Effect of superoxide dismutase on hydroxylase activity and hydrogen peroxide formation in anthranilamide hydroxylation by a rat liver microsomal monooxygenase system.
Anthranilamide was slightly hydroxylated by a reconstituted rat liver microsomal monooxygenase system with NADPH, but a large amount of hydrogen peroxide was formed with a consumption of NADPH during the reaction. Superoxide dismutase stimulated the hydroxylation by depressing the hydrogen peroxide formation, in that there was a reverse correlation between the two effects due to the dismutase. In addition, a trace of 3-hydroxyanthranilamide, one of the products, not only stimulated NADPH-dependent hydrogen peroxide formation via NADPH-cytochrome c (P-450) reductase, but also inhibited the reduction of cytochrome P-450 by NADPH in the reconstituted system. These effects of 3-hydroxyanthranilamide were also diminished by superoxide dismutase.
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D006900:Hydroxylation; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D013482:Superoxide Dismutase / Q000378:metabolism* / Q000494:pharmacology; D062367:ortho-Aminobenzoates / Q000378:metabolism*
D062367:ortho-Aminobenzoates; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; D013482:Superoxide Dismutase; C000219:anthranilamide