水液相下羟自由基与谷氨酸分子反应机理的量子化学研究  

Quantum Chemistry Study on the Reaction Mechanism of Hydroxyl Radical with Glutamate Molecule in Water-Liquid Phase Environment

作　　者：牛鹤丽[1] 杨应[2] 徐岩 孙艳雨 郝成欣[3] 王佐成[2] 姜春旭 赵丽红[3] NIU Heli;YANG Ying;XU Yan;SUN Yanyu;HAO Chengxin;WANG Zuocheng;JIANG Chunxu;ZHAO Lihong(Department of Medical Technology,Baicheng Medical College,Baicheng Jilin,137000,China;Theoretical Computing Center,Baicheng Normal University,Baicheng Jilin,137000,China;College of Basic Medicine,Baicheng Medical College,Baicheng Jilin,137000,China)

机构地区：[1]白城医学高等专科学校医学技术学院,吉林白城137000 [2]白城师范学院理论计算中心,吉林白城137000 [3]白城医学高等专科学校基础医学院,吉林白城137000

出　　处：《复旦学报（自然科学版）》2024年第1期143-154,共12页Journal of Fudan University：Natural Science

基　　金：白城医学高等专科学校高层次人才团队建设项目(BCYZ20220302);白城医学高等专科学校科研平台重点项目(BYKPT202207);吉林省科技厅自然科学基金(20130101131JC)。

摘　　要：采用密度泛函理论的M06-2X和MN15方法,结合自洽反应场理论的SMD模型方法,研究了水液相下羟自由基(OH)与谷氨酸分子(Glu)反应的机理。研究发现:Glu的损伤可通过OH抽取其不同位置的H原子、OH加成到羧基和去质子羧基C以及单电子从Glu分子向OH转移3个途径实现。势能面计算表明:OH加成到羧基和去质子羧基C的反应通道最具优势,反应无势垒;OH抽取质子化氨基H、α-H、β-H、γ-H和羧基H的最低能垒分别是28.7、17.6、8.0、18.3和29.0 kJ/mol;电子从Glu分子向OH转移为劣势通道,反应能垒是255.2 kJ/mol。结果表明,水液相下OH加成和抽H均可诱导Glu分子损伤,损伤的Glu绝大多数难以修复,Glu具有清除羟自由基的能力。M06-2X and MN15 methods of density functional theory and SMD model method of self consistent reaction field theory are used to study the reaction mechanism of hydroxyl radical with amphoteric glutamate molecule in water-liquid phase environment.The study shows that the damage of Glu can be achieved by three ways:OH extracting H atoms from different positions of it,OH adding to carboxyl C and deprotonation of carboxyl C,single electron transferring to OH from Glu molecule,all of which could induce Glu damage.Investigation on the potential energy surface shows that there is no potential barrier on the second reaction channel,it has the most advantage;the lowest energy barrier of OH extracts the protonation of amino group H,α-H,β-H,γ-H and carboxyl H are 28.7,17.6,8.0,18.3 and 29.0 kJ/mol respectively;the channel of single electron transfers to OH from Glu molecule is a inferior channel,and the reaction energy barrier of it is 255.2 kJ/mol.The results show that both OH addition and H extraction can induce Glu molecular damage in water-liquid phase environment,and most of the damaged Glu are difficult to be repaired,glutamate has the ability to clear OH free radical.

关 键 词：谷氨酸 羟自由基 密度泛函理论 过渡态 电子转移 能垒 损伤 

分 类 号：O641.12[理学—物理化学]