化工学报 ›› 2018, Vol. 69 ›› Issue (10): 4335-4341.DOI: 10.11949/j.issn.0438-1157.20180246

• 生物化学工程与技术 • 上一篇    下一篇

定点突变提高菜豆环氧水解酶的对映选择性

宗迅成1, 胡蝶2, 阚婷婷3, 王婷婷3, 邬敏辰2   

  1. 1. 江南大学生物工程学院, 江苏 无锡 214122;
    2. 江南大学无锡医学院, 江苏 无锡 214122;
    3. 江南大学药学院, 江苏 无锡 214122
  • 收稿日期:2018-03-09 修回日期:2018-07-24 出版日期:2018-10-05 发布日期:2018-10-05
  • 通讯作者: 邬敏辰
  • 基金资助:

    国家自然科学基金项目(21676117);2017年江苏省研究生实践创新计划项目(SJCX17_0467)。

Single site mutation of Phaseolus vulgaris epoxide hydrolase improving its enantioselectivity

ZONG Xuncheng1, HU Die2, KAN Tingting3, WANG Tingting3, WU Minchen2   

  1. 1. School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China;
    2. Wuxi Medical School, Jiangnan University, Wuxi 214122, Jiangsu, China;
    3. School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, Jiangsu, China
  • Received:2018-03-09 Revised:2018-07-24 Online:2018-10-05 Published:2018-10-05
  • Supported by:

    supported by the National Natural Science Foundation of China (21676117).

摘要:

为了提高菜豆环氧水解酶(PvEH1)催化对氯环氧苯乙烷(pCSO)的对映选择性,利用定点突变构建了PvEH1W102LPvEH1P137KPvEH1I151V三种突变体,分别研究了突变体全细胞动力学拆分rac-pCSO的催化特性,优化了PvEH1W102L动力学拆分rac-pCSO的初始底物浓度及反应时间,通过分子模拟分析了PvEH1W102L对映选择性提高的机理。结果表明,最优突变体PvEH1W102LE值为25.5,相对酶活为212.6%,分别是PvEH1的11.6倍与2.1倍;PvEH1W102L动力学拆分150 mmol·L-1 rac-pCSO,反应4 h后,可获得(R)-pCSO(产率为45.62%,ees为96.30%)和(R)-对氯苯基乙二醇(产率为50.91%,eep为90.26%)。分子模拟结果分析表明,PvEH1的102位色氨酸(W)突变为亮氨酸(L)降低了酶与(R)-pCSO的结合能力,从而提高了PvEH1W102LpCSO的对映选择性。

关键词: 生物催化, 定点突变, 环氧水解酶, 对氯环氧苯乙烷, 对氯苯基乙二醇, 分子模拟

Abstract:

For improving the enantioselectivity of Phaseolus vulgaris epoxide hydrolase1 (PvEH1) towards p-chlorostyrene oxide (pCSO), three mutations (PvEH1W102L, PvEH1P137K and PvEH1I151V) were constructed by site-directed mutagenesis. Firstly, catalytic characteristics of the enzymatic hydrolysis of rac-pCSO by the whole cell of E. coli expressing PvEH1W102L, PvEH1P137K or PvEH1I151V were studied respectively. After then, the rac-pCSO initial concentration in the kinetic resolution of rac-pCSO by PvEH1W102L were optimized, in additional the course was monitored to determine the reaction time. At last, the mechanism of PvEH1W102L's improvement in enantioselectivity towards pCSO was analyzed by molecular simulation. The result indicated that, the E value and relative activity of the best mutation PvEH1W102L were 25.5 and 212.6%, which were 11.6 and 2.1 times of PvEH1, respectively. After four-hour reaction, the yield of (R)-pCSO in the kinetic resolution was 45.62% (ees=96.30%), when the yield of (R)-p-chlorophenyl-1,2-ethanediol was 50.91% (eep=90.26%). Molecular simulation analysis showed that the mutation of the tryptophan (W) at position 102 of PvEH1 to leucine (L) reduced the binding ability of the enzyme to (R)-pCSO, thereby increasing the enantioselectivity of PvEH1W102L to pCSO.

Key words: biocatalysis, site-directed mutagenesis, epoxide hydrolase, p-chlorostyrene oxide, (R)-p-chlorophenyl-1,2-ethanediol, molecular simulation

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