Peroxygenases from the CYP152 family catalyze oxidative transformations of fatty acids using hydrogen peroxide and bypass the canonical redox partners. A subset of these enzymes performs fatty acid decarboxylation to generate terminal alkenes, which serve as key intermediates for renewable fuels and petrochemicals. A central unanswered question is how CYP152 enzymes orchestrate the branching between decarboxylation and hydroxylation, a balance that ultimately defines their utility as selective biocatalysts. Here, we uncover a temperature-dependent switch in the peroxygenase from Nosocomiicoccus massiliensis (OleTNS) that governs its regioselectivity. OleTNS displays a distinctive temperature-dependent catalytic profile, with enhanced β-regioselectivity at milder temperatures, a behavior not previously reported for other members of the family. Our analyses show that its enhanced chemoselectivity arises from coordinated motions between the F-G loop and catalytic His85, which promote deeper substrate burial and selectively favor decarboxylation. At elevated temperatures, this coordination is disrupted, leading to rearranged hydrogen-bonding networks and decreased alkene yields. The combination of loop flexibility and a charged surface typical of cold-active enzymes provides a layer of catalytic control. OleTNS establishes a new model for understanding how structural dynamics and thermodynamic adaptation shape the reactivity of P450 enzymes, highlighting principles for engineering selective biocatalysts for sustainable alkene production.
Ávila et al. (Sun,) studied this question.