Enantioselective Hydrolysis of Styrene Oxide and Benzyl Glycidyl Ether by a Variant of Epoxide Hydrolase from Agromyces mediolanus

Abstract

Enantiopure epoxides are versatile synthetic intermediates for producing optically active pharmaceuticals. In an effort to provide more options for the preparation of enantiopure epoxides, a variant of the epoxide hydrolase (vEH-Am) gene from a marine microorganism Agromyces mediolanus was synthesized and expressed in Escherichia coli. Recombiant vEH-Am displayed a molecular weight of 43 kDa and showed high stability with a half-life of 51.1 h at 30 °C. The purified vEH-Am exhibited high enantioselectivity towards styrene oxide (SO) and benzyl glycidyl ether (BGE). The vEH-Am preferentially converted (S)-SO, leaving (R)-SO with the enantiomeric excess (ee) >99%. However, (R)-BGE was preferentially hydrolyzed by vEH-Am, resulting in (S)-BGE with >99% ee. To investigate the origin of regioselectivity, the interactions between vEH-Am and enantiomers of SO and BGE were analyzed by molecular docking simulation. In addition, it was observed that the yields of (R)-SO and (S)-BGE decreased with the increase of substrate concentrations. The yield of (R)-SO was significantly increased by adding 2% (v/v) Tween-20 or intermittent supplementation of the substrate. To our knowledge, vEH-Am displayed the highest enantioselectivity for the kinetic resolution of racemic BGE among the known EHs, suggesting promising applications of vEH-Am in the preparation of optically active BGE.

IsPETase Is a Novel Biocatalyst for Poly(ethylene terephthalate) (PET) Hydrolysis

“…The substrate specificity and enantioselectivity of α/β‐hydrolase fold enzymes are frequently engineered for different purposes. For instance, esterases, [41] lipases, [42] and epoxide hydrolases [43] have all been engineered for higher enantioselectivity. Therefore, there is great potential to modify the substrate spectrum of Is PETases to expand its applications.…”

Marine Skeletal Biopolymers and Proteins and Their Biomedical Application

“…The article by Jin et al reports on the kinetic resolution of racemic styrene oxide (SO) and benzyl glycidyl ether (BGE) obtained by the variant of epoxide hydrolase from Agromyces mediolanus (vEH-Am). This study describes the theoretical foundation for the application of vEH-Am in the preparation of enantiopure SO and BGE [ 23 ].…”