中山大学学报(自然科学版) ›› 2020, Vol. 59 ›› Issue (1): 144-153.doi: 10.13471/j.cnki.jsysusse.2020.01.017

• • 上一篇    

水液相环境下氢氧根催化天冬氨酸手性对映体转变及质子的作用

乔朝阳1,闫红彦1,孙永清2,刘一司3,吕路瑶3, 佟华3,王佐成3   

  1. 1.白城师范学院计算机科学学院,吉林 白城 137000;
    2.白城技师学院基础部,吉林 白城 137000;
    3.白城师范学院物理学院,吉林 白城 137000
  • 收稿日期:2018-09-30 出版日期:2020-01-25 发布日期:2020-02-28
  • 通讯作者: 佟华 (1970年生),女;研究方向:原子与分子物理;E-mail: 164912372@qq.com 王佐成(1963年生),男;研究方向:计算化学;E-mail: wangzc188@163.com

Chiral enantiomer transition of Asp molecules catalyzed by hydroxyl ion and role of proton in water liquid phase environment#br#
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QIAO Chaoyang1, YAN Hongyan1, SUN Yongqing2,LIU Yisi3, LV Luyao3, TONG Hua3, WANG Zuocheng3   



  • Received:2018-09-30 Online:2020-01-25 Published:2020-02-28

摘要: 采用色散校正密度泛函的ωB97XD方法、微扰理论的MP2方法和自洽反应场的SMD模型方法,研究了Asp分子2种稳定构象(Asp_1和Asp_2)的标题反应。反应通道与势能面的研究发现:Asp分子经过氢氧根(水分子簇)和α-碳抽氢及α-羧羟基、β-羧羟基、β-羧基和R-基旋转的一系列过渡态,实现了手性对映体转变。氢氧根抽α氢和α碳抽水分子的氢致Asp_1Asp_2旋光异构的决速步内禀能垒在27.0 kJ/mol左右;水分子辅助氢氧根离子抽α氢和α碳抽2个水分子簇的氢致Asp_1Asp_2旋光异构的决速步内禀能垒分别是34.0和40.0 kJ/mol左右。质子攻击中间体碳负离子的α碳会加快Asp手性转变的进程。

关键词: 手性对映体, 天冬氨酸, 氢氧根, 水分子, 密度泛函理论, 微扰理论, SMD模型, 能垒

Abstract: Using the dispersion correction density functional ωB97X-D method, the MP2 method of perturbation theory and the SMD model method of selfconsistent reaction field, the title reaction of two stable conformations(Asp_1 and Asp_2) of Asp was investigated. The study of reaction channel and potential energy surface showed that the chiral enantiomer transition was realized by a series of Asp transition states of Hatom abstraction of hydroxyl ion(water clusters) and α-carbon, as well as the rotation of αcarboxy hydroxyl, β-carboxy hydroxyl, β-carboxyl and R-group. The intrinsic energy barrier of the rate-determining step of optical isomerization of Asp_1 and Asp_2 induced by α-H abstraction of hydroxyl ion and H abstraction of water molecule of αcarbon was about 27.0 kJ/mol, and the corresponding intrinsic energy barriers induced by H-atom abstraction of hydroxyl ion assisted with water molecule and H-atom abstraction of two water molecule of α-carbon were about 34.0 and 40.0 kJ/mol, respectively. It could accelerate the process of Asp chiral transition that proton attacks the α-carbon of intermediate carbon anion.


Key words: chiral enantiomer, aspartic, hydroxyl, water molecule, density functional theory, perturbation theory, SMD model, energy barrier

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