Keeping the spotlight on cytochrome P450.

This review describes the recent advances utilizing photosensitizers and visible light to harness the synthetic potential of P450 enzymes. The structures of the photosensitizers investigated to date are first presented along with their photophysical and redox properties. Functional photosensitizers range from organic and inorganic complexes to nanomaterials as well as the biological photosystem I complex. The focus is then on the three distinct approaches that have emerged for the activation of P450 enzymes. The first approach utilizes the in situ generation of reactive oxygen species entering the P450 mechanism via the peroxide shunt pathway. The other two approaches are sustained by electron injections into catalytically competent heme domains either facilitated by redox partners or through direct heme domain reduction. Achievements as well as pitfalls of each approach are briefly summarized. This article is part of a Special Issue entitled: Cytochrome P450 biodiversity and biotechnology, edited by Erika Plettner, Gianfranco Gilardi, Luet Wong, Vlada Urlacher, Jared Goldstone.