Engineering Rieske Non-Heme Iron Oxygenases for the Asymmetric Dihydroxylation of Alkenes

Abstract

The asymmetric dihydroxylation of olefins is of special interest due to the facile transformation of the chiral diol products into valuable derivatives. Rieske non-heme iron oxygenases (ROs) represent promising biocatalysts for this reaction as they can be engineered to efficiently catalyze the selective mono- and dihydroxylation of various olefins. The introduction of a single point mutation improved selectivities (≥95 %) and conversions (>99 %) towards selected alkenes. By modifying the size of one active site amino acid side chain, we were able to modulate the regio- and stereoselectivity of these enzymes. For distinct substrates, mutants displayed altered regioselectivities or even favored opposite enantiomers compared to the wild-type ROs, offering a sustainable approach for the oxyfunctionalization of a wide variety of structurally different olefins.

Keywords: asymmetric dihydroxylation; biocatalysis; cis-diols; protein engineering; rieske non-heme iron oxygenases.