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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

Chlorine dioxide (Cl02) has been proposed as an alternative disinfectant to chlorine to avoid formation of organohalides. Cl02 and metabolites, chlorite (Cl0-2) and chlorate (Cl0-3) in drinking water produced decreases in rat and chicken blood GSH. The GSH dependent system was studied in rat and chicken blood after chronic treatment for 6 months with CL02 (0, 1, 10, 100, 1000 MG/L), Cl0-2 or Cl0-3 (10, 100 mg/l) in drinking water. There was a 60% increase in GSH reductase in the Cl02 treatment groups of rats and chickens. A similar increase was shown in rats treated with Cl0-2 but with Cl0-3 no change was observed. GSH peroxidase was without change in rat but chickens drinking 1000 mg/l Cl02 had decreased activity. Catalase was significantly higher than control in rat and chicken in the 1000 mg/l groups. However, catalase activity was decreased in rat treated with Cl0-2 and at the same time that GSH was decreased. These studies support the view that catalase is the first line of defense against the oxidative stress of Cl02 in rat and chicken erythrocytes.
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PMID:Effect of chlorine dioxide and metabolites on glutathione dependent system in rat, mouse and chicken blood. 54 25

Three 6 week-old lambs were injected with carrier-free selenium-75 as sodium selenite initially and again after 6 days. One lamb received no further injections whereas the other two received injections of either vitamin E or unlabeled Na2SeO3 when the first selenium-75 injection was given. Selected tissues were removed at autopsy 10 days after the first injection. The cytosol from homogenates of these tissues was subjected to gel chromatography, and the elution profiles determined for radioactivity, protein content, and glutathione peroxidase activity using either hydrogen peroxide or cumene hydroperoxide as substrates. The selenium-75 was found to be distributed mainly between 2 different MW peaks. The larger MW seleno-peak (90,000) possessed both glutathione:hydrogen peroxide oxidoreductase, and glutathione:cumene hydroperoxide oxidoreductase activities, but the smaller MW seleno-peak (about 10,000) possessed no glutathione peroxidase activity. A peak of about 60,000 daltons containing only glutathione:cumene hydroperoxide oxidoreductase activity and no selenium-75 was found primarily in the liver and kidney. Vitamin E had no effect on the elution profiles. Selenium status of the animal had only a minor effect on the selenium-75 distribution in the cytosol, but had a marked effect on the absolute amount of the label taken up by tissues.
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PMID:Selenium proteins in ovine tissues: III. Distribution of selenium and glutathione peroxidases in tissue cytosols. 63 9

Metal-chelating agents inhibited platelet aggregation and the accompanying generation of rabbit aorta contracting and PG-like activities, when platelets were challenged with arachidonic acid. Inhibition required the presence of the chelating agents in the medium, and was insured by reagents avid for free or protein-bound copper. Catalase also prevented aggregation and generation of pharmacologically active substances; its activity was reversed by aminothiol agents and by Cu2+ and Zn2+, shown previously to potentiate the platelet effects of arachidonic acid. Inhibition by indomethacin was not prevented by amino-thiol drugs nor by Cu2+ or Zn2+. The catalase-induced inhibition was not affected by scavenging of thiol groups; this rules out, as a mechanism of action of catalase, the increased destruction of popoperoxides by glutathione peroxidase, which requires reduced glutathione as hydrogen donor. The results are compatible with the hypothesis that the agent that mediates platelet aggregation by arachidonic acid is a popoperoxide, requiring the presence either of H2O2 or of a similarly catalase-sensitive substance to be generated.
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PMID:Blockade by metal complexing agents and by catalase of the effects of arachidonic acid on platelets: relevance to the study of anti-inflammatory mechanisms. 117 85

Radiation produces a number of damaging radicals as well as peroxide. The chief cellular protection against these radicals, their secondary reactants and peroxide is the cellular glutathione (GSH), GSH peroxidase, GSH-S-transferase (GSHTase), and catalase enzymes. Inhibition of cellular catalase alone does not enhance the aerobic radiation response because cellular GSH peroxidase is equally effective in reducing peroxide. However, inhibition of GSHTase, and partial inhibition of peroxidase by L-buthionine sulfoximine (LBSO)-linked GSH depletion, results in an increased aerobic radiation response. The major pathway for peroxide reduction is the GSH peroxidase. The enzyme is accountable for 70% inactivation of low peroxide concentrations. Catalase accounts for the remaining inactivation. However, it is difficult to assess the relative contributions of GSHTase and peroxidase to the inactivation of radiation-produced hydroperoxides. Our data suggest that GSH depletion results in the inhibition of cellular GSHTase before it inhibits GSH peroxidase. Therefore, part of the increased aerobic radiation response maybe due to cellular inability to reduce hydroperoxides. Peroxide is not a substrate for GSHTase. However, total inhibition of peroxidase by L-BSO plus N-ethylmaleimide (NEM) treatment maximizes the aerobic radiation response. Total inhibition of GSH-S-transferase and peroxidase would block both peroxide and hydroperoxide reduction.
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PMID:The importance of peroxide and superoxide in the X-ray response. 131 73

Oxygen free radicals and hydroperoxides have been postulated to play a causal role in the aging process, implying that antioxidant enzymes may act as longevity determinants. Catalase (H2O2:H2O2 oxidoreductase; EC1.11.1.6) is the sole enzyme involved in the elimination of H2O2 in Drosophila melanogaster; glutathione peroxidase being absent. A genomic fragment containing the Drosophila catalase gene was used to construct transgenic Drosophila lines by means of P element-mediated transformation. Enhanced levels of catalase (up to 80%) did not prolong the life span of flies, nor did they provide improved protection against oxidative stress induced by hyperoxia or paraquat treatment. However, enhanced resistance to hydrogen peroxide was observed in the overexpressors.
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PMID:The effects of catalase gene overexpression on life span and resistance to oxidative stress in transgenic Drosophila melanogaster. 137 30

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

Injury to the gastrointestinal tract by oxygen dependent processes is important in ischemia, inflammatory bowel disease, and necrotizing enterocolitis. The Caco-2 cell line is an important tool in assessing various gastrointestinal functions and offers a unique opportunity to assess gastrointestinal oxidant metabolism on a cellular level. However, some Caco-2 cell functions change with time after confluence. To determine if antioxidant enzyme activity changes during differentiation, Caco-2 cells were grown to confluence, and superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and specific mRNA content were quantitated. With time after confluence the enzymes demonstrated a small, but statistically significant increase in activity. Neither superoxide dismutase nor glutathione peroxidase mRNA levels correlated with enzyme activity changes. Catalase mRNA levels increased as catalase activity increased. Thus, differentiated Caco-2 cells express superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and the superoxide dismutase, glutathione peroxidase, and catalase genes. Superoxide dismutase activity and glutathione peroxidase activity do not correlate with mRNA levels, and suggest that regulation may be at a level other than transcription. The correlation between catalase activity and catalase mRNA suggests differentiation may occur at transcription. If Caco-2 cells are used to elucidate oxidative metabolism, changes in activities of antioxidant enzymes as a function of cell differentiation should be considered.
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PMID:Antioxidant enzymes in the differentiated Caco-2 cell line. 142 66

Ten patients with chronic renal failure (CRF) treated by hemodialysis (HD) were examined. All the patients demonstrated remarkable anemia. The red blood cell count was (2.7 +/- 0.2) x 10(12)/I the concentration of hemoglobin 79.5 +/- 5.6 g/l, on the average, hematocrit 23.2 +/- 1.8%. The content of malonic dialdehyde in the patients' red blood cells was far greater than in controls, amounting to 132% (per 1 ml of hemolysate), 134% (per 1 mg of protein) (p < 0.05). Catalase and glutathione peroxidase activity in the patients' red blood cells did not differ from that in controls. Superoxide dismutase activity reduced by 43% as compared to that in donors (p < 0.001). The authors review possible mechanisms of lipid peroxidation (LPO) and a decrease of antioxidant defense in red blood cells of CRF patients on hemodialysis. It is concluded that activation of LPO processes and the decrease of antioxidant defense produce a noticeable destructive effect on the integrity of the red blood cell membrane. They also influence the development of hemolysis.
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PMID:[Lipid peroxidation as a possible mechanism of erythrocyte damage in patients with chronic kidney failure on hemodialysis]. 144 Mar 43

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


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