基于氨基作为质子迁移桥梁的蛋氨酸分子旋光异构机理  

Optical Isomerism Mechanism of Methionine Molecule Based on Amino Group as Proton Transfer Bridge

作　　者：高峰[1] 姜丽莎[2] 闫红彦[3] 杨晓翠[1] 王佐成[1] 佟华[1] GAO Feng JIANG Lisha YAN Hongyan YANG Xiaocui WANG Zuocheng TONG Hua(College of Physics and Electronic Information, Baicheng Normal University, Baicheng 137000, Jilin Province, China College of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, Liaoning Province, China College of Computer Science, Baicheng Normal University, Baicheng 137000, Jilin Province, China)

机构地区：[1]白城师范学院物理与电子信息学院,吉林白城137000 [2]辽宁师范大学化学化工学院,辽宁大连116029 [3]白城师范学院计算机科学学院,吉林白城137000

出　　处：《吉林大学学报（理学版）》2017年第4期1012-1019,共8页Journal of Jilin University:Science Edition

基　　金：吉林省科技发展计划项目(批准号:20130101308JC)

摘　　要：采用密度泛函理论的B3LYP方法和微扰理论的MP2方法,研究两种最稳定构型的蛋氨酸分子(Met)基于氨基作为质子迁移桥梁的旋光异构反应.结果表明:基于氨基作为质子迁移桥梁的蛋氨酸分子旋光异构反应有2条通道a和b;构型1的主反应通道为通道a,决速步骤为第1基元反应,自由能垒为264.2kJ/mol,由质子从手性C直接向氨基N迁移的过渡态产生;构型2的主反应通道也为通道a,决速步骤为第2基元反应,自由能垒为266.1kJ/mol,由羧基异构后质子从手性C向氨基N迁移的过渡态产生;两种构型的Met分子旋光异构速控步骤的反应速率常数分别为3.04×10^(-34),1.41×10^(-34) s^(-1).We studied the optical isomerism reaction of two kinds of the most stable configurations of methionine molecules based on amino group as proton transfer bridge by using the B3LYP method of density functional theory and the MP2 method of perturbation theory.The results show that there are two channels a and b in the optical isomerism reaction of methionine molecules based on amino group as proton transfer bridge.The dominant reaction channel of the configuration one is channel a,the rate-determining step is the first elementary reaction,and the free energy barrier is 264.2kJ/mol that is generated by the transition state of proton transfer from the chiral C to the amino N.The dominant reaction channel of the configuration two is the channel a,the rate-determining step is the second elementary reaction,and the free energy barrier is 266.1kJ/mol that is generated by the transition state of proton transfer from the chiral C to the amino N after carboxyl group isomerism.The reactionrate constants of the optical isomerism rate-determining step of two configurations of methionine molecules are 3.04×10^（-34）,1.41×10^（-34） s^（-1）,respectively.

关 键 词：蛋氨酸 旋光异构 手性 密度泛函理论 过渡态 微扰论 

分 类 号：O641.12[理学—物理化学]