Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether
Biotechnology and Bioengineering|Updated:2026-01-06
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Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether
Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether
中国化学工程学报(英文版)2020年28卷第8期 页码:2181-2189
Affiliations:
Lab of Applied Biocatalysis, School of Food Science and Engineering, South China University of Technology,Guangzhou,China,510640
Yao Li, Xiaoyang Ou, Zewang Guo, 等. Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether[J]. 中国化学工程学报(英文版), 2020,28(8):2181-2189. DOI: 10.1016/j.cjche.2020.03.025.
Yao Li, Xiaoyang Ou, Zewang Guo, 等. Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether[J]. 中国化学工程学报(英文版), 2020,28(8):2181-2189. DOI: 10.1016/j.cjche.2020.03.025.DOI:
Using multiple site-directed modification of epoxide hydrolase to significantly improve its enantioselectivity in hydrolysis of rac-glycidyl phenyl ether
sp. HXN-200 was synthesized and expressed in robust
Escherichia coli
cells that had a dual protection system. The enantioselectivity (
E
-value) of the recombinant
Sp
EH was 7.7 and the yield of the remaining (
R
)-PGE was 24.3% for the hydrolysis of racemic phenyl glycidyl ether (
rac
-PGE). To improve the catalytic properties of
Sp
EH
the site-directed mutagenesis was carried out based on homology modeling
sequence alignment and molecular docking. Six residues (V195
V196
F218
N226
Q312
and M332) near the active site were mutated to hydrophobic amino acids and the positive mutations were selected for combinatorial mutation. The optimal mutant
Sp
EH
V196A/N226A/M332A
had an enhanced
E
-value of 21.2 and a specific activity of 4.57 U·mg
-1
-wet cells
which were 2.8-
and 2.3-fold higher than those of wild-type
Sp
EH. The optimal temperature and pH for purified
Sp
EH
V196A/N226A/M332A
to catalyze the hydrolysis of
rac
-PGE were 25 ℃ and 7.0 with 200 U·mg
-1
. The
enantioselectivity and yield of the remaining (
R
)-PGE of
E. coli
_
Sp
EH
V196A/N226A/M332A
increased from 7.7 to 21.2 and 24.3% to 40.9%
respectively. The molecular docking and kinetic parameter analyses showed that
Sp
EH
V196A/N226A/M332A
has a greater affinity toward (
S
)-PGE than (
R
) - PGE
and that it was more difficult for the
O
-atom of ASP170 to achieve the nucleophilic attack on the Cα of (
R
)-PGE
resulting in its improved enantioselectivity.
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