Reduction of nitro and azo compounds by NADPH-cytochrome P-450 reductase-cytochrome c heme peptide system.
Octa heme peptide, an enzymic digestion product of Candida Krusei cytochrome c, was found to catalyze nitro and azo reduction in the presence of NADPH and NADPH-cytochrome P-450 reductase under anerobic conditions. The reduction was dependent on the concentrations of heme peptide and reductase, and inhibited by carbon monoxide and oxygen. Comparison of the activities of the reductase-heme peptide system with liver microsomes revealed that heme peptide was as effective as cytochrome P-450 in nitro reduction, although less effective in azo reduction. Thus, cytochrome c heme peptide may serve as an artificial substitute for cytochrome P-450 at least in the reductive metabolism of xenobiotics.
Masuda
Y
Y
Division of Toxicology, Niigata College of Pharmacy, Japan.
Ozaki
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001391:Azo Compounds / Q000378:metabolism*; D002248:Carbon Monoxide / Q000494:pharmacology; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008969:Molecular Sequence Data; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism*; D009574:Nitro Compounds / Q000378:metabolism*; D009603:Nitroso Compounds / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000494:pharmacology; D010544:Peroxidases / Q000378:metabolism*; D051381:Rats
D001391:Azo Compounds; D009574:Nitro Compounds; D009603:Nitroso Compounds; D002248:Carbon Monoxide; D010544:Peroxidases; C021799:microperoxidase; D009251:NADPH-Ferrihemoprotein Reductase; D010100:Oxygen