Short communicationDirected modification of a novel epoxide hydrolase from Phaseolus vulgaris to improve its enantioconvergence towards styrene epoxides

- Directed modification of a novel PvEH1 was carried out based on the rational design.
- The best mutant, PvEH1L105I/M160A/M175I, had high activity of 10.66 U/g towards 1a.
- The eep of (R)-1b by PvEH1L105I/M160A/M175I was 87.8% much higher than that by PvEH1.
- PvEH1L105I/M160A/M175I completely hydrolyzed 2a-5a to (R)-2b-5b with 52.3-70.9% eep.

To improve the enantioconvergence of an epoxide hydrolase from Phaseolus vulgaris (PvEH1) towards styrene epoxides, its directed modification was performed based on the rational design by using the molecule docking simulation and the multiple alignment. The single- and multi-site mutation genes of pveh1 were constructed as designed theoretically by PCR, and expressed in E. coli BL21(DE3), respectively. Among all PvEH1 mutants tested, a three-site mutant, PvEH1L105I/M160A/M175I, was selected having the highest activity of 10.66 U/g wet cell and the best regioselectivity (αS > 99%, βR = 86.4%), by which rac-1a was transformed into (R)-1b with 87.8% enantiomeric excess (eep), much higher than that (33.6% eep) by PvEH1. Furthermore, it completely hydrolyzed rac-2a-5a into (R)-2b-5b with 52.3-70.9% eep.