An efficient catalytic route in haem peroxygenases mediated by O2/small-molecule reductant pairs for sustainable applications

Abstract

Haem peroxygenases are attractive biocatalysts for incorporating oxygen into organic molecules using H₂O₂. However, their practical applications are hindered by irreversible oxidative inactivation due to exogenous H₂O₂ usage. Here we present an alternative catalytic route in haem peroxygenases that uses O₂ and small-molecule reductants such as ascorbic acid and dehydroascorbic acid (DHA) to drive reactions. Our experimental and computational studies indicated that DHAA, the hydrated form of DHA, serves as the key co-substrate that activates oxygen to generate the active oxyferryl haem compound I. We also demonstrate the broad applicability of this O₂/reductant-dependent route across various haem peroxygenases, highlighting its biological significance for mono-oxygenase functionality. Importantly, this innovative route avoids the use of H₂O₂, thereby preventing the risk of irreversible enzyme inactivation. Finally, scaled-up reactions yielded chiral, value-added products with excellent productivity, underscoring the synthetic potential of this developed peroxygenase technology for sustainable chemical transformations.