Solar‐Powered Whole‐Cell P450 Catalytic Platform for C‐Hydroxylation Reactions

Photobiocatalysis is a green platform for driving redox enzymatic reactions using solar energy, not needing high‐cost cofactors and redox partners. Here, a visible light‐driven whole‐cell platform for human cytochrome P450 (CYP) photobiocatalysis was developed using natural flavins as a photosensitizer. Photoexcited flavins mediate NADPH/reductase‐free, light‐driven biocatalysis by human CYP2E1 both in vitro and in the whole‐cell systems. In vitro tests demonstrated that the photobiocatalytic activity of CYP2E1 is dependent on the substrate type, the presence of catalase, and the acid type used as a sacificial electron donor. A protective effect of catalase was found against the inactivation of CYP2E1 heme by H2O2 and the direct transfer of photo‐induced electrons to the heme iron not by peroxide shunt. Furthermore, the P450 photobiocatalysis in whole cells containing human CYPs 1A1, 1A2, 1B1, and 3A4 demonstrated the general applicability of the solar‐powered, flavin‐mediated P450 photobiocatalytic system. Photobiocatalysis: The catalytic turnover of human cytochrome P450 CYP2E1 is mediated by photosensitized flavin mononucleotide (FMN) that directly transfers electrons from the sacrificial electron donor to the heme of CYP2E1. The FMN‐sensitized P450 biocatalysis in whole cells expressing human CYPs 1A1, 1A2, 1B1, and 3A4 for the bioconversion of marketed drugs and a steroid demonstrates general applicability of the photobiocatalytic system.