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

Abstract

Cytochrome P450_SPα (P450_SPα) and cytochrome P450_BSβ (P450_BSβ) belonging to the CYP152 family of enzymes (CYP152s) can utilize H₂O₂ efficiently as an oxidant for the generation of compound I. Although P450_SPα and P450_BSβ 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_SPα and P450_BSβ 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_BSβ in the presence of 1 M acetate anion reached 590 ± 30 min⁻¹.