals. Furfural is considered to be one of the most toxic compounds among these inhibitors. Here, we describe the detoxification of furfural in Corynebacterium glutamicum ATCC13032 under both aerobic and anaerobic conditions. Under aerobic culture conditions, furfuryl alcohol and 2-furoic acid were produced as detoxification products of furfural. The ratio of the products varied depending on the initial furfural concentration. Neither furfuryl alcohol nor 2-furoic acid showed any toxic effect on cell growth, and both compounds were determined to be the end products of furfural degradation. Interestingly, unlike under aerobic conditions, most of the furfural was converted to furfuryl alcohol under anaerobic conditions, without affecting the glucose consumption rate. Both the NADH/NAD(+) and NADPH/NADP(+) ratio decreased in the accordance with furfural concentration under both aerobic and anaerobic conditions. These results indicate the presence of a single or multiple endogenous enzymes with broad and high affinity for furfural and co-factors in C. glutamicum ATCC13032.

  18. Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2017-04-01

    Full Text Available Mycotoxins, the secondary metabolites of mycotoxigenic fungi, have been found in almost all agricultural commodities worldwide, causing enormous economic losses in livestock production and severe human health problems. Compared to traditional physical adsorption and chemical reactions, interest in biological detoxification methods that are environmentally sound, safe and highly efficient has seen a significant increase in recent years. However, researchers in this field have been facing tremendous unexpected challenges and are eager to find solutions. This review summarizes and assesses the research strategies and methodologies in each phase of the development of microbiological solutions for mycotoxin mitigation. These include screening of functional microbial consortia from natural samples, isolation and identification of single colonies with biotransformation activity, investigation of the physiological characteristics of isolated strains, identification and assessment of the toxicities of biotransformation products, purification of functional enzymes and the application of mycotoxin decontamination to feed/food production. A full understanding and appropriate application of this tool box should be helpful towards the development of novel microbiological solutions on mycotoxin detoxification.

  19. Compound parabolic concentrator technology development to commercial solar detoxification applications

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, J.; Malato, S.; Fernandez, P. [CIEMAT, Plataforma Solar de Almeria (ES)] (and others)

    1999-07-01

    An EC-DGXII BRITE-EURAM-III-financed project called Solar detoxification technology in the treatment of persistent non-biodegradable chlorinated industrial water contaminants' is described. The objectives are to develop a simple, efficient and commercially competitive solar water treatment technology based on compound parabolic collectors (CPC) enabling design and erection of turnkey installations. A European industrial consortium, SOLARDETOX, representing industry and research in Spain, Portugal, Germany and Italy has been created through this project. Some of the most up-to-date scientific and technological results are given, including the design of the first industrial European solar detoxification treatment plant, the main project deliverable. (author)

  20. Mathematical model insights into arsenic detoxification

    Directory of Open Access Journals (Sweden)

    Nijhout H Frederik

    2011-08-01

    Full Text Available Abstract Background Arsenic in drinking water, a major health hazard to millions of people in South and East Asia and in other parts of the world, is ingested primarily as trivalent inorganic arsenic (iAs, which then undergoes hepatic methylation to methylarsonic acid (MMAs and a second methylation to dimethylarsinic acid (DMAs. Although MMAs and DMAs are also known to be toxic, DMAs is more easily excreted in the urine and therefore methylation has generally been considered a detoxification pathway. A collaborative modeling project between epidemiologists, biologists, and mathematicians has the purpose of explaining existing data on methylation in human studies in Bangladesh and also testing, by mathematical modeling, effects of nutritional supplements that could increase As methylation. Methods We develop a whole body mathematical model of arsenic metabolism including arsenic absorption, storage, methylation, and excretion. The parameters for arsenic methylation in the liver were taken from the biochemical literature. The transport parameters between compartments are largely unknown, so we adjust them so that the model accurately predicts the urine excretion rates of time for the iAs, MMAs, and DMAs in single dose experiments on human subjects. Results We test the model by showing that, with no changes in parameters, it predicts accurately the time courses of urinary excretion in mutiple dose experiments conducted on human subjects. Our main purpose is to use the model to study and interpret the data on the effects of folate supplementation on arsenic methylation and excretion in clinical trials in Bangladesh. Folate supplementation of folate-deficient individuals resulted in a 14% decrease in arsenicals in the blood. This is confirmed by the model and the model predicts that arsenicals in the liver will decrease by 19% and arsenicals in other body stores by 26% in these same individuals. In addition, the model predicts that arsenic

  1. The expression of proteins involved in digestion and detoxification are regulated in Helicoverpa armigera to cope up with chlorpyrifos insecticide.

    Science.gov (United States)

    Dawkar, Vishal V; Chikate, Yojana R; More, Tushar H; Gupta, Vidya S; Giri, Ashok P

    2016-02-01

    Helicoverpa armigera is a key pest in many vital crops, which is mainly controlled by chemical strategies. To manage this pest is becoming challenging due to its ability and evolution of resistance against insecticides. Further, its subsequent spread on nonhost plant is remarkable in recent times. Hence, decoding resistance mechanism against phytochemicals and synthetic insecticides is a major challenge. The present work describes that the digestion, defense and immunity related enzymes are associated with chlorpyrifos resistance in H. armigera. Proteomic analysis of H. armigera gut tissue upon feeding on chlorpyrifos containing diet (CH) and artificial diet (AD) using nano-liquid chromatography-mass spectrometry identified upregulated 23-proteins in CH fed larvae. Database searches combined with gene ontology analysis revealed that the identified gut proteins engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification. Biochemical and quantitative real-time polymerase chain reaction analysis of candidate proteins indicated that insects were struggling to get nutrients and energy in presence of CH, while at the same time endeavoring to metabolize chlorpyrifos. Moreover, we proposed a potential processing pathway of chlorpyrifos in H. armigera gut by examining the metabolites using gas chromatography-mass spectrometry. H. armigera exhibit a range of intriguing behavioral, morphological adaptations and resistance to insecticides by regulating expression of proteins involved in digestion and detoxification mechanisms to cope up with chlorpyrifos. In these contexts, as gut is a rich repository of biological information; profound analysis of gut tissues can give clues of detoxification and resistance mechanism in insects.

  2. Physiological responses and detoxific mechanisms to Pb, Zn, Cu and Cd in young seedlings of Paulownia fortunei.

    Science.gov (United States)

    Wang, Jiang; Li, Weihua; Zhang, Chongbang; Ke, Shisheng

    2010-01-01

    Paulownia fortunei has been successfully used in the phytoremediation of many Pb/Zn mine tailings. However, seed germination and young seedlings of P. fortunei rarely occurred in these mine tailings. The physiological responses and detoxific mechanisms of P. fortunei young seedling to Pb, Zn, Cu and Cd stress were investigated. The germinated rate, shoot length, chlorophyll and carotenoid contents in leaves of young seedlings had a great reduction under Zn and Cu treatments, but had little decrease under Pb and Cd treatments. The production rate of O2*-, H2O2 and malondialdehyde (MDA) contents significantly increased in response to added Zn and Cu indicating great oxidative stress for young seedlings, but they had no significant change to added Pb and Cd. Young seedlings had effective detoxific mechanism to Pb and Cd, as antioxidant enzymes activities, phytochelatins (PCs-SH) and proline contents increased with increasing rates of added Pb and Cd. However, young seedlings had un-effective detoxific mechanisms to Zn and Cu stress. Results revealed the heavy metals (such as Cu) that present at low concentrations in mine tailings may be major constraint for the survival of young seedlings.

  3. A study of liver microsomal enzymes in rats following propoxur (Baygon) administration.

    Science.gov (United States)

    Nelson, D L; Lamb, D W; Mihail, F

    1984-08-01

    Groups of rats were given either propoxur, were left as untreated controls, or were given phenobarbital, DDT, chlordane or toxaphene which are known to induce liver microsomal detoxification enzymes. Microsomal enzyme activity was measured by testing the ability of liver homogenates to degrade EPN (O-ethyl O-(4-nitrophenyl) phenylphosphonothioate) to p-nitrophenol. The activity of aminopyrine-N-demethylase, cytochrome P-450 and p-nitroanisole-O-demethylase in liver homogenates of rats receiving propoxur was measured. Liver microsomal detoxification enzymes were not induced by propoxur exposure.

  4. Simultaneous detoxification and bioethanol fermentation of furans-rich synthetic hydrolysate by digestate-based pyrochar.

    Science.gov (United States)

    Sambusiti, C; Monlau, F; Antoniou, N; Zabaniotou, A; Barakat, A

    2016-12-01

    Pyrolysis is a sustainable pathway to transform renewable biomasses into both biofuels and advanced carbonaceous materials (i.e. pyrochar) which can be used as adsorbent of furan compounds. In particular, the aim of this study was to: i) evaluate the effect of vibro-ball milling on physical characteristics of pyrochar and its consequent performance on solely detoxification of a synthetic medium, containing furans and soluble sugars; ii) study the simultaneous detoxification and bioethanol fermentation, by adding activated pyrochar into fermentation medium. Results demonstrated that, compared to untreated pyrochar, the use of milled pyrochar increased by 52% furfural removal from the synthetic medium. Furfural removal rate was also increased (adsorption kinetic constant increased from 0.015 min(-1) up to 0.215 min(-1)), at a pyrochar loading of 40 g L(-1). Although, the simultaneous addition of pyrochar into the fermentation medium did not improve the bioethanol yield of the synthetic medium, it has significantly increased the bioethanol production rate.

  5. Fanweed toxicosis in cattle: case history, analytical method, suggested treatment, and fanweed detoxification.

    Science.gov (United States)

    Smith, R A; Crowe, S P

    1987-04-01

    Two hundred and twenty head of pregnant cows were fed virtually 100% fanweed (Thlaspi arvense) in November 1984. One hundred became distressed and colicy within 4 hr of feeding. Eight died over the next 5 days despite removal of the feed and symptomatic treatment. Necropsy revealed massive submucosal edema of the wall of the forestomachs, particularly the rumen. Four abortions occurred. The feed was analyzed and was found to liberate 250 mg/100g of AITC. Possible methods of treatment were devised in case the problem should recur. Fanweed contains sinigrin and the enzyme myrosin. When the plant is crushed and moistened, allylisothiocyanate (AITC) is formed along with glucose and potassium acid sulfate. Application of Le Chatelier's principle led to an investigation of the effect of pH on in vitro generation of AITC. Methods of destroying AITC were also examined, and detoxification studies were undertaken on fanweed.

  6. Effects of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers on lymphangiogenesis of gastric cancer in a nude mouse model

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; CAI Shi-rong; ZHANG Chang-hua; HE Yu-long; ZHAN Wen-hua; WU Hui; PENG Jian-jun

    2008-01-01

    Background Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II type 1 receptor blockers (ARB) can inhibit tumor growth by inhibition of angiogenesis.This study was designed to study the anticancer effects of ACEI and ARB on tumor growth and lymphangiogenesis in an implanted gastric cancer mouse model.Methods A model of gastric cancer was established by subcutaneously inoculating human gastric cancer cell line SGC-7901 into 60 nude mice.One week later,all mice were randomly divided into 5 groups.A control group received physiologic saline once daily for 21 days.Mice in the 4 treatment groups received one of the following agents by gavage once daily for 21 days:perindopril,2 mg/kg;captopril,5 mg/kg;Iosartan,50 mg/kg;or valsartan,40 mg/kg.Twenty-one clays after treatment,all the mice were sacrificed and the tumors were removed.Tumor sections were processed,and immunohistochemical methods were used to observe the expressions of vascular endothelial growth factor C (VEGF-C),matrix metalloproteinase 7 (MMP-7),and lymphatic microvessel density (LMVD).Results Tumor volume was significantly inhibited in all ACEI and ARB groups,compared with the control group (all P <0.01).LMVD in the ACEI and ARB groups was also significantly lower than that of the control group (all P<0.01).In the ACEI groups,the expressions of VEGF-C and MMP-7 were both significantly decreased,compared with the control group (all P<0.05).In the ARB groups,expression of VEGF-C was significantly decreased compared with the control group (all P<0.05).However,no significant difference was found in the expression of MMP-7 between ARB groups and the control group.Conclusion In a mouse model,ACEI and ARB might inhibit gastric cancer tumor growth by suppressing lymphangiogenesis.

  7. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in patients with abdominal aortic aneurysms: nation-wide cohort study.

    Science.gov (United States)

    Kristensen, Karl Emil; Torp-Pedersen, Christian; Gislason, Gunnar Hilmar; Egfjord, Martin; Rasmussen, Henrik Berg; Hansen, Peter Riis

    2015-03-01

    The renin-angiotensin system is thought to play a pivotal role in the pathogenesis of abdominal aortic aneurysms (AAAs). However, effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs) on human AAAs remain unclear. We therefore examined whether treatment with ACEIs or ARBs influenced hard clinical end points in a nation-wide cohort of patients with AAA. All patients diagnosed with AAA during the period 1995 to 2011 were identified from the Danish nation-wide registries. Subjects were divided according to ACEI and ARB treatment status and followed up for an average of 5 years. Study outcomes were evaluated by time-dependent Cox proportional hazard models. Of 9441 patients with AAA, 12.6% were treated with ACEIs and 5.0% received ARBs. Incidence rates of death from AAA per 100 patient-years were 3.7, 3.6, 4.0, and 4.7 for treatment with ACEIs or ARBs, ACEIs, ARBs, and no ACEI/ARB, respectively. Hazard ratios of death from AAA were 0.64 (95% confidence interval, 0.51-0.80; PACEIs and 0.65 (95% confidence interval, 0.48-0.88; P=0.006) for those receiving ARBs, respectively (P for difference=0.944). The risk of surgery for AAA was significantly reduced in patients receiving ACEIs (hazard ratio, 0.86 [95% confidence interval, 0.74-0.99]; P=0.040) but not in patients receiving ARBs (hazard ratio, 1.02 [95% confidence interval, 0.84-1.23]; P=0.867; P for difference=0.119). In this observational study, treatment with ACEIs or ARBs was associated with a comparable reduction in mortality but not in surgery for AAA among patients with AAA. Randomized controlled trials are warranted to confirm these findings. © 2015 American Heart Association, Inc.

  8. Comparative Effectiveness of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Terms of Major Cardiovascular Disease Outcomes in Elderly Patients

    Science.gov (United States)

    Chien, Shu-Chen; Ou, Shuo-Ming; Shih, Chia-Jen; Chao, Pei-Wen; Li, Szu-Yuan; Lee, Yi-Jung; Kuo, Shu-Chen; Wang, Shuu-Jiun; Chen, Tzeng-Ji; Tarng, Der-Cherng; Chu, Hsi; Chen, Yung-Tai

    2015-01-01

    Abstract Renin and aldosterone activity levels are low in elderly patients, raising concerns about the benefits and risks of angiotensin-converting-enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARB) use. However, data from direct comparisons of the effects of ACEIs on ARBs in the elderly population remain inconclusive. In this nationwide study, all patients aged ≥ 70 years were retrieved from the Taiwan National Health Insurance database for the period 2000 to 2009 and were followed up until the end of 2010. The ARB cohort (12,347 patients who continuously used ARBs for ≥ 90 days) was matched to ACEI cohort using high-dimensional propensity score (hdPS). Intention-to-treat (ITT) and as-treated (AT) analyses were conducted. In the ITT analysis, after considering death as a competing risk, the ACEI cohort had similar risks of myocardial infarction (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.79–1.06), ischemic stroke (HR 0.98, 95% CI 0.90–1.07), and heart failure (HR 0.93, 95% CI 0.83–1.04) compared with the ARB cohort. No difference in adverse effects, such as acute kidney injury (HR 0.99, 95% CI 0.89–1.09) and hyperkalemia (HR 1.02, 95% CI 0.87–1.20), was observed between cohorts. AT analysis produced similar results to those of ITT analysis. We were unable to demonstrate a survival difference between cohorts (HR 1.03, 95% CI 0.88–1.21) after considering drug discontinuation as a competing risk in AT analysis. Our study supports the notion that ACEI and ARB users have similar risks of major adverse cardiovascular events (MACE), even in elderly populations. PMID:26512568

  9. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have no beneficial effect on ablation outcome in chronic persistent atrial fibrillation.

    Science.gov (United States)

    Zheng, Bin; Kang, Junping; Tian, Ying; Tang, Ribo; Long, Deyong; Yu, Ronghui; He, Hua; Zhang, Ming; Shi, Lisheng; Tao, Hailong; Liu, Xingpeng; Dong, Jianzeng; Ma, Changsheng

    2009-06-01

    Previous studies have shown that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) could reverse structural and electrical atria remodelling and decrease atrial fibrillation (AF) onset or recurrence. The aim of this retrospective study was to investigate whether ACEIs/ARBs had beneficial effects on ablation outcome of chronic persistent AF. This study included 139 patients with chronic persistent AF who underwent radiofrequency ablation in our centre. Patients were divided into an ACEIs/ARBs group or a non-ACEIs/ARBs group. During follow-up (14.6 +/- 8.9 months) after AF ablation, AF-free survival in the ACEIs/ARBs group was not significantly different from the non-ACEIs/ARBs group (P = 0.339). Univariate analysis showed that predictors for AF-free survival were AF history (HR, 1.064; 95% CI, 1.021-1.108; P = 0.003) and duration of chronic persistent AF (HR, 1.012; 95% CI, 1.005-1.019; P = 0.001). Multivariate analysis showed that predictors for AF-free survival were AF history (HR, 1.051; 95% CI, 1.004-1.101; P = 0.035) and duration of chronic persistent AF (HR, 1.012; 95% CI, 1.004-1.020; P = 0.004). ACEIs/ARBs therapy was not a predictor for AF-free survival neither in univariate nor multivariate analysis. In this observational study, no effect of ACEIs or ARBs was seen on the AF recurrence after ablation of chronic persistent AF.ACEIs/ARBs did not help to predict a better ablation outcome. Predictors for ablation outcome are AF history and duration of chronic persistent AF.

  10. Gene polymorphisms of angiotensin-converting enzyme and angiotensin II type 1 receptor among chronic kidney disease patients in a Chinese population.

    Science.gov (United States)

    Su, Sui-Lung; Lu, Kuo-Cheng; Lin, Yuh-Feng; Hsu, Yu-Juei; Lee, Pong-Ying; Yang, Hsin-Yi; Kao, Sen-Yeong

    2012-03-01

    Chronic kidney disease (CKD) is highly prevalent in Taiwan and an increasing number of patients are affected, with a high risk of progression to end-stage renal disease and huge medical expenses. It has been predicted that the presence of hypertension increases with decreasing renal function due to a decrease in sodium excretion and activation of the renin-angiotensin system (RAS). The aim of this study was to investigate the influence of genetic variants of the RAS gene on CKD. We performed a case control association study and genotyped 135 CKD patients and 270 healthy controls among Han Chinese in Taiwan. All subjects were genotyped for angiotensinogen (AGT-M235T, T174M, A-20C), angiotensin-I converting enzyme (ACE-A2350G) and angiotensin II type 1 receptor (AGTR1-A1166C, C573T, C-521T) polymorphisms of RAS genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Significant associations were observed in ACE-A2350G and AGTR1-C573T polymorphism between CKD patients and controls. In regard to ACE-A2350G, compared with the AA genotype the GG genotype protected against CKD (adjusted odds ratio [OR] = 0.34; p = 0.01). In regard to AGTR1-C573T, the CT genotype was a risk for CKD compared with the CC genotype (adjusted OR = 1.82; p = 0.03). We conclude that ACE-A2350G and AGTR1-C573T polymorphisms are likely candidate determinants of CKD.

  11. Ab initio structural modeling of and experimental validation for Chlamydia trachomatis protein CT296 reveal structural similarity to Fe(II) 2-oxoglutarate-dependent enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Kemege, Kyle E.; Hickey, John M.; Lovell, Scott; Battaile, Kevin P.; Zhang, Yang; Hefty, P. Scott (Michigan); (Kansas); (HWMRI)

    2012-02-13

    Chlamydia trachomatis is a medically important pathogen that encodes a relatively high percentage of proteins with unknown function. The three-dimensional structure of a protein can be very informative regarding the protein's functional characteristics; however, determining protein structures experimentally can be very challenging. Computational methods that model protein structures with sufficient accuracy to facilitate functional studies have had notable successes. To evaluate the accuracy and potential impact of computational protein structure modeling of hypothetical proteins encoded by Chlamydia, a successful computational method termed I-TASSER was utilized to model the three-dimensional structure of a hypothetical protein encoded by open reading frame (ORF) CT296. CT296 has been reported to exhibit functional properties of a divalent cation transcription repressor (DcrA), with similarity to the Escherichia coli iron-responsive transcriptional repressor, Fur. Unexpectedly, the I-TASSER model of CT296 exhibited no structural similarity to any DNA-interacting proteins or motifs. To validate the I-TASSER-generated model, the structure of CT296 was solved experimentally using X-ray crystallography. Impressively, the ab initio I-TASSER-generated model closely matched (2.72-{angstrom} C{alpha} root mean square deviation [RMSD]) the high-resolution (1.8-{angstrom}) crystal structure of CT296. Modeled and experimentally determined structures of CT296 share structural characteristics of non-heme Fe(II) 2-oxoglutarate-dependent enzymes, although key enzymatic residues are not conserved, suggesting a unique biochemical process is likely associated with CT296 function. Additionally, functional analyses did not support prior reports that CT296 has properties shared with divalent cation repressors such as Fur.

  12. Pectic enzymes

    NARCIS (Netherlands)

    Benen, J.A.E.; Voragen, A.G.J.; Visser, J.

    2003-01-01

    The pectic enzymes comprise a diverse group of enzymes. They consist of main-chain depolymerases and esterases active on methyl- and acetylesters of galacturonosyl uronic acid residues. The depolymerizing enzymes comprise hydrolases as wel as lyases

  13. Pectic enzymes

    NARCIS (Netherlands)

    Benen, J.A.E.; Voragen, A.G.J.; Visser, J.

    2003-01-01

    The pectic enzymes comprise a diverse group of enzymes. They consist of main-chain depolymerases and esterases active on methyl- and acetylesters of galacturonosyl uronic acid residues. The depolymerizing enzymes comprise hydrolases as wel as lyases

  14. Time-of-day specific changes in metabolic detoxification and insecticide resistance in the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Balmert, Nathaniel J; Rund, Samuel S C; Ghazi, John P; Zhou, Peng; Duffield, Giles E

    2014-05-01

    Mosquitoes exhibit ∼24 h rhythms in physiology and behavior, regulated by the cooperative action of an endogenous circadian clock and the environmental light:dark cycle. Here, we characterize diel (observed under light:dark conditions) time-of-day changes in metabolic detoxification and resistance to insecticide challenge in Anopheles gambiae mosquitoes. A better understanding of mosquito chronobiology will yield insights into developing novel control strategies for this important disease vector. We have previously identified >2000 rhythmically expressed An. gambiae genes. These include metabolic detoxification enzymes peaking at various times throughout the day. Especially interesting was the identification of rhythmic genes encoding enzymes capable of pyrethroid and/or DDT metabolism (CYP6M2, CYP6P3, CYP6Z1, and GSTE2). We hypothesized that these temporal changes in gene expression would confer time-of-day specific changes in metabolic detoxification and responses to insecticide challenge. An. gambiae mosquitoes (adult female Pimperena and Mali-NIH strains) were tested by gene expression analysis for diel rhythms in key genes associated with insecticidal resistance. Biochemical assays for total GST, esterase, and oxidase enzymatic activities were undertaken on time-specific mosquito head and body protein lysates. To determine for rhythmic susceptibility to insecticides by survivorship, mosquitoes were exposed to DDT or deltamethrin across the diel cycle. We report the occurrence of temporal changes in GST activity in samples extracted from the body and head with a single peak at late-night to dawn, but no rhythms were detected in oxidase or esterase activity. The Pimperena strain was found to be resistant to insecticidal challenge, and subsequent genomic analysis revealed the presence of the resistance-conferring kdr mutation. We observed diel rhythmicity in key insecticide detoxification genes in the Mali-NIH strain, with peak phases as previously reported in

  15. Gamma-hydroxybutyrate detoxification by titration and tapering

    NARCIS (Netherlands)

    Jong, C.A.J. de; Kamal, R.; Dijkstra, B.A.; Haan, H.A. de

    2012-01-01

    OBJECTIVE: To determine the effectiveness and safety of a new detoxification procedure in gamma-hydroxybutyrate (GHB)-dependent patients. GHB is an endogenous inhibitory neurotransmitter and anesthetic agent that is being abused as a club drug. In many GHB-dependent patients a severe withdrawal synd

  16. Enzyme assays.

    Science.gov (United States)

    Reymond, Jean-Louis; Fluxà, Viviana S; Maillard, Noélie

    2009-01-07

    Enzyme assays are analytical tools to visualize enzyme activities. In recent years a large variety of enzyme assays have been developed to assist the discovery and optimization of industrial enzymes, in particular for "white biotechnology" where selective enzymes are used with great success for economically viable, mild and environmentally benign production processes. The present article highlights the aspects of fluorogenic and chromogenic substrates, sensors, and enzyme fingerprinting, which are our particular areas of interest.

  17. Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice.

    Science.gov (United States)

    Fu, Zidong Donna; Klaassen, Curtis D

    2014-01-01

    Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver.

  18. Identification of two Nereis virens [Annelida: Polychaeta] cytochrome P450 enzymes and induction by xenobiotics

    DEFF Research Database (Denmark)

    Rewitz, Kim; Kjellerup, C; Jørgensen, A

    2004-01-01

    compounds such as fatty acids. Crude oil and benz(a)anthracene significantly induced CYP42 gene expression 2.6-fold, and because CYP enzymes often are induced by their own substrates, this induction may indicate involvement of N. virens CYP4 enzymes in the detoxification of environmental contaminants...

  19. High enzyme activity UGT1A1 or low activity UGT1A8 and UGT2B4 genotypes increase esophageal cancer risk.

    NARCIS (Netherlands)

    Dura, P.; Salomon, J.; Morsche, R.H.M. te; Schaap-Roelofs, H.M.J.; Kristinsson, J.O.; Wobbes, T.; Witteman, B.J.; Tan, A.C.; Drenth, J.P.H.; Peters, W.H.M.

    2012-01-01

    Esophageal cancer (EC) has a globally increasing incidence with poor curative treatment options and survival rates. Environmental and dietary factors have crucial roles in esophageal carcinogenesis. Polymorphisms in the UGT genes, a superfamily of enzymes essential for the detoxification of

  20. Widespread Chemical Detoxification of Alkaloid Venom by Formicine Ants.

    Science.gov (United States)

    LeBrun, Edward G; Diebold, Peter J; Orr, Matthew R; Gilbert, Lawrence E

    2015-10-01

    The ability to detoxify defensive compounds of competitors provides key ecological advantages that can influence community-level processes. Although common in plants and bacteria, this type of detoxification interaction is extremely rare in animals. Here, using laboratory behavioral assays and analyses of videotaped interactions in South America, we report widespread venom detoxification among ants in the subfamily Formicinae. Across both data sets, nine formicine species, representing all major clades, used a stereotyped grooming behavior to self-apply formic acid (acidopore grooming) in response to fire ant (Solenopsis invicta and S. saevissima) venom exposure. In laboratory assays, this behavior increased the survivorship of species following exposure to S. invicta venom. Species expressed the behavior when exposed to additional alkaloid venoms, including both compositionally similar piperidine venom of an additional fire ant species and the pyrrolidine/pyrroline alkaloid venom of a Monomorium species. In addition, species expressed the behavior following exposure to the uncharacterized venom of a Crematogaster species. However, species did not express acidopore grooming when confronted with protein-based ant venoms or when exposed to monoterpenoid-based venom. This pattern, combined with the specific chemistry of the reaction of formic acid with venom alkaloids, indicates that alkaloid venoms are targets of detoxification grooming. Solenopsis thief ants, and Monomorium species stand out as brood-predators of formicine ants that produce piperidine, pyrrolidine, and pyrroline venom, providing an important ecological context for the use of detoxification behavior. Detoxification behavior also represents a mechanism that can influence the order of assemblage dominance hierarchies surrounding food competition. Thus, this behavior likely influences ant-assemblages through a variety of ecological pathways.

  1. Xenobiotic metabolism capacities of human skin in comparison with a 3D-epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: phase II enzymes.

    Science.gov (United States)

    Götz, Christine; Pfeiffer, Roland; Tigges, Julia; Ruwiedel, Karsten; Hübenthal, Ulrike; Merk, Hans F; Krutmann, Jean; Edwards, Robert J; Abel, Josef; Pease, Camilla; Goebel, Carsten; Hewitt, Nicola; Fritsche, Ellen

    2012-05-01

    The 7th Amendment to the EU Cosmetics Directive prohibits the use of animals in cosmetic testing for certain endpoints, such as genotoxicity. Therefore, skin in vitro models have to replace chemical testing in vivo. However, the metabolic competence neither of human skin nor of alternative in vitro models has so far been fully characterized, although skin is the first-pass organ for accidentally or purposely (cosmetics and pharmaceuticals) applied chemicals. Thus, there is an urgent need to understand the xenobiotic-metabolizing capacities of human skin and to compare these activities to models developed to replace animal testing. We have measured the activity of the phase II enzymes glutathione S-transferase, UDP-glucuronosyltransferase and N-acetyltransferase in ex vivo human skin, the 3D epidermal model EpiDerm 200 (EPI-200), immortalized keratinocyte-based cell lines (HaCaT and NCTC 2544) and primary normal human epidermal keratinocytes. We show that all three phase II enzymes are present and highly active in skin as compared to phase I. Human skin, therefore, represents a more detoxifying than activating organ. This work systematically compares the activities of three important phase II enzymes in four different in vitro models directly to human skin. We conclude from our studies that 3D epidermal models, like the EPI-200 employed here, are superior over monolayer cultures in mimicking human skin xenobiotic metabolism and thus better suited for dermatotoxicity testing. © 2012 John Wiley & Sons A/S.

  2. Structure of soybean [beta]-cyanoalanine synthase and the molecular basis for cyanide detoxification in plants

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Hankuil; Juergens, Matthew; Jez, Joseph M. (WU)

    2012-09-07

    Plants produce cyanide (CN{sup -}) during ethylene biosynthesis in the mitochondria and require {beta}-cyanoalanine synthase (CAS) for CN{sup -} detoxification. Recent studies show that CAS is a member of the {beta}-substituted alanine synthase (BSAS) family, which also includes the Cys biosynthesis enzyme O-acetylserine sulfhydrylase (OASS), but how the BSAS evolved distinct metabolic functions is not understood. Here we show that soybean (Glycine max) CAS and OASS form {alpha}-aminoacrylate reaction intermediates from Cys and O-acetylserine, respectively. To understand the molecular evolution of CAS and OASS in the BSAS enzyme family, the crystal structures of Gm-CAS and the Gm-CAS K95A mutant with a linked pyridoxal phosphate (PLP)-Cys molecule in the active site were determined. These structures establish a common fold for the plant BSAS family and reveal a substrate-induced conformational change that encloses the active site for catalysis. Comparison of CAS and OASS identified residues that covary in the PLP binding site. The Gm-OASS T81M, S181M, and T185S mutants altered the ratio of OASS:CAS activity but did not convert substrate preference to that of a CAS. Generation of a triple mutant Gm-OASS successfully switched reaction chemistry to that of a CAS. This study provides new molecular insight into the evolution of diverse enzyme functions across the BSAS family in plants.

  3. A review of biological delignification and detoxification methods for lignocellulosic bioethanol production.

    Science.gov (United States)

    Moreno, Antonio D; Ibarra, David; Alvira, Pablo; Tomás-Pejó, Elia; Ballesteros, Mercedes

    2015-01-01

    Future biorefineries will integrate biomass conversion processes to produce fuels, power, heat and value-added chemicals. Due to its low price and wide distribution, lignocellulosic biomass is expected to play an important role toward this goal. Regarding renewable biofuel production, bioethanol from lignocellulosic feedstocks is considered the most feasible option for fossil fuels replacement since these raw materials do not compete with food or feed crops. In the overall process, lignin, the natural barrier of the lignocellulosic biomass, represents an important limiting factor in biomass digestibility. In order to reduce the recalcitrant structure of lignocellulose, biological pretreatments have been promoted as sustainable and environmentally friendly alternatives to traditional physico-chemical technologies, which are expensive and pollute the environment. These approaches include the use of diverse white-rot fungi and/or ligninolytic enzymes, which disrupt lignin polymers and facilitate the bioconversion of the sugar fraction into ethanol. As there is still no suitable biological pretreatment technology ready to scale up in an industrial context, white-rot fungi and/or ligninolytic enzymes have also been proposed to overcome, in a separated or in situ biodetoxification step, the effect of the inhibitors produced by non-biological pretreatments. The present work reviews the latest studies regarding the application of different microorganisms or enzymes as useful and environmentally friendly delignification and detoxification technologies for lignocellulosic biofuel production. This review also points out the main challenges and possible ways to make these technologies a reality for the bioethanol industry.

  4. The role of glutathione detoxification pathway in MCLR-induced hepatotoxicity in SD rats.

    Science.gov (United States)

    Li, Shangchun; Chen, Jun; Xie, Ping; Guo, Xiaochun; Fan, Huihui; Yu, Dezhao; Zeng, Cheng; Chen, Liang

    2015-12-01

    In the present study, we investigated the role of glutathione (GSH) and its related enzymes in Sprague Dawley (SD) rats subjected to microcystin-leucine-arginine (MCLR)-induced hepatotoxicity. SD rats were intraperitoneally (i.p.) injected with MCLR after pretreating with or without buthionine-(S,R)-sulfoximine (BSO), an inhibitor of GSH synthesis. The depletion of GSH with BSO enhanced MCLR-induced oxidative stress, resulting in more severe liver damage and higher MCLR accumulation. Similarly, the contents of malondialdehyde (MDA), total GSH (T-GSH), oxidized GSH (GSSG) and GSH were significantly enhanced in BSO pretreated rats following MCLR treatment. The study showed that the transcription of GSH-related enzymes such as glutathione-S-transferase (GST), γ-glutamylcysteine synthetase (γ-GCS), glutathione reductase (GR) varied in different ways (expect for glutathione peroxidase (GPx), whose gene expression was induced in all treated groups) with or without BSO pretreatment before MCLR exposure, suggesting an adaptative response of GSH-related enzymes at transcription level to combat enhancement of oxidative stress induced by MCLR when pretreated with BSO. These data suggested the tissues with low GSH concentration are highly vulnerable to MCLR toxicity and GSH was critical for the detoxification in MCLR-induced hepatotoxicity in vivo.

  5. Detoxification of Abrus precatorius L. seeds by Ayurvedic Shodhana process and anti-inflammatory potential of the detoxified extract

    Directory of Open Access Journals (Sweden)

    Sagar B Dhoble

    2014-01-01

    Full Text Available Background: Abrus precatorius seeds traditionally used for the treatment of sciatica and alopecia contains the toxic protein, abrin, a Type II Ribosome Inactivating Protein. Ayurveda recommends the use of Abrus seeds after the Shodhana process (detoxification. Objective: The current study was aimed at performing the Shodhana process, swedana (boiling of Abrus precatorius seeds using water as a medium and to evaluate the anti-inflammatory potential of seed extract post detoxification. Materials and Methods: Non-detoxified and detoxified extracts were prepared and subsequently subjected to various in vitro and in vivo assays. In hemagglutination assay, the non-detoxified extract shows higher agglutination of RBCs than detoxified extract indicating riddance of toxic hemagglutinating proteins by Shodhana. This was confirmed by the SDSPAGE analysis of detoxified extract revealing the absence of abrin band in detoxified extract when compared to non-detoxified extract. Results: The cytotoxicity assay in HeLa cell line expresses a higher reduction in growth percentage of the cells with non-detoxified extract as compared to detoxified extract indicating successful detoxification. Brine shrimp lethality test indicated the reduction in toxicity index of detoxified extract as compared to non-detoxified extract. Further, the whole body apoptosis assay in zebrafish revealed that percentage of viable cells were greater for detoxified extract than non-detoxified extract. The anti-inflammatory studies using carrageenan induced paw edema model in rats was carried out on the extracts with doses of 100 mg/kg and 200 mg/kg, per oral, where the detoxified extract exhibited significant inhibition of rat paw edema at both the doses comparable to that of Diclofenac sodium. Conclusion: Absence of toxicity and the retention of the anti-inflammatory activity of detoxified Abrus seed extract confirmed that the Swedana process is effective in carrying out the detoxification

  6. Effects of angiotensin converting enzyme inhibitor, angio- tensin II type I receptor blocker and their combination on postinfarcted ventricular remodeling in rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background Transforming growth factor (TGF) β1-Smads signal plays an important role in cardiac remodeling following myocardial infarction (MI). In addition, both angiotensin converting enzyme inhibitor (ACEI) and angiotensin II type I receptor blocker (ARB) can effectively prevent left ventricular remodeling. The current study focused on whether the combination of ACEI and ARB is more beneficial for preventing ventricular remodeling and whether Smad proteins mediate this beneficial effect.Results VW/BW significantly increased in the placebo groups compared with that in the control group (P<0.01). This increase was limited in ACEI, ARB, and combined groups (P<0.01 compared with placebo group). There was no significant difference among the three actively treated groups. Collagen was increased in placebo group (5.68±0.5)% compared with that in control group (P<0.01). ACEI, ARB and combined treatment attenuated this increase of collagen [(4.3±0.5)%, (3.5±0.5)%, (3.2±0.4)%] in comparison with that in placebo group (P<0.01 respectively). Combined treatment showed more significant effect on collagen deposition. EF and FS significantly decreased, LVDd and E/A significantly increased in placebo group compared with that in control group (P<0.01 respectively). ACEI, ARB and combined treatment ameliorated these indexes (P<0.01 compared with placebo group). The mRNA expression of TGFβ1, Smad 2, and Smad 3 (0.700±0.045, 0.959±0.037 and 0.850±0.051) increased in placebo group compared with that in control group (P<0.01). ACEI, ARB and combined treatment normalized the increase (P<0.01). Furthermore, ARB and combined treatment proved to be more effective in decreasing TGF β1 and Smad mRNA expression than ACEI treatment (P<0.01). The expression of Smad 2 and Smad 3 protein increased in placebo group compared with that in control group (P<0.01). ACEI, ARB and combined treatment normalized the increase (P<0.01). Furthermore, ARB and combined treatment proved to be more

  7. Lead detoxification by coontail (Ceratophyllum demersum L.) involves induction of phytochelatins and antioxidant system in response to its accumulation.

    Science.gov (United States)

    Mishra, Seema; Srivastava, S; Tripathi, R D; Kumar, R; Seth, C S; Gupta, D K

    2006-11-01

    Coontail (Ceratophyllum demersum L.) plants when exposed to various concentrations of Pb (1-100microM) for 1-7days, exhibited both phytotoxic and tolerance responses. The specific responses were function of concentration and duration. Plants accumulated 1748mugPbg(-1) dw after 7d which reflected its metal accumulation ability, however most of the metal (1222microgg(-1) dw, 70%) was accumulated after 1d exposure only. The toxic effect and oxidative stress caused by Pb were evident by the reduction in biomass and photosynthetic pigments and increase in malondialddehyde (MDA) content and electrical conductivity with increase in metal concentration and exposure duration. Morphological symptoms of senescence phenomena such as chlorosis and fragmentation of leaves were observed after 7d. The metal tolerance and detoxification strategy adopted by the plant was investigated with reference to antioxidant system and synthesis of phytochelatins. Protein and antioxidant enzymes viz., superoxide dismutase (SOD, EC 1.15.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7) ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2) showed induction at lower concentration and duration followed by decline. All enzymes except GPX showed maximum activity after 1d. An increase in cysteine, non-protein thiols (NP-SH) and glutathione (GSH) content was observed at moderate exposure conditions followed by decline. Phytochelatins (PC(2) and PC(3)) were synthesized to significant levels at 10 and 50microM Pb with concomitant decrease in GSH levels. Thus production of PCs seems important for the detoxification of metal, however it may lead to depletion of GSH and consequently oxidative stress. Results suggest that plants responded positively to moderate Pb concentrations and accumulated high amount of metal. Due to metal accumulation coupled with detoxification potential, the plant appears to have potential for its use as phytoremediator species

  8. Detoxification of acidic catalyzed hydrolysate of Kappaphycus alvarezii (cottonii).

    Science.gov (United States)

    Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

    2012-01-01

    Red seaweed, Kappaphycus alvarezii, holds great promise for use in biofuel production due to its high carbohydrate content. In this study, we investigated the effect of fermentation inhibitors to the K. alvarezii hydrolysate on cell growth and ethanol fermentation. In addition, detoxification of fermentation inhibitors was performed to decrease the fermentation inhibitory effect. 5-Hydroxymethylfurfural and levulinic acid, which are liberated from acidic hydrolysis, was also observed in the hydrolysate of K. alvarezii. These compounds inhibited ethanol fermentation. In order to remove these inhibitors, activated charcoal and calcium hydroxide were introduced. The efficiency of activated charcoals was examined and over-liming was used to remove the inhibitors. Activated charcoal was found to be more effective than calcium hydroxide to remove the inhibitors. Detoxification by activated charcoal strongly improved the fermentability of dilute acid hydrolysate in the production of bioethanol from K. alvarezii with Saccharomyces cerevisiae. The optimal detoxifying conditions were found to be below an activated charcoal concentration of 5%.

  9. Detoxification mechanism of asbestos materials by microwave treatment.

    Science.gov (United States)

    Yoshikawa, N; Kashimura, K; Hashiguchi, M; Sato, M; Horikoshi, S; Mitani, T; Shinohara, N

    2015-03-02

    The detoxification mechanism of asbestos materials was investigated through simulations and experiments. The permittivities of pure CaO and Mg3Si4O12, as quasi-asbestos materials, were measured using the cavity perturbation method. The real and imaginary parts of the relative permittivity (ɛr' and ɛr″) of CaO are functions of temperature, and numerical simulations revealed the thermal distributions in an electromagnetic field with respect to both asbestos shape and material configuration based on permittivity. Optical microscopic observation revealed that the thickness of chrysotile fibers decreased as a result of CaO heating. The heating mechanism of asbestos materials has been determined using CaO phase, and the detoxification mechanism of asbestos materials was discussed based on the heating mechanism.

  10. Review of mycotoxin reduction in food and feed: from prevention in the field to detoxification by adsorption or transformation.

    Science.gov (United States)

    Jard, G; Liboz, T; Mathieu, F; Guyonvarc'h, A; Lebrihi, A

    2011-11-01

    Mycotoxins are secondary metabolites present worldwide in agricultural commodities and produced by filamentous fungi that cause a toxic response (mycotoxicosis) when ingested by animals. Prevention of mycotoxicoses includes pre- and post-harvest strategies. The best way to reduce the mycotoxin content in food and feed is the prevention of mycotoxin formation in the field, but this is often not sufficient, so other methods are needed. To decontaminate and/or detoxify mycotoxin-contaminated food and feed, the most prevalent approach in the feed industry is the inclusion of sorbent materials in the feed thus obtaining more or less selective removal of toxins by adsorption during passage through the gastrointestinal tract. Another reliable approach is to add enzymes or microorganisms capable of detoxifying some mycotoxins. Through a comprehensive review of published reports on the strategies for mycotoxin removal, this present work aims to update our understanding of mycotoxin removal. It provides an insight into the detoxification of mycotoxin present in food and feed. In the future, more emphasis needs to be placed on adsorption of mycotoxins in the gastrointestinal tract. Concerning the enzymatic transformation of mycotoxins, further efforts are required in understanding detoxification reactions, the toxicity of transformation products and in the characterization of enzymes responsible for transformations.

  11. Membrane phospholipid augments cytochrome P4501a enzymatic activity by modulating structural conformation during detoxification of xenobiotics.

    Directory of Open Access Journals (Sweden)

    Manik C Ghosh

    Full Text Available Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites. Accumulated body of evidence indicates that phospholipids play a crucial role in determining the enzymatic activity of cytochrome P450 in the microenvironment by modulating its structure during detoxification; however, the structure-function relationship of cytochrome P4501A, a family of enzymes responsible for degrading lipophilic aromatic hydrocarbons, is still not well defined. Inducibility of cytochrome P4501A in cultured catfish hepatocytes in response to carbofuran, a widely used pesticide around the world, was studied earlier in our laboratory. In this present investigation, we observed that treating catfish with carbofuran augmented total phospholipid in the liver. We examined the role of phospholipid on the of cytochrome P4501A-marker enzyme which is known as ethoxyresorufin-O-deethylase (EROD in the context of structure and function. We purified the carbofuran-induced cytochrome P4501A protein from catfish liver. Subsequently, we examined the enzymatic activity of purified P4501A protein in the presence of phospholipid, and studied how the structure of purified protein was influenced in the phospholipid environment. Membrane phospholipid appeared to accelerate the enzymatic activity of EROD by changing its structural conformation and thus controlling the detoxification of xenobiotics. Our study revealed the missing link of how the cytochrome P450 restores its enzymatic activity by changing its structural conformation in the phospholipid microenvironment.

  12. Rice Transcriptome Analysis to Identify Possible Herbicide Quinclorac Detoxification Genes

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    Wenying eXu

    2015-09-01

    Full Text Available Quinclorac is a highly selective auxin-type herbicide, and is widely used in the effective control of barnyard grass in paddy rice fields, improving the world’s rice yield. The herbicide mode of action of quinclorac has been proposed and hormone interactions affect quinclorac signaling. Because of widespread use, quinclorac may be transported outside rice fields with the drainage waters, leading to soil and water pollution and environmental health problems.In this study, we used 57K Affymetrix rice whole-genome array to identify quinclorac signaling response genes to study the molecular mechanisms of action and detoxification of quinclorac in rice plants. Overall, 637 probe sets were identified with differential expression levels under either 6 or 24 h of quinclorac treatment. Auxin-related genes such as GH3 and OsIAAs responded to quinclorac treatment. Gene Ontology analysis showed that genes of detoxification-related family genes were significantly enriched, including cytochrome P450, GST, UGT, and ABC and drug transporter genes. Moreover, real-time RT-PCR analysis showed that top candidate P450 families such as CYP81, CYP709C and CYP72A genes were universally induced by different herbicides. Some Arabidopsis genes for the same P450 family were up-regulated under quinclorac treatment.We conduct rice whole-genome GeneChip analysis and the first global identification of quinclorac response genes. This work may provide potential markers for detoxification of quinclorac and biomonitors of environmental chemical pollution.

  13. Enzymatic Mercury Detoxification: The Regulatory Protein MerR

    CERN Multimedia

    Ctortecka, B; Walsh, C T; Comess, K M

    2002-01-01

    Mercury ions and organomercurial reagents are extremely toxic due to their affinity for thiol groups. Many bacteria contain an elaborate detoxification system for a metabolic conversion of toxic Hg$^{2+}$ or organomercurials to less toxic elemental Hg$^0$. The main components of the enzymatic mercury detoxification (see Fig. 1) are the regulatory protein MerR (mercury responsive genetic switch), the organomercurial lyase MerB (cleavage of carbon mercury bonds), and the mercuric ion reductase MerA (reduction of mercuric ions). In these proteins Hg$^{2+}$ is usually coordinated by the thiol groups of cysteines. We utilize the nuclear quadrupole interaction (NQI) of ${\\rm^{199m}}$Hg detected by time differential perturbed angular correlation (TDPAC) to identify the Hg metal site geometries in these proteins in order to elucidate the molecular origin of the ultrasensitivity, selectivity and reaction mechanism of this detoxification system. The short lived TDPAC probe ${\\rm^{199m}}$Hg ($\\tau_{1/2} =$ 43 min) is su...

  14. Effect of Semecarpus anacardium Linn. nut extract on mammary and hepatic expression of xenobiotic enzymes in DMBA-induced mammary carcinoma.

    Science.gov (United States)

    Mathivadhani, P; Shanthi, P; Sachdanandam, P

    2007-05-01

    Breast cancer is the major cause of cancer death in women worldwide. Environmental risk factors particularly genotoxic chemicals such as polycyclic aromatic hydrocarbons (PAH) are likely to account for a much higher mortality. Xenobiotic metabolising enzymes in breast tissue are potentially important determinants in both the susceptibility to the mutagenic effects of chemical carcinogens and in the response of breast tumors to chemotherapy. The well known carcinogen 7,12-dimethylbenz(a)anthrazene of PAH family was given (25mg/ml) orally by gastric intubation to induce mammary carcinoma in Sprague-Dawley rats. Increased level of cytochromes (P(450), B(5)), EROD, PROD activities, Phase I biotransformation enzymes (NADPH-cytochrome (P(450)) reductase, NADPH-cytochrome (b(5)) reductase, epoxide hydrolase) and expression of CYP1A1, CYP1A2 and CYP1B1 in liver and breast tissue microsome were documented in DMBA treated group. Phase II enzyme activities (glutathione-S-transferase, gluthatione peroxidase, gluatathione reductase, UDP-glucuronyl transferease) were decreased markedly in cancerous rats. The nut extract of Semecarpus anacardium was administered orally (200mg/kg body wt/day) to the mammary carcinoma rats for 14 days. Drug treatment restored back the altered Phase I and II biotransformation enzymes thus achieving complete detoxification of the carcinogen. These findings suggest that S. anacardium can effectively modulate the catabolism of xenobiotics in rats. Copyright © 2007. Published by Elsevier B.V.

  15. The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS prisons project pilot study: protocol for a randomised controlled trial comparing dihydrocodeine and buprenorphine for opiate detoxification

    Directory of Open Access Journals (Sweden)

    Dalton Richard

    2007-01-01

    Full Text Available Abstract Background In the United Kingdom (UK, there is an extensive market for the class 'A' drug heroin. Many heroin users spend time in prison. People addicted to heroin often require prescribed medication when attempting to cease their drug use. The most commonly used detoxification agents in UK prisons are buprenorphine, dihydrocodeine and methadone. However, national guidelines do not state a detoxification drug of choice. Indeed, there is a paucity of research evaluating the most effective treatment for opiate detoxification in prisons. This study seeks to address the paucity by evaluating routinely used interventions amongst drug using prisoners within UK prisons. Methods/Design The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS Prisons Pilot Study will use randomised controlled trial methodology to compare the open use of buprenorphine and dihydrocodeine for opiate detoxification, given in the context of routine care, within HMP Leeds. Prisoners who are eligible and give informed consent will be entered into the trial. The primary outcome measure will be abstinence status at five days post detoxification, as determined by a urine test. Secondary outcomes during the detoxification and then at one, three and six months post detoxification will be recorded.

  16. Do heavy metals and metalloids influence the detoxification of organic xenobiotics in plants?

    Science.gov (United States)

    Schröder, Peter; Lyubenova, Lyudmila; Huber, Christian

    2009-11-01

    Mixed pollution with trace elements and organic industrial compounds is characteristic for many spill areas and dumping sites. The danger for the environment and human health from such sites is large, and sustainable remediation strategies are urgently needed. Phytoremediation seems to be a cheap and environmentally sound option for the removal of unwanted compounds, and the hyperaccumulation of trace elements and toxic metals is seemingly independent from the metabolism of organic xenobiotics. However, stress reactions, ROS formation and depletion of antioxidants will also cause alterations in xenobiotic detoxification. Here, we investigate the capability of plants to detoxify chlorophenols via glutathione conjugation in a mixed pollution situation. Typha latifolia and Phragmites australis plants for the present study were grown under greenhouse conditions in experimental ponds. A Picea abies L. suspension culture was grown in a growth chamber. Cadmium sulphate, sodium arsenate and lead chloride in concentrations from 10 to 500 microM were administered to plants. Enzymes of interest for the present study were: glutathione transferase (GST), glutathione reductase, ascorbate peroxidase and peroxidase. Measurements were performed according to published methods. GST spectrophotometric assays included the model substrates CDNB, DCNB, NBC, NBoC and the herbicide Fluorodifen. Heavy metals lead to visible stress symptoms in higher plants. Besides one long-term experiment of 72 days duration, the present study shows time and concentration-dependent plant alterations already after 24 and 72 h Cd incubation. P. abies spruce cell cultures react to CdSO(4) and Na(2)HAsO(4) with an oxidative burst, similar to that observed after pathogen attack or elicitor treatment. Cd application resulted in a reduction in GSH and GSSG contents. When a heavy metal mixture containing Na(2)HAsO(4), CdSO(4) and PbCl(2) was applied to cultures, both GSH and GSSG levels declined. Incubation with

  17. Detoxification of rats subjected to nickel chloride by a biomaterial-based carbonated orthophosphate.

    Science.gov (United States)

    Boulila, S; El Feki, A; Oudadesse, H; Kallel, C; El Feki, H

    2014-09-01

    Recently, the therapeutic approaches of the detoxification against the metals (nickel) in the body are the use of biomaterials such as carbonated hydroxyapatite. The aim of this study is therefore to analyze the physiological and physicochemical parameters of strain white rats "Wistar" receiving nickel chloride and to study the protective associative of apatite against adverse effects of this metal, and this in comparison with control rats. Our results showed that the nickel induced in rats an oxidative stress objectified by elevated levels of thiobarbituric acid-reactive substances and conjugated dienes associated with inhibition of the activity of the antioxidant defense system such as glutathione peroxidase, superoxide dismutase and catalase in the liver, kidney, spleen and erythrocyte. Disorders balances of ferric, phosphocalcic, a renal failure and a liver toxicity were observed in rats exposed to nickel. As well as a significant increase in the rate of nickel in the bones and microcytic anemia was revealed. However, the implantation of carbonated hydroxyapatite in capsule form protects rats intoxicated by the nickel against the toxic effects of this metal by lowering the levels of markers of lipid peroxidation and improving the activities of defense enzymes. Our implantation technique is effective to correct ferric balance and phosphocalcic equilibrium, to protect liver and kidney function, to reduce the rate of bone nickel and to correct anemia. They clearly explain the beneficial and protective of our biomaterial which aims the detoxification of rats receiving nickel by substituting cationic (Ca(2+) by Ni(2+)) and anionic (OH(-) by Cl(-)) confirmed by physicochemical characterization like the IR spectroscopy and X-ray diffraction. These techniques have shown on the one hand a duplication of OH(-) bands (IR) and on the other hand the increase of the volume of the apatite cell after these substitutions (X-ray diffraction).

  18. Detoxification of azo dyes in the context of environmental processes.

    Science.gov (United States)

    Rawat, Deepak; Mishra, Vandana; Sharma, Radhey Shyam

    2016-07-01

    Azo dyes account for >70% of the global industrial demand (∼9 million tons). Owing to their genotoxic/carcinogenic potential, the annual disposal of ∼4,500,000 tons of dyes and/or degraded products is an environmental and socio-economic concern. In comparison to physico-chemical methods, microbe-mediated dye degradation is considered to be low-input, cost-effective and environmentally-safe. However, under different environmental conditions, interactions of chemically diverse dyes with metabolically diverse microbes produce metabolites of varying toxicity. In addition, majority of studies on microbial dye-degradation focus on decolorization with least attention towards detoxification. Therefore, the environmental significance of microbial dye detoxification research of past >3 decades is critically evaluated with reference to dye structure and the possible influence of microbial interactions in different environments. In the absence of ecosystem-based studies, the results of laboratory-based studies on dye degradation, metabolite production and their genotoxic impact on model organisms are used to predict the possible fate and consequences of azo dyes/metabolites in the environment. In such studies, the predominance of fewer numbers of toxicological assays that too at lower levels of biological organization (molecular/cellular/organismic) suggests its limited ecological significance. Based on critical evaluation of these studies the recommendations on inclusion of multilevel approach (assessment at multiple levels of biological organization), multispecies microcosm approach and native species approach in conjunction with identification of dye metabolites have been made for future studies. Such studies will bridge the gap between the fundamental knowledge on dye-microbe-environment interactions and its application to combat dye-induced environmental toxicity. Thus an environmental perspective on dye toxicity in the background of dye structure and effects of

  19. Updates on the treatment of essential hypertension: a summary of AHRQ's comparative effectiveness review of angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and direct renin inhibitors.

    Science.gov (United States)

    Powers, Benjamin; Greene, Laurence; Balfe, Lisa M

    2011-10-01

    In 2007, the Agency for Healthcare Research and Quality (AHRQ) published a comparative effectiveness review (CER) on the benefits and risks of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) for treating essential hypertension in adults. The main findings indicated that the 2 classes of antihypertensive medications caused similar reductions in blood pressure, although higher rates of adverse events, especially cough, were reported by patients treated with ACEIs. In addition, the 2007 review indicated no treatment related differences in lipid levels, glycemic control, or progression of kidney disease among the agents. Since 2007, 39 relevant studies have been published that compare outcomes for adults treated with ACEIs versus ARBs or a drug in one of these 2 classes versus a direct renin inhibitor (DRI). To systematically analyze findings from the new research, AHRQ commissioned and, in June 2011, published an updated comparative effectiveness review on the benefits and risks of agents that target the renin-angiotensin- aldosterone system (RAAS), specifically ACEIs, ARBs, and DRIs. To (a) familiarize health care professionals with the methods and findings from AHRQ's 2011 comparative effectiveness review on ACEIs, ARBs, and DRIs for adults with essential hypertension; (b) provide commentary and encourage consideration of the clinical and managed care applications of the review findings; and (c) identify limitations to the existing research on the benefits and risks of ACEIs, ARBs, and DRIs. Consistent with the findings from AHRQ's 2007 report, the 2011 update indicated no overall differences in blood pressure control, mortality rates, and major cardiovascular events in patients treated with ACEIs versus ARBs. With a low strength of evidence, 2 studies reported a small significantly greater blood pressure reduction for patients treated with the DRI aliskiren versus the ACEI ramipril. Studies evaluating the DRI aliskiren

  20. Generation of Nutrients and Detoxification: Possible Roles of Yeasts in Leaf-Cutting Ant Nests

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    Fernando C. Pagnocca

    2012-02-01

    Full Text Available The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellulolytic enzymes, 44% exhibited pectinolytic activity while 27% and 17% possess enzyme systems for the degradation of protease and amylase, respectively. Galacturonic acid, which had been reported in previous work to be poorly assimilated by the ant fungus and also to have a negative effect on ants’ survival, was assimilated by 64% and 79% of yeasts isolated from nests of A. texana and Acromyrmex respectively. Our results suggest that yeasts found in ant nests may participate in generation of nutrients and removal of potentially toxic compounds, thereby contributing to the stability of the complex microbiota found in the leaf-cutting ant nests.

  1. Assimilation, dissimilation, and detoxification of formaldehyde, a central metabolic intermediate of methylotrophic metabolism.

    Science.gov (United States)

    Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

    2005-01-01

    Methanol is a valuable raw material used in the manufacture of useful chemicals as well as a potential source of energy to replace coal and petroleum. Biotechnological interest in the microbial utilization of methanol has increased because it is an ideal carbon source and can be produced from renewable biomass. Formaldehyde, a cytotoxic compound, is a central metabolic intermediate in methanol metabolism. Therefore, microorganisms utilizing methanol have adopted several metabolic strategies to cope with the toxicity of formaldehyde. Formaldehyde is initially detoxified through trapping by some cofactors, such as glutathione, mycothiol, tetrahydrofolate, and tetrahydromethanopterin, before being oxidized to CO2. Alternatively, free formaldehyde can be trapped by sugar phosphates as the first reaction in the C1 assimilation pathways: the xylulose monophosphate pathway for yeasts and the ribulose monophosphate (RuMP) pathway for bacteria. In yeasts, although formaldehyde generation and consumption takes place in the peroxisome, the cytosolic formaldehyde oxidation pathway also plays a role in formaldehyde detoxification as well as energy formation. The key enzymes of the RuMP pathway are found in a variety of microorganisms including bacteria and archaea. Regulation of the genes encoding these enzymes and their catalytic mechanisms depend on the physiological traits of these organisms during evolution.

  2. Decolourization and detoxification of textile industry wastewater by the laccase-mediator system.

    Science.gov (United States)

    Khlifi, Rim; Belbahri, Lassad; Woodward, Steve; Ellouz, Mariem; Dhouib, Abdelhafidh; Sayadi, Sami; Mechichi, Tahar

    2010-03-15

    Decolourization and detoxification of a textile industry effluent by laccase from Trametes trogii in the presence and the absence of laccase mediators was investigated. Laccase alone was not able to decolourize the effluent efficiently even at the highest enzyme concentration tested: less than 10% decolourization was obtained with 9 U/mL reaction mixture. To enhance effluent decolourization, several potential laccase mediators were tested at concentrations ranging from 0 to 1mM. Most potential mediators enhanced decolourization of the effluent, with 1-hydroxybenzotriazol (HBT) being the most effective. The effect of several physico-chemical parameters that could influence enzyme activity, such as pH, temperature and dye concentration was tested. Optimal decolourization occurred with 20% effluent at pH 5, a temperature of 50 degrees C, and in the presence of 1mM HBT. The toxicities of crude, laccase-HBT treated and laccase-acetosyringone treated effluent were evaluated using the Microtox assay. Only laccase-acetosyringone treated effluent was not toxic; crude and laccase-HBT treated effluent retained toxicity.

  3. Molecular methods for genotyping selected detoxification and DNA repair enzymes / J. Labuschagne

    OpenAIRE

    Labuschagne, Jeanine

    2010-01-01

    The emerging field of personalized medicine and the prediction of side effects experienced due to pharmaceutical drugs is being studied intensively in the post genomic era. The molecular basis of inheritance and disease susceptibility is being unravelled, especially through the use of rapidly evolving new technologies. This in turn facilitates analyses of individual variations in the whole genome of both single subjects and large groups of subjects. Genetic variation is a common occurrence...

  4. Functional Characterization and Expression of Molluscan Detoxification Enzymes and Transporters Involved in Dietary Allelochemical Resistance

    Science.gov (United States)

    2008-06-01

    2006, Blanchette et al. 38 2007, Myrnes & Nilsen 2007, Vasconcelos et al. 2007, Doyen et al. 2008) and may prove to be an equally vital adaptive...Chemistry 266:24226- 24231 Vasconcelos VM, Wiegand C, Pflugmacher S (2007) Dynamics ofglutathione S- transferase in Mytilus galloprovincialis exposed to...samples were analyzed using a Eksigent Nano LC 2-D system (Eksigent, Dublin, CA) coupled to an LTQ ion trap mass spectrometer (Thermo- Fisher, San Jose

  5. The structure at 2.4 Å resolution of the protein from gene locus At3g21360, a putative FeII/2-oxo­glutarate-dependent enzyme from Arabidopsis thaliana

    Science.gov (United States)

    Bitto, Eduard; Bingman, Craig A.; Allard, Simon T. M.; Wesenberg, Gary E.; Aceti, David J.; Wrobel, Russell L.; Frederick, Ronnie O.; Sreenath, Hassan; Vojtik, Frank C.; Jeon, Won Bae; Newman, Craig S.; Primm, John; Sussman, Michael R.; Fox, Brian G.; Markley, John L.; Phillips, George N.

    2005-01-01

    The crystal structure of the gene product of At3g21360 from Arabidopsis thaliana was determined by the single-wavelength anomalous dispersion method and refined to an R factor of 19.3% (R free = 24.1%) at 2.4 Å resolution. The crystal structure includes two monomers in the asymmetric unit that differ in the conformation of a flexible domain that spans residues 178–230. The crystal structure confirmed that At3g21360 encodes a protein belonging to the clavaminate synthase-like superfamily of iron(II) and 2-oxoglutarate-dependent enzymes. The metal-binding site was defined and is similar to the iron(II) binding sites found in other members of the superfamily. PMID:16511070

  6. Efficient catalytic phosphate diester cleavage by the synergetic action of two Cu(II) centers in a dinuclear cis-diaqua Cu(II) calix[4]arene enzyme model

    NARCIS (Netherlands)

    Molenveld, Peter; Engbersen, Johan F.J.; Kooijman, Huub; Spek, Anthony L.; Reinhoudt, David N.

    1998-01-01

    A calix[4]arene derivative 2-[Cu(II)]2 functionalized with two cis-diaqua Cu(II) centers at the distal positions of the upper rim was synthesized and investigated as a model for dinuclear metalloenzymes that catalyze chemical transformations of phosphate esters. The flexible dinuclear calix[4]arene

  7. Opioid-induced hyperalgesia and rapid opioid detoxification after tacrolimus administration.

    Science.gov (United States)

    Siniscalchi, Antonio; Piraccini, Emanuele; Miklosova, Zuzana; Taddei, Stefania; Faenza, Stefano; Martinelli, Gerardo

    2008-02-01

    Opioids can induce central sensitization and hyperalgesia, referred to as "opioid-induced hyperalgesia." Our report describes a patient who underwent intestinal transplant followed by immunosuppressant-related neuropathic pain. Her pain was treated with limited success over the course of 3 yr with different therapies, including i.v. morphine. She developed opioid-induced hyperalgesia, which was successfully treated with rapid detoxification under general anesthesia. Detoxification improved her quality of life, including the ability to resume physiotherapy. Six months after treatment, she remained opioid free. Our experience suggests that rapid detoxification under general anesthesia may be an effective treatment for opioid-induced hyperalgesia and merits comparison to traditional detoxification methods.

  8. High dietary sodium blunts affects of angiotensin-converting enzyme inhibition on vascular angiotensin I-to-angiotensin II conversion in rats

    NARCIS (Netherlands)

    Kocks, Menno J A; Buikema, Hendrik; Gschwend, Simone; Boomsma, Frans; de Zeeuw, Dick; Navis, Gerjan

    2003-01-01

    High sodium intake blunts the efficacy of angiotensin (Ang)-converting enzyme (ACE) inhibition (ACEi), but the underlying mechanism is incompletely characterized. High sodium has been reported to increase vascular expression and vascular activity of ACE. To investigate whether high-dietary sodium-in

  9. High dietary sodium blunts effects of angiotensin-converting enzyme inhibition on vascular angiotensin I-to-angiotensin II conversion in rats

    NARCIS (Netherlands)

    Kocks, MJA; Buikema, H; Gschwend, S; Boomsma, F; de Zeeuw, D; Navis, G

    2003-01-01

    High sodium intake blunts the efficacy of angiotensin (Ang)-converting enzyme (ACE) inhibition (ACEi), but the underlying mechanism is incompletely characterized. High sodium has been reported to increase vascular expression and vascular activity of ACE. To investigate whether high-dietary sodium-in

  10. Subunit Structure and Activity of the Mannitol-Specific Enzyme II of the Escherichia coli Phosphoenolpyruvate-Dependent Phosphotransferase System Solubilized in Detergent

    NARCIS (Netherlands)

    Lolkema, Juke S.; Robillard, George T.

    1990-01-01

    The original proposal stating that P-enolpyruvate-dependent mannitol phosphorylation is catalyzed by the monomeric form of the bacterial phosphotransferase enzyme IImtl, which would be the form predominantly existing in the phospholipid bilayer, whereas mannitol/mannitol-P exchange would depend on

  11. High dietary sodium blunts affects of angiotensin-converting enzyme inhibition on vascular angiotensin I-to-angiotensin II conversion in rats

    NARCIS (Netherlands)

    Kocks, Menno J A; Buikema, Hendrik; Gschwend, Simone; Boomsma, Frans; de Zeeuw, Dick; Navis, Gerjan

    2003-01-01

    High sodium intake blunts the efficacy of angiotensin (Ang)-converting enzyme (ACE) inhibition (ACEi), but the underlying mechanism is incompletely characterized. High sodium has been reported to increase vascular expression and vascular activity of ACE. To investigate whether high-dietary sodium-in

  12. High dietary sodium blunts affects of angiotensin-converting enzyme inhibition on vascular angiotensin I-to-angiotensin II conversion in rats

    NARCIS (Netherlands)

    Kocks, Menno J A; Buikema, Hendrik; Gschwend, Simone; Boomsma, Frans; de Zeeuw, Dick; Navis, Gerjan

    2003-01-01

    High sodium intake blunts the efficacy of angiotensin (Ang)-converting enzyme (ACE) inhibition (ACEi), but the underlying mechanism is incompletely characterized. High sodium has been reported to increase vascular expression and vascular activity of ACE. To investigate whether high-dietary

  13. High dietary sodium blunts effects of angiotensin-converting enzyme inhibition on vascular angiotensin I-to-angiotensin II conversion in rats

    NARCIS (Netherlands)

    Kocks, MJA; Buikema, H; Gschwend, S; Boomsma, F; de Zeeuw, D; Navis, G

    2003-01-01

    High sodium intake blunts the efficacy of angiotensin (Ang)-converting enzyme (ACE) inhibition (ACEi), but the underlying mechanism is incompletely characterized. High sodium has been reported to increase vascular expression and vascular activity of ACE. To investigate whether high-dietary

  14. Sequence Analysis of Insecticide Action and Detoxification-Related Genes in the Insect Pest Natural Enemy Pardosa pseudoannulata.

    Directory of Open Access Journals (Sweden)

    Xiangkun Meng

    Full Text Available The pond wolf spider Pardosa pseudoannulata, an important natural predatory enemy of rice planthoppers, is found widely distributed in paddy fields. However, data on the genes involved in insecticide action, detoxification, and response are very limited for P. pseudoannulata, which inhibits the development and appropriate use of selective insecticides to control insect pests on rice. We used transcriptome construction from adult spider cephalothoraxes to analyze and manually identify genes enconding metabolic enzymes and target receptors related to insecticide action and detoxification, including 90 cytochrome P450s, 14 glutathione S-transferases (GSTs, 17 acetylcholinesterases (AChEs, 17 nicotinic acetylcholine receptors (nAChRs, and 17 gamma-aminobutyric acid (GABA receptors, as well as 12 glutamate-gated chloride channel (GluCl unigenes. Sequence alignment and phylogenetic analysis revealed the different subclassifications of P450s and GSTs, some important sequence diversities in nAChRs and GABA receptors, polymorphism in AChEs, and high similarities in GluCls. For P450s in P. pseudoannulata, the number of unigenes belonging to the CYP2 clade was much higher than that in CYP3 and CYP4 clades. The results differed from insects in which most P450 genes were in CYP3 and CYP4 clades. For GSTs, most unigenes belonged to the delta and sigma classes, and no epsilon GST class gene was found, which differed from the findings for insects and acarina. Our results will be useful for studies on insecticide action, selectivity, and detoxification in the spider and other related animals, and the sequence differences in target genes between the spider and insects will provide important information for the design of selective insecticides.

  15. Glutathione S-Transferase (GST Gene Diversity in the Crustacean Calanus finmarchicus--Contributors to Cellular Detoxification.

    Directory of Open Access Journals (Sweden)

    Vittoria Roncalli

    Full Text Available Detoxification is a fundamental cellular stress defense mechanism, which allows an organism to survive or even thrive in the presence of environmental toxins and/or pollutants. The glutathione S-transferase (GST superfamily is a set of enzymes involved in the detoxification process. This highly diverse protein superfamily is characterized by multiple gene duplications, with over 40 GST genes reported in some insects. However, less is known about the GST superfamily in marine organisms, including crustaceans. The availability of two de novo transcriptomes for the copepod, Calanus finmarchicus, provided an opportunity for an in depth study of the GST superfamily in a marine crustacean. The transcriptomes were searched for putative GST-encoding transcripts using known GST proteins from three arthropods as queries. The identified transcripts were then translated into proteins, analyzed for structural domains, and annotated using reciprocal BLAST analysis. Mining the two transcriptomes yielded a total of 41 predicted GST proteins belonging to the cytosolic, mitochondrial or microsomal classes. Phylogenetic analysis of the cytosolic GSTs validated their annotation into six different subclasses. The predicted proteins are likely to represent the products of distinct genes, suggesting that the diversity of GSTs in C. finmarchicus exceeds or rivals that described for insects. Analysis of relative gene expression in different developmental stages indicated low levels of GST expression in embryos, and relatively high expression in late copepodites and adult females for several cytosolic GSTs. A diverse diet and complex life history are factors that might be driving the multiplicity of GSTs in C. finmarchicus, as this copepod is commonly exposed to a variety of natural toxins. Hence, diversity in detoxification pathway proteins may well be key to their survival.

  16. Glutathione S-Transferase (GST) Gene Diversity in the Crustacean Calanus finmarchicus – Contributors to Cellular Detoxification

    Science.gov (United States)

    Roncalli, Vittoria; Cieslak, Matthew C.; Passamaneck, Yale; Christie, Andrew E.; Lenz, Petra H.

    2015-01-01

    Detoxification is a fundamental cellular stress defense mechanism, which allows an organism to survive or even thrive in the presence of environmental toxins and/or pollutants. The glutathione S-transferase (GST) superfamily is a set of enzymes involved in the detoxification process. This highly diverse protein superfamily is characterized by multiple gene duplications, with over 40 GST genes reported in some insects. However, less is known about the GST superfamily in marine organisms, including crustaceans. The availability of two de novo transcriptomes for the copepod, Calanus finmarchicus, provided an opportunity for an in depth study of the GST superfamily in a marine crustacean. The transcriptomes were searched for putative GST-encoding transcripts using known GST proteins from three arthropods as queries. The identified transcripts were then translated into proteins, analyzed for structural domains, and annotated using reciprocal BLAST analysis. Mining the two transcriptomes yielded a total of 41 predicted GST proteins belonging to the cytosolic, mitochondrial or microsomal classes. Phylogenetic analysis of the cytosolic GSTs validated their annotation into six different subclasses. The predicted proteins are likely to represent the products of distinct genes, suggesting that the diversity of GSTs in C. finmarchicus exceeds or rivals that described for insects. Analysis of relative gene expression in different developmental stages indicated low levels of GST expression in embryos, and relatively high expression in late copepodites and adult females for several cytosolic GSTs. A diverse diet and complex life history are factors that might be driving the multiplicity of GSTs in C. finmarchicus, as this copepod is commonly exposed to a variety of natural toxins. Hence, diversity in detoxification pathway proteins may well be key to their survival. PMID:25945801

  17. Sequence Analysis of Insecticide Action and Detoxification-Related Genes in the Insect Pest Natural Enemy Pardosa pseudoannulata.

    Science.gov (United States)

    Meng, Xiangkun; Zhang, Yixi; Bao, Haibo; Liu, Zewen

    2015-01-01

    The pond wolf spider Pardosa pseudoannulata, an important natural predatory enemy of rice planthoppers, is found widely distributed in paddy fields. However, data on the genes involved in insecticide action, detoxification, and response are very limited for P. pseudoannulata, which inhibits the development and appropriate use of selective insecticides to control insect pests on rice. We used transcriptome construction from adult spider cephalothoraxes to analyze and manually identify genes enconding metabolic enzymes and target receptors related to insecticide action and detoxification, including 90 cytochrome P450s, 14 glutathione S-transferases (GSTs), 17 acetylcholinesterases (AChEs), 17 nicotinic acetylcholine receptors (nAChRs), and 17 gamma-aminobutyric acid (GABA) receptors, as well as 12 glutamate-gated chloride channel (GluCl) unigenes. Sequence alignment and phylogenetic analysis revealed the different subclassifications of P450s and GSTs, some important sequence diversities in nAChRs and GABA receptors, polymorphism in AChEs, and high similarities in GluCls. For P450s in P. pseudoannulata, the number of unigenes belonging to the CYP2 clade was much higher than that in CYP3 and CYP4 clades. The results differed from insects in which most P450 genes were in CYP3 and CYP4 clades. For GSTs, most unigenes belonged to the delta and sigma classes, and no epsilon GST class gene was found, which differed from the findings for insects and acarina. Our results will be useful for studies on insecticide action, selectivity, and detoxification in the spider and other related animals, and the sequence differences in target genes between the spider and insects will provide important information for the design of selective insecticides.

  18. Study on Atherosclerosis Treated with Theory of Detoxification

    Institute of Scientific and Technical Information of China (English)

    Xu Yingchun; Wang Hualiang; Ding Jing

    2006-01-01

    Starting with the contents, classification and pathogenic characteristics of the toxic pathogen and combining the modem medical research on the correlation of atherosclerosis with inflammation and immune reaction,authors have studied and expounded the interrelationship between the toxic pathogen and atherosclerosis.The toxic pathogen affecting the whole pathological process of atherosclerosis is a key factor for the disease to remain lingering and a cause of various cardiocerebrovascular diseases. Detoxification can be used to treat atherosclerosis so as to enhance the toxin-removing ability of the body and resist the damage to the body from the toxic pathogen.

  19. PEI detoxification of pretreated spruce for high solids ethanol fermentation

    DEFF Research Database (Denmark)

    Cannella, David; Sveding, Per Viktor; Jørgensen, Henning

    2014-01-01

    ethanol production from spruce performing the whole process, from pretreatment to hydrolysis and fermentation, at 30% dry matter (equivalent to similar to 20% WIS). Hydrolysis and fermentation was performed in a horizontal free fall mixing reactor enabling efficient mixing at high solids loadings....... In batch simultaneous saccharification and fermentation (SSF), up to 76% cellulose to ethanol conversion was achieved resulting in a concentration of 51 g/kg of ethanol. Key to obtaining this high ethanol yield at these conditions was the use of a detoxification technology based on applying a soluble...

  20. Proteomic and Physiological Analyses Reveal Detoxification and Antioxidation Induced by Cd Stress in Kandelia candel Roots

    Institute of Scientific and Technical Information of China (English)

    Zhaoxia Weng; Lingxia Wang; Fanglin Tan; Li Huang; Jianhong Xing; Shipin Chen; Chilien Cheng

    2012-01-01

    The heavy metal Cadmium (Cd),added to the water bodies through weathering of rocks and human activities,constitutes one of the major environmental pollutants toxic to plants.This study examines the proteome changes in roots of actively growing Kandelia candel (L.) Druce when challenged with Cd.This mangrove-like species proliferates in estuaries and bays and is a potential choice for phytoremediation of Cd.A total of 53 proteins were up-or down-regulated following a short-term Cd treatment.The identities of the differentially expressed proteins were determined by MALDI-TOF/TOF.Approximately half of the up-regulated proteins are involved in oxidative response,including antioxidant enzymes,enzymes required for glutathione biosynthesis,enzymes in TCA and PPP cycles for generating ATP,NADH and NADPH.These results support the prediction that a prompt antioxidative response is necessary for the reduction of the oxidative stress caused by Cd and set the stage for further investigating of Cd up-regulated proteins in Kandelia candel.In summary,this investigation of global proteomic changes in K.candel roots reveals a complex cellular network affected by Cd stress.The network covers a broad range of metabolic processes,including protein synthesis,antioxidative/detoxifying reactions,energy generation,and metabolites production against Cd stress.Particularly important,our results support the predicted key roles of glutathione biosynthesis,ascorbate-glutathione cycle and antioxidative defense system in Cd detoxification in K.candel roots.This understanding is necessary for developing the woody plant K.candel for phytoremediation of Cd and other heavy metals and may be critical for maintaining health mangrove ecology.

  1. Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts.

    Science.gov (United States)

    De Fine Licht, Henrik H; Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Nygaard, Sanne; Roepstorff, Peter; Boomsma, Jacobus J

    2013-01-08

    Leaf-cutting ants combine large-scale herbivory with fungus farming to sustain advanced societies. Their stratified colonies are major evolutionary achievements and serious agricultural pests, but the crucial adaptations that allowed this mutualism to become the prime herbivorous component of neotropical ecosystems has remained elusive. Here we show how coevolutionary adaptation of a specific enzyme in the fungal symbiont has helped leaf-cutting ants overcome plant defensive phenolic compounds. We identify nine putative laccase-coding genes in the fungal genome of Leucocoprinus gongylophorus cultivated by the leaf-cutting ant Acromyrmex echinatior. One of these laccases (LgLcc1) is highly expressed in the specialized hyphal tips (gongylidia) that the ants preferentially eat, and we confirm that these ingested laccase molecules pass through the ant guts and remain active when defecated on the leaf pulp that the ants add to their gardens. This accurate deposition ensures that laccase activity is highest where new leaf material enters the fungus garden, but where fungal mycelium is too sparse to produce extracellular enzymes in sufficient quantities to detoxify phenolic compounds. Phylogenetic analysis of LgLcc1 ortholog sequences from symbiotic and free-living fungi revealed significant positive selection in the ancestral lineage that gave rise to the gongylidia-producing symbionts of leaf-cutting ants and their non-leaf-cutting ant sister group. Our results are consistent with fungal preadaptation and subsequent modification of a particular laccase enzyme for the detoxification of secondary plant compounds during the transition to active herbivory in the ancestor of leaf-cutting ants between 8 and 12 Mya.

  2. Synthesis and evaluation of the complex-forming ability of hydroxypyranones and hydroxypyridinones with Ni (II) as possible inhibitors for urease enzyme in Helicobacter pylori.

    Science.gov (United States)

    Palizban, Abbasali; Saghaie, Lotfollah

    2016-07-01

    The complex-forming ability of 2-methyl-3-hydroxypyran-4-one (1a), 2-ethyl-3-hydroxypyran-4-one (1b), 1,2-dimethyl-3-hydroxypyridin-4-one (4a) and 1-ethyl-2-methyl-3-hydroxypyridin-4-one (4b) with nickel(Ni(II)) were characterized by infrared, ultraviolet, proton nuclear magnetic resonance spectroscopy and melting point. The mole-ratio of nickel:ligands was analyzed by atomic-absorption-spectrometry. The partition-coefficients (KOW) of the compounds were also determined. The binding of ligands with Ni(II) are through deprotonated hydroxyl group (-O(-), disapeared at 3259 cm(-1)) and ioan-pairs of carbonyl group (=CO(.), shifted from 1650 to 1510-1515 cm(-1)). The characterization of complex geometry for bis-(2-methyl-3-hydroxypyranonato)Ni(II) (5a) and bis-(2-ethyl-3-hydroxypyranonato)Ni(II) (5b) predicted to be square-planer while for bis-(1,2-dimethyl-3-hydroxypyridinonato)Ni(II) (5c) and bis-(1-ethyl-2-methyl-3-hydroxypyridinonato)Ni(II) (5d) distorted to tetrahedral-geometry. Inhibitors of Helicobacter pylori urease are nickel chelators. The compounds 1a, 4a and 4b are likely suitable ligands with complex forming-ability to make complexes of 5a, 5c and 5d with nickel. The KOW values show the compound 5c with low partition-coefficient is more suitable ligand with lower penetration from GI lumen. Future studies demand to find out the biological activity of developed compounds on H. pylori.

  3. Synthesis and evaluation of the complex-forming ability of hydroxypyranones and hydroxypyridinones with Ni (II as possible inhibitors for urease enzyme in Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Abbasali Palizban

    2016-01-01

    Full Text Available The complex-forming ability of 2-methyl-3-hydroxypyran-4-one ( 1a , 2-ethyl-3-hydroxypyran-4-one ( 1b , 1,2-dimethyl-3-hydroxypyridin-4-one ( 4a and 1-ethyl-2-methyl-3- hydroxypyridin-4-one ( 4b with nickel(Ni(II were characterized by infrared, ultraviolet, proton nuclear magnetic resonance spectroscopy and melting point. The mole-ratio of nickel:ligands was analyzed by atomic-absorption-spectrometry. The partition-coefficients (K OW of the compounds were also determined. The binding of ligands with Ni(II are through deprotonated hydroxyl group (-O - , disapeared at 3259 cm -1 and ioan-pairs of carbonyl group (=CO . , shifted from 1650 to 1510-1515 cm -1 . The characterization of complex geometry for bis-(2-methyl-3-hydroxypyranonatoNi(II ( 5a and bis-(2-ethyl-3-hydroxypyranonatoNi(II ( 5b predicted to be square-planer while for bis-(1,2-dimethyl-3-hydroxypyridinonatoNi(II ( 5c and bis-(1-ethyl-2-methyl-3-hydroxypyridinonatoNi(II ( 5d distorted to tetrahedral-geometry. Inhibitors of Helicobacter pylori urease are nickel chelators. The compounds 1a , 4a and 4b are likely suitable ligands with complex forming-ability to make complexes of 5a , 5c and 5d with nickel. The K OW values show the compound 5c with low partition-coefficient is more suitable ligand with lower penetration from GI lumen. Future studies demand to find out the biological activity of developed compounds on H. pylori.

  4. Mechanisms of Cellular Uptake of Thrombin-Antithrombin II Complexes Role of the Low-Density Lipoprotein Receptor-Related Protein as a Serpin-Enzyme Complex Receptor.

    Science.gov (United States)

    Strickland, D K; Kounnas, M Z

    1997-01-01

    Serine proteinase inhibitors (serpins) such as antithrombin III inhibit target proteinases by forming a stable complexwith the enzyme. Once formed, several serpin-enzyme complexes (SECs) are removed from the circulation by a receptor, termed the SEC receptor, that is present in the liver. Until recently, the identity of this clearance receptor remained unknown; however, data are now available that strongly implicates one member of the low-density lipoprotein (LDL) receptor family as a candidate for the SEC receptor. This receptor, known as the LDL receptor-related protein (LRP), is a prominent liver receptor that is known to bind numerous ligands that include proteinase-inhibitor complexes, matrix proteins, and certain apolipoprotein E- and lipoprotein lipase-enriched lipoproteins. © 1997, Elsevier Science Inc. (Trends Cardiovasc Med 1997;7:9-16).

  5. A heptameric peptide purified from Spirulina sp. gastrointestinal hydrolysate inhibits angiotensin I-converting enzyme- and angiotensin II-induced vascular dysfunction in human endothelial cells.

    Science.gov (United States)

    Heo, Seong-Yeong; Ko, Seok-Chun; Kim, Chang Su; Oh, Gun-Woo; Ryu, Bomi; Qian, Zhong-Ji; Kim, Geunhyung; Park, Won Sun; Choi, Il-Whan; Phan, Thi Tuong Vy; Heo, Soo-Jin; Kang, Do-Hyung; Yi, Myunggi; Jung, Won-Kyo

    2017-05-01

    In this study, a marine microalga Spirulina sp.-derived protein was hydrolyzed using gastrointestinal enzymes to produce an angiotensin I (Ang I)-converting enzyme (ACE) inhibitory peptide. Following consecutive purification, the potent ACE inhibitory peptide was composed of 7 amino acids, Thr-Met‑Glu‑Pro‑Gly‑Lys-Pro (molecular weight, 759 Da). Analysis using the Lineweaver-Burk plot and molecular modeling suggested that the purified peptide acted as a mixed non-competitive inhibitor of ACE. The inhibitory effects of the peptide against the cellular production of vascular dysfunction-related factors induced by Ang II were also investigated. In human endothelial cells, the Ang II-induced production of nitric oxide and reactive oxygen species was inhibited, and the expression of inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1) was downregulated when the cells were cultured with the purified peptide. Moreover, the peptide blocked the activation of p38 mitogen‑activated protein kinase. These results indicated that this Spirulina sp.-derived peptide warrants further investigation as a potential pharmacological inhibitor of ACE and vascular dysfunction.

  6. Iron mediates catalysis of nucleic acid processing enzymes: support for Fe(II) as a cofactor before the great oxidation event.

    Science.gov (United States)

    Okafor, C Denise; Lanier, Kathryn A; Petrov, Anton S; Athavale, Shreyas S; Bowman, Jessica C; Hud, Nicholas V; Williams, Loren Dean

    2017-03-15

    Life originated in an anoxic, Fe2+-rich environment. We hypothesize that on early Earth, Fe2+ was a ubiquitous cofactor for nucleic acids, with roles in RNA folding and catalysis as well as in processing of nucleic acids by protein enzymes. In this model, Mg2+ replaced Fe2+ as the primary cofactor for nucleic acids in parallel with known metal substitutions of metalloproteins, driven by the Great Oxidation Event. To test predictions of this model, we assay the ability of nucleic acid processing enzymes, including a DNA polymerase, an RNA polymerase and a DNA ligase, to use Fe2+ in place of Mg2+ as a cofactor during catalysis. Results show that Fe2+ can indeed substitute for Mg2+ in catalytic function of these enzymes. Additionally, we use calculations to unravel differences in energetics, structures and reactivities of relevant Mg2+ and Fe2+ complexes. Computation explains why Fe2+ can be a more potent cofactor than Mg2+ in a variety of folding and catalytic functions. We propose that the rise of O2 on Earth drove a Fe2+ to Mg2+ substitution in proteins and nucleic acids, a hypothesis consistent with a general model in which some modern biochemical systems retain latent abilities to revert to primordial Fe2+-based states when exposed to pre-GOE conditions.

  7. Reactions of the class II peroxidases, lignin peroxidase and Arthromyces ramosus peroxidase, with hydrogen peroxide. Catalase-like activity, compound III formation, and enzyme inactivation.

    Science.gov (United States)

    Hiner, Alexander N P; Hernández-Ruiz, Josefa; Rodríguez-López, José Neptuno; García-Cánovas, Francisco; Brisset, Nigel C; Smith, Andrew T; Arnao, Marino B; Acosta, Manuel

    2002-07-26

    The reactions of the fungal enzymes Arthromyces ramosus peroxidase (ARP) and Phanerochaete chrysosporium lignin peroxidase (LiP) with hydrogen peroxide (H(2)O(2)) have been studied. Both enzymes exhibited catalase activity with hyperbolic H(2)O(2) concentration dependence (K(m) approximately 8-10 mm, k(cat) approximately 1-3 s(-1)). The catalase and peroxidase activities of LiP were inhibited within 10 min and those of ARP in 1 h. The inactivation constants were calculated using two independent methods; LiP, k(i) approximately 19 x 10(-3) s(-1); ARP, k(i) approximately 1.6 x 10(-3) s(-1). Compound III (oxyperoxidase) was detected as the majority species after the addition of H(2)O(2) to LiP or ARP, and its formation was accompanied by loss of enzyme activity. A reaction scheme is presented which rationalizes the turnover and inactivation of LiP and ARP with H(2)O(2). A similar model is applicable to horseradish peroxidase. The scheme links catalase and compound III forming catalytic pathways and inactivation at the level of the [compound I.H(2)O(2)] complex. Inactivation does not occur from compound III. All peroxidases studied to date are sensitive to inactivation by H(2)O(2), and it is suggested that the model will be generally applicable to peroxidases of the plant, fungal, and prokaryotic superfamily.

  8. Identification of essential histidine residues involved in heme binding and Hemozoin formation in heme detoxification protein from Plasmodium falciparum.

    Science.gov (United States)

    Nakatani, Keisuke; Ishikawa, Haruto; Aono, Shigetoshi; Mizutani, Yasuhisa

    2014-08-20

    Malaria parasites digest hemoglobin within a food vacuole to supply amino acids, releasing the toxic product heme. During the detoxification, toxic free heme is converted into an insoluble crystalline form called hemozoin (Hz). Heme detoxification protein (HDP) in Plasmodium falciparum is one of the most potent of the hemozoin-producing enzymes. However, the reaction mechanisms of HDP are poorly understood. We identified the active site residues in HDP using a combination of Hz formation assay and spectroscopic characterization of mutant proteins. Replacement of the critical histidine residues His122, His172, His175, and His197 resulted in a reduction in the Hz formation activity to approximately 50% of the wild-type protein. Spectroscopic characterization of histidine-substituted mutants revealed that His122 binds heme and that His172 and His175 form a part of another heme-binding site. Our results show that the histidine residues could be present in the individual active sites and could be ligated to each heme. The interaction between heme and the histidine residues would serve as a molecular tether, allowing the proper positioning of two hemes to enable heme dimer formation. The heme dimer would act as a seed for the crystal growth of Hz in P. falciparum.

  9. Exploring the potential of fungal-bacterial consortium for low-cost biodegradation and detoxification of textile effluent

    Directory of Open Access Journals (Sweden)

    Lade Harshad

    2016-12-01

    Full Text Available In the present study, the enrichment and isolation of textile effluent decolorizing bacteria were carried out in wheat bran (WB medium. The isolated bacterium Providencia rettgeri strain HSL1 was then tested for decolorization of textile effluent in consortium with a dyestuff degrading fungus Aspergillus ochraceus NCIM 1146. Decolorization study suggests that A. ochraceus NCIM 1146 and P. rettgeri strain HSL1 alone re moves only 6 and 32% of textile effluent American Dye Manufacturing Institute respectively in 30 h at 30 ±0.2°C of microaerophilic incubation, while the fungal-bacterial consortium does 92% ADMI removal within the same time period. The fungal-bacterial consortium exhibited enhanced decolorization rate due to the induction in activities of catalytic enzymes laccase (196%, lignin peroxidase (77%, azoreductase (80% and NADH-DCIP reductase (84%. The HPLC analysis confirmed the biodegradation of textile effluent into various metabolites. Detoxification studies of textile effluent before and after treatment with fungal-bacterial consortium revealed reduced toxicity of degradation metabolites. The efficient degradation and detoxification by fungal-bacterial consortium pre-grown in agricultural based medium thus suggest a promising approach in designing low-cost treatment technologies for textile effluent.

  10. Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Zidong Donna [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

    2014-01-01

    Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. - Highlights: • Utilized a graded CR model in male mice • The mRNA profiles of xenobiotic processing genes (XPGs) in liver were investigated. • CR up-regulates many phase-II enzymes. • CR tends to feminize the mRNA profiles of XPGs.

  11. Characterization and profiling of hepatic cytochromes P450 and phase II xenobiotic-metabolizing enzymes in beluga whales (Delphinapterus leucas) from the St. Lawrence River Estuary and the Canadian Arctic.

    Science.gov (United States)

    McKinney, Melissa A; Arukwe, Augustine; De Guise, Sylvain; Martineau, Daniel; Béland, Pierre; Dallaire, André; Lair, Stéphane; Lebeuf, Michel; Letcher, Robert J

    2004-07-30

    Cytochromes P450 (CYP, phase I) and conjugating (phase II) enzymes can be induced by and influence the toxicokinetics (metabolism) and toxicity of xenobiotic contaminants in exposed organisms. Beluga whale (Delphinapterus leucas) from the endangered St. Lawrence (SL) River Estuary population exhibit deleterious health effects and various severe pathologies that have been associated with contaminant exposure. In contrast, such effects (e.g. reproductive and immunological impairment) are generally less frequent in less exposed populations in the Canadian Arctic (CA). In the present study, opportunistic sampling resulted in the collection immediately after death of liver tissue from a single female neonate SL beluga (SL6) and male and female CA beluga (n=10) from the Arviat region of western Hudson Bay, in addition to sampling of stranded carcasses of male and female SL beluga (n=5) at least 12 h postmortem. We immunologically characterized cross-reactive proteins of hepatic microsomal CYP1A, CYP2B, CYP3A, CYP2E, epoxide hydrolase (EH) and uridine diphosphoglucuronosyl transferase (UDPGT) isozymes. Cross-reactive proteins were found in all SL and CA beluga using anti-rat CYP1A1, anti-rainbow trout CYP3A, anti-human CYP2E1, anti-rabbit EH and anti-human UDPGT1A1 polyclonal antibodies (Abs), whereas faintly cross-reactive CYP2B proteins were only found in SL6 and the CA samples using an anti-rabbit CYP2B1 Ab. In corresponding catalytic activity assessments, only SL6 and all CA beluga microsomal samples exhibited CYP1A-mediated 7-ethoxyresorufin O-deethylase (EROD) activity (51-260 pmol/mg/min), CYP3A-mediated activity (113-899 pmol/mg/min) based on the formation of 6beta-hydroxytestosterone using a testosterone hydroxylase assay, and UDPGT activity (830-4956 pmol/mg/min) based on 1-naphthylglucuronide formation. The marginal cross-reactivity with the anti-CYP2B1 Ab and lack of catalytically measurable hydroxytestosterone isomers associated with CYP2B-type activity in

  12. Carbasugar probes to explore the enzyme binding pocket at the anomeric position: application to the design of Golgi mannosidase II inhibitors.

    Science.gov (United States)

    Vinader, M V; Afarinkia, K

    2013-01-01

    A methodology is described for the highly efficient and divergent synthesis of pseudosugars which allows the stereoselective introduction of polar groups at either the α or the β pseudoanomeric positions. Using this method, a series of 3-deoxycarbasugar analogues of mannose bearing a pyridyl group are rationally designed, prepared and tested for inhibition of Golgi α-mannosidase II.

  13. DETOXIFICATION OF CYANIDE IN GOLD PROCESSING WASTEWATER BY HYDROGEN PEROXIDE

    Directory of Open Access Journals (Sweden)

    A. Khodadadi, M. Abdolahi and P. Teimoury

    2005-07-01

    Full Text Available Utilizing cyanide compounds in mining and chemical industry is one of the most important environmental issues due to the acute toxic properties of many cyanide compounds to humans and aquatic life. Cyanide tends to react readily with most other chemical elements, producing a wide variety of toxic, cyanide related compounds. This research was aimed at investigating a feasible and economical technique for the detoxification of cyanide from the tailing effluent of Muteh gold mine in Isfahan, Iran. In this research cyanide detoxification was achieved through the oxidation of cyanide by hydrogen peroxide using various hydrogen peroxide solutions at pH levels between 7-13 and temperatures between 12-65 °C using copper sulfate as a catalyst. The optimum pH and dose of hydrogen peroxide for complete cyanide removal in the presence of 30 mg/L copper sulfate as a catalyst were determined as 9.7 and 9.98 g/L, respectively. At high temperatures > 35°C, cyanide was completely removed perfectly at constant pH = 9.7 which was mainly due to cyanide evaporation in the form of HCN.

  14. Metal-based nanotoxicity and detoxification pathways in higher plants.

    Science.gov (United States)

    Ma, Chuanxin; White, Jason C; Dhankher, Om Parkash; Xing, Baoshan

    2015-06-16

    The potential risks from metal-based nanoparticles (NPs) in the environment have increased with the rapidly rising demand for and use of nanoenabled consumer products. Plant's central roles in ecosystem function and food chain integrity ensure intimate contact with water and soil systems, both of which are considered sinks for NPs accumulation. In this review, we document phytotoxicity caused by metal-based NPs exposure at physiological, biochemical, and molecular levels. Although the exact mechanisms of plant defense against nanotoxicity are unclear, several relevant studies have been recently published. Possible detoxification pathways that might enable plant resistance to oxidative stress and facilitate NPs detoxification are reviewed herein. Given the importance of understanding the effects and implications of metal-based NPs on plants, future research should focus on the following: (1) addressing key knowledge gaps in understanding molecular and biochemical responses of plants to NPs stress through global transcriptome, proteome, and metablome assays; (2) designing long-term experiments under field conditions at realistic exposure concentrations to investigate the impact of metal-based NPs on edible crops and the resulting implications to the food chain and to human health; and (3) establishing an impact assessment to evaluate the effects of metal-based NPs on plants with regard to ecosystem structure and function.

  15. Distribution of components of the glutathione detoxification system across the human placenta after uncomplicated vaginal deliveries

    NARCIS (Netherlands)

    Raijmakers, MTM; Bruggeman, SWM; Steegers, EAP; Peters, WHM

    The function of the glutathione-related detoxification system plays an important role to ensure an uncomplicated pregnancy outcome. This study was performed to investigate whether the components of the glutathione-related detoxification system are equally distributed among the different cotelydons

  16. Distribution of components of the glutathione detoxification system across the human placenta after uncomplicated vaginal deliveries

    NARCIS (Netherlands)

    Raijmakers, MTM; Bruggeman, SWM; Steegers, EAP; Peters, WHM

    2002-01-01

    The function of the glutathione-related detoxification system plays an important role to ensure an uncomplicated pregnancy outcome. This study was performed to investigate whether the components of the glutathione-related detoxification system are equally distributed among the different cotelydons i

  17. Detoxificatie van patiënten met GHB-afhankelijkheid [Detoxification of patients with GHB dependence

    NARCIS (Netherlands)

    Weert-van Oene, G.H. de; Schellekens, A.F.A.; Dijkstra, B.A.G.; Kamal, R.M.; Jong, C.A.J. de

    2013-01-01

    background A new detoxification method for ghb dependence was developed recently in the Netherlands. The method involves the use of pharmaceutical ghb. aim To describe the characteristics of ghb dependent inpatients, the course of the detoxification process and patients' progress in the three months

  18. Detoxificatie van patiënten met GHB-afhankelijkheid [Detoxification of patients with GHB dependence

    NARCIS (Netherlands)

    Weert-van Oene, G.H. de; Schellekens, A.F.A.; Dijkstra, B.A.G.; Kamal, R.M; Jong, C.A.J. de

    2013-01-01

    BACKGROUND: A new detoxification method for GHB dependence was developed recently in the Netherlands. The method involves the use of pharmaceutical GHB. AIM: To describe the characteristics of GHB dependent inpatients, the course of the detoxification process and patients' progress in the three mont

  19. Addition of fish oil to diets for dairy cows. II. Effects on milk fat and gene expression of mammary lipogenic enzymes.

    Science.gov (United States)

    Ahnadi, Charaf E; Beswick, Naomi; Delbecchi, Louis; Kennelly, John J; Lacasse, Pierre

    2002-11-01

    Sixteen Holstein cows in mid-lactation were used to determine whether alterations of mammary fatty acid metabolism are responsible for the milk fat depression associated with consumption of fish oil. Cows were given a total mixed ration with no added fish oil (control), unprotected fish oil (3.7 % of dry matter), or glutaraldehyde-protected microcapsules of fish oil (1.5% or 3.0% of dry matter) for 4 weeks. Milk samples were taken once a week and a mammary biopsy was taken from a rear quarter at the end of the treatment period. Milk fat content was lower in cows given unprotected fish oil (26.0 g/kg), 1.5% protected fish oil (24.6 g/kg) and 3% protected fish oil (20.4 g/kg) than in cows fed the control diet (36.0 g/kg). This was mainly due to a decrease in the synthesis of short-chain fatty acids. Consumption of protected fish oil decreased the abundance of lipogenic enzymes mRNA in the mammary gland. Acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase mRNAs for cows given 3% protected fish oil averaged only 30%, 25% and 25% of control values, respectively. Dietary addition of unprotected fish oil slightly decreased mRNA abundance of these enzymes but markedly reduced the amount of lipoprotein lipase mRNA. Milk fat content was significantly correlated with gene expression of acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase but not lipoprotein lipase. These results suggest that fish oil reduces milk fat percentage by inhibiting gene expression of mammary lipogenic enzymes.

  20. Design, synthesis and bioactivity of novel ALS enzyme inhibitors (II)——Molecular mechanics, quantum chemistry and structure-activity relationship studies on the herbicidal heterocyclic sulfonamide

    Institute of Scientific and Technical Information of China (English)

    陆荣健; 杨华铮; 尚贞锋; 汪惟为; 潘荫明; 赵学庄

    1996-01-01

    In view of quantum pharmacology, the structure-activity relationships of different kinds of fused heterocydic sulfonamides with the same mode of action were first investigated using molecular mechanics, quantum chemistry and discriminatory analysis. It has been found that the process of the interaction of the fused heterocydic sulfonamide with ALS enzyme involves the electropositive region of the sulfonyl bridge chain and the electronegative region of the heterocydic moiety. The herbicidal activity is related to the potency of electric charge translocation of the related regions.

  1. Factors associated with frequent utilization of crisis substance use detoxification services.

    Science.gov (United States)

    Carrier, Emily; McNeely, Jennifer; Lobach, Iryna; Tay, Shane; Gourevitch, Marc N; Raven, Maria C

    2011-04-01

    Previous research suggests that some substance users have multiple crisis detoxification visits and never access rehabilitation care. This care-seeking pattern leads to poorer outcomes and higher costs. The authors aimed to identify predictors of repeat detoxification visits by analyzing state-level data routinely collected at the time of substances use services admission. Repeat detoxification clients were more likely to be homeless, city-dwelling fee-for-service Medicaid recipients. Repeat detoxification clients were less likely than those with one admission to enter rehabilitation within 3 days. Treatment providers should aim for rapid transfer to rehabilitation and consider expanding detoxification intake data to improve risk stratification. © Taylor & Francis Group, LLC

  2. Lipid signalling couples translational surveillance to systemic detoxification in Caenorhabditis elegans.

    Science.gov (United States)

    Govindan, J Amaranath; Jayamani, Elamparithi; Zhang, Xinrui; Breen, Peter; Larkins-Ford, Jonah; Mylonakis, Eleftherios; Ruvkun, Gary

    2015-10-01

    Translation in eukaryotes is followed to detect toxins and virulence factors and coupled to the induction of defence pathways. Caenorhabditis elegans germline-specific mutations in translation components are detected by this system to induce detoxification and immune responses in distinct somatic cells. An RNA interference screen revealed gene inactivations that act at multiple steps in lipid biosynthetic and kinase pathways upstream of MAP kinase to mediate the systemic communication of translation defects to induce detoxification genes. Mammalian bile acids can rescue the defect in detoxification gene induction caused by C. elegans lipid biosynthetic gene inactivations. Extracts prepared from C. elegans with translation deficits but not from the wild type can also rescue detoxification gene induction in lipid-biosynthesis-defective strains. These eukaryotic antibacterial countermeasures are not ignored by bacteria: particular bacterial species suppress normal C. elegans detoxification responses to mutations in translation factors.

  3. Disentangling detoxification: gene expression analysis of feeding mountain pine beetle illuminates molecular-level host chemical defense detoxification mechanisms.

    Science.gov (United States)

    Robert, Jeanne A; Pitt, Caitlin; Bonnett, Tiffany R; Yuen, Macaire M S; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

    2013-01-01

    The mountain pine beetle, Dendroctonus ponderosae, is a native species of bark beetle (Coleoptera: Curculionidae) that caused unprecedented damage to the pine forests of British Columbia and other parts of western North America and is currently expanding its range into the boreal forests of central and eastern Canada and the USA. We conducted a large-scale gene expression analysis (RNA-seq) of mountain pine beetle male and female adults either starved or fed in male-female pairs for 24 hours on lodgepole pine host tree tissues. Our aim was to uncover transcripts involved in coniferophagous mountain pine beetle detoxification systems during early host colonization. Transcripts of members from several gene families significantly increased in insects fed on host tissue including: cytochromes P450, glucosyl transferases and glutathione S-transferases, esterases, and one ABC transporter. Other significantly increasing transcripts with potential roles in detoxification of host defenses included alcohol dehydrogenases and a group of unexpected transcripts whose products may play an, as yet, undiscovered role in host colonization by mountain pine beetle.

  4. Disentangling detoxification: gene expression analysis of feeding mountain pine beetle illuminates molecular-level host chemical defense detoxification mechanisms.

    Directory of Open Access Journals (Sweden)

    Jeanne A Robert

    Full Text Available The mountain pine beetle, Dendroctonus ponderosae, is a native species of bark beetle (Coleoptera: Curculionidae that caused unprecedented damage to the pine forests of British Columbia and other parts of western North America and is currently expanding its range into the boreal forests of central and eastern Canada and the USA. We conducted a large-scale gene expression analysis (RNA-seq of mountain pine beetle male and female adults either starved or fed in male-female pairs for 24 hours on lodgepole pine host tree tissues. Our aim was to uncover transcripts involved in coniferophagous mountain pine beetle detoxification systems during early host colonization. Transcripts of members from several gene families significantly increased in insects fed on host tissue including: cytochromes P450, glucosyl transferases and glutathione S-transferases, esterases, and one ABC transporter. Other significantly increasing transcripts with potential roles in detoxification of host defenses included alcohol dehydrogenases and a group of unexpected transcripts whose products may play an, as yet, undiscovered role in host colonization by mountain pine beetle.

  5. Enzyme immunoassay of serum beta-2-microglobulin levels in various histological forms of leprosy with special reference to its elevation in type I and type II lepra reactions.

    Science.gov (United States)

    Saha, K; Bhatnagar, A; Sharma, V K; Chakrabarty, A K

    1985-04-01

    The mean beta-2-microglobulin level in serum (3,362 +/- 2,494 micrograms/liter) for 76 leprosy patients, including 9 borderline-tuberculoid, 8 borderline-borderline, 9 borderline-lepromatous, and 16 lepromatous-lepromatous patients and 34 patients with type I or type II lepra reactions, was significantly higher (P less than 0.001) than that (2,122 +/- 1,844 micrograms/liter) for 35 normal subjects. It decreased significantly (P less than 0.001) as the disease glided down from borderline tuberculoid (3,173 +/- 899 micrograms/liter) to the lepromatous end (1,813 +/- 1,391 micrograms/liter). At the onset of type I or type II reaction, the mean beta-2-microglobulin level in serum increased (4,447 +/- 2,863 micrograms/liter), and it remained unchanged (4,433 +/- 2,623 micrograms/liter) after clinical remission. The beta-2-microglobulin level in serum decreased in 55.5% of the patients tested after subsidence of reaction. The level was significantly higher in patients with type II reactions (5,433 +/- 3,299 micrograms/liter) than in patients with type I reactions (3,558 +/- 2,171 micrograms/liter).

  6. Genetic polymorphisms of smoking-related carcinogen detoxifying enzymes and head and neck cancer susceptibility.

    NARCIS (Netherlands)

    Lacko, M.; Oude Ophuis, M.B.; Peters, W.H.M.; Manni, J.J.

    2009-01-01

    Smoking and the consumption of alcohol are the main risk factors for head and neck cancer. However, interindividual variation in the activity of enzymes involved in the detoxification of tobacco smoke (pro)carcinogens, such as microsomal epoxide hydrolase (mEH), glutathione-S-transferases (GSTs) and

  7. The role of enzyme activities in soil ecosystem services: Location, origin and connection to the phytobiome

    Science.gov (United States)

    Soil enzymes are important components of soil quality and its health because of their involvement in ecosystem services related to biogeochemical cycling, global C and organic matter dynamics, and soil detoxification. This talk will provide an overview of the field of soil enzymology, the location a...

  8. Mitochondrial Sulfide Detoxification Requires a Functional Isoform O-Acetylserine(thiol)lyase C in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Consolación (A)lvarez; Irene García; Luis C.Romero; Cecilia Gotor

    2012-01-01

    In non-cyanogenic species,the main source of cyanide derives from ethylene and camalexin biosyntheses.In mitochondria,cyanide is a potent inhibitor of the cytochrome c oxidase and is metabolized bythe β-cyanoalanine synthase CYS-C1,catalyzing the conversion of cysteine and cyanide to hydrogen sulfide and β-cyanoalanine.The hydrogen sulfide released also inhibits the cytochrome c oxidase and needs to be detoxified by the O-acetylserine(thiol)lyase mitochondrial isoform,OAS-C,which catalyzes the incorporation of sulfide to O-acetylserine to produce cysteine,thus generating a cyclic pathway in the mitochondria.The loss of functional OAS-C isoforms causes phenotypic characteristics very similar to the loss of the CYS-C1 enzyme,showing defects in root hair formation.Genetic complementation with the OAS-C gene rescues the impairment of root hair elongation,restoring the wild-type phenotype.The mitochondria compromise their capacity to properly detoxify cyanide and the resulting sulfide because the latter cannot re-assimilate into cysteine in the oas-c null mutant.Consequently,we observe an accumulation of sulfide and cyanide and of the alternative oxidase,which is unable to prevent the production of reactive oxygen species probably due to the accumulation of both toxic molecules.Our results allow us to suggest that the significance of OAS-C is related to its role in the proper sulfide and cyanide detoxification in mitochondria.

  9. The detoxification process, bioaccumulation and damage effect in juvenile white shrimp Litopenaeus vannamei exposed to chrysene.

    Science.gov (United States)

    Ren, Xianyun; Pan, Luqing; Wang, Lin

    2015-04-01

    This study aimed to evaluate the effect of chrysene (CHR) on detoxification enzymes, bioaccumulation and effect of CHR on biomolecule damage in different organs of the juvenile white shrimp Litopenaeus vannamei. In this study, juvenile white shrimp L. vannamei were exposed to CHR for 21 days at four different concentrations as 0, 0.3, 2.1 and 14.7 μg/L. Results showed that CHR bioaccumulation increased rapidly at first then reached a plateau. The activities of aryl hydrocarbon hydroxylase (AHH), 7-ethoxyresorufin O-deethylase (EROD), epoxide hydrolase (EH), glutathione-S-transferase (GST), sulfotransferase (SULT) and uridinediphosphate glucuronyltransferase (UGT) were induced and then became stable gradually. Moreover, 2.1 and 14.7 μg/L CHR treatments increased activity of superoxide dismutase (SOD) in gills and hepatopancreas, while total antioxidant capacity (T-AOC) and GSH/GSSG were suppressed after CHR exposure. Additionally, lipid peroxidation (LPO) levels, protein carbonyl (PC) contents and DNA damage were induced throughout the exposure period, and different trends were detected with time of exposure. Overall, these novel findings of CHR bioaccumulation and resulted toxicity demonstrate that CHR could affect the physical status of L. vannamei. This study will form a solid basis for a realistic extrapolation scientific data for aquaculture water monitoring and food security.

  10. Cyanide detoxification in an insect herbivore: Molecular identification of β-cyanoalanine synthases from Pieris rapae.

    Science.gov (United States)

    van Ohlen, Maike; Herfurth, Anna-Maria; Kerbstadt, Henrike; Wittstock, Ute

    2016-03-01

    Cyanogenic compounds occur widely in the plant kingdom. Therefore, many herbivores are adapted to the presence of these compounds in their diet by either avoiding cyanide release or by efficient cyanide detoxification mechanisms. The mechanisms of adaptation are not fully understood. Larvae of Pieris rapae (Lepidoptera: Pieridae) are specialist herbivores on glucosinolate-containing plants. They are exposed to cyanide during metabolism of phenylacetonitrile, a product of benzylglucosinolate breakdown catalyzed by plant myrosinases and larval nitrile-specifier protein (NSP) in the gut. Cyanide is metabolized to β-cyanoalanine and thiocyanate in the larvae. Here, we demonstrate that larvae of P. rapae possess β-cyanoalanine activity in their gut. We have identified three gut-expressed cDNAs designated PrBSAS1-PrBSAS3 which encode proteins with similarity to β-substituted alanine synthases (BSAS). Characterization of recombinant PrBSAS1-PrBSAS3 shows that they possess β-cyanoalanine activity. In phylogenetic trees, PrBSAS1-PrBSAS3, the first characterized insect BSAS, group together with a characterized mite β-cyanoalanine synthase and bacterial enzymes indicating a similar evolutionary history. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Detoxification of α-tomatine by Cladosporium fulvum is required for full virulence on tomato.

    Science.gov (United States)

    Ökmen, Bilal; Etalo, Desalegn W; Joosten, Matthieu H A J; Bouwmeester, Harro J; de Vos, Ric C H; Collemare, Jérôme; de Wit, Pierre J G M

    2013-06-01

    · α-Tomatine is an antifungal glycoalkaloid that provides basal defense to tomato (Solanum lycopersicum). However, tomato pathogens overcome this basal defense barrier by the secretion of tomatinases that degrade α-tomatine into the less fungitoxic compounds β-tomatine and tomatidine. Although pathogenic on tomato, it has been reported that the biotrophic fungus Cladosporium fulvum is unable to detoxify α-tomatine. · Here, we present a functional analysis of the glycosyl hydrolase (GH10), CfTom1, which is orthologous to fungal tomatinases. · We show that C. fulvum hydrolyzes α-tomatine into tomatidine in vitro and during the infection of tomato, which is fully attributed to the activity of CfTom1, as shown by the heterologous expression of this enzyme in tomato. Accordingly, ∆cftom1 mutants of C. fulvum are more sensitive to α-tomatine and are less virulent than the wild-type fungus on tomato. · Although α-tomatine is thought to be localized in the vacuole, we show that it is also present in the apoplast, where it is hydrolyzed by CfTom1 on infection. The accumulation of tomatidine during infection appears to be toxic to tomato cells and does not suppress defense responses, as suggested previously. Altogether, our results show that CfTom1 is responsible for the detoxification of α-tomatine by C. fulvum, and is required for full virulence of this fungus on tomato.

  12. Decolorization and detoxification of two textile industry effluents by the laccase/1-hydroxybenzotriazole system.

    Science.gov (United States)

    Benzina, Ouafa; Daâssi, Dalel; Zouari-Mechichi, Héla; Frikha, Fakher; Woodward, Steve; Belbahri, Lassaad; Rodriguez-Couto, Susana; Mechichi, Tahar

    2013-08-01

    The aim of this work was to determine the optimal conditions for the decolorization and the detoxification of two effluents from a textile industry-effluent A (the reactive dye bath Bezactive) and effluent B (the direct dye bath Tubantin)-using a laccase mediator system. Response surface methodology (RSM) was applied to optimize textile effluents decolorization. A Box-Behnken design using RSM with the four variables pH, effluent concentration, 1-hydroxybenzotriazole (HBT) concentration, and enzyme (laccase) concentration was used to determine correlations between the effects of these variables on the decolorization of the two effluents. The optimum conditions for pH and concentrations of HBT, effluent and laccase were 5, 1 mM, 50 % and 0.6 U/ml, respectively, for maximum decolorization of effluent A (68 %). For effluent B, optima were 4, 1 mM, 75 %, and 0.6 U/ml, respectively, for maximum decolorization of approximately 88 %. Both effluents were treated at 30 °C for 20 h. A quadratic model was obtained for each decolorization through this design. The experimental and predicted values were in good agreement and both models were highly significant. In addition, the toxicity of the two effluents was determined before and after laccase treatment using Saccharomyces cerevisiae, Bacillus cereus, and germination of tomato seeds.

  13. Lack of in vitro and in vitro effects of fenbendazole on phase I and phase II biotransformation enzymes in rats, mice and chickens.

    Science.gov (United States)

    Dalvi, R R; Gawai, K R; Dalvi, P S

    1991-12-01

    Intraperitoneal administration of 10 mg fenbendazole/kg bw daily for 5 d caused no significant alterations in the activities of hepatic microsomal drug-metabolizing enzymes viz aminopyrine N-demethylase, aniline hydroxylase and cytosolic glutathione S-transferase in rats, mice and chickens. Similarly no significant difference in the amount of microsomal cytochrome P-450 and NADPH-cytochrome c reductase was found between control and treated animals. In vitro incubation of fenbendazole with rat, mouse and chicken microsomes suggests that the drug neither binds to microsomal protein cytochrome P-450 nor inhibits the activities of aminopyrine N-demethylase and aniline hydroxylase. Similarly in vitro addition of fenbendazole to cytosolic glutathione S-transferase from the above species did not alter the activity of this enzyme. The results indicate that fenbendazole does not alter the activity of hepatic microsomal monooxygenase system significantly in rats, mice and chickens at a dosage level of 10 mg/kg body weight. In vitro studies also indicate that fenbendazole does not interact with the hepatic microsomal monooxygenase system, indicating it is not a substrate for cytochrome P-450-dependent monooxygenase system.

  14. Concentrations, patterns and metabolites of organochlorine pesticides in relation to xenobiotic phase I and II enzyme activities in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Routti, Heli, E-mail: heli.routti@npolar.n [Norwegian Polar Institute, Polar Environmental Centre, 9296 Tromso (Norway); Centre of Excellence in Evolutionary Genetics and Physiology, Department of Biology, University of Turku, 20014 Turku (Finland); Bavel, Bert van [MTM Research Centre, Orebro University, 70182 Orebro (Sweden); Letcher, Robert J. [Wildlife Toxicology and Disease Program, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, Ontario K1A 0H3 (Canada); Arukwe, Augustine [Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Chu Shaogang [Wildlife Toxicology and Disease Program, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, Ontario K1A 0H3 (Canada); Gabrielsen, Geir W. [Norwegian Polar Institute, Polar Environmental Centre, 9296 Tromso (Norway)

    2009-08-15

    The present study investigates the concentrations and patterns of organochlorine pesticides (OCPs) and their metabolites in liver and plasma of two ringed seal populations (Phoca hispida): lower contaminated Svalbard population and more contaminated Baltic Sea population. Among OCPs, p,p'-DDE and sum-chlordanes were the highest in concentration. With increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p'-DDE and the concentration ratios of pentachlorophenol/hexachlorobenzene increased, and the toxaphene pattern shifted more towards persistent Parlar-26 and -50 and less towards more biodegradable Parlar-44. Relative concentrations of the chlordane metabolites, oxychlordane and -heptachlorepoxide, to sum-chlordanes were higher in the seals from Svalbard compared to the seals from the Baltic, while the trend was opposite for cis- and trans-nonachlor. The observed differences in the OCP patterns in the seals from the two populations are probably related to the catalytic activity of xenobiotic-metabolizing enzymes, and also to differences in dietary exposure. - Contrasting patterns of organochlorine pesticides in two ringed seal populations.

  15. A novel approach in the detoxification of intravenous buprenorphine dependence

    Science.gov (United States)

    Sarkar, Sukanto; Subramaniam, Eswaran; Konthoujam, Janet

    2016-01-01

    Background: Opioid dependence remains a significant problem in India, and of late intravenous (IV) buprenorphine use has increased in India, especially in combination with antihistamines and benzodiazepines. Its usage has many serious consequences in the form of needle-transmitted hepatitis and HIV, which is showing an increasing trend. Buprenorphine is a partial agonist at μ-opioid receptors. In tablet form (and rarely as IV), it is widely used in the treatment of opioid detoxification. We assessed the safety and efficacy of transdermal patch of buprenorphine with week long duration of action in the treatment of detoxification of IV buprenorphine dependence in view of its many advantages. Materials and Methods: Six consecutive patients with International Classification of Diseases diagnosis of Opioid Dependence Syndrome (IV buprenorphine) were given a buprenorphine patch for treatment of withdrawal symptoms after receiving consent. Severity of opioid dependence was assessed by using Severity of Opioid Dependence Questionnaire on the day of presentation. Subjective and objective rating for opioid withdrawal was done by subjective opiate withdrawal scale (SOWS) and objective opiate withdrawal scale (OOWS) prepatch and postpatch 3rd and 7th day. Buprenorphine side effect checklist was applied on a daily basis. Results: The patients had a mean age of 30 years, of whom 83.3% are males. All were educated and 50% were currently employed. All of them had additional comorbid substance use as well as a comorbid psychiatric diagnosis. Each of them received a patch of varying dosage. The patch dose used initially was based on clinical considerations alone and was fairly adequate in controlling acute withdrawal symptoms. There is a significant improvement in SOWS and OOWS while comparing the baseline (prepatch) with 3rd and 7th day (postpatch) (P ≤ 0.05). None of the patients reported any side effect with the patch. Conclusion: This study shows that transdermal

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

    Science.gov (United States)

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

    2015-05-01

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

  17. Variants of Phosphotriesterase for the Enhanced Detoxification of the Chemical Warfare Agent VR.

    Science.gov (United States)

    Bigley, Andrew N; Mabanglo, Mark F; Harvey, Steven P; Raushel, Frank M

    2015-09-08

    The V-type organophosphorus nerve agents are among the most hazardous compounds known. Previous efforts to evolve the bacterial enzyme phosphotriesterase (PTE) for the hydrolytic decontamination of VX resulted in the identification of the variant L7ep-3a, which has a kcat value more than 2 orders of magnitude higher than that of wild-type PTE for the hydrolysis of VX. Because of the relatively small size of the O-ethyl, methylphosphonate center in VX, stereoselectivity is not a major concern. However, the Russian V-agent, VR, contains a larger O-isobutyl, methylphosphonate center, making stereoselectivity a significant issue since the SP-enantiomer is expected to be significantly more toxic than the RP-enantiomer. The three-dimensional structure of the L7ep-3a variant was determined to a resolution of 2.01 Å (PDB id: 4ZST ). The active site of the L7ep-3a mutant has revealed a network of hydrogen bonding interactions between Asp-301, Tyr-257, Gln-254, and the hydroxide that bridges the two metal ions. A series of new analogues that mimic VX and VR has helped to identify critical structural features for the development of new enzyme variants that are further enhanced for the catalytic detoxification of VR and VX. The best of these mutants has been shown to have a reversed stereochemical preference for the hydrolysis of VR-chiral center analogues. This mutant hydrolyzes the two enantiomers of VR 160- and 600-fold faster than wild-type PTE hydrolyzes the SP-enantiomer of VR.

  18. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification.

    Science.gov (United States)

    Li, Jianhua; Peng, Jianbiao; Zhang, Ya; Ji, Yuefei; Shi, Huanhuan; Mao, Liang; Gao, Shixiang

    2016-06-05

    This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H2O2 concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H2O2 concentration, while the optimal pH and H2O2 concentration were 7.0 and 8μM, respectively. 98% TCS was removed with only 0.1UmL(-1) SBP in 30min reaction time, while an HRP dose of 0.3UmL(-1) was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (KCAT) and catalytic efficiency (KCAT/KM) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via CC and CO coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water/wastewater treatment.

  19. Angiotensin-converting enzyme and angiotensin II receptor subtype 2 genotypes in type 1 diabetes and severe hypoglycaemia requiring emergency treatment: a case cohort study

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, Ulrik; Nielsen, Søren L; Akram, Kamran

    2009-01-01

    . METHODS: The case cohort study consisted of 108 cases of type 1 diabetic patients with severe hypoglycaemia requiring medical emergency treatment during a 1-year period and 262 consecutive controls without such events. ACE I/D and AT2R 1675G>A genotype distributions were compared between cases......AIMS: In type 1 diabetes, individual susceptibility to severe hypoglycaemia is likely to be influenced by genetic factors. We have previously reported an association of the deletion (D-) allele of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the A...... and controls. RESULTS: The proportion of D-allele carriers was higher amongst cases than controls (83 vs. 73%; P=0.032). In contrast, AT2R genotype distribution was similar in cases and controls. In a multiple regression analysis, D-allele carriage remained a significant risk factor for being a case [odds...

  20. Solar photocatalytic degradation and detoxification of EU priority substances

    Energy Technology Data Exchange (ETDEWEB)

    Hincapie, M. [Facultad de Ingeniera Ambiental, Universidad de Medellin, Carrera 87 No. 30-65, P.O. Box 1983, Medellin (Colombia); Maldonado, M.I.; Oller, I.; Gernjak, W.; Malato, S. [Plataforma Solar de Almeria-CIEMAT, Carretera Senes km4, 04200 Tabernas (Almeria) (Spain); Sanchez-Perez, J.A.; Ballesteros, M.M. [Departamento de Ingenieria Quimica, Universidad de Almeria Crta de Sacramento s/n, 04120 Almeria (Spain)

    2005-04-15

    Several different pesticides (alachlor, atrazine, chlorfenvinphos, diuron, isoproturon and pentachlorophenol) considered PS (priority substances) by the European Commission and dissolved in water at 50mg/L (or at maximum water solubility) have been degraded at pilot-plant scale using photo-Fenton and TiO{sub 2} photocatalysis driven by solar energy. Two different iron concentrations (2 and 55mg/L) and TiO{sub 2} at 200mg/L have been tested and discussed, using mainly TOC mineralisation for comparison of treatment effectiveness. Vibrio fischeri (Microtox{sup (}R)) toxicity assays were also employed for evaluating the photocatalytic treatments, and comparison between these results and parent compound disappearance, TOC evolution and anion (or ammonia) release were discussed. Almost complete mineralisation and total detoxification were always attained. It has been demonstrated that evolution of chloride could be a key-parameter for predicting toxicity of chlorinated compounds.

  1. Thimet oligopeptidase: similarity to 'soluble angiotensin II-binding protein' and some corrections to the published amino acid sequence of the rat testis enzyme.

    Science.gov (United States)

    McKie, N; Dando, P M; Rawlings, N D; Barrett, A J

    1993-01-01

    The deduced amino acid sequence of pig liver soluble angiotensin II-binding protein [Sugiura, Hagiwara and Hirose (1992) J. Biol. Chem. 267, 18067-18072] is similar over most of its length to that reported for rat testis thimet oligopeptidase (EC 3.4.24.15) by Pierotti, Dong, Glucksman, Orlowski and Roberts [(1990) (Biochemistry 29, 10323-10329]. We have found that homogeneous rat testis thimet oligopeptidase binds angiotensin II with the same distinctive characteristics as the pig liver protein. Analysis of the nucleotide sequences reported for the two proteins pointed to the likelihood that sequencing errors had caused two segments of the amino acid sequence of the rat protein to be translated out of frame, and re-sequencing of selected parts of the clone (kindly provided by the previous authors) confirmed this. The revised deduced amino acid sequence of rat thimet oligopeptidase contains 687 residues, representing a protein of 78,308 Da, and is more closely related to those of the pig liver protein and other known homologues of thimet oligopeptidase than that described previously. Images Figure 1 PMID:8216239

  2. Direct Comparison of Manganese Detoxification/Efflux Proteins and Molecular Characterization of ZnT10 Protein as a Manganese Transporter.

    Science.gov (United States)

    Nishito, Yukina; Tsuji, Natsuko; Fujishiro, Hitomi; Takeda, Taka-Aki; Yamazaki, Tomohiro; Teranishi, Fumie; Okazaki, Fumiko; Matsunaga, Ayu; Tuschl, Karin; Rao, Rajini; Kono, Satoshi; Miyajima, Hiroaki; Narita, Hiroshi; Himeno, Seiichiro; Kambe, Taiho

    2016-07-08

    Manganese homeostasis involves coordinated regulation of specific proteins involved in manganese influx and efflux. However, the proteins that are involved in detoxification/efflux have not been completely resolved nor has the basis by which they select their metal substrate. Here, we compared six proteins, which were reported to be involved in manganese detoxification/efflux, by evaluating their ability to reduce manganese toxicity in chicken DT40 cells, finding that human ZnT10 (hZnT10) was the most significant contributor. A domain swapping and substitution analysis between hZnT10 and the zinc-specific transporter hZnT1 showed that residue Asn(43), which corresponds to the His residue constituting the potential intramembranous zinc coordination site in other ZnT transporters, is necessary to impart hZnT10's unique manganese mobilization activity; residues Cys(52) and Leu(242) in transmembrane domains II and V play a subtler role in controlling the metal specificity of hZnT10. Interestingly, the His → Asn reversion mutant in hZnT1 conferred manganese transport activity and loss of zinc transport activity. These results provide important information about manganese detoxification/efflux mechanisms in vertebrate cells as well as the molecular characterization of hZnT10 as a manganese transporter.

  3. Veterans' Service Utilization Patterns After Alcohol and Opioid Detoxification in VHA Care.

    Science.gov (United States)

    Timko, Christine; Gupta, Shalini; Schultz, Nicole; Harris, Alex H S

    2016-04-01

    This study aimed to examine detoxification-related service utilization in the Veterans Health Administration (VHA). VHA data for 266,908 patients were used to examine rates and predictors of receiving detoxification, attending post-detoxification appointments, and entering specialty treatment. Multilevel, mixed-effects logistic regressions were used to examine associations between patient and facility characteristics and service utilization. Nationally, 8.0% of VHA patients with alcohol or opiate dependence received detoxification in fiscal year 2013 (facility range=.1%-20.4%); 43.1% of detoxified patients received follow-up (11.1%-76.4%), and 49.9% entered specialty treatment (13.0%-77.2%). In adjusted analyses, detoxification was more likely among male, younger, white, and homeless patients with documented alcohol or opiate disorders and comorbid general medical conditions but without previous addiction treatment. Detoxification was also more likely in facilities with fewer vacant addiction therapist positions. Follow-up and specialty treatments were more likely among younger, healthier homeless patients with previous addiction treatment and a documented alcohol use disorder. Detoxification-related service utilization was highly variable across the VHA. Interventions are needed to optimize use.

  4. Buprenorphine versus dihydrocodeine for opiate detoxification in primary care: a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Adams Clive E

    2007-01-01

    Full Text Available Abstract Background Many drug users present to primary care requesting detoxification from illicit opiates. There are a number of detoxification agents but no recommended drug of choice. The purpose of this study is to compare buprenorphine with dihydrocodeine for detoxification from illicit opiates in primary care. Methods Open label randomised controlled trial in NHS Primary Care (General Practices, Leeds, UK. Sixty consenting adults using illicit opiates received either daily sublingual buprenorphine or daily oral dihydrocodeine. Reducing regimens for both interventions were at the discretion of prescribing doctor within a standard regimen of not more than 15 days. Primary outcome was abstinence from illicit opiates at final prescription as indicated by a urine sample. Secondary outcomes during detoxification period and at three and six months post detoxification were recorded. Results Only 23% completed the prescribed course of detoxification medication and gave a urine sample on collection of their final prescription. Risk of non-completion of detoxification was reduced if allocated buprenorphine (68% vs 88%, RR 0.58 CI 0.35–0.96, p = 0.065. A higher proportion of people allocated to buprenorphine provided a clean urine sample compared with those who received dihydrocodeine (21% vs 3%, RR 2.06 CI 1.33–3.21, p = 0.028. People allocated to buprenorphine had fewer visits to professional carers during detoxification and more were abstinent at three months (10 vs 4, RR 1.55 CI 0.96–2.52 and six months post detoxification (7 vs 3, RR 1.45 CI 0.84–2.49. Conclusion Informative randomised trials evaluating routine care within the primary care setting are possible amongst drug using populations. This small study generates unique data on commonly used treatment regimens.

  5. The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS prisons project: a randomised controlled trial comparing dihydrocodeine and buprenorphine for opiate detoxification

    Directory of Open Access Journals (Sweden)

    Li Ryan

    2009-02-01

    Full Text Available Abstract Background Many opiate users entering British prisons require prescribed medication to help them achieve abstinence. This commonly takes the form of a detoxification regime. Previously, a range of detoxification agents have been prescribed without a clear evidence base to recommend a drug of choice. There are few trials and very few in the prison setting. This study compares dihydrocodeine with buprenorphine. Methods Open label, pragmatic, randomised controlled trial in a large remand prison in the North of England. Ninety adult male prisoners requesting an opiate detoxification were randomised to receive either daily sublingual buprenorphine or daily oral dihydrocodeine, given in the context of routine care. All participants gave written, informed consent. Reducing regimens were within a standard regimen of not more than 20 days and were at the discretion of the prescribing doctor. Primary outcome was abstinence from illicit opiates as indicated by a urine test at five days post detoxification. Secondary outcomes were collected during the detoxification period and then at one, three and six months post detoxification. Analysis was undertaken using relative risk tests for categorical data and unpaired t-tests for continuous data. Results 64% of those approached took part in the study. 63 men (70% gave a urine sample at five days post detoxification. At the completion of detoxification, by intention to treat analysis, a higher proportion of people allocated to buprenorphine provided a urine sample negative for opiates (abstinent compared with those who received dihydrocodeine (57% vs 35%, RR 1.61 CI 1.02–2.56. At the 1, 3 and 6 month follow-up points, there were no significant differences for urine samples negative for opiates between the two groups. Follow up rates were low for those participants who had subsequently been released into the community. Conclusion These findings would suggest that dihydrocodeine should not be routinely

  6. Technological progress on detoxification and comprehensive utilization of chromium-containing slag

    Institute of Scientific and Technical Information of China (English)

    柴立元; 何德文; 于霞; 刘恢; 闵小波; 陈为亮

    2002-01-01

    Chromium salt is an important industrial material, but vast waste slag containing chrome(Ⅵ) is brought out in the process of its production. The slag is seriously harmful to environments and human health. The technologies on detoxification and comprehensive utilization of chromium-containing slag were summarized abroad and at home. And various methods were also described for the detoxification mechanism, technology process, and practical application effects in detail. A new concept for detoxification of chromium-containing slag, furthermore, was put forward by using microorganism.

  7. Asparaginase II-GFP fusion as a tool for studying the secretion of the enzyme under nitrogen starvation Fusão asparaginase II-GFP como ferramenta para estudo da via secretora de enzima sobre depleção por nitrogênio

    Directory of Open Access Journals (Sweden)

    Adriana Sotero-Martins

    2003-12-01

    Full Text Available Production of asparaginase II of Saccharomyces cerevisiae is regulated by nitrogen and can be used as a model system for studying other secreted proteins in yeast. Green fluorescent protein (GFP from Aequorea victoria was fused to the carboxy-terminus of the enzyme by genomic integration to the locus ASP3 of S. cerevisiae. We determined asparaginase II activity, mRNA ASP3, mRNA ASP3-GFP and GFP fluorescence. Nitrogen starvation in cells carrying the chimera ASP3-GFP caused an increase in fluorescence and in the expression of ASP3. We have shown that cells producing the chimera Asp3-GFPp displayed the same response to nitrogen starvation as control cells. We demonstrated that Asp3-GFPp can be used for studying asparaginase II secretion under nitrogen starvation in vivo.A produção de asparaginase II de Saccharomyces cerevisiae é regulada por nitrogênio e pode ser utilizada como um sistema modelo para estudar outras proteínas secretadas, em leveduras. A proteína "green fluorescent protein" (GFP de Aequorea victoria foi fusionada à porção carboxi-terminal de Asp3p por integração genômica da sequência de GFP ao locus ASP3. Determinaram-se os níveis de atividade de asparaginase II, mRNA ASP3, mRNA ASP3-GFP e de fluorescência para GFP. A depleção para nitrogênio, em células portadoras do gene quimérico ASP3-GFP, fez aumentar a fluorescência, assim como a expressão de ASP3. Demonstramos que Asp3-GFPp pode ser utilizada para estudar a secreção de asparaginase II em células submetidas à privação de nitrogênio in vivo.

  8. The structure at 2.4 Å resolution of the protein from gene locus At3g21360, a putative Fe{sup II}/2-oxoglutarate-dependent enzyme from Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Bitto, Eduard; Bingman, Craig A.; Allard, Simon T. M.; Wesenberg, Gary E.; Aceti, David J.; Wrobel, Russell L.; Frederick, Ronnie O.; Sreenath, Hassan; Vojtik, Frank C.; Jeon, Won Bae; Newman, Craig S.; Primm, John; Sussman, Michael R.; Fox, Brian G.; Markley, John L.; Phillips, George N. Jr, E-mail: phillips@biochem.wisc.edu [Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison (United States)

    2005-05-01

    The crystal structure of the 37.2 kDa At3g21360 gene product from A. thaliana was determined at 2.4 Å resolution. The structure establishes that this protein binds a metal ion and is a member of a clavaminate synthase-like superfamily in A. thaliana. The crystal structure of the gene product of At3g21360 from Arabidopsis thaliana was determined by the single-wavelength anomalous dispersion method and refined to an R factor of 19.3% (R{sub free} = 24.1%) at 2.4 Å resolution. The crystal structure includes two monomers in the asymmetric unit that differ in the conformation of a flexible domain that spans residues 178–230. The crystal structure confirmed that At3g21360 encodes a protein belonging to the clavaminate synthase-like superfamily of iron(II) and 2-oxoglutarate-dependent enzymes. The metal-binding site was defined and is similar to the iron(II) binding sites found in other members of the superfamily.

  9. A novel mercuric reductase from the unique deep brine environment of atlantis II in the red sea

    KAUST Repository

    Sayed, Ahmed Anazadeh

    2013-11-26

    Aunique combination of physicochemical conditions prevails in the lower convective layer (LCL) of the brine pool at Atlantis II (ATII) Deep in the Red Sea. With a maximum depth of over 2000 m, the pool is characterized by acidic pH (5.3), high temperature (68 °C), salinity (26%), low light levels, anoxia, and high concentrations of heavy metals. We have established a metagenomic dataset derived from the microbial community in the LCL, and here we describe a gene for a novel mercuric reductase, a key component of the bacterial detoxification system for mercuric and organomercurial species. The metagenome-derived gene and an ortholog from an uncultured soil bacterium were synthesized and expressed in Escherichia coli. The properties of their products show that, in contrast to the soil enzyme, the ATII-LCL mercuric reductase is functional in high salt, stable at high temperatures, resistant to high concentrations of Hg2+, and efficiently detoxifies Hg2+ in vivo. Interestingly, despite the marked functional differences between the orthologs, their amino acid sequences differ by less than 10%. Site-directed mutagenesis and kinetic analysis of the mutant enzymes, in conjunction with three-dimensional modeling, have identified distinct structural features that contribute to extreme halophilicity, thermostability, and high detoxification capacity, suggesting that these were acquired independently during the evolution of this enzyme. Thus, our work provides fundamental structural insights into a novel protein that has undergone multiple biochemical and biophysical adaptations to promote the survival of microorganisms that reside in the extremely demanding environment of the ATII-LCL. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Food Enzymes

    Science.gov (United States)

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  11. Food Enzymes

    Science.gov (United States)

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  12. Enzyme immunoassay

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, B; Dinesen, B; Deckert, M

    1985-01-01

    An enzyme linked immunoadsorbent assay for urinary albumin using commercially available reagents is described. The assay range is 2.5-120 micrograms/l. When samples are analysed in two standard dilutions, the assayable albumin concentration range is 2.5-240 mg/l, covering the clinical range from...

  13. Metabolic detoxification determines species differences in coumarin-induced hepatotoxicity.

    Science.gov (United States)

    Vassallo, Jeffrey D; Hicks, Sarah M; Daston, George P; Lehman-McKeeman, Lois D

    2004-08-01

    Hepatotoxicity of coumarin is attributed to metabolic activation to an epoxide intermediate, coumarin 3,4-epoxide (CE). However, whereas rats are most susceptible to coumarin-induced hepatotoxicity, formation of CE is greatest in mouse liver microsomes, a species showing little evidence of hepatotoxicity. Therefore, the present work was designed to test the hypothesis that detoxification of CE is a major determinant of coumarin hepatotoxicity. CE can either rearrange spontaneously to o-hydroxyphenylacetaldehyde (o-HPA) or be conjugated with gluatathione (GSH). o-HPA is hepatotoxic and is further detoxified by oxidation to o-hydroxyphenylacetic acid (o-HPAA). In vitro experiments were conducted using mouse liver microsomes to generate a constant amount of CE, and cytosols from F344 rats, B6C3F1 mice, and human liver were used to characterize CE detoxification. All metabolites were quantified by HPLC methods with UV detection. In rats and mice, GSH conjugation occurred non-enzymatically and through glutathione-S-transferases (GSTs), and the kinetics of GSH conjugation were similar in rats and mice. In rat liver cytosol, oxidation of o-HPA to o-HPAA was characterized with a high affinity K(m) of approximately 12 microM, and a V(max) of approximately 1.5 nmol/min/mg protein. In contrast, the K(m) and V(max) for o-HPA oxidation in mouse liver cytosol were approximately 1.7 microM and 5 nmol/min/mg protein, respectively, yielding a total intrinsic clearance through oxidation to o-HPAA that was 20 times higher in mouse than in rats. Human cytosols (two separate pools) detoxified CE through o-HPA oxidation with an apparent K(m) of 0.84 microM and a V(max) of 5.7 nmol/min/mg protein, for a net intrinsic clearance that was more than 50 times higher than the rat. All species also reduced o-HPA to o-hydroxyphenylethanol (o-HPE), but this was only a major reaction in rats. In the presence of a metabolic reaction replete with all necessary cofactors, GSH conjugation accounted

  14. Celecoxib enhances the detoxification of diethylnitrosamine in rat liver cancer

    Institute of Scientific and Technical Information of China (English)

    Martha Estela Salcido-Neyoy; Adolfo Sierra-Santoyo; Olga Beltrán-Ramírez; José Roberto Macías-Pérez; Saúl Villa-Trevi(n)o

    2009-01-01

    AIM: To study the effect of celecoxib (CXB) on diethylnitrosamine activation through the regulation of cytochrome P450 in a hepatocarcinogenesis model. METHODS: Six-week-old male Sprague-Dawley rats were randomly divided into five groups, a nontreated group (NT), a diethylnitrosamine-treated group (DEN), a DEN+CXB-treated group (DEN+CXB), and CXB 8 d-treated and CXB 32 d-treated groups. The effects of celecoxib on the enzymatic activities of CYP1A1, 2A, 2B1/2, and 2E1 were assessed in hepatic microsomes 24 h after DEN administration.Changes in CYP1A1 and CYP2B1/2 protein expression were also evaluated. The rate of DEN metabolism was measured by the production of the deethylation metabolite acetaldehyde, and the denitrosation metabolite nitrite.RESULTS: DEN+CXB administration produced a significant increase in the enzymatic activities of CYP2B1/2 and 1A1, whereas it did not change the activities of CYP2A and 2E1, compared to that of the DEN group. CXB treatment for eight days did not produce a significant effect on enzymatic activity when compared to the NT group; however, when it was administered for prolonged times (CXB 32 d group), the enzymatic activities were increased in a similar pattern to those in the DEN+CXB group. The observed increase in the enzymatic activities in the DEN+CXB group was accompanied by an increase in the CYP2B1/2 protein levels; no changes were observed in the levels of CYP1A1. In vitro, CXB increased the denitrosation of DEN, a pathway of metabolic detoxification. The addition of SKF-525A, a preferential inhibitor of CYP2B, abrogated the denitrosation of DEN. CONCLUSION: These results suggest that the mechanism of action of CXB involves enhancement of the detoxification of DEN by an increasing denitrosation via CYP2B1/2.

  15. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianhua; Peng, Jianbiao [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Zhang, Ya [Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection of the People’s Republic of China, Nanjing 210042 (China); Ji, Yuefei [College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095 (China); Shi, Huanhuan; Mao, Liang [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Gao, Shixiang, E-mail: ecsxg@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China)

    2016-06-05

    Highlights: • Enzymatic treatment of triclosan in water by soybean and horseradish peroxidases. • pH, H{sub 2}O{sub 2} concentration and enzyme dosage affected the removal efficiency of TCS. • The removal of TCS by SBP was more efficient than that of HRP. • K{sub CAT} and K{sub CAT}/K{sub M} values for SBP toward TCS were much higher than those for HRP. • Polymers formed via radical coupling mechanism were nontoxic to the growth of alga. - Abstract: This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H{sub 2}O{sub 2} concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H{sub 2}O{sub 2} concentration, while the optimal pH and H{sub 2}O{sub 2} concentration were 7.0 and 8 μM, respectively. 98% TCS was removed with only 0.1 U mL{sup −1} SBP in 30 min reaction time, while an HRP dose of 0.3 U mL{sup −1} was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (K{sub CAT}) and catalytic efficiency (K{sub CAT}/K{sub M}) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via C−C and C−O coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water

  16. Esterase detoxification of acetylcholinesterase inhibitors by human or rat liver in vitro

    Science.gov (United States)

    Organophosphate (OP) and N-methylcarbamate pesticides inhibit acetylcholinesterase (AChE), but differences in metabolism and detoxification can influence potency of these pesticides across and within species. Carboxylesterase (CaE) and A-esterase (paraoxonase, PON) are considered...

  17. A novel aldo-keto reductase from Jatropha curcas L. (JcAKR) plays a crucial role in the detoxification of methylglyoxal, a potent electrophile.

    Science.gov (United States)

    Mudalkar, Shalini; Sreeharsha, Rachapudi Venkata; Reddy, Attipalli Ramachandra

    2016-05-20

    Abiotic stress leads to the generation of reactive oxygen species (ROS) which further results in the production of reactive carbonyls (RCs) including methylglyoxal (MG). MG, an α, β-dicarbonyl aldehyde, is highly toxic to plants and the mechanism behind its detoxification is not well understood. Aldo-keto reductases (AKRs) play a role in detoxification of reactive aldehydes and ketones. In the present study, we cloned and characterised a putative AKR from Jatropha curcas (JcAKR). Phylogenetically, it forms a small clade with AKRs of Glycine max and Rauwolfia serpentina. JcAKR was heterologously expressed in Escherichia coli BL-21(DE3) cells and the identity of the purified protein was confirmed through MALDI-TOF analysis. The recombinant protein had high enzyme activity and catalytic efficiency in assays containing MG as the substrate. Protein modelling and docking studies revealed MG was efficiently bound to JcAKR. Under progressive drought and salinity stress, the enzyme and transcript levels of JcAKR were higher in leaves compared to roots. Further, the bacterial and yeast cells expressing JcAKR showed more tolerance towards PEG (5%), NaCl (200mM) and MG (5mM) treatments compared to controls. In conclusion, our results project JcAKR as a possible and potential target in crop improvement for abiotic stress tolerance.

  18. Conflicting demands on detoxification pathways influence how common brushtail possums choose their diets.

    Science.gov (United States)

    Marsh, Karen J; Wallis, Ian R; McLean, Stuart; Sorensen, Jennifer S; Foley, William J

    2006-08-01

    Most herbivores eat more and survive better when they have access to a variety of foods. One explanation involves the detoxification of plant secondary metabolites (PSMs). By feeding from a variety of plants that contain different classes of PSMs, animals can use multiple detoxification pathways and presumably consume more food. Although popular, this theory is difficult to test because it requires knowledge of the detoxification pathways of each PSM in the diet. We established that common brushtail possums (Trichosurus vulpecula) use various combinations of oxidation, hydrolysis, and conjugation with glucuronic acid (GA) or glycine to detoxify six PSMs. Compared to their ingestion of a single PSM, possums ate more when offered a choice between two diets containing PSMs that require apparently independent detoxification pathways (benzoate and 1,8-cineole, benzoate and p-cymene, benzoate and orcinol, benzoate and salicin, or orcinol and 1,8-cineole). However, possums still did not eat as much of these diets as they did of a basal diet free of PSMs. This suggests that detoxification pathways are never independent, but are separated instead by degrees. In contrast, possums offered a choice of two PSMs that require competing detoxification pathways (1,8-cineole and p-cymene, 1,8-cineole and salicin, or orcinol and salicin) ate no more than when offered diets containing one of the compounds. There was an exception: even though both rutin and orcinol are detoxified via conjugation with GA, the feeding behavior of possums did not suggest competition for detoxification pathways. This implies that the supply of GA is not limiting. This study provides the first convincing evidence that herbivorous mammals can eat more by selecting mixed diets with a diversity of PSMs that make full use of their detoxification potential. It also emphasizes that other behavioral and physiological factors, such as transient food aversions, influence feeding behavior.

  19. Changes in nutrition-related behaviors in alcohol-dependent patients after outpatient detoxification

    OpenAIRE

    Rohdemann, Maren E. H.

    2016-01-01

    Background: Previous studies have reported changes in nutrition-related behaviors in alcohol-dependent patients after alcohol detoxification, but prospective studies assessing the effects of these changes on maintaining abstinence are lacking. Aim: To assess changes in craving and consumption of coffee, cigarettes, chocolate and other sweets over time up to six months after outpatient alcohol detoxification treatment and to detect differences in abstinent versus non-abstinent patients. ...

  20. Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

    OpenAIRE

    Xing-Xing Liu; Chang-Bin Sun; Ting-Tong Yang; Da Li; Chun-Yan Li; Yan-Jie Tian; Ming Guo; Yu Cao; Shi-Sheng Zhou

    2012-01-01

    The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Ra...

  1. Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

    OpenAIRE

    Xing-Xing Liu; Chang-Bin Sun; Ting-Tong Yang; Da Li; Chun-Yan Li; Yan-Jie Tian; Ming Guo; Yu Cao; Shi-Sheng Zhou

    2012-01-01

    The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Ra...

  2. Dimeric Fe (II, III) complex of quinoneoxime as functional model of PAP enzyme: Moessbauer, magneto-structural and DNA cleavage studies

    Energy Technology Data Exchange (ETDEWEB)

    Salunke-Gawali, Sunita; Ahmed, Khursheed [University of Pune, Department of Chemistry (India); Varret, Francois; Linares, Jorge [Universite de Versailles, Laboratoire de Magnetisme et d' Optique, CNRS, UMR 8634 (France); Zaware, Santosh [University of Pune, Department of Chemistry (India); Date, Sadgopal [University of Pune, Department of Physics (India); Rane, Sandhya, E-mail: syrane@chem.unipune.ernet.in [University of Pune, Department of Chemistry (India)

    2008-07-15

    {chi}{sub m}{sup corr}.T were best fitted by using HDVV spin pair model S = 2, 3/2 resulting in antiferromagnetic exchange (J = -13.5 cm{sup -1} with an agreement factor of R = 1.89 x 10{sup -5}). The lower J value of antiferromagnetic exchange leads to Fe{sup +3}{mu}-(OH) Fe{sup +2} bridging in Fe-1 dimer instead of {mu}-oxo bridge. The intermolecular association through H-bonds may lead to weakly coupled antiferromagnetic interaction between two Fe-2 molecules having Fe{sup +3}(h.s.) centers. Using S = 5/2, 5/2 spin pair model we obtained best-fitted parameters such as J = -12.4 cm{sup -1}, g = 2.3 with R = 3.58 x 10{sup -5}. Synthetic strategy results in non-equivalent iron sites in Fe-1 dimer analogues to PAP enzyme hence its reconstitution results in pUC-19 DNA cleavage activity, as physiological functionality of APase. It is compared with nuclease activity of Fe-2 RAPase.

  3. Core-shell polymer nanoparticles for prevention of GSH drug detoxification and cisplatin delivery to breast cancer cells.

    Science.gov (United States)

    Surnar, Bapurao; Sharma, Kavita; Jayakannan, Manickam

    2015-11-14

    Platinum drug delivery against the detoxification of cytoplasmic thiols is urgently required for achieving efficacy in breast cancer treatment that is over expressed by glutathione (GSH, thiol-oligopeptide). GSH-resistant polymer-cisplatin core-shell nanoparticles were custom designed based on biodegradable carboxylic functional polycaprolactone (PCL)-block-poly(ethylene glycol) diblock copolymers. The core of the nanoparticle was fixed as 100 carboxylic units and the shell part was varied using various molecular weight poly(ethylene glycol) monomethyl ethers (MW of PEGs = 100-5000 g mol(-1)) as initiator in the ring-opening polymerization. The complexation of cisplatin aquo species with the diblocks produced core-shell nanoparticles of 75 nm core with precise size control the particles up to 190 nm. The core-shell nanoparticles were found to be stable in saline solution and PBS and they exhibited enhanced stability with increase in the PEG shell thickness at the periphery. The hydrophobic PCL layer on the periphery of the cisplatin core behaved as a protecting layer against the cytoplasmic thiol residues (GSH and cysteine) and exhibited drug detoxification. In vitro drug-release studies revealed that the core-shell nanoparticles were ruptured upon exposure to lysosomal enzymes like esterase at the intracellular compartments. Cytotoxicity studies were performed both in normal wild-type mouse embryonic fibroblast cells (Wt-MEFs), and breast cancer (MCF-7) and cervical cancer (HeLa) cell lines. Free cisplatin and polymer drug core-shell nanoparticles showed similar cytotoxicity effects in the HeLa cells. In MCF-7 cells, the free cisplatin drug exhibited 50% cell death whereas complete cell death (100%) was accomplished by the polymer-cisplatin core-shell nanoparticles. Confocal microscopic images confirmed that the core-shell nanoparticles were taken up by the MCF-7 and HeLa cells and they were accumulated both at the cytoplasm as well at peri-nuclear environments

  4. Detoxification of toxins by bacillithiol in Staphylococcus aureus.

    Science.gov (United States)

    Newton, Gerald L; Fahey, Robert C; Rawat, Mamta

    2012-04-01

    Bacillithiol (BSH), an α-anomeric glycoside of l-cysteinyl-d-glucosaminyl-l-malate, is a major low-molecular-mass thiol found in bacteria such as Bacillus sp., Staphylococcus aureus and Deinococcus radiodurans. Like other low-molecular-mass thiols such as glutathione and mycothiol, BSH is likely to be involved in protection against environmental toxins including thiol-reactive antibiotics. We report here a BSH-dependent detoxification mechanism in S. aureus. When S. aureus Newman strain was treated with monobromobimane and monochlorobimane, the cellular BSH was converted to the fluorescent S-conjugate BS-bimane. A bacillithiol conjugate amidase activity acted upon the BS-bimane to produce Cys-bimane, which was then acetylated by an N-acetyltransferase to generate N-acetyl-Cys-bimane, a mercapturic acid. An S. aureus mutant lacking BSH did not produce mercapturic acid when treated with monobromobimane and monochlorobimane, confirming the involvement of bacillithiol. Furthermore, treatment of S. aureus Newman with rifamycin, the parent compound of the first-line anti-tuberculosis drug, rifampicin, indicated that this thiol-reactive antibiotic is also detoxified in a BSH-dependent manner, since mercapturic acids of rifamycin were observed in the culture medium. These data indicate that toxins and thiol-reactive antibiotics are detoxified to less potent mercapturic acids in a BSH-dependent manner and then exported out of the cell in S. aureus.

  5. Ultraviolet reflector materials for solar detoxification of hazardous waste

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Govindarajan, R.

    1991-07-01

    Organic waste detoxification requires cleavage of carbon bonds. Such reactions can be photo-driven by light that is energetic enough to disrupt such bonds. Alternately, light can be used to activate catalyst materials, which in turn can break organic bonds. In either case, photons with wavelengths less than 400 nm are required. Because the terrestrial solar resource below 400 nm is so small (roughly 3% of the available spectrum), highly efficient optical concentrators are needed that can withstand outdoor service conditions. In the past, optical elements for solar application have been designed to prevent ultraviolet (uv) radiation from reaching the reflective layer to avoid the potentially harmful effects of such light on the collector materials themselves. This effectively forfeits the uv part of the spectrum in return for some measure of protection against optical degradation. To optimize the cost/performance benefit of photochemical reaction systems, optical materials must be developed that are not only highly efficient but also inherently stable against the radiation they are designed to concentrate. The requirements of uv optical elements in terms of appropriate spectral bands and level of reflectance are established based upon the needs of photochemical applications. Relevant literature on uv reflector materials is reviewed which, along with discussions with industrial contacts, allows the establishment of a data base of currently available materials. Although a number of related technologies exist that require uv reflectors, to date little attention has been paid to achieving outdoor durability required for solar applications. 49 refs., 3 figs.

  6. Brassica napus responses to short-term excessive copper treatment with decrease of photosynthetic pigments, differential expression of heavy metal homeostasis genes including activation of gene NRAMP4 involved in photosystem II stabilization.

    Science.gov (United States)

    Zlobin, I E; Kholodova, V P; Rakhmankulova, Z F; Kuznetsov, Vl V

    2015-08-01

    In the present study, the influence of 50 and 100 µM CuSO4 was investigated starting from 3 h till 72 h treatment of 4-weeks Brassica napus plants. High CuSO4 concentrations in nutrient medium resulted in the rapid copper accumulation in plants, especially in roots, much slower and to lower degree in leaves. Copper excess induced early decrease in the leaf water content and temporary leaf wilting. The decrease in content of photosynthetic pigments became significant to 24 h of excessive copper treatments and reached 35 % decrease to 72 h, but there were no significant changes in maximum quantum efficiency of photosystem II photochemistry. The copper excess affected the expression of ten genes involved in heavy metal homeostasis and copper detoxification. The results showed the differential and organ-specific expression of most genes. The potential roles of copper-activated genes encoding heavy metal transporters (ZIP5, NRAMP4, YSL2, and MRP1), metallothioneins (MT1a and MT2b), low-molecular chelator synthesis enzymes (PCS1 and NAS2), and metallochaperones (CCS and HIPP06) in heavy metal homeostasis and copper ion detoxification were discussed. The highest increase in gene expression was shown for NRAMP4 in leaves in spite of relatively moderate Cu accumulation there. The opinion was advanced that the NRAMP4 activation can be considered among the early reactions in the defense of the photosystem II against copper excess.

  7. Benzoxazolinone detoxification by N-Glucosylation: The multi-compartment-network of Zea mays L.

    Science.gov (United States)

    Schulz, Margot; Filary, Barbara; Kühn, Sabine; Colby, Thomas; Harzen, Anne; Schmidt, Jürgen; Sicker, Dieter; Hennig, Lothar; Hofmann, Diana; Disko, Ulrich; Anders, Nico

    2016-01-01

    The major detoxification product in maize roots after 24 h benzoxazolin-2(3H)-one (BOA) exposure was identified as glucoside carbamate resulting from rearrangement of BOA-N-glucoside, but the pathway of N-glucosylation, enzymes involved and the site of synthesis were previously unknown. Assaying whole cell proteins revealed the necessity of H2O2 and Fe(2+) ions for glucoside carbamate production. Peroxidase produced BOA radicals are apparently formed within the extraplastic space of the young maize root. Radicals seem to be the preferred substrate for N-glucosylation, either by direct reaction with glucose or, more likely, the N-glucoside is released by glucanase/glucosidase catalyzed hydrolysis from cell wall components harboring fixed BOA. The processes are accompanied by alterations of cell wall polymers. Glucoside carbamate accumulation could be suppressed by the oxireductase inhibitor 2-bromo-4´-nitroacetophenone and by peroxidase inhibitor 2,3-butanedione. Alternatively, activated BOA molecules with an open heterocycle may be produced by microorganisms (e.g., endophyte Fusarium verticillioides) and channeled for enzymatic N-glucosylation. Experiments with transgenic Arabidopsis lines indicate a role of maize glucosyltransferase BX9 in BOA-N-glycosylation. Western blots with BX9 antibody demonstrate the presence of BX9 in the extraplastic space. Proteomic analyses verified a high BOA responsiveness of multiple peroxidases in the apoplast/cell wall. BOA incubations led to shifting, altered abundances and identities of the apoplast and cell wall located peroxidases, glucanases, glucosidases and glutathione transferases (GSTs). GSTs could function as glucoside carbamate transporters. The highly complex, compartment spanning and redox-regulated glucoside carbamate pathway seems to be mainly realized in Poaceae. In maize, carbamate production is independent from benzoxazinone synthesis.

  8. Possible Roles of Plant Sulfurtransferases in Detoxification of Cyanide, Reactive Oxygen Species, Selected Heavy Metals and Arsenate

    Directory of Open Access Journals (Sweden)

    Parvin Most

    2015-01-01

    Full Text Available Plants and animals have evolved various potential mechanisms to surmount the adverse effects of heavy metal toxicity. Plants possess low molecular weight compounds containing sulfhydryl groups (-SH that actively react with toxic metals. For instance, glutathione (γ-Glu-Cys-Gly is a sulfur-containing tripeptide thiol and a substrate of cysteine-rich phytochelatins (γ-Glu-Cys2–11-Gly (PCs. Phytochelatins react with heavy metal ions by glutathione S-transferase in the cytosol and afterwards they are sequestered into the vacuole for degradation. Furthermore, heavy metals induce reactive oxygen species (ROS, which directly or indirectly influence metabolic processes. Reduced glutathione (GSH attributes as an antioxidant and participates to control ROS during stress. Maintenance of the GSH/GSSG ratio is important for cellular redox balance, which is crucial for the survival of the plants. In this context, sulfurtransferases (Str, also called rhodaneses, comprise a group of enzymes widely distributed in all phyla, paving the way for the transfer of a sulfur atom from suitable sulfur donors to nucleophilic sulfur acceptors, at least in vitro. The best characterized in vitro reaction is the transfer of a sulfane sulfur atom from thiosulfate to cyanide, leading to the formation of sulfite and thiocyanate. Plants as well as other organisms have multi-protein families (MPF of Str. Despite the presence of Str activities in many living organisms, their physiological role has not been clarified unambiguously. In mammals, these proteins are involved in the elimination of cyanide released from cyanogenic compounds. However, their ubiquity suggests additional physiological functions. Furthermore, it is speculated that a member of the Str family acts as arsenate reductase (AR and is involved in arsenate detoxification. In summary, the role of Str in detoxification processes is still not well understood but seems to be a major function in the organism.

  9. SET overexpression decreases cell detoxification efficiency: ALDH2 and GSTP1 are downregulated, DDR is impaired and DNA damage accumulates.

    Science.gov (United States)

    Almeida, Luciana O; Goto, Renata N; Pestana, Cezar R; Uyemura, Sérgio A; Gutkind, Silvio; Curti, Carlos; Leopoldino, Andréia M

    2012-12-01

    Alcohol and tobacco consumption are risk factors for head and neck squamous cell carcinoma (HNSCC). Aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferase pi 1 (GSTP1) are important enzymes for cellular detoxification and low efficiencies are implicated in cancer. We assessed the potential role of SET protein overexpression, a histone acetylation modulator accumulated in HNSCC, in gene regulation and protein activity of ALDH2 and GSTP1. SET was knocked down in HN13, HN12 and Cal27, and overexpressed in HEK293 cells; ethanol and cisplatin were the chemical agents. Cells with SET overexpression (HEK293/SET, HN13 and HN12) showed lower ALDH2 and GSTP1 mRNA levels and trichostatin A increased them (real-time PCR). Ethanol upregulated GSTP1 and ALDH2 mRNAs, whereas cisplatin upregulated GSTP1 in HEK293 cells. SET-chromatin binding revealed SET interaction with ALDH2 and GSTP1 promoters, specifically via SET NAP domain; ethanol and cisplatin abolished SET binding. ALDH2 and GSTP1 efficiency was assessed by enzymatic and comet assay. A lower ALDH2 activity was associated with greater DNA damage (tail intensity) in HEK293/SET compared with HEK293 cells, whereas HN13/siSET showed ALDH2 activity higher than HN13 cells. HN13/siSET cells showed increased tail intensity. Cisplatin-induced DNA damage response showed negative relationship between SET overexpression and BRCA2 recruitment. SET downregulated repair genes ATM, BRCA1 and CHEK2 and upregulated TP53. Cisplatin-induced cell-cycle arrest occurred in G(0) /G(1) and S in HEK293 cells, whereas HEK293/SET showed G(2) /M stalling. Overall, cisplatin was more cytotoxic for HN13 than HN13/siSET cells. Our data suggest a role for SET in cellular detoxification, DNA damage response and genome integrity.

  10. Different enzyme kinetics during the glutathione conjugation of the four stereoisomers of the fjord-region diolepoxides of benzo[c]phenanthrene by the mu-class rat liver glutathione S-transferase HTP II.

    Science.gov (United States)

    Funk, M; Gath, I; Seidel, A; Platt, K L; Oesch, F; Zeller, H D

    1994-02-09

    The enzyme-catalysed conjugation of each of the four stereoisomers of trans-3,4-dihydroxy-1,2-epoxy-1,2,3,4-tetrahydrobenzo[c]phenanthrene (B[c]PhDE) with glutathione (GSH) by HTP II, a novel isolated mu-class GSH transferase from the liver of untreated rat, was studied. All four stereoisomers were substrates for GSH transferase HTP II. The enzymatic reaction shows three different types of enzyme kinetics: substrate inhibition for (-)-anti-B[c]PhDE with (R,S,S,R)-absolute configuration, allosteric behavior using (+)-anti-B[c]PhDE with (S,R,R,S)-absolute configuration and Henri-Michaelis-Menten kinetics with both the (-)-syn- and (+)-syn-enantiomers, with (S,R,S,R)- and (R,S,R,S)-absolute configuration, respectively. When the concentration of these diolepoxides was varied (using 2 mM GSH), the apparent Vmax values were 1975 nmol/min x mg for (-)-anti-B[c]PhDE and about 60 nmol/min x mg for both (-)-syn- and (+)-syn-B[c]PhDE, with the corresponding Km values of 1.05 and 0.20 mM. The reaction of (+)-anti-B[c]PhDE determined by applying the Hill equation had an estimated Vmax value of 930 nmol/min x mg. On varying the concentration of GSH, linear Lineweaver-Burk plots were obtained. No competitive effect could be observed using a mixture of (-)-anti- and (+)-anti-enantiomers, indicating that their binding sites are different and independent. It was also shown, that the binding sites of (+)-anti- and both syn-enantiomers were different and independent of each other, while there was a small effect on the binding of the syn-enantiomers caused by (-)-anti-B[c]PhDE. All products of the reaction between GSH and the dihydrodiol epoxides of benzo[c]phenanthrene could be resolved by HPLC and were identified and quantitated using the corresponding synthetic GSH conjugates.

  11. Multiple abiotic stress tolerance in Vigna mungo is altered by overexpression of ALDRXV4 gene via reactive carbonyl detoxification.

    Science.gov (United States)

    Singh, Preeti; Kumar, Deepak; Sarin, Neera Bhalla

    2016-06-01

    Vigna mungo (blackgram) is an important leguminous pulse crop, which is grown for its protein rich edible seeds. Drought and salinity are the major abiotic stresses which adversely affect the growth and productivity of crop plants including blackgram. The ALDRXV4 belongs to the aldo-keto reductase superfamily of enzymes that catalyze the reduction of carbonyl metabolites in the cells and plays an important role in the osmoprotection and detoxification of the reactive carbonyl species. In the present study, we developed transgenic plants of V. mungo using Agrobacterium mediated transformation. The transgene integration was confirmed by Southern blot analysis whereas the expression was confirmed by RT-PCR, Western blot and enzyme activity. The T1 generation transgenic plants displayed improved tolerance to various environmental stresses, including drought, salt, methyl viologen and H2O2 induced oxidative stress. The increased aldose reductase activity, higher sorbitol content and less accumulation of the toxic metabolite, methylglyoxal in the transgenic lines under non-stress and stress (drought and salinity) conditions resulted in increased protection through maintenance of better photosynthetic efficiency, higher relative water content and less photooxidative damage. The accumulation of reactive oxygen species was remarkably decreased in the transgenic lines as compared with the wild type plants. This study of engineering multiple stress tolerance in blackgram, is the first report to date and this strategy for trait improvement is proposed to provide a novel germplasm for blackgram production on marginal lands.

  12. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wosten-van Asperen, Roelie M.; Bos, Albert; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, Rene

    2013-01-01

    Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts

  13. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wosten-van Asperen, Roelie M.; Bos, Albert; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, Rene

    2013-01-01

    Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts a

  14. Kathepsine C : Een allosterisch enzyme

    NARCIS (Netherlands)

    Gorter, Jeannette

    1969-01-01

    In chapter I an introduction into allosteric systems is given. In chapter II is a detailed method is described for the applica of Gly-Phe--p. nitroanilide (GPNA) as a substrate for the activity assay of the lysosomal enzyme cathepsin C. It is an allosteric which is activated by Cl-, Br-, 1-, CNS-, N

  15. Trial of Tramadol Plus Gabapentin for Opioid Detoxification

    Science.gov (United States)

    Ziaaddini, Hassan; Ziaaddini, Ahmad; Asghari, Neda; Nakhaee, Nozar; Eslami, Mahin

    2014-01-01

    Background: Substance abuse or drug addiction is one of the most important health issues in every society, which can lead to physical and mental problems. Objectives: This study aimed to compare the efficacy of tramadol plus gabapentin versus methadone use in the treatment of opiate withdrawal. Patients and Methods: Consenting male subjects who fulfilled the DSM-4 criteria for opiate dependence syndrome (opium, residue, and heroin) were randomly assigned in two groups to receive tramadol plus gabapentin or methadone. Assessment tools were Adjective Rating Scale for Withdrawal (ARSW), Clinical Opiate Withdrawal Scale (COWS) and Visual Analogue craving Scale (VAS). Fifty-nine subjects were enrolled and evaluated on days 1, 2, 3, 4, 6, and 8 during their 10 days of admission. Twenty-nine participants received methadone and the other 30 received tramadol plus gabapentin for their treatment. Results: Mean (SD) age of the patients in methadone group and tramadol plus gabapentin group were 33.9 (7.1) and 32.4. (8.1), respectively (P = 0.462). The overall ARSW (P value = 0.263) and COWS (P = 0.862) scores between the two groups were comparable. The differences in the VAS score for craving between the two groups was marginally significant (P = 0.057). The highest VAS score was at the third day of admission in both groups and it was generally higher in methadone group. Conclusions: The severity of withdrawal syndrome in two groups was not significantly different. The craving was higher in the group receiving methadone from the second day of admission even though the usage amount was higher in the tramadol plus gabapentin group. The findings of this study suggest that the combination of tramadol plus gabapentin is an efficient method for opioid detoxification. PMID:25763266

  16. Transepithelial transport and enzymatic detoxification of gluten in gluten-sensitive rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Michael T Bethune

    Full Text Available BACKGROUND AND AIMS: In a previous report, we characterized a condition of gluten sensitivity in juvenile rhesus macaques that is similar in many respects to the human condition of gluten sensitivity, celiac disease. This animal model of gluten sensitivity may therefore be useful toward studying both the pathogenesis and the treatment of celiac disease. Here, we perform two pilot experiments to demonstrate the potential utility of this model for studying intestinal permeability toward an immunotoxic gluten peptide and pharmacological detoxification of gluten in vivo by an oral enzyme drug candidate. METHODS: Intestinal permeability was investigated in age-matched gluten-sensitive and control macaques by using mass spectrometry to detect and quantify an orally dosed, isotope labeled 33-mer gluten peptide delivered across the intestinal epithelium to the plasma. The protective effect of a therapeutically promising oral protease, EP-B2, was evaluated in a gluten-sensitive macaque by administering a daily gluten challenge with or without EP-B2 supplementation. ELISA-based antibody assays and blinded clinical evaluations of this macaque and of an age-matched control were conducted to assess responses to gluten. RESULTS: Labeled 33-mer peptide was detected in the plasma of a gluten-sensitive macaque, both in remission and during active disease, but not in the plasma of healthy controls. Administration of EP-B2, but not vehicle, prevented clinical relapse in response to a dietary gluten challenge. Unexpectedly, a marked increase in anti-gliadin (IgG and IgA and anti-transglutaminase (IgG antibodies was observed during the EP-B2 treatment phase. CONCLUSIONS: Gluten-sensitive rhesus macaques may be an attractive resource for investigating important aspects of celiac disease, including enhanced intestinal permeability and pharmacology of oral enzyme drug candidates. Orally dosed EP-B2 exerts a protective effect against ingested gluten. Limited data

  17. BOA detoxification of four summer weeds during germination and seedling growth.

    Science.gov (United States)

    Schulz, Margot; Marocco, Adriano; Tabaglio, Vincenzo

    2012-07-01

    A recent greenhouse study revealed a significant reduction of germination and growth of redroot pigweed (Amaranthus retroflexus) and common purslane (Portulaca oleracea) by rye mulch, whereas velvetleaf (Abutilon theophrasti) and common lambsquarters (Chenopodium album) were not suppressed. Since BOA detoxification by metabolic alteration may influence the relation between the benzoxazinoid content of the soil mulch and weed suppression, we tested the dynamics in BOA detoxification in different plant organs of three and 10-day-old seedlings of four warm season weeds incubated with five BOA concentrations (4, 20, 40, 80, and 200 μmol g(-1) fresh weight). In addition, germination and length of 3-day-old seedlings were measured after exposure to 0, 0.3, 1.5, 3, 6, and 15 μmol BOA. Finally, we tested the influence of the MDR translocator inhibitors verapamil, nifedipine, and the GST inhibitor ethycrynic acid on BOA accumulation and detoxification activity. Due to BOA-detoxification, all weeds were able to grow in environments with low BOA contents. At higher contents, Abutilon theophrasti and Chenopodium album had a better chance to survive because of highly active mechanisms that avoided the uptake of BOA (A. theophrasti) and of efficient detoxification activities in youngest seedlings (C. album). The interpretation of all of the data gave the following sequence of increasing sensitivity: A. theophrasti weeds by rye mulches and their benzoxazinoid contents. Our studies demonstrate for the first time that the detoxification of BOA influences the survival of certain weeds in environments enriched with this allelochemical. Therefore, detoxification processes affect the potential for weed suppression by soil allelochemicals in sustainable weed management.

  18. Association of Angiotensin-Converting Enzyme Intron 16 Insertion/Deletion and Angiotensin II Type 1 Receptor A1166C Gene Polymorphisms with Preeclampsia in South East of Iran

    Directory of Open Access Journals (Sweden)

    Saeedeh Salimi

    2011-01-01

    Full Text Available Some evidence suggests that a variety of genetic factors contributed in pathogenesis of the preeclampsia. The aim of this study was to assess the association between the angiotensin-converting enzyme (ACE I/D and angiotensin II type1 receptor A1166C polymorphisms with preeclampsia. This study was performed in 125 preeclamptic pregnant women and 132 controls. The I/D Polymorphism of the ACE gene was assessed by polymerase chain reaction and the A1166C Polymorphism of the AT1R gene was determined by restriction fragment length polymorphism. The genotype and allele frequencies of I/D polymorphism differed between two groups. The risk of preeclampsia was 3.2-fold in pregnant women with D allele (OR, 3.2 [95% CI, 1.1 to 3.8]; P=0.01. The distribution of the AT1R gene A1166C polymorphism was similar in affected and control groups. Our results supported that presence of the I/D polymorphism of ACE gene is a marker for the increased risk of preeclampsia.

  19. Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene.

    Science.gov (United States)

    Gunning, Vanda; Tzafestas, Kyriakos; Sparrow, Helen; Johnston, Emily J; Brentnall, Andrew S; Potts, Jennifer R; Rylott, Elizabeth L; Bruce, Neil C

    2014-06-01

    The explosive 2,4,6-trinitrotoluene (TNT) is a major worldwide military pollutant. The presence of this toxic and highly persistent pollutant, particularly at military sites and former manufacturing facilities, presents various health and environmental concerns. Due to the chemically resistant structure of TNT, it has proven to be highly recalcitrant to biodegradation in the environment. Here, we demonstrate the importance of two glutathione transferases (GSTs), GST-U24 and GST-U25, from Arabidopsis (Arabidopsis thaliana) that are specifically up-regulated in response to TNT exposure. To assess the role of GST-U24 and GST-U25, we purified and characterized recombinant forms of both enzymes and demonstrated the formation of three TNT glutathionyl products. Importantly, GST-U25 catalyzed the denitration of TNT to form 2-glutathionyl-4,6-dinitrotoluene, a product that is likely to be more amenable to subsequent biodegradation in the environment. Despite the presence of this biochemical detoxification pathway in plants, physiological concentrations of GST-U24 and GST-U25 result in only a limited innate ability to cope with the levels of TNT found at contaminated sites. We demonstrate that Arabidopsis plants overexpressing GST-U24 and GST-U25 exhibit significantly enhanced ability to withstand and detoxify TNT, properties that could be applied for in planta detoxification of TNT in the field. The overexpressing lines removed significantly more TNT from soil and exhibited a corresponding reduction in glutathione levels when compared with wild-type plants. However, in the absence of TNT, overexpression of these GSTs reduces root and shoot biomass, and although glutathione levels are not affected, this effect has implications for xenobiotic detoxification.

  20. Identification of Genes Putatively Involved in Chitin Metabolism and Insecticide Detoxification in the Rice Leaf Folder (Cnaphalocrocis medinalis Larvae through Transcriptomic Analysis

    Directory of Open Access Journals (Sweden)

    Hai-Zhong Yu

    2015-09-01

    Full Text Available The rice leaf roller (Cnaphalocrocis medinalis is one of the most destructive agricultural pests. Due to its migratory behavior, it is difficult to control worldwide. To date, little is known about major genes of C. medinalis involved in chitin metabolism and insecticide detoxification. In order to obtain a comprehensive genome dataset of C. medinalis, we conducted de novo transcriptome sequencing which focused on the major feeding stage of fourth-instar larvae, and our work revealed useful information on chitin metabolism and insecticide detoxification and target genes of C. medinalis. We acquired 29,367,797 Illumina reads and assembled these reads into 63,174 unigenes with an average length of 753 bp. Among these unigenes, 31,810 were annotated against the National Center for Biotechnology Information non-redundant (NCBI nr protein database, resulting in 24,246, 8669 and 18,176 assigned to Swiss-Prot, clusters of orthologous group (COG, and gene ontology (GO, respectively. We were able to map 10,043 unigenes into 285 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG. Specifically, 16 genes, including five chitin deacetylases, two chitin synthases, five chitinases and four other related enzymes, were identified to be putatively involved in chitin biosynthesis and degradation, whereas 360 genes, including cytochrome P450s, glutathione S-transferases, esterases, and acetylcholinesterases, were found to be potentially involved in insecticide detoxification or as insecticide targets. The reliability of the transcriptome data was determined by reverse transcription quantitative PCR (RT-qPCR for the selected genes. Our data serves as a new and valuable sequence resource for genomic studies on C. medinalis. The findings should improve our understanding of C. medinalis genetics and contribute to management of this important agricultural pest.

  1. Identification of Genes Putatively Involved in Chitin Metabolism and Insecticide Detoxification in the Rice Leaf Folder (Cnaphalocrocis medinalis) Larvae through Transcriptomic Analysis.

    Science.gov (United States)

    Yu, Hai-Zhong; Wen, De-Fu; Wang, Wan-Lin; Geng, Lei; Zhang, Yan; Xu, Jia-Ping

    2015-09-10

    The rice leaf roller (Cnaphalocrocis medinalis) is one of the most destructive agricultural pests. Due to its migratory behavior, it is difficult to control worldwide. To date, little is known about major genes of C. medinalis involved in chitin metabolism and insecticide detoxification. In order to obtain a comprehensive genome dataset of C. medinalis, we conducted de novo transcriptome sequencing which focused on the major feeding stage of fourth-instar larvae, and our work revealed useful information on chitin metabolism and insecticide detoxification and target genes of C. medinalis. We acquired 29,367,797 Illumina reads and assembled these reads into 63,174 unigenes with an average length of 753 bp. Among these unigenes, 31,810 were annotated against the National Center for Biotechnology Information non-redundant (NCBI nr) protein database, resulting in 24,246, 8669 and 18,176 assigned to Swiss-Prot, clusters of orthologous group (COG), and gene ontology (GO), respectively. We were able to map 10,043 unigenes into 285 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). Specifically, 16 genes, including five chitin deacetylases, two chitin synthases, five chitinases and four other related enzymes, were identified to be putatively involved in chitin biosynthesis and degradation, whereas 360 genes, including cytochrome P450s, glutathione S-transferases, esterases, and acetylcholinesterases, were found to be potentially involved in insecticide detoxification or as insecticide targets. The reliability of the transcriptome data was determined by reverse transcription quantitative PCR (RT-qPCR) for the selected genes. Our data serves as a new and valuable sequence resource for genomic studies on C. medinalis. The findings should improve our understanding of C. medinalis genetics and contribute to management of this important agricultural pest.

  2. Computational Enzymology and Organophosphorus Degrading Enzymes: Promising Approaches Toward Remediation Technologies of Warfare Agents and Pesticides.

    Science.gov (United States)

    Ramalho, Teodorico C; de Castro, Alexandre A; Silva, Daniela R; Silva, Maria Cristina; Franca, Tanos C C; Bennion, Brian J; Kuca, Kamil

    2016-01-01

    The re-emergence of chemical weapons as a global threat in hands of terrorist groups, together with an increasing number of pesticides intoxications and environmental contaminations worldwide, has called the attention of the scientific community for the need of improvement in the technologies for detoxification of organophosphorus (OP) compounds. A compelling strategy is the use of bioremediation by enzymes that are able to hydrolyze these molecules to harmless chemical species. Several enzymes have been studied and engineered for this purpose. However, their mechanisms of action are not well understood. Theoretical investigations may help elucidate important aspects of these mechanisms and help in the development of more efficient bio-remediators. In this review, we point out the major contributions of computational methodologies applied to enzyme based detoxification of OPs. Furthermore, we highlight the use of PTE, PON, DFP, and BuChE as enzymes used in OP detoxification process and how computational tools such as molecular docking, molecular dynamics simulations and combined quantum mechanical/molecular mechanics have and will continue to contribute to this very important area of research.

  3. A Stage I Pilot Study of Acceptance and Commitment Therapy for Methadone Detoxification

    Science.gov (United States)

    Stotts, Angela L.; Green, Charles; Masuda, Akihiko; Grabowski, John; Wilson, Kelly; Northrup, Thomas; Moeller, F. Gerard; Schmitz, Joy

    2012-01-01

    BACKGROUND While agonist replacement therapies are effective for managing opioid dependence, community treatment programs are increasingly choosing detoxification. Unfortunately, success rates for opioid detoxification are very low, in part, due to physical and psychological symptoms associated with opioid withdrawal. Few behavior therapies specifically address the distressing experiences specific to opioid withdrawal. A novel behavioral treatment, Acceptance and Commitment Therapy (ACT), works from the premise that the avoidance of unpleasant private experiences (thoughts, feelings, bodily sensations) is ubiquitous yet may be pathogenic, resulting in treatment drop-out and further drug use. METHODS This Stage I pilot study developed and tested an ACT-based opioid detoxification behavioral therapy. Opioid dependent patients (N = 56) who were attending a licensed methadone clinic were randomized to receive either 24 individual therapy sessions of ACT or Drug Counseling (DC) in the context of a 6-month methadone dose reduction program. RESULTS While no difference was found on opioid use during treatment, 37% of participants in the ACT condition were successfully detoxified at the end of treatment compared to 19% of those who received DC. Fear of detoxification was also reduced across time in the ACT condition relative to DC. CONCLUSION This first study of ACT to assist opioid detoxification indicates promise. Research is needed to refine specific treatment strategies for this population to further strengthen effects. PMID:22425411

  4. Impact of adaptive functioning on readmission to alcohol detoxification among Alaska Native People.

    Science.gov (United States)

    Running Bear, Ursula; Anderson, Heather; Manson, Spero M; Shore, Jay H; Prochazka, Allan V; Novins, Douglas K

    2014-07-01

    This study examined predictors associated with readmission to detoxification in a sample of adult Alaska Native patients admitted to inpatient alcohol detoxification. Even though Alaska Native people diagnosed with alcoholism have been identified as frequent utilizers of the health care system and at elevated risk of death, little is known about factors associated with readmission to detoxification for this group. We sought to predict readmission using a retrospective cohort study. The sample included 383 adult Alaska Native patients admitted to an inpatient detoxification unit and diagnosed with alcohol withdrawal during 2006 and 2007. Cox proportional hazard modeling was used to estimate unadjusted and adjusted associations with time to readmission within one year. Forty-two percent of the patients were readmitted within one year. Global Assessment Functioning (GAF; Axis V in the multi-axial diagnostic system of the Diagnostic and Statistical Manual of Mental Disorders [DSM IV]) score measured at the time of intake was associated with readmission. A one point increase in the GAF score (HR=.96, 95% CL=.94, .99, P=.002) was associated with a four percent decrease in readmission. The results also indicated that the GAF mediated the relationship between readmission and: employment and housing status. The GAF measures both illness severity and adaptive functioning, is part of standard behavioral health assessments, and is easy to score. Readmission rates potentially could be decreased by creating clinical protocols that account for differences in adaptive functioning and illness severity during detoxification treatment and aftercare. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Endotoxin detoxification by alkaline phosphatase in cholestatic livers

    NARCIS (Netherlands)

    Poelstra, K; Bakker, WW; Hardonk, MJ; Meijer, DKF; Wisse, E; Knook, DL; Balabaud, C

    1997-01-01

    Increased expression of alkaline phosphatase (AP) in the liver is a hallmark of cholestasis but the pathophysiological role of this is not clear. We argue that deprotonation of carboxyl groups at the active site of the enzyme may be a prerequisite for optimal AP activity. Such a creation of negative

  6. Expression profiling of Crambe abyssinica under arsenate stress identifies genes and gene networks involved in arsenic metabolism and detoxification

    Directory of Open Access Journals (Sweden)

    Kandasamy Suganthi

    2010-06-01

    Full Text Available Abstract Background Arsenic contamination is widespread throughout the world and this toxic metalloid is known to cause cancers of organs such as liver, kidney, skin, and lung in human. In spite of a recent surge in arsenic related studies, we are still far from a comprehensive understanding of arsenic uptake, detoxification, and sequestration in plants. Crambe abyssinica, commonly known as 'abyssinian mustard', is a non-food, high biomass oil seed crop that is naturally tolerant to heavy metals. Moreover, it accumulates significantly higher levels of arsenic as compared to other species of the Brassicaceae family. Thus, C. abyssinica has great potential to be utilized as an ideal inedible crop for phytoremediation of heavy metals and metalloids. However, the mechanism of arsenic metabolism in higher plants, including C. abyssinica, remains elusive. Results To identify the differentially expressed transcripts and the pathways involved in arsenic metabolism and detoxification, C. abyssinica plants were subjected to arsenate stress and a PCR-Select Suppression Subtraction Hybridization (SSH approach was employed. A total of 105 differentially expressed subtracted cDNAs were sequenced which were found to represent 38 genes. Those genes encode proteins functioning as antioxidants, metal transporters, reductases, enzymes involved in the protein degradation pathway, and several novel uncharacterized proteins. The transcripts corresponding to the subtracted cDNAs showed strong upregulation by arsenate stress as confirmed by the semi-quantitative RT-PCR. Conclusions Our study revealed novel insights into the plant defense mechanisms and the regulation of genes and gene networks in response to arsenate toxicity. The differential expression of transcripts encoding glutathione-S-transferases, antioxidants, sulfur metabolism, heat-shock proteins, metal transporters, and enzymes in the ubiquitination pathway of protein degradation as well as several unknown

  7. Bacterial molybdoenzymes: old enzymes for new purposes.

    Science.gov (United States)

    Leimkühler, Silke; Iobbi-Nivol, Chantal

    2016-01-01

    Molybdoenzymes are widespread in eukaryotic and prokaryotic organisms where they play crucial functions in detoxification reactions in the metabolism of humans and bacteria, in nitrate assimilation in plants and in anaerobic respiration in bacteria. To be fully active, these enzymes require complex molybdenum-containing cofactors, which are inserted into the apoenzymes after folding. For almost all the bacterial molybdoenzymes, molybdenum cofactor insertion requires the involvement of specific chaperones. In this review, an overview on the molybdenum cofactor biosynthetic pathway is given together with the role of specific chaperones dedicated for molybdenum cofactor insertion and maturation. Many bacteria are involved in geochemical cycles on earth and therefore have an environmental impact. The roles of molybdoenzymes in bioremediation and for environmental applications are presented.

  8. Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.

    Science.gov (United States)

    Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

    2011-04-01

    Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion.

  9. Effect of flow on the detoxification function of rat hepatocytes in a bioartificial liver reactor.

    Science.gov (United States)

    Roy, P; Washizu, J; Tilles, A W; Yarmush, M L; Toner, M

    2001-01-01

    Ethoxyresorufin-o-deethylation (EROD) can be used as a sensitive measure of hepatic detoxification function. In this study, we employed a fluorescence assay based on EROD to study the effect of varying Peclet number (or flow) on hepatic function in a microchannel flat-plate bioartificial liver (BAL) reactor containing a coculture of hepatocytes and fibroblasts. Static culture and reactor flow experiments established that: 1) a pseudo-steady-state detoxification rate could be attained at each Peclet number, 2) the steady-state detoxification rate increased nonlinearly with Peclet number (ranging from 167 to 2500), 3) the uptake rate of substrate was a linear function of cell surface substrate concentration (reactor for human application.

  10. Metabolic Enzymes of Cocaine Metabolite Benzoylecgonine.

    Science.gov (United States)

    Chen, Xiabin; Zheng, Xirong; Zhan, Max; Zhou, Ziyuan; Zhan, Chang-Guo; Zheng, Fang

    2016-08-19

    Cocaine is one of the most addictive drugs without a U.S. Food and Drug Administration (FDA)-approved medication. Enzyme therapy using an efficient cocaine-metabolizing enzyme is recognized as the most promising approach to cocaine overdose treatment. The actual enzyme, known as RBP-8000, under current clinical development for cocaine overdose treatment is our previously designed T172R/G173Q mutant of bacterial cocaine esterase (CocE). The T172R/G173Q mutant is effective in hydrolyzing cocaine but inactive against benzoylecgonine (a major, biologically active metabolite of cocaine). Unlike cocaine itself, benzoylecgonine has an unusually stable zwitterion structure resistant to further hydrolysis in the body and environment. In fact, benzoylecgonine can last in the body for a very long time (a few days) and, thus, is responsible for the long-term toxicity of cocaine and a commonly used marker for drug addiction diagnosis in pre-employment drug tests. Because CocE and its mutants are all active against cocaine and inactive against benzoylecgonine, one might simply assume that other enzymes that are active against cocaine are also inactive against benzoylecgonine. Here, through combined computational modeling and experimental studies, we demonstrate for the first time that human butyrylcholinesterase (BChE) is actually active against benzoylecgonine, and that a rationally designed BChE mutant can not only more efficiently accelerate cocaine hydrolysis but also significantly hydrolyze benzoylecgonine in vitro and in vivo. This sets the stage for advanced studies to design more efficient mutant enzymes valuable for the development of an ideal cocaine overdose enzyme therapy and for benzoylecgonine detoxification in the environment.

  11. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine.

    Science.gov (United States)

    Leke, Renata; Bak, Lasse K; Anker, Malene; Melø, Torun M; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Portela, Luis V; Sonnewald, Ursula; Schousboe, Arne; Waagepetersen, Helle S

    2011-04-01

    Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme. Moreover, it has been suggested that cerebral tricarboxylic acid (TCA) cycle metabolism is inhibited and glycolysis enhanced during hyperammonemia. The aim of this study was to characterize the ammonia-detoxifying mechanisms as well as the effects of ammonia on energy-generating metabolic pathways in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important for ammonia detoxification as a supplement to formation of glutamine.

  12. Ethanol from lignocellulose - Fermentation inhibitors, detoxification and genetic engineering of Saccharomyces cerevisiae for enhanced resistance

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Simona

    2000-07-01

    Ethanol can be produced from lignocellulose by first hydrolysing the material to sugars, and then fermenting the hydrolysate with the yeast Saccharomyces cerevisiae. Hydrolysis using dilute sulphuric acid has advantages over other methods, however, compounds which inhibit fermentation are generated during this kind of hydrolysis. The inhibitory effect of aliphatic acids, furans, and phenolic compounds was investigated. The generation of inhibitors during hydrolysis was studied using Norway spruce as raw material. It was concluded that the decrease in the fermentability coincided with increasing harshness of the hydrolysis conditions. The decrease in fermentability was not correlated solely to the content of aliphatic acids or furan derivatives. To increase the fermentability, detoxification is often employed. Twelve detoxification methods were compared with respect to the chemical composition of the hydrolysate and the fermentability after treatment. The most efficient detoxification methods were anion-exchange at pH 10.0, overliming and enzymatic detoxification with the phenol-oxidase laccase. Detailed analyses of ion exchange revealed that anion exchange and unspecific hydrophobic interactions greatly contributed to the detoxification effect, while cation exchange did not. The comparison of detoxification methods also showed that phenolic compounds are very important fermentation inhibitors, as their selective removal with laccase had a major positive effect on the fermentability. Selected compounds; aliphatic acids, furans and phenolic compounds, were characterised with respect to their inhibitory effect on ethanolic fermentation by S. cerevisiae. When aliphatic acids or furans were compared, the inhibitory effects were found to be in the same range, but the phenolic compounds displayed widely different inhibitory effects. The possibility of genetically engineering S. cerevisiae to achieve increased inhibitor resistance was explored by heterologous expression of

  13. Terapia de reposição enzimática para as mucopolissacaridoses I, II e VI: recomendações de um grupo de especialistas brasileiros Enzyme replacement therapy for mucopolysaccharidoses I, II and VI: recommendations from a group of Brazilian F experts

    Directory of Open Access Journals (Sweden)

    Roberto Giugliani

    2010-01-01

    já está em desenvolvimento clínico, com perspectivas para o tratamento da MPS III A e do déficit cognitivo na MPS II através de administração da enzima diretamente no sistema nervoso central (SNC. Um grande número de centros brasileiros, incluindo serviços de todas as regiões do país, já têm experiência com TRE para MPS I, II e VI. Essa experiência foi adquirida não só com o tratamento de pacientes como também com a participação de alguns grupos em ensaios clínicos envolvendo TRE para essas condições. Somados os três tipos de MPS, mais de 250 pacientes já foram tratados com TRE em nosso país. A experiência dos profissionais brasileiros, somada aos dados disponíveis na literatura internacional, permitiu elaborar este documento, produzido com o objetivo de reunir e harmonizar as informações disponíveis sobre o tratamento destas doenças graves e progressivas, mas que, felizmente, são hoje tratáveis, uma realidade que traz novas perspectivas para os pacientes brasileiros afetados por essas condições.Mucopolysaccharidoses (MPS are rare genetic diseases caused by deficiency of specific lysosomal enzymes that affect catabolism of glycosaminoglycans (GAG. Accumulation of GAG in various organs and tissues in MPS patients results in a series of signs and symptoms, producing a multisystemic condition affecting bones and joints, the respiratory and cardiovascular systems and many other organs and tissues, including in some cases, cognitive performance. So far, eleven enzyme defects that cause seven different types of MPS have been identified. Before introduction of therapies to restore deficient enzyme activity, treatment of MPS focused primnarily on prevention and care of complications, still a very important aspect in the management of these patients. In the 80's treatment of MPS with bone marrow transplantation/hematopoietic stem cells transplantation (BMT/HSCT was proposed and in the 90's, enzyme replacement therapy (ERT,began to be

  14. Rapid detoxification of benzodiazepine or Z-drugs dependence using acetylcholinesterase inhibitors.

    Science.gov (United States)

    Lin, Shih-Ku

    2014-07-01

    Dependence on benzodiazepines (BZDs) or Z-drugs (zolpidem, zopicline and zaleplon) is a common clinical phenomenon. Traditional detoxification of BZDs dependence includes tapering used dose gradually and using equivalent doses of long-acting BZDs as substitutes. This kind of regimen tends to take a long time (up to 4weeks) and may require hospitalization. Acetylcholinesterase inhibitors have been shown to reverse BZDs induced sedation. We propose that oral form acetylcholinesterase inhibitors (donepezil, galantamine and rivastigmine) also posses the effect of inhibiting GABA receptors, and act as indirect antagonist, to be applied in the rapid detoxification treatment of BZDs and Z-drug dependence.

  15. N-carbamylglutamate enhances ammonia detoxification in a patient with decompensated methylmalonic aciduria.

    Science.gov (United States)

    Gebhardt, Boris; Vlaho, Stefan; Fischer, Doris; Sewell, Adrian; Böhles, Hansjosef

    2003-08-01

    In patients with methylmalonic aciduria (MMA), the accumulating metabolite propiony-CoA results in an inhibition of the urea circle via the decreased synthesis of N-acetylglutamate, an essential activator of carbamylphosphat synthetase (CPS). This results in one of the major clinical problems which is hyperammonaemia. In a patient with decompensated MMA, the CPS activator carbamylglutamate was tested for its ability to antagonize the propionyl-CoA-induced hyperammonaemia. Oral carbamylgutamate administration resulted in an impressive increase in ammonia detoxification compared to peritoneal dialysis. Safe, fast and easy to administer, carbamylglutamate improves the acute therapy of decompensated MMA by increasing ammonia detoxification and avoiding hyperammonaemia.

  16. Impact of Detoxification Techniques on Pulmonary Gas Exchange Function in Patients with Generalized Peritonitis

    Directory of Open Access Journals (Sweden)

    R. A. Mlinnik

    2012-01-01

    Full Text Available Objective: to analyze the impact of different detoxification techniques on pulmonary gas exchange function in patients with generalized peritonitis complicated by multiple organ failure. Subjects and methods. One hundred and thirty patients with generalized peritonitis were examined. According to the used detoxification techniques, the patients were divided into 5 groups. All the patients underwent a comprehensive examination, the key element of which was the evaluation of gas exchange parameters. Results. Membrane plasmapheresis and plasmapheresis with sodium hypochlorite infusion to the plasma filter in patients with peritonitis are shown to improve pulmonary blood oxygenation.

  17. A physiologically based in silico model for trans-2-hexenal detoxification and DNA adduct formation in human including interindividual variation indicates efficient detoxification and a negligible genotoxicity risk.

    Science.gov (United States)

    Kiwamoto, R; Spenkelink, A; Rietjens, I M C M; Punt, A

    2013-09-01

    A number of α,β-unsaturated aldehydes are present in food both as natural constituents and as flavouring agents. Their reaction with DNA due to their electrophilic α,β-unsaturated aldehyde moiety may result in genotoxicity as observed in some in vitro models, thereby raising a safety concern. A question that remains is whether in vivo detoxification would be efficient enough to prevent DNA adduct formation and genotoxicity. In this study, a human physiologically based kinetic/dynamic (PBK/D) model of trans-2-hexenal (2-hexenal), a selected model α,β-unsaturated aldehyde, was developed to examine dose-dependent detoxification and DNA adduct formation in humans upon dietary exposure. The kinetic model parameters for detoxification were quantified using relevant pooled human tissue fractions as well as tissue fractions from 11 different individual subjects. In addition, a Monte Carlo simulation was performed so that the impact of interindividual variation in 2-hexenal detoxification on the DNA adduct formation in the population as a whole could be examined. The PBK/D model revealed that DNA adduct formation due to 2-hexenal exposure was 0.039 adducts/10⁸ nucleotides (nt) at the estimated average 2-hexenal dietary intake (0.04 mg 2-hexenal/kg bw) and 0.18 adducts/10⁸ nt at the 95th percentile of the dietary intake (0.178 mg 2-hexenal/kg bw) in the most sensitive people. These levels are three orders of magnitude lower than natural background DNA adduct levels that have been reported in disease-free humans (6.8-110 adducts/10⁸ nt), suggesting that the genotoxicity risk for the human population at realistic dietary daily intakes of 2-hexenal may be negligible.

  18. Thyroid hormone levels and hepatic enzyme activity in lactating dams after gestational exposure to low dose PBDE 47

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, S.N.; Grande, S.W.; Akkoc, Z.; Souza, C.A.M. de; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin; Fidalgo-Neto, A.A. [Oswaldo Cruz Foundation, Rio de Janeiro (Brazil). Lab. of Environmental Toxicology

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are found extensively in the environment (shown by several studies on sentinel animal species), as well as in humans. In rodents, technical commercial PBDE mixtures and individual congeners have shown to interfere with thyroid hormone homeostasis, produce a mix-type induction of hepatic microsomal enzymes, disrupt spontaneous behaviour, impair learning and memory and alter the cholinergic transmitter system. In rat and mice, some technical PBDE commercial mixtures such as DE-71 and Bromkal 70 and the congener PBDE 47 have shown to decrease circulating thyroid hormone levels. PBDEs are also able to induce both hepatic phase I and phase II detoxification enzymes, demonstrated by several investigations in laboratory animals. For example, induction of ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-Odespenthylase (PROD) and uridinediphospho-glucuronosyltransferase (UDPGT) has been shown in rodents and cell lines after exposure to technical mixtures or individual congeners. However, these studies deal with doses much higher than that found in human tissues, highlighting the importance of assessing the adverse effects of doses close to human exposure levels. PBDE 47 is the most predominant congener found in environmental and human samples (including human milk) and, therefore, hazard identification is extremely important for human risk assessment. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW of the congener, 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47). These doses are pertinent to human exposure levels because a study by She et al. found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat. In this study, thyroid hormone levels and hepatic enzyme activity were evaluated in lactating dams after in utero administration of low dose PBDE 47.

  19. Towards a Mechanistic Understanding of Anaerobic Nitrate Dependent Iron Oxidation: Balancing Electron Uptake and Detoxification

    Directory of Open Access Journals (Sweden)

    Hans Karl Carlson

    2012-02-01

    Full Text Available The anaerobic oxidation of Fe(II by subsurface microorganisms is an important part of biogeochemical cycling in the environment, but the biochemical mechanisms used to couple iron oxidation to nitrate respiration are not well understood. Based on our own work and the evidence available in the literature, we propose a mechanistic model for anaerobic nitrate dependent iron oxidation. We suggest that anaerobic iron oxidizing microorganisms likely exist along a continuum including: 1 bacteria that inadvertently oxidize Fe(II by abiotic or biotic reactions with enzymes or chemical intermediates in their metabolic pathways (e.g. denitrification and suffer from toxicity or energetic penalty, 2 Fe(II tolerant bacteria that gain little or no growth benefit from iron oxidation but can manage the toxic reactions, and 3 bacteria that efficiently accept electrons from Fe(II to gain a growth advantage while preventing or mitigating the toxic reactions. Predictions of the proposed model are highlighted and experimental approaches are discussed.

  20. Modulation of xenobiotic metabolising enzymes by anticarcinogens-focus on glutathione S-transferases and their role as targets of dietary chemoprevention in colorectal carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Pool-Zobel, Beatrice [Department of Nutritional Toxicology, Institute for Nutrition, Friedrich Schiller University Jena, 07743 Jena (Germany)]. E-mail: b8pobe@uni-jena.de; Veeriah, Selvaraju [Department of Nutritional Toxicology, Institute for Nutrition, Friedrich Schiller University Jena, 07743 Jena (Germany); Boehmer, Frank-D. [Institute of Molecular Cell Biology, University Hospital, Friedrich Schiller University Jena, 07743 Jena (Germany)

    2005-12-11

    There is evidence that consumption of certain dietary ingredients may favourably modulate biotransformation of carcinogens. Associated with this is the hypothesis that the risk for developing colorectal cancer could be reduced, since its incidence is related to diet. Two main groups of biotransformation enzymes metabolize carcinogens, namely Phase I enzymes, which convert hydrophobic compounds to more water-soluble moieties, and Phase II enzymes (e.g. glutathione S-transferases [GST]), which primarily catalyze conjugation reactions. The conjugation of electrophilic Phase I intermediates with glutathione, for instance, frequently results in detoxification. Several possible colon carcinogens may serve as substrates for GST isoenzymes that can have marked substrate specificity. The conjugated products could be less toxic/genotoxic if GSTs are induced, thereby reducing exposure. Thus, numerous studies have shown that the induction of GSTs by antioxidants enables experimental animals to tolerate exposure to carcinogens. One important mechanism of GST induction involves an antioxidant-responsive response element (ARE) and the transcription factor nuclear factor E2-related factor 2 (Nrf2), which is bound to the Kelch-like ECH associated protein 1 (Keap1) in the cytoplasm. Antioxidants may disrupt the Keap-Nrf2 complex, allowing Nrf2 to translocate to the nucleus and mediate expression of Phase II genes via interaction with the ARE. GSTs are also induced by butyrate, a product of gut flora-derived fermentation of plant foods, which may act via different mechanisms, e.g. by increasing histone acetylation. GSTs are expressed with high inter-individual variability in human colonocytes, which points to large differences in cellular susceptibility to xenobiotics. Enhancing expression of GSTs in human colon tissue could therefore contribute to reducing cancer risks. However, it has not been demonstrated in humans that this mechanism is associated with cancer prevention. In the

  1. cobalt (ii), nickel (ii)

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The manganese (II), cobalt (II), nickel (II) and copper (II) complexes of N, N' – ... temperature and coordinated water were determined ... indicating fairly stable complex compounds (Table 1). The complex compounds are insoluble [Table 2] in water and common organic solvents, but are readily soluble in ...

  2. Detoxification of selenite and mercury by reduction and mutual protection in the assimilation of both elements by Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Belzile, Nelson [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6 (Canada)]. E-mail: nbelzile@laurentian.ca; Wu Gaojun [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6 (Canada); Chen, Yu-Wei [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6 (Canada); Appanna, Vasu D. [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6 (Canada)

    2006-08-31

    A study on the assimilation and detoxification of selenium and mercury and on the interaction between these two elements was conducted on Pseudomonas fluorescens. P. fluorescens was able to convert separately both elements to their elemental forms, which are less toxic and biologically less available. To study the converting mechanism of selenite to elemental Se, cells were grown in the presence of various selenite concentrations and several parameters such as extracellular protein concentrations, pH, carbohydrate concentrations, isocitrate dehydrogenase (ICDH) and malic enzyme were monitored. Transmission electron microscopy (TEM) and various analytical methods were applied to confirm the interaction between selenium and cell. The former appeared as a red precipitate localized predominantly in the consumed culture medium. P. fluorescens also resisted to the toxic effect of mercury by converting Hg{sup 2+} to the volatile and less toxic form Hg . Mercury reductase was likely responsible for the conversion of Hg{sup 2+} to Hg . More importantly, the interaction between mercury and selenium was also studied. The presence of selenite significantly reduced the accumulation of mercury in P. fluorescens. It was also interesting to note that mercury appeared to behave as a protecting agent against selenium intoxication as the bioaccumulation of Se was also inhibited by this metal. The formation of Se-Hg complexes could explain this mutual protective effect. No precipitate of elemental Se could be detected when Hg was present in the cultures.

  3. Biodegradation and detoxification of textile dye Disperse Red 54 by Brevibacillus laterosporus and determination of its metabolic fate.

    Science.gov (United States)

    Kurade, Mayur B; Waghmode, Tatoba R; Khandare, Rahul V; Jeon, Byong-Hun; Govindwar, Sanjay P

    2016-04-01

    Bioremediation is one of the milestones achieved by the biotechnological innovations. It is generating superior results in waste management such as removal of textile dyes, which are considered xenobiotic compounds and recalcitrant to biodegradation. In the present bioremedial approach, Brevibacillus laterosporus was used as an effective microbial tool to decolorize disperse dye Disperse Red 54 (DR54). Under optimized conditions (pH 7, 40°C), B. laterosporus led to 100% decolorization of DR54 (at 50 mg L(-1)) within 48 h. Yeast extract and peptone, supplemented in medium enhanced the decolorization efficiency of the bacterium. During the decolorization process, activities of enzymes responsible for decolorization, such as tyrosinase, veratryl alcohol oxidase and NADH--DCIP reductase were induced by 1.32-, 1.51- and 4.37-fold, respectively. The completely different chromatographic/spectroscopic spectrum of metabolites obtained after decolorization confirmed the biodegradation of DR54 as showed by High pressure liquid chromatography, High pressure thin layer chromatography and Fourier transform infrared spectroscopy. Gas chromatography-Mass spectroscopy studies suggested the parent dye was biodegraded into simple final product, N-(1λ(3)-chlorinin-2-yl)acetamide. Phytotoxicity study suggested that the metabolites obtained after biodegradation of DR54 were non-toxic as compared to the untreated dye signifying the detoxification of the DR54 by B. laterosporus.

  4. Exploiting the efficacy of Lysinibacillus sp. RGS for decolorization and detoxification of industrial dyes, textile effluent and bioreactor studies.

    Science.gov (United States)

    Saratale, Rijuta G; Saratale, Ganesh D; Govindwar, Sanjay P; Kim, Dong S

    2015-01-01

    Complete decolorization and detoxification of Reactive Orange 4 within 5 h (pH 6.6, at 30°C) by isolated Lysinibacillus sp. RGS was observed. Significant reduction in TOC (93%) and COD (90%) was indicative of conversion of complex dye into simple products, which were identified as naphthalene moieties by various analytical techniques (HPLC, FTIR, and GC-MS). Supplementation of agricultural waste extract considered as better option to make the process cost effective. Oxido-reductive enzymes were found to be involved in the degradation mechanism. Finally Loofa immobilized Lysinibacillus sp. cells in a fixed-bed bioreactor showed significant decolorization with reduction in TOC (51 and 64%) and COD (54 and 66%) for synthetic and textile effluent at 30 and 35 mL h(-1) feeding rate, respectively. The degraded metabolites showed non-toxic nature revealed by phytotoxicity and photosynthetic pigments content study for Sorghum vulgare and Phaseolus mungo. In addition nitrogen fixing and phosphate solubilizing microbes were less affected in treated wastewater and thus the treated effluent can be used for the irrigation purpose. This work could be useful for the development of efficient and ecofriendly technologies to reduce dye content in the wastewater to permissible levels at affordable cost.

  5. Wound-induced apoplastic peroxidase activities: their roles in the production and detoxification of reactive oxygen species.

    Science.gov (United States)

    Minibayeva, F; Kolesnikov, O; Chasov, A; Beckett, R P; Lüthje, S; Vylegzhanina, N; Buck, F; Böttger, M

    2009-05-01

    Production of reactive oxygen species (ROS) is a widely reported response of plants to wounding. However, the nature of enzymes responsible for ROS production and metabolism in the apoplast is still an open question. We identified and characterized the proteins responsible for the wound-induced production and detoxification of ROS in the apoplast of wheat roots (Triticum aestivum L.). Compared to intact roots, excised roots and leachates derived from them produced twice the amount of superoxide (O2(*-)). Wounding also induced extracellular peroxidase (ECPOX) activity mainly caused by the release of soluble peroxidases with molecular masses of 37, 40 and 136 kD. Peptide mass analysis by electrospray ionization-quadrupole time-of-flight-tandem mass spectrometry (ESI-QTOF-MS/MS) following lectin affinity chromatography of leachates showed the presence of peroxidases in unbound (37 kD) and bound (40 kD) fractions. High sensitivity of O2(*-)-producing activity to peroxidase inhibitors and production of O2(*-) by purified peroxidases in vitro provided evidence for the involvement of ECPOXs in O2(*-) production in the apoplast. Our results present new insights into the rapid response of roots to wounding. An important component of this response is mediated by peroxidases that are released from the cell surface into the apoplast where they can display both oxidative and peroxidative activities.

  6. Alcohol detoxification completion, acceptance of referral to substance abuse treatment, and entry into substance abuse treatment among Alaska Native people.

    Science.gov (United States)

    Running Bear, Ursula; Beals, Janette; Novins, Douglas K; Manson, Spero M

    2017-02-01

    Little is known about factors associated with detoxification treatment completion and the transition to substance abuse treatment following detoxification among Alaska Native people. This study examined 3 critical points on the substance abuse continuum of care (alcohol detoxification completion, acceptance of referral to substance abuse treatment, entry into substance abuse treatment following detoxification). The retrospective cohort included 383 adult Alaska Native patients admitted to a tribally owned and managed inpatient detoxification unit. Three multiple logistic regression models estimated the adjusted associations of each outcome separately with demographic/psychosocial characteristics, clinical characteristics, use related behaviors, and health care utilization. Seventy-five percent completed detoxification treatment. Higher global assessment functioning scores, longer lengths of stay, and older ages of first alcohol use were associated with completing detoxification. A secondary drug diagnosis was associated with not completing detoxification. Thirty-six percent accepted a referral to substance abuse treatment following detoxification. Men, those with legal problems, and those with a longer length of stay were more likely to accept a referral to substance abuse treatment. Fifty-eight percent had a confirmed entry into a substance abuse treatment program at discharge. Length of stay was the only variable associated with substance abuse treatment entry. Services like motivational interviewing, counseling, development of therapeutic alliance, monetary incentives, and contingency management are effective in linking patients to services after detoxification. These should be considered, along with the factors associated with each point on the continuum of care when linking patients to follow-up services. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Defining the Molecular-Cellular-Field Continuum of Mercury Detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Susan M. [UCSF

    2014-09-04

    Hg is of special interest to DOE due to past use at the Oak Ridge Reservation (ORR). Its facile redox [Hg2+/0] chemistry, bonding to carbon [e.g. MeHg+] and unique physical properties [e.g., Hg0 volatility] underlie a complex global Hg cycle involving biotic and abiotic chemical and physical transport and transformations in soils, sediments, waterways and the atmosphere. Facultative and anaerobic bacteria make MeHg+, which is neurotoxic to wildlife and humans. Sustainable stewardship requires eliminating both MeHg+ and even more toxic Hg2+, which is also the substrate for methylation. The proteins encoded by the mer locus in aerobic and facultative mercury resistant (HgR) bacteria convert soil or waterborne Hg2+ or MeHg+ to less toxic, gaseous Hg0. HgR microbes live in highly Hg-contaminated sites and depress MeHg+ formation >500-fold in such zones. So, enhancing the capacity of natural HgR microbes to remove Hg2+/MeHg+ from wetlands and waterways is a logical component of contaminated site stewardship. To apply enhancement in the field requires knowing how the HgR pathway works including the metabolic demands it makes on the cell, i.e., the entire cell is the relevant catalytic unit. HgR loci occur in metabolically diverse bacteria and unique mer-host co-evolution has been found. In this project we extended our previous studies of mer enzymes in γ-proteobacteria, which are abundant in high Hg areas of the ORR to include studies of mer enzymes from HgR α-proteobacteria and HgR actinobacteria, which also increase in the high Hg regions of the ORR. Specifically, we (1) examined interactions between structural compoenents of MerA and MerB enzymes from γ-proteobacteria, (2) investigated effects of mutations on kinetic efficiency of Hg2+ reduction by γ-proteobacterial MerA, (3) cloned and performed initital characterization of MerA and MerB enzymes from Streptomyces lividans, an actinobacterium, (4) cloned and performed initial characterization of a fused Mer

  8. Modulating effects of thyroid state on the induction of biotransformation enzymes byu 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    NARCIS (Netherlands)

    Schuur, A.G.; Tacken, P.J.; Visser, T.J.; Brouwer, A.

    1998-01-01

    In this study we investigated to what extent the induction of detoxification enzymes by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is modulated by concomitant TCDD-induced changes in thyroid state. Euthyroid (Eu) male Sprague-Dawley rats, surgically thyroidectomized (Tx) rats and Tx rats receiving s

  9. Missense polymorphisms in three oxidative-stress enzymes (GSTP1, SOD2, and GPX1) and dyskinesias in Russian psychiatric inpatients from Siberia

    NARCIS (Netherlands)

    Al Hadithy, A. F. Y.; Ivanova, S. A.; Pechlivanoglou, P.; Wilffert, B.; Semke, A.; Fedorenko, O.; Kornetova, E.; Ryadovaya, L.; Brouwers, J. R. B. J.; Loonen, A. J. M.

    2010-01-01

    Neuronal degeneration due to oxidative stress (OS) has been proposed as a mechanism for tardive dyskinesia (TD) pathogenesis. Cellular defense mechanisms against OS may involve detoxification enzymes (e.g., glutathione peroxidase-1, GPX1; superoxide dismutase-2, SOD2 [also commonly known as MnSOD];

  10. Defining the Molecular-Cellular-Field Continuum of Mercury Detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Summers, Anne O. [Univ. of Georgia, Athens, GA (United States)

    2016-04-25

    Hg is of special interest to DOE due to past intensive use in manufacture of nuclear weapons at the Oak Ridge Reservation (ORR). Because of its facile oxidation/reduction [Hg(II)/Hg(0)] chemistry, ability to bond to carbon [as in highly toxic methylmercury: MeHg(I)] and its unique physical properties [e.g., volatility of Hg(0)], Hg has a complex environmental cycle involving soils, sediments, waterways and the atmosphere and including biotic and abiotic chemical and physical transport and transformations.1 Understanding such processes well enough to design stewardship plans that minimize negative impacts in diverse ecological settings requires rich knowledge of the contributing abiotic and biotic processes. Prokaryotes are major players in the global Hg cycle. Facultative and anaerobic bacteria can form MeHg(I) with consequent intoxication of wildlife and humans. Sustainable stewardship of Hg-contaminated sites requires eliminating not only MeHg(I) but also the Hg(II) substrate for methylation. Fortunately, a variety of mercury resistant (HgR) aerobic and facultative bacteria and archaea can do both things. Prokaryotes harboring narrow or broad Hg resistance (mer) loci detoxify Hg(II) or RHg(I), respectively, to relatively inert, less toxic, volatile Hg(0). HgR microbes are enriched in highly contaminated sites and extensive field data show they depress levels of MeHg >500-fold in such zones2. So, enhancing the natural capacity of indigenous HgR microbes to remove Hg(II) and RHg(I) from soils, sediments and waterways is a logical component of a comprehensive plan for clean up and stewardship of contaminated sites.

  11. Detoxification of ammonia in mouse cortical GABAergic cell cultures increases neuronal oxidative metabolism and reveals an emerging role for release of glucose-derived alanine

    DEFF Research Database (Denmark)

    Leke, Renata; Bak, Lasse Kristoffer; Anker, Malene

    2011-01-01

    in a mouse neuronal-astrocytic co-culture model of the GABAergic system. We found that 5 mM ammonium chloride affected energy metabolism by increasing the neuronal TCA cycle activity and switching the astrocytic TCA cycle toward synthesis of substrate for glutamine synthesis. Furthermore, ammonia exposure...... enhanced the synthesis and release of alanine. Collectively, our results demonstrate that (1) formation of glutamine is seminal for detoxification of ammonia; (2) neuronal oxidative metabolism is increased in the presence of ammonia; and (3) synthesis and release of alanine is likely to be important......Cerebral hyperammonemia is believed to play a pivotal role in the development of hepatic encephalopathy (HE), a debilitating condition arising due to acute or chronic liver disease. In the brain, ammonia is thought to be detoxified via the activity of glutamine synthetase, an astrocytic enzyme...

  12. Detoxification of biomass hydrolysates with nucleophilic amino acids enhances alcoholic fermentation.

    Science.gov (United States)

    Xie, Rui; Tu, Maobing; Carvin, Jamarius; Wu, Yonnie

    2015-06-01

    Carbonyl compounds generated in biomass pretreatment hinder the biochemical conversion of biomass hydrolysates to biofuels. A novel approach of detoxifying hydrolysates with amino acids for ethanol production was developed. Among the 20 amino acids assessed for their detoxification efficiency and nucleophilicity, cysteine was the most effective one. It increased both ethanol productivity and final yield of biomass hydrolysates from 0.18 (untreated) to 1.77 g/L/h and from 0.02 to 0.42 g/g, respectively. Detoxification efficiency was followed by histidine and it increased the final yield to 0.42 g/g, then by lysine, tryptophan and asparagine. It was observed all five effective amino acids contained reactive side-chain functional groups, which played important roles in the amino acid detoxification reaction. The study further showed cysteine and glycine detoxifications were temperature and pH dependent. The mechanistic study using mass spectrometry revealed thiazolidine carboxylic acid, a Schiff base, was formed by condensation of aldehyde and cysteine.

  13. ASSESSING DETOXIFICATION AND DEGRADATION OF WOOD PRESERVING AND PETROLEUM WASTES IN CONTAMINATED SOIL

    Science.gov (United States)

    This study was undertaken to evaluate in-situ soil bioremediation processes, including degradation and detoxification, for two types of wood preserving wastes and two types of petroleum refining wastes at high concentrations in an unacclimated soil. The soil solid phase, water so...

  14. 77 FR 72752 - Opioid Drugs in Maintenance and Detoxification Treatment of Opiate Addiction; Proposed...

    Science.gov (United States)

    2012-12-06

    ... HUMAN SERVICES 42 CFR Part 8 RIN 0930-AA14 Opioid Drugs in Maintenance and Detoxification Treatment of... Combination as Used in Approved Opioid Treatment Medications AGENCY: Substance Abuse and Mental Health.... SUMMARY: This final rule amends the federal opioid treatment program regulations by modifying the...

  15. Esterase detoxification of acetylcholinesterase inhibitors using human liver samples in vitro

    Science.gov (United States)

    Organophosphate (OP) and N-methylcarbamate pesticides inhibit acetylcholinesterase (AChE), but differences in metabolism and detoxification can influence potency of these pesticides across and within species. Carboxylesterase (CaE) and A-esterase (paraoxonase, PON1) are consider...

  16. Randomized, placebo-controlled pilot trial of gabapentin during an outpatient, buprenorphine-assisted detoxification procedure.

    Science.gov (United States)

    Sanders, Nichole C; Mancino, Michael J; Gentry, W Brooks; Guise, J Benjamin; Bickel, Warren K; Thostenson, Jeff; Oliveto, Alison H

    2013-08-01

    This pilot study examined the efficacy of the N-type calcium channel blocker gabapentin to improve outcomes during a brief detoxification protocol with buprenorphine. Treatment-seeking opioid-dependent individuals were enrolled in a 5-week, double-blind, placebo-controlled trial examining the effects of gabapentin during a 10-day outpatient detoxification from buprenorphine. Participants were inducted onto buprenorphine sublingual tablets during Week 1, were randomized and inducted onto gabapentin or placebo during Week 2, underwent a 10-day buprenorphine taper during Weeks 3 and 4, and then were tapered off gabapentin/placebo during Week 5. Assessments included thrice-weekly opioid withdrawal scales, vitals, and urine drug screens. Twenty-four individuals (13 male; 17 Caucasian, 3 African American, 4 Latino; mean age 29.7 years) participated in the detoxification portion of the study (gabapentin, n = 11; placebo, n = 13). Baseline characteristics did not differ significantly between groups. Self-reported and observer-rated opioid withdrawal ratings were relatively low and did not differ between groups during the buprenorphine taper. Urine results showed a Drug × Time interaction, such that the probability of opioid-positive urines significantly decreased over time in the gabapentin versus placebo groups during Weeks 3 and 4 (OR = 0.73, p = .004). These results suggest that gabapentin reduces opioid use during a 10-day buprenorphine detoxification procedure.

  17. Motivational interviewing group at inpatient detoxification, its influence in maintaining abstinence and treatment retention after discharge.

    Science.gov (United States)

    Bachiller, Diana; Grau-López, Lara; Barral, Carmen; Daigre, Constanza; Alberich, Cristina; Rodríguez-Cintas, Laia; Valero, Sergi; Casas, Miquel; Roncero, Carlos

    2015-06-17

    The relapse rate after discharge from inpatient detoxification is high. The objective of this pilot study is to assess the sociodemographic, clinical and therapeutic factors associated with maintaining abstinence in patients who participated in a brief motivational interviewing group during admission for detoxification. A total of 46 patients, diagnosed substance dependent according to DSM -IV, and admitted to the Hospital Detoxification Unit, participated in a brief motivational interviewing group. Sociodemographic, clinical, motivation to change (University of Rhode Island Change Assessment, URICA) and satisfaction with the treatment group (Treatment Perceptions Questionnaire, CPT) data were collected. Abstinence and treatment retention two months after discharge were assessed by weekly telephone calls. A survival analysis was performed. Being male, having more cognitions of the maintenance stage of change at discharge, being satisfied with group therapy and therapist during hospitalization are associated with longer abstinence after discharge. The brief motivational interviewing group approach with patients admitted for detoxification is related to greater likelihood of maintaining abstinence and subsequent treatment retention.

  18. Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

    Science.gov (United States)

    Deng, Li-Hong; Tang, Yong; Liu, Yun

    2014-01-01

    Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA) pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification. PMID:25133211

  19. Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

    Directory of Open Access Journals (Sweden)

    Li-Hong Deng

    2014-01-01

    Full Text Available Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification.

  20. Growth characteristics of Dayak Borneo yam (Dioscorea hispida and detoxification techniques as alternative food

    Directory of Open Access Journals (Sweden)

    RUDITO

    2017-03-01

    Full Text Available Abstract. Rudito, Suwarto, Azkiyah L, Witono Y, Saragih B, Arung ET. 2017. Growth characteristics of Dayak Borneo yam (Dioscorea hispida and detoxification techniques as alternative food. Pros Sem Nas Masy Biodiv Indon 3: 99-103. Finding of local food sources to enhance food security areas. This study focuses on the characteristics of growth Dayak Borneo yam observation, toxic substances and detoxification techniques development of non nutritional. The objective of the research was to find out a more concrete picture, as well as comparing it with Java yam non nutritional components as a basis for further exploration of alternative food. Observations indicate that the plant growth of Dayak Borneo yam had specific characteristics, and can be grown in intercropping with other crops. Yam tubers have negative image due to the toxins contained by this commodity, as well as technology management (detoxification and processing of yam products that have not been controlled by the community. But based on the results of physical and chemical detoxification, indicates that the Dayak Borneo yam can be exploited further as food. Dayak Borneo yam need to be developed modification process in raw materials of Dayak Borneo yam as modified starch through fermentation techniques which also intended to obtain intermediate product from which Dayak Borneo yam has a larger functionality as a food ingredient.

  1. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

  2. Insight on trace element detoxification in the Black-tailed Godwit (Limosa limosa) through genetic, enzymatic and metallothionein analyses

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, Magali, E-mail: m.lucia33@laposte.net [Littoral, Environnement et Societes (LIENSs), UMR 7266 CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Bocher, Pierrick [Littoral, Environnement et Societes (LIENSs), UMR 7266 CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Cosson, Richard P. [Mer Molecules Sante (MMS), Universite de Nantes, EA 2663, 2 rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Churlaud, Carine; Robin, Frederic; Bustamante, Paco [Littoral, Environnement et Societes (LIENSs), UMR 7266 CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France)

    2012-04-15

    Trace element concentrations (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Zn) were investigated in the liver, kidneys, muscle and feathers of 31 black-tailed godwits (Limosa limosa) accidentally killed during catches by mist net in the Pertuis Charentais, Atlantic coast of France. Analyses of carbon and nitrogen stable isotope ratios were carried out in liver, muscle and feathers in order to elucidate dietary patterns and to determine whether differences in diet explained the variation in elemental uptake. This study also aimed to have a preliminary assessment of sub-lethal effects triggered by trace elements through the investigation of gene expressions by quantitative real-time PCR, antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase), and metallothionein (MT) levels. The results showed that Cr and Ni concentrations in tissues of adults were lower than in juveniles in part because adults may have eliminated these trace elements through moulting. Except for Cd and Ni, trace element concentrations were negatively correlated to the body mass of godwits. Ag, As, Hg and Se concentrations were positively linked with the trophic position of birds. The diet could be considered as a fundamental route of exposure for these elements demonstrating therefore the qualitative linkage between dietary habits of godwits and their contaminant concentrations. Our results strongly suggest that even though trace element concentrations were mostly below toxicity threshold level, the elevated concentrations of As, Ag, Cd, Cu, Fe and Se may however trigger sub-lethal effects. Trace elements appear to enhance expression of genes involved in oxidative stress defence, which indicates the production of reactive oxygen species. Moreover, birds with the highest concentrations appeared to have an increased mitochondrial metabolism suggesting that the fight against trace element toxicity requires additional energetic needs notably to produce detoxification

  3. Effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on all-cause mortality, cardiovascular deaths, and cardiovascular events in patients with diabetes mellitus: a meta-analysis.

    Science.gov (United States)

    Cheng, Jun; Zhang, Wen; Zhang, Xiaohui; Han, Fei; Li, Xiayu; He, Xuelin; Li, Qun; Chen, Jianghua

    2014-05-01

    Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) may have different effects on cardiovascular (CV) events in patients with diabetes mellitus (DM). To conduct a meta-analysis to separately evaluate the effects of ACEIs and ARBs on all-cause mortality, CV deaths, and major CV events in patients with DM. DATA SOURCES Data sources included MEDLINE (1966-2012), EMBASE (1988-2012), the Cochrane Central Register of Controlled Trials, conference proceedings, and article reference lists. We included randomized clinical trials reporting the effects of ACEI and ARB regimens for DM on all-cause mortality, CV deaths, and major CV events with an observation period of at least 12 months. Studies were excluded if they were crossover trials. Dichotomous outcome data from individual trials were analyzed using the risk ratio (RR) measure and its 95% CI with random-effects models. We estimated the difference between the estimates of the subgroups according to tests for interaction. We performed meta-regression analyses to identify sources of heterogeneity. Primary end points were all-cause mortality and death from CV causes. Secondary end points were the effects of ACEIs and ARBs on major CV events. Twenty-three of 35 identified trials compared ACEIs with placebo or active drugs (32,827 patients) and 13 compared ARBs with no therapy (controls) (23,867 patients). When compared with controls (placebo/active treatment), ACEIs significantly reduced the risk of all-cause mortality by 13% (RR, 0.87; 95% CI, 0.78-0.98), CV deaths by 17% (0.83; 0.70-0.99), and major CV events by 14% (0.86; 0.77-0.95), including myocardial infarction by 21% (0.79; 0.65-0.95) and heart failure by 19% (0.81; 0.71-0.93). Treatment with ARBs did not significantly affect all-cause mortality (RR, 0.94; 95% CI, 0.82-1.08), CV death rate (1.21; 0.81-1.80), and major CV events (0.94; 0.85-1.01) with the exception of heart failure (0.70; 0.59-0.82). Both ACEIs and ARBs were

  4. Degradation products of the artificial azo dye, Allura red, inhibit esterase activity of carbonic anhydrase