Cytochrome P450-catalyzed O-dealkylation coupled with photochemical NADPH regeneration

Cytochrome P450 monooxygenases are multifunctional enzymes with potential applications in chemoenzymatic synthesis of complex chemicals as well as in studies of metabolism and xenobiotics. Widespread application of cytochrome P450s, however, is encumbered by the critical need for redox equivalents in their catalytic function. To overcome this limitation, we studied visible light‐driven regeneration of NADPH for P450‐catalyzed O‐dealkylation reaction; we used eosin Y as a photosensitizing dye, triethanolamine as an electron donor, and [Cp*Rh(bpy)H2O] as an electron mediator. We analyzed catalytic activity of cell‐free synthesized P450 BM3 monooxygenase variant (Y51F/F87A, BM3m2) in the presence of key components for NADPH photoregeneration. The P450‐catalyzed O‐dealkylation reaction sustainably maintained its turnover with the continuous supply of photoregenerated NADPH. Visible light‐driven, non‐enzymatic NADPH regeneration provides a new route for efficient, sustainable utilization of P450 monooxygenases. Biotechnol. Bioeng. 2013; 110: 383–390. © 2012 Wiley Periodicals, Inc. Cytochrome P450 monooxygenases are multi‐functional enzymes with widespread applications in chemoenzymatic synthesis of complex chemicals as well as in studies of metabolism and xenobiotics. Lee and coworkers performed a visible light‐driven photoenzymatic O‐dealkylation reaction by using a cell‐free synthesized P450 BM3 monooxygenase variant (BM3m2). A sustainable photoenzymatic reaction of the P450 BM3 was performed through visible light‐driven regeneration of NADPH from NADPH. The P450 biocatalysis, coupled with photochemical cofactor regeneration, suggests an excellent strategy for visible a light‐driven selective oxidation reaction.