Light-driven enzymatic conversion of mevastatin into pravastatin by coupling P450sca-2 with cyanobacterial photosynthetic system

Abstract

Cytochrome P450 enzymes (P450s) are highly attractive green biocatalysts with application potential in fields of synthetic chemistry and synthetic biology. However, most P450 enzymatic reactions rely on expensive cofactor NAD(P)H and complex redox partner protein(s) to supply catalytically required electrons, which greatly limits their investigation and application. Here we develop a light-driven P450 system to transform mevastatin into pravastatin by coupling P450sca-2 from Streptomyces carbophilus with the photosynthetic machinery of the cyanobacterium Synechococcus elongatus PCC 7942 via their shared electron-transfer component ferredoxin. Using the extracted cyanobacterial thylakoid membrane as an electron generator and transporter, we show that the P450sca-2 catalyzed hydroxylation of mevastatin can be driven by visible light. We designed and tested three different light-driven P450 pathways by using water, artificial low-cost electron donors and in situ produced NADPH as electron sources and finally improved the product yields from 12.7 ​% to 70.1 ​%. Our results not only provide a ‘green’ approach for pravastatin production, but also demonstrate that the cyanobacterial thylakoid membrane can act as an efficient electron donor to drive P450 reactions in vitro, which can be applied in the construction of photosynthetic and CO2-fixing P450 reaction systems in the future.