Hydrogen peroxide-supported activities of semisynthetic flavocytochrome 2B4.
Semisynthetic flavocytochromes, obtained by covalent binding of riboflavin with cytochromes P450 2B4, were able to catalyze the H2O2-mediated reactions of aniline p-hydroxylation, aminopyrine N-demethylation and p-nitroanizole' O-dealkylation. The rates of the flavocytochrome-catalyzed, H2O2-supported reactions far exceeded those of the appropriate NADH-dependent reactions and were comparable with the cytochrome P450 2B4-catalyzed, peroxide-mediated reaction rates. The kinetic parameters (kcat, K(m)) for the peroxide-dependent flavocytochrome P450 2B4 reactions were obtained. Sodium cyanide and SKF-525A, a specific P450 inhibitor, were both shown to inhibit these reactions. The generation of active oxygen species by flavocytochrome 2B4 was registered by chemiluminescence intensity.
Shumyantseva
V V
VV
Institute of Biomedical Chemistry, Moscow, Russia.
Avdeenko
Y L
YL
Moskvitina
T L
TL
Bulko
T V
TV
Archakov
A I
AI
D000632:Aminopyrine / Q000378:metabolism; D000814:Aniline Compounds / Q000378:metabolism; D000840:Anisoles / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases; D002384:Catalysis; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006035:Glycyrrhiza; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics; D008163:Luminescent Measurements; D008165:Luminol / Q000378:metabolism; D010946:Plants, Medicinal; D011335:Proadifen / Q000494:pharmacology; D012966:Sodium Cyanide / Q000494:pharmacology; D013250:Steroid Hydroxylases / Q000378:metabolism*
D000814:Aniline Compounds; D000840:Anisoles; D000632:Aminopyrine; D008165:Luminol; D003577:Cytochrome P-450 Enzyme System; D011335:Proadifen; D006861:Hydrogen Peroxide; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C050356:steroid 15-alpha-hydroxylase; C005306:4-nitroanisole; D012966:Sodium Cyanide; C023650:aniline