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)

Low-potential electron acceptors of photosystem I of chloroplast lamellae produce superoxide anions (0-2) and hydrogen peroxide by autoxidation, but have no effect on ethylene formation from methionine; equimolar amounts of ferredoxin are less active in photosynthetic O-2 and H2O2 production but strongly stimulate ethylene production from methionine. 2. Ten to fifty units of superoxide dismutase inhibit fifty to two hundred units of superoxide dismutase stimulate ethylene formation from methionine by chloroplast lamellae in the presence of ferredoxin. This stimulation is stronger at pH 7.0 than at pH 7.8. Catalase inhibits ethylene formation from methionine. 3. Pulse-radiolytic production of nitrite (NO-2) from hydroxylamine, initiated by hydroxyl radicals (.OH) or O-2, shows no difference in the presence or absence of ferredoxin, nor do the decay kinetics of O2. 4. From the above observations and from model reactions (xanthine/xanthine oxidase; iron salts in the presence of H2O2), it is concluded that reduced ferredoxin in the presence of H2O2 forms a Fenton-type oxidizing species for methionine, generating ethylene in the presence of pyridoxal phosphate. 5. Inhibitory effects of both superoxide dismutase and catalase in oxygen-dependent reactions need not necessarily indicate the participation of the 'Haber-Weiss' reaction.
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PMID:Oxygen activation in isolated chloroplasts. Mechanism of ferredoxin-dependent ethylene formation from methionine. 21 71

A method was developed to determine the total content of the oxypurines, xanthine and hypoxanthine, in animal tissues. The developed method was constructed mainly from the following successive steps: (1) conversion of the oxypurines to uric acid and hydrogen peroxidase by xanthine oxidase; (2) decomposition of the hydrogen peroxide by catalase and subsequent inactivation of this enzyme; (3) fluorometric measurement of the uric acid based on the coupled enzyme reaction of uricase and peroxidase. In applying this method to a sample containing uric acid, preliminary removal of this uric acid was necessary and this was carried out by treating the sample with uricase, followed by subsequent inactivation of this enzyme. The present method was more specific than the existing fluorometric method and permitted to measure the total content of the oxypurines (as low as 1 nmol) without mutual separation of them. The actual application of this method to the rat liver was demonstrated together with the method to prepare the tissue sample for the assay.
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PMID:Fluorometric determination of xanthine and hypoxanthine in tissue. 58 29

To investigate the possibility that human polymorphonuclear leukocytes (PMN) elaborate sufficient amounts of hydrogen peroxide (H2O2) and other radicals of reduced oxygen to be autotoxic and retard directed cell movement and phagocytosis, the rate of ingestion of opsonized lipopolysaccharide-paraffin oil particles and movement through Nuclepore filters were studied. Ingestion rates were increased under anaerobic conditions and in normal aerobic conditions in the presence of extracellular catalase but not superoxide dismutase (SOD) or scavengers of singlet oxygen or hydroxyl radicals. Conversely, ingestion rates were decreased when cells were exposed to H2O2 or a superoxide anion (O2-)-H2O2 generating system of xanthine-xanthine oxidase. Catalase, but not SOD, prevented the effect and also enhanced the directed movement of PMN in normal aerobic conditions. PMN from volunteers administered 1600 U/day of the membrane lipid antioxidant alpha-tocopherol were hyperphagocytic but killed Staphylococcus aureus 502A less effectively than controls, suggesting that less H2O2 was available to damage PMN or kill bacteria. H2O2-dependent stimulation of the hexose monophosphate shunt, H2O2 release from phaogytizing PMN, and fluoresceinated concanavalin A cap formation promoted by H2O2 damage to microtubules were all diminished, but the release of O2- from phagocytizing PMN was not diminished in the vitamin E group. These results support the hypothesis that directed movement and phagocytosis by PMN are attenuated by autooxidative damage to the cell membrane by endogenously derived H2O2 and that the administration in vivo of vitamin E may prevent this damage by scavenging H2O2.
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PMID:Autooxidation as a basis for altered function by polymorphonuclear leukocytes. 87 28

The effects of xanthine + xanthine oxidase-generated reactive oxygen species (ROS) on rabbit muscle creatine kinase (CK) were studied. Xanthine (0.1 mM) + xanthine oxidase (30 mU/ml) inhibited activity of rabbit muscle CK (1.2 mU/ml). Catalase (100 U/ml), but not SOD (100 Uml), deferoxamine (100 microM) or mannitol (20 mM), protected CK from inactivation; suggesting that H2O2 was responsible for inactivation. These results were different from previously reported findings on bovine heart CK that superoxide radicals inactivate the enzyme. Thus, enzymes with homologous structures may have different reactivities to different ROS. H2O2-induced inactivation of rabbit muscle CK was accompanied by a decrease in its thiol group content, whereas no significant changes in the protein structure were detected by SDS-PAGE or carbonyl content. These results suggest that oxidation of -SH groups by H2O2 seems to be a major mechanism of activation of rabbit muscle CK by xanthine + xanthine oxidase. Such inactivation of CK by H2O2 may be important in ROS-induced pathology.
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PMID:Inactivation of rabbit muscle creatine kinase by hydrogen peroxide. 132 Oct 75

Active oxygen species cause gastric mucosal damage in vivo. However, it is not known if these species are directly cytotoxic toward gastric cells. Prostaglandins have important physiological roles in the gastric mucosa, including direct cell protection against damaging factors. So, to find if active oxygen species affect prostaglandin synthesis in gastric mucosal cells is important, but this also is not known. This study was done to investigate the effects of such species on damage to and prostaglandin synthesis in cultured mucus-producing cells from rat gastric mucosa. Active oxygen species were produced by the addition of xanthine and xanthine oxidase to the culture medium. Cytotoxicity was assayed by 51Cr release. Xanthine (1 mM) and xanthine oxidase (100 mU/ml) increased specific 51Cr release as the thiobarbituric acid reactants increased. This increase in 51Cr release was inhibited by catalase, a scavenger of hydrogen peroxide, or dimethyl sulfoxide, a scavenger of hydroxyl radicals, but not by superoxide dismutase, a scavenger of superoxide, nor deferoxamine, an inhibitor of hydroxyl radical generation. Catalase, dimethyl sulfoxide, and superoxide dismutase each had no effect on prostaglandin E2 synthesis when xanthine and xanthine oxidase were not added. In the presence of xanthine and xanthine oxidase, catalase and dimethyl sulfoxide stimulated the synthesis of prostaglandin E2 and superoxide dismutase inhibited it. Indomethacin, a prostaglandin synthetase inhibitor, did not affect the decrease in 51Cr release caused by catalase in the presence of xanthine and xanthine oxidase, but it abolished the decrease caused by dimethyl sulfoxide. These results suggest that hydrogen peroxide, but not superoxide nor hydroxyl radicals, is involved in damage to cultured rat gastric cells, and that superoxide stimulates prostaglandin E2 synthesis, but that hydrogen peroxide inhibits it. Protection of the cells by dimethyl sulfoxide may be related to stimulation of prostaglandin E2 synthesis in the cells, but not via scavenging hydroxyl radicals.
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PMID:Effects of active oxygen species on damage to and prostaglandin synthesis in cultured rat gastric cells. 132 36

Oxidative damage to bovine serum albumin (BSA) was induced by hydroxyl radical (HO.) generating systems of xanthine oxidase (XO) + EDTA-Fe3+ and ascorbate + EDTA-Fe3+. Formation of bityrosine and loss of tryptophan were observed in the ascorbate + EDTA-Fe3+ system and carbonyl formation was induced by both systems. Mannitol and ethanol very strongly inhibited the carbonyl and/or bityrosine formation, indicating that the oxidative damage to BSA was due to HO(.). The sulfhydryl (SH) groups of BSA were very sensitive to the XO + EDTA-Fe3+ but not to the ascorbate + EDTA-Fe3+ system. Catalase but not hydroxyl radical scavengers or superoxide dismutase strongly inhibited the loss of SH groups, indicating that H2O2 is involved in their oxidation. Fragmentation of BSA was observed during exposure to the XO + EDTA-Fe3+ and ascorbate + EDTA-Fe3+ systems and the products presented a broad band on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Little formation of amine groups was observed in these systems, indicating that little peptide bond cleavage occurred. BSA exposed to the ascorbate + EDTA-Fe3+ system was more readily degraded by trypsin than that exposed to the XO + EDTA-Fe3+ system. Elastase degraded BSA exposed to the ascorbate + EDTA-Fe3+ system but not to the XO + EDTA-Fe3+ system.
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PMID:Oxidative damage to bovine serum albumin induced by hydroxyl radical generating systems of xanthine oxidase + EDTA-Fe3+ and ascorbate + EDTA-Fe3+. 133 12

Quantification of intracellular and extracellular levels and production rates of reactive oxygen species is crucial to understanding their contribution to tissue pathophysiology. We measured basal rates of oxidant production and the activity of xanthine oxidase, proposed to be a key source of O2- and H2O2, in endothelial cells. Then we examined the influence of tumor necrosis factor-alpha and lipopolysaccharide on endothelial cell oxidant metabolism, in response to the proposal that these inflammatory mediators initiate vascular injury in part by stimulating endothelial xanthine oxidase-mediated production of O2- and H2O2. We determined a basal intracellular H2O2 concentration of 32.8 +/- 10.7 pM in cultured bovine aortic endothelial cells by kinetic analysis of aminotriazole-mediated inactivation of endogenous catalase. Catalase activity was 5.72 +/- 1.61 U/mg cell protein and glutathione peroxidase activity was much lower, 8.13 +/- 3.79 mU/mg protein. Only 0.48 +/- 0.18% of total glucose metabolism occurred via the pentose phosphate pathway. The rate of extracellular H2O2 release was 75 +/- 12 pmol.min-1.mg cell protein-1. Intracellular xanthine dehydrogenase/oxidase activity determined by pterin oxidation was 2.32 +/- 0.75 microU/mg with 47.1 +/- 11.7% in the oxidase form. Intracellular purine levels of 1.19 +/- 1.04 nmol hypoxanthine/mg protein, 0.13 +/- 0.17 nmol xanthine/mg protein, and undetectable uric acid were consistent with a low activity of xanthine dehydrogenase/oxidase. Exposure of endothelial cells to 1000 U/ml tumor necrosis factor (TNF) or 1 microgram/ml lipopolysaccharide (LPS) for 1-12 h did not alter basal endothelial cell oxidant production or xanthine dehydrogenase/oxidase activity. These results do not support a casual role for H2O2 in the direct endothelial toxicity of TNF and LPS.
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PMID:Responses of vascular endothelial oxidant metabolism to lipopolysaccharide and tumor necrosis factor-alpha. 156 24

The oxidative demethylenation reactions of (methylendioxy)phenyl compounds (MDPs), (methylenedioxy)benzene (MDB), (methylenedioxy)amphetamine (MDA), and (methylenedioxy)methamphetamine (MDMA), were evaluated by using two hydroxyl radical generating systems, the autoxidation of ascorbate in the presence of iron-EDTA and the iron-catalyzed Haber-Weiss reaction conducted by xanthine/xanthine oxidase with iron-EDTA. Reaction products generated when MDB, MDA, and MDMA were incubated with the ascorbate or xanthine oxidase system were catechol, dihydroxyamphetamine (DHA), and dihydroxymethamphetamine (DHMA), respectively. The reaction required the presence of either ascorbic acid or xanthine oxidase. Levels of each catechol increased in proportion to ferric ion concentration and were suppressed by desferrioxamine B methanesulfonate (desferal). Catalase (CAT) inhibited the oxidation by the ascorbate system whereas superoxide dismutase (SOD) had little effect. The addition of hydrogen peroxide to the reaction mixture stimulated the oxidation, but the reaction was not initiated by hydrogen peroxide alone, suggesting that hydrogen peroxide acts as a precursor of hydroxyl radical. SOD and CAT suppressed the demethylenation reactions in the xanthine oxidase system. Hydroxyl radical scavenging agents such as ethanol, benzoate, DMSO, and thiourea effectively inhibited the oxidation by both systems. Urea, which has little effect on hydroxyl radical, was without any effect. These results indicated that hydroxyl radical can effect the cleavage of methylenedioxy group on MDPs.
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PMID:Hydroxyl radical mediated demethylenation of (methylenedioxy)phenyl compounds. 168 Apr 77

Reactive oxygen intermediates (ROI) play a major role in the mucosal damage developing during the reperfusion period following intestinal ischemia. We have shown previously that histamine (H) release is related to the ROI generated by xanthine oxidase during intestinal ischemia-reperfusion. The present study sought to determine the possible chain of events leading to H liberation. The artery supplying a segment of the ileum was occluded for 2 hr in 51 anesthetized dogs, and plasma levels of H were determined radioenzymatically in the venous effluent. Catalase was applied to scavenge hydrogen peroxide; dimethylsulfoxide and mannitol were used as hydroxyl radical scavengers; the role of catalytically active iron was assessed by using desferrioxamine. Pretreatment with either catalase or desferrioxamine, but not with dimethyl sulfoxide or mannitol, was effective in reducing the postocclusive H release. The results provide further in vivo evidence that ROI are causative agents in H liberation during reperfusion of the ischemic gut. Hydrogen peroxide can interact with catalytically active iron and generate highly reactive oxidants, which in turn are responsible for H release. The exact nature of these oxidants is still uncertain.
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PMID:Histamine release during intestinal ischemia-reperfusion: role of iron ions and hydrogen peroxide. 172 54

The objective of this study was to determine whether agents that either scavenge or inhibit the production of oxygen radicals can alter the adhesive interactions between leukocytes and venular endothelium elicited by ischemia-reperfusion. Cat mesenteric and intestinal blood flows were reduced to 20% of baseline for 1 hr, followed by 1 hr of reperfusion. Sixty minutes after reperfusion, red blood cell velocity (Vr), leukocyte rolling velocity (Vw), and the number of adherent leukocytes were measured in mesenteric venules. Then, either manganese-superoxide dismutase (Mn-SOD), catalase, desferrioxamine, or oxypurinol was administered intravascularly. Ten minutes later, repeat measurements were obtained and compared with pretreatment values. Catalase, Mn-SOD, and oxypurinol significantly attenuated neutrophil adherence while neither inactivated-catalase nor desferrioxamine altered the reperfusion-induced leukocyte adhesion. The ratio of Vw to erythrocyte velocity, an index of the fracture stress between rolling leukocytes and venular endothelium, was not altered by any of the agents studied. These results and data in the literature indicate that many of the agents that are commonly used to either scavenge or inhibit the production of oxygen radicals in postischemic tissues exert a significant inhibitory influence on leukocyte adhesion to microvascular endothelium in vivo. Our results are also consistent with the view that xanthine oxidase-derived oxidants contribute to the leukocyte-endothelial cell adhesive interactions associated with reperfusion of ischemic tissues.
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PMID:Leukocyte-endothelial cell adhesive interactions: role of xanthine oxidase-derived oxidants. 174 42


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