Evaluation of cytochrome P450(BSbeta) reactivity against polycyclic aromatic hydrocarbons and drugs.

The oxidation of 10 polycyclic aromatic hydrocarbons (PAH) by cytochrome P450(BSbeta) using three different electron acceptors is reported. Three PAH were found to be substrates for the oxidation by P450(BSbeta), namely anthracene, 9-methyl-anthracene and azulene. The respective oxidation products were identified by reversed-phase high-performance liquid chromatography coupled to electrospray ionization-mass spectrometry. In addition, 10 drug-like compounds were investigated for their effects on the catalytic activity of P450(BSbeta) by carrying out inhibition studies. The stability of P450(BSbeta) against hydrogen peroxide, cumene, and ter-butyl hydroperoxide was determined. Overall, the results of this study suggested that the P450(BSbeta) enzyme represents a powerful catalyst in terms of the catalytic activity and operational stability.