Position 123 of halohydrin dehalogenase HheG plays an important role in stability, activity, and enantioselectivity.

ABSTRACT: HheG from Ilumatobacter coccineus is a halohydrin dehalogenase with synthetically useful activity in the ring opening of cyclic epoxides with various small anionic nucleophiles. This enzyme provides access to chiral β-substituted alcohols that serve as building blocks in the pharmaceutical industry. Wild-type HheG suffers from low thermostability, which poses a significant drawback for potential applications. In an attempt to thermostabilize HheG by protein engineering, several single mutants at position 123 were identified which displayed up to 14 °C increased apparent melting temperatures and up to three-fold higher activity. Aromatic amino acids at position 123 resulted even in a slightly higher enantioselectivity. Crystal structures of variants T123W and T123G revealed a flexible loop

SUBMITTER: Solarczek J 

PROVIDER: S-EPMC6434027 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature