Improvement opportunities for P450 biocatalytic applications in the pharmaceutical industry.

Selective oxygenation reactions are highly valuable for the pharmaceutical industry, as they provide new pharmacokinetic and physicochemical properties to a compound. Yet, conventional methods often suffer from low yields, poor selectivity, and numerous steps. In that context, P450 enzymes appear as an attractive alternative. This superfamily of enzymes catalyses the incorporation of an oxygen atom into complex molecular scaffolds with high regio- and stereoselectivity. Despite their potential, industrial implementation remains limited due to challenges such as low stability and activity. In this review, we identify activity, selectivity, stability, and scalability as the key industrial needs for a P450-based pharmaceutical process to reach industrial scale. Additionally, we dissect the P450 biocatalyst into seven components (haem, cofactor NAD(P)H, reductase partner, substrate, oxygen donor, product, and catalytic format) and explore recent advances aimed at improving each component. Emphasis is placed on the complexity of a multicomponent system and the need for a multidisciplinary approach to process design that comes with it. We find that tools in the fields of enzyme, cell, and process engineering are available, highlighting their advantages and disadvantages. Finally, we discuss relationships and trade-offs among design opportunities and propose experimental directions to better understand them. We conclude that components with greater degrees of freedom will be key in enabling more constraining strategies to expand the opportunities for P450-based biocatalysis.