To further improve the activity and enantioconvergency of PvEH3^G170E for racemic (rac-) p-chlorostyrene oxide (pCSO), its F187 was randomly substituted by saturation mutagenesis. The double-site variants of pveh3, pET-28a-pveh3^G170E/F187X (X: any one of 20 residues), were transformed into E. coli BL21(DE3), thereby constructing a mutagenesis library (E. coli/pveh3^G170E/F187X). E. coli/pveh3^G170E/F187L had the highest EH activity of 19.64 U/g wet cell, while /pveh3^G170E/F187I the highest α_S of 94.5%. The enantioconvergent hydrolysis of 150 mM rac-pCSO by E. coli/pveh3^G170E/F187I produced (R)-p-chlorophenyl-1,2-ethanediol with 92.8% ee_p and 8.68 mmol/h/L space-time yield. The mechanism of PvEH3^G170E/F187I with improved enantioconvergency was analyzed by molecular docking simulation.

为了进一步提高Pv EH3 ^G170E对外消旋（rac-）对氯苯乙烯氧化物（p CSO）的活性和对^映体收敛性，其F187被饱和诱变随机取代。将pveh3的双位点变体pET-28a-pveh3 G170E ^{/ F187X}（X：20个残基中的任何一个）转化到大肠杆菌BL21（DE3）中，从而构建诱变文库（E. coli / pveh3 ^{G170E / F187X}）。大肠杆菌/ pveh3 ^{G170E / F187L}的EH活性最高，为19.64 U / g湿细胞，而/ pveh3^{G170E / F187I}的最高_αS为94.5％。大肠杆菌/ pveh3 ^{G170E / F187I}对映体对150 mM rac - p CSO的对映体水解产生了（R）-对氯苯基-1,2-乙二醇，其ee _p为92.8％，时空产率为8.68 mmol / h。通过分子对接模拟分析了对^{映体收敛性}提高的Pv EH3 ^{G170E / F187I}的机理。