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)

Incubation of aqueous solutions of 2-nitropropane in air causes a slow oxidation reaction that generates H(2)O(2). Purified horseradish peroxidase catalyses the oxidation of such preincubated 2-nitropropane solutions according to the equation: [Formula: see text] The pH optimum is 4.5 and K(m) for 2-nitropropane is 16mm. Other nitroalkanes or nitro-aromatics tested are not oxidized at significant rates by peroxidase. H(2)O(2) or 2,4-dichlorophenol increases the rate of 2-nitropropane oxidation by peroxidase. Catalase inhibits the reaction completely. Superoxide dismutase or mannitol, a scavenger of the hydroxyl radical, OH(.), each inhibits partially. Aniline and guaiacol are also powerful inhibitors of 2-nitropropane oxidation. It is suggested that peroxidase uses the traces of H(2)O(2) generated during preincubation of 2-nitropropane to catalyse oxidation of this substrate into a radical species that can reduce O(2) to the superoxide ion, O(2) (-.).O(2) (-.), or OH(.) derived from it, then appears to react with more nitropropane, generating further radicals and H(2)O(2) to continue the oxidation. Inhibition by aniline and guaiacol seems to be due to a competition for H(2)O(2).
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PMID:Oxidation of 2-nitropropane by horseradish peroxidase. Involvement of hydrogen peroxide and of superoxide in the reaction mechanism. 21 46

The effects of exposure to different concentrations of phenoxyherbicides and their metabolites were studied in human erythrocytes, with particular attention to catalase (CAT-EC. 1.11.1. 6- hydrogen peroxide: hydrogen peroxide oxidoreductase). 4-chloro-2-methylphenoxyacetic acid (MCPA), 2,4-dimethylphenol (2, 4-DMP) and 2,4-dichlorophenoxyacetic acid (2,4-D) did not affect CAT activity, but 2,4-dichlorophenol (2,4-DCP) and 2,4,5-trichlorophenol (2,4,5-TCP) decrease its activity, the latter being the more inhibitory.
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PMID:Catalase activity in human erythrocytes: effect of phenoxyherbicides and their metabolites. 1102 48