水液相下羟基自由基(水分子簇)诱导脯氨酸分子损伤的机理  

Mechanism of Proline Damage Induced by Hydroxyl Radicals(Water Molecules Clusters)in Water/Liquid Phase Environment

作　　者：罗香怡[1] 高浩溟 姜丰 刘军 范艳杰 姜春旭 王佐成[1] LUO Xiangyi;GAO Haoming;JIANG Feng;LIU Jun;FAN Yanjie;JIANG Chunxu;WANG Zuocheng(College of Physics, Baicheng Normal University, Baicheng, Jilin 137000, China;Ophthalmology Department, PLA 321st Hospital, Baicheng, Jilin 130700, China;Nadanbo Middle School, DongFeng, Liaoyuan, Jilin 136000, China;College of Computer Science, Baicheng Normal University, Baicheng, Jilin 137000, China)

机构地区：[1]白城师范学院物理学院,吉林白城137000 [2]解放军第三二一医院眼科,吉林白城137000 [3]那丹伯镇中学,吉林辽源136000 [4]白城师范学院计算机科学学院,吉林白城137000

出　　处：《复旦学报（自然科学版）》2022年第1期104-114,共11页Journal of Fudan University：Natural Science

基　　金：吉林省教育厅科学研究规划项目(JJKH20200002KJ);吉林省科技厅自然科学基金(20160101308JC)。

摘　　要：本工作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,研究了水液相下羟基自由基(水分子簇)诱导的两性脯氨酸分子损伤。反应通道研究表明:Pro的损伤可以通过羟基自由基(水分子簇)抽取α-H原子和五元杂环上不同位置的H原子实现。势能面计算表明:羟基自由基(水分子簇)抽取α-H的自由能垒在41.3至48.3 kJ·mol^(-1)之间,抽取五元杂环上不同位置的H的自由能垒在33.3至48.9 kJ·mol^(-1)之间。抽取五元杂环的与α-C邻位C上的H的损伤反应最具优势,自由能垒在33.3至36.5 kJ·mol^(-1)之间。损伤修复的最低自由能垒是126.9 kJ·mol^(-1)。结果表明,水液相下羟基自由基存在时脯氨酸分子很容易损伤,且损伤后很难修复。The damage of amphoteric proline induced by hydroxyl radicals(water clusters) is studied in water-liquid phase environment by means of M06-2 X and MN15 methods based on density functional theory and SMD model method of self-consistent reaction field theory. The study of reaction channels shows that the damage of proline can be achieved by hydroxyl radicals(water molecules clusters) extracting α-H atoms and H atoms at different positions on the five-membered heterocycle. The calculation of potential energy surface shows that the energy barrier of α-H-atom abstraction by hydroxyl radicals(water clusters) is between 41.3 and 48.3 kJ·mol^(-1), and the energy barrier of five-membered heterocycle-H atoms abstraction by hydroxyl radicals at different positions is between 33.3 and 48.9 kJ·mol^(-1). The damage reaction has the most advantages when extracting H on C that the ortho-position of five-membered heterocyclic α-C, with the energy barrier between 33.3 and 36.5 kJ·mol^(-1). The minimum energy barrier for damage repair is 126.9 kJ·mol^(-1). The results show that proline molecules are easily to be damaged in the presence of hydroxyl radicals in aqueous solution, and it is difficult to repair after damage.

关 键 词：脯氨酸 羟基自由基 损伤 密度泛函理论 自洽反应场理论 过渡态 自由能垒 

分 类 号：O641.12[理学—物理化学]