Dmd058636 1493..1497

A large set of Bacillus megaterium CYP102A1 mutants are known to metabolize various drugs to form human metabolites. Omeprazole (OMP), a proton pump inhibitor, has been widely used as an acid inhibitory agent for the treatment of gastric acid hypersecretion disorders. It is primarily metabolized by human CYP2C19 and CYP3A4 to 59-OH OMP and a sulfone product, respectively. It was recently reported that several CYP102A1 mutants can oxidize racemic and S-OMP to 59-OH OMP and that these mutants can further oxidize 59-OH racemic OMP to 59-COOH OMP. Here, we report that the Sand R-enantiomers of OMP are hydroxylated by 26 mutants of CYP102A1 to produce 1 major metabolite (59-OH OMP) regardless of the chirality of the parent substrates. Although the binding of R-OMP to the CYP102A1 active site caused a more apparent change of heme environment compared with binding of S-OMP, there was no correlation between the spectral change upon substrate binding and catalytic activity of either enantiomer. The 59-OH OMP produced from racemic, S-, and R-OMP could be obtained with a high conversion rate and high selectivity when the triple R47L/F87V/L188Q mutant was used. These results suggest that bacterial CYP102A1 mutants can be used to produce the human metabolite 59-OH OMP from both the Sand R-enantiomers