Acetate anion-triggered peroxygenation of non-native substrates by wild-type cytochrome P450s

Cytochrome P450(SP alpha) (P450(SP alpha)) and cytochrome P450(BS beta) (P450(BS beta)) belonging to the CYP152 family of enzymes (CYP152s) can utilize H2O2 efficiently as an oxidant for the generation of compound I. Although P450(SP alpha) and P450(BS beta) have very high substrate specificity and catalyse hydroxylation of long-chain fatty acids exclusively, we found that they can oxidize non-native substrates such as styrene simply by including medium chain length n-alkyl carboxylic acids as decoy molecules. Although we had assumed that acetic acid did not serve as a decoy molecule, P450(SP alpha) and P450(BS beta) efficiently catalysed oxidation of non-native substrates when the reaction was carried out at a high concentration of acetate anion. The turnover rate for epoxidation of styrene catalysed by P450(BS beta) in the presence of 1 M acetate anion reached 590 (+/-) 30 min(-1).