Generation of human metabolites of 7-ethoxycoumarin by bacterial cytochrome P450 BM3.
Recently, wild-type and mutant forms of bacterial cytochrome P450 BM3 (CYP102A1) have been found to metabolize various drugs through reactions similar to those catalyzed by human cytochromes P450 (P450s). Therefore, it has been suggested that CYP102A1 may be used to produce large quantities of the metabolites of human P450-catalyzed reactions. In this report, we show that the oxidation of 7-ethoxycoumarin, a typical human P450 substrate, is catalyzed by both wild-type and mutant forms of CYP102A1. Two major products were produced as a result of O-deethylation and 3-hydroxylation reactions. These results demonstrate that CYP102A1 mutants catalyze the same reactions as human P450s. High noncompetitive intermolecular kinetic deuterium isotope effects were observed for 7-ethoxycoumarin O-deethylation in the CYP102A1 system. These results suggest that there is a common mechanism for the oxidation reactions catalyzed by both the bacterial CYP102A1 and human P450 enzymes.
Kim
Dong-Hyun
DH
School of Biological Sciences and Technology and Hormone Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea.
Kim
Keon-Hee
KH
Kim
Dae-Hwan
DH
Liu
Kwang-Hyeon
KH
Jung
Heung-Chae
HC
Pan
Jae-Gu
JG
Yun
Chul-Ho
CH
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003374:Coumarins / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity / Q000235:genetics
D001426:Bacterial Proteins; D003374:Coumarins; C017299:7-ethoxycoumarin; D003577:Cytochrome P-450 Enzyme System; D009251:NADPH-Ferrihemoprotein Reductase; C052423:flavocytochrome P450 BM3 monoxygenases