Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glutathione peroxidase (glutathione:hydrogen peroxide oxidoreductase, EC 1.11.1.9) was purified from rat liver mitochondria. The enzyme was shown to be pure by polyacrylamide-gel electrophoresis and to contain multiple forms that differed in charge. Selenium was specifically associated with the enzyme. The enzyme was inhibited by iodoacetic acid and iodoacetamide in an unusual pattern of reduction by sulfhydryl compounds and pH dependency. The mitochondrial and cytoplasmic forms of the enzyme were compared, and an explanation of the inhibition patterns is offered.
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PMID:Purification and properties of rat liver mitochondrial glutathione peroxidase. 2 81

Vitamin K is an essential cofactor for a microsomal carboxylase that converts glutamyl residues in endogenous precursor proteins to gamma-carboxyglutamyl residues in completed proteins. The same microsomal preparations convert vitamin K to its 2,3-epoxide, and it has been suggested that these two reactions (carboxylation and epoxidation) are coupled. Glutathione peroxidase, which reduces hydrogen peroxide and organic hydroperoxides, inhibits both of these reactions in a prepartion of microsomes solubilized by Triton X-100. Catalase has no effect. In the absence of vitamin K, and in the presence of NADPH, tert-butyl hydroperoxide acts as a weak vitamin K analog. At lower concentrations, tert-butyl hydroperoxide is an apparent competitive inhibitor of vitamin K for both the carboxylase and epoxidase reactions. These data are consistent with the hypothesis that both of these vitamin K-requiring reactions involve a common oxygenated intermediate, and that a hydroperoxide of the vitamin is the species involved.
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PMID:Vitamin K-dependent carboxylase: evidence for a hydroperoxide intermediate in the reaction. 28 91

Erythrocyte antioxidants catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase were studied in cells harbouring different growth stages of Plasmodium falciparum. Catalase and superoxide dismutase showed significant decrease during parasite maturation indicating hampered metabolism of hydrogen peroxide and superoxide anions. Glutathione peroxidase also exhibited a downward trend during the growth of P. falciparum, while there was a moderate accumulation of reduced glutathione. These findings suggest decreased utilization of the reduction potential in detoxification of reactive oxygen species. The fall in all three antioxidant enzymes studied was highly significant (P less than 0.001) in erythrocytes with mature stages of the parasite (trophozoites, schizonts). The increased vulnerability of erythrocytes to damage, which parallels the growth phases of the parasite emphasizes the need for early treatment of P. falciparum malaria to minimise red cell destruction and the resulting anaemia.
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PMID:Plasmodium falciparum induced perturbations of the erythrocyte antioxidant system. 139 36

The effect of iron-overload on both hepatic lipid peroxidation and chemiluminescence was studied in early stages after iron-dextran injection. Total hepatic iron content was markedly elevated over control values 2-6 h after iron dose. A 4-fold increase in light emission was detected after 4-6 h after iron injection. Plasma GOT, GPT and LDH activities were not affected by the treatment suggesting that cell permeability was not affected by necrosis. Increases in the generation of thiobarbituric acid reactive substances (TBARS) and chemiluminescence in liver homogenates, were determined as a function of time after iron administration, in the presence of NADPH as cofactor. Under the same experimental conditions, microsomal cytochrome P-450 content was decreased by 40%, 2 h after iron treatment. To evaluate liver antioxidant defenses, catalase, superoxide dismutase and glutathione peroxidase activities were determined. Glutathione peroxidase activity in the homogenate was not affected by the treatment. Catalase and superoxide dismutase activities declined by 25 and 36%, respectively, compared with control values 4 h after the iron dose. Our data suggest that lipid peroxidation occurs after mild iron overload even though the liver remains functional.
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PMID:Hepatic chemiluminescence and lipid peroxidation in mild iron overload. 147 93

The effect of diabetes mellitus induced by streptozotocin on the activities of peroxisomal oxidases and H2O2-metabolizing enzymes, and lipid peroxidation in various rat tissues were investigated. Peroxisomal acyl-CoA oxidase, D-amino acid oxidase and L-alpha-hydroxyacid oxidase were measured by a sensitive spectrophotometric method using dichlorofluorescein/peroxidase as the detector of H2O2. Acyl-CoA oxidase activity was increased most markedly in the heart of diabetic rats, less markedly in the liver, and tended to be increased in the kidneys. The activities of other peroxisomal oxidases were much lower than that of acyl-CoA oxidase in the liver and kidneys, and were undetectable in the heart. Catalase activity was decreased in the liver and kidneys of diabetics, and was increased in the heart. Glutathione peroxidase activity was increased more markedly in the kidneys of the diabetics, and less markedly in the heart than in the liver. Lipid peroxide level was higher in the kidneys of the diabetics than in the controls, unchanged in the heart, and was lower in the liver of the diabetics than in the controls. Thus, peroxisomal beta-oxidation and the H2O2 production coupled with that, were activated in various tissues of diabetic rats, presumably as a part of the overall increase in lipid oxidation. However, they did not appear to contribute to the enhanced oxidative stress induced by diabetes mellitus.
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PMID:Peroxisomal oxidases in various tissues of diabetic rats. 167 55

We have isolated, following one-step mutagenesis, a Chinese hamster ovary cell mutant hypersensitive to the intercalating agent, adriamycin (4-fold compared to parental CHO-K1 cells). This agent exerts at least part of its cytotoxic action via inhibition of the nuclear enzyme, topoisomerase II. The mutant, designated ADR-3, showed hypersensitivity to all classes of topoisomerase II inhibitors, including actinomycin D, amsacrine (m-AMSA), etoposide (VP16) and mitoxantrone. ADR-3 cells also showed cross-sensitivity to ionizing radiation, but not to UV light. Cellular accumulation of radiolabeled actinomycin D was similar in parental and mutant cells. At equimolar doses, adriamycin induced more protein-associated DNA single- and double-strand breaks in ADR-3 cells than in CHO-K1 cells. Topoisomerase II activity was elevated to a small but significant degree in ADR-3 cells, and this was reflected in a 1.5-fold higher level of topoisomerase II protein in ADR-3 than in CHO-K1 cells, as judged by Western blotting. ADR-3 cells were hypersensitive to cumene hydroperoxide but cross-resistant to hydrogen peroxide, suggesting possible abnormality in the detoxification of peroxides by glutathione peroxidase or catalase. Glutathione peroxidase activity against hydrogen peroxide was similar in CHO-K1 and ADR-3 cell extracts, but activity against cumene hydroperoxide was evaluated to a small but significant extent in mutant cells. Catalase levels were not significantly different in ADR-3 and CHO-K1 cells. ADR-3 cells were recessive in hybrids with parental CHO-K1 cells with respect to sensitivity to topoisomerase II inhibitors and X-rays, and represent a different genetic complementation group from the previously reported adriamycin-sensitive mutant, ADR-1 [Davies et al., J. Biol. Chem., 263 (1988) 17724-17729].
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PMID:Isolation and partial characterisation of a mammalian cell mutant hypersensitive to topoisomerase II inhibitors and X-rays. 215 84

Glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase are the most important enzymes of the cell antioxidant defense system. However, these molecules are themselves susceptible to oxidation. The aim of this work was to estimate to what extent this system could be inactivated by its own substrates. We tested the effect of hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide and hydroxyl and superoxide radicals on GPX, SOD and catalase. For GPX, a 50% inactivation was observed at 10(-1) M (30 min, 37 degrees C) for hydrogen peroxide, 3 x 10(-4) M (15 min, 37 degrees C) for cumene hydroperoxide and 5 x 10(-5) M (11 min, 37 degrees C) for t-butyl hydroperoxide. Unlike the hydroxyl radicals, superoxide anions did not inactivate this enzyme. Catalase was inactivated by hydroxyl radicals and by superoxide anions but organic peroxides had no effect. SOD was inactivated by 50% by hydrogen peroxide at 4 x 10(-4) M (20 min, 37 degrees C), but organic peroxides and hydroxyl radicals were ineffective on this enzyme. Since the three enzymes of the antioxidant system are susceptible to at least one of the oxidative reactive molecules, in the case of high oxidative stresses such an inhibition could take place, leading to an irreversible autocatalytical process in which the production rate of the oxidants will continuously increase, leading to cell death.
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PMID:Glutathione peroxidase, superoxide dismutase, and catalase inactivation by peroxides and oxygen derived free radicals. 230 98

Glutathione peroxidase (GSH-Px; glutathione: hydrogen peroxide oxidoreductase; EC 1.11.1.9), catalase (H2O2: H2O2 oxidoreductase; EC 1.11.1.6) and superoxide dismutase (superoxide: superoxide oxidoreductase; EC 1.15.1.1) were coisolated from human erythrocyte lysate by chromatography on DEAE-cellulose. Glutathione peroxidase was separated from superoxide dismutase and catalase by thiol-disulfide exchange chromatography and then purified to approximately 90% homogeneity by gel permeation chromatography and dye-ligand affinity chromatography. Catalase and superoxide dismutase were separated from each other and purified further by gel permeation chromatography. Catalase was then purified to approximately 90% homogeneity by ammonium sulfate precipitation and superoxide dismutase was purified to apparent homogeneity by hydrophobic interaction chromatography. The results for glutathione peroxidase represent an improvement of approximately 10-fold in yield and 3-fold in specific activity compared with the established method for the purification of this enzyme. The yields for superoxide dismutase and catalase were high (45 mg and 232 mg, respectively, from 820 ml of washed packed cells), and the specific activities of both enzymes were comparable to values found in the literature.
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PMID:Coisolation of glutathione peroxidase, catalase and superoxide dismutase from human erythrocytes. 231 35

The effects of cell-free generated oxidants on migrating and developing stages of Schistosoma mansoni were investigated and the levels of antioxidant enzymes and of glutathione were determined for each stage. Schistosomula and 2-week-old parasites recovered from the livers of infected mice showed similar susceptibility to killing by added hydrogen peroxide and t-butylhydroperoxide. However, when glucose (0.5 mM)-glucose oxidase (2.5 mU ml-1) and xanthine (0.5 mM) or hypoxanthine (0.5 mM)-xanthine oxidase (5.0 mU ml-1) systems were used to generate hydrogen peroxide and oxygen free-radicals, schistosomula were more susceptible to oxidative killing than the 2-week-old parasites. The 4- and 8-week-old worms were more resistant to oxidants than all of the younger stages. High levels of superoxide dismutase (16.2-24.8 U mg-1 protein) were present in all stages. Catalase was not detected. Glutathione peroxidase activity with cumene hydroperoxide as substrate was not detectable in the schistosomula but the activity was present in the 2-week-old parasites. However, hydrogen peroxide-sensitive glutathione peroxidase activity was present in all the stages with a threefold difference in activity between schistosomula and the adult stages. Glutathione-s-transferase activity was significantly lower in the schistosomula, lung stages, and the 2-week-old parasites than in the older stages. Progressive increases in the levels of glutathione reductase and glutathione were also observed with development. The differences in the levels of antioxidants between different stages of development may partly explain the increase in resistance to oxidant-mediated damage as the parasite develops.
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PMID:Schistosoma mansoni: levels of antioxidants and resistance to oxidants increase during development. 232 92

Repeated bleomycin administration in animals and humans produces significant lung fibrosis. The pathogenesis of this toxicity may be multifactorial, but it appears to be initiated through the production of radical oxygen species by an activated bleomycin-iron-oxygen ternary complex. Protection of lung tissue from bleomycin-induced toxicity may occur through both specific metabolic inactivation of bleomycin by the enzyme bleomycin hydrolase, as well as by such non-specific antioxidants as catalase and the glutathione system. The effect of chronic, systemic administration of bleomycin on the activities and levels of these enzymes and proteins in pulmonary tissue is unknown. C57BL/6 mice were injected subcutaneously with saline, non-fibrogenic (2 mg/kg) and fibrogenic (10 mg/kg) doses of bleomycin twice-weekly for 6 weeks. Animals were killed at 0, 1.5, 3, and 6 weeks after initiation of bleomycin treatment. Catalase activity was increased more than 50% at 3 weeks in the low-dose animals, and was decreased over 40% at 6 weeks in the high-dose animals. Total lung glutathione levels were unaffected in both groups, although glutathione reductase activity was increased significantly (over 2-fold) at 1.5 and 3 weeks in the high-dose animals. At 6 weeks glutathione reductase was increased 7- and 12-fold in low and high-dose animals respectively. Glutathione peroxidase activity also was elevated more than 2-fold above control values at 6 weeks in both sets of animals. There was no evidence of induction of bleomycin hydrolase activity at any time point. Rather, bleomycin hydrolase activity was decreased significantly to 30 and 40% of control values at 3 and 6 weeks, respectively, in mice receiving the fibrogenic doses of bleomycin. These results demonstrate that chronic, systemic administration of non-fibrogenic and fibrogenic doses of bleomycin produces changes in activity of lung antioxidant defense mechanisms. The early loss of lung bleomycin hydrolase activity may contribute to the pathogenesis of bleomycin-induced pulmonary toxicity following repeated drug exposure.
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PMID:Alterations in pulmonary protective enzymes following systemic bleomycin treatment in mice. 245 25


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