摘要
本文采用紫外光谱法、荧光光谱法、圆二色谱法、电化学分析法和分子对接技术,对1,8-二川芎嗪基大黄酸(DBR)与牛血清白蛋白(BSA)的相互作用机制进行了研究。结果表明DBR和BSA间存在强相互作用,在温度290、300、310 K时,两者间的结合常数Ka的数量级达10^(5),结合位点数为1.1,表明两者之间有着较强的相互作用并形成1∶1复合物;Kq两者的猝灭常数值分别为5.5924×10^(12)、4.9853×10^(12)、4.1665×10^(12)L·mol^(-1)·s^(-1),推测猝灭方式为静态猝灭。根据F9rster的非辐射能量转移机制求算出给体与受体间的结合距离r=4.8 nm、能量转移效率E=0.5793,推测两者之间存在非辐射能量转移;通过计算该体系的热力学参数得到ΔH<0,ΔS<0,ΔG<0,表明二者作用力类型为氢键和范德华力。另外,随着DBR的加入BSA的构象发生了改变,BSA的α-螺旋结构从60.55%减少到58.5%;电化学分析法表明两者形成了非电活性的超分子化合物;分子对接模拟结果推测出DBR分子进入了BSA分子的疏水腔内,其结合位置位于domainⅠA亚域。
This study employs UV spectroscopy,fluorescence spectroscopy,circular dichroism,electrochemical analysis,and molecular docking techniques to elucidate the interaction mechanism between 1,8-ditetramethylpyrazine based rhein(DBR)and bovine serum albumin(BSA).Experimental results demonstrate a strong interaction between DBR and BSA:At 290,300,and 310 K,the order of magnitude of the binding constant K a between DBR and BSA is over 105,and the number of binding sites is 1.1,inferring a strong interaction between DBR and BSA to form a 1∶1 complex.With the K q values are 5.5924×10^(12) L·mol^(-1)·s^(-1),4.9853×10^(12) L·mol^(-1)·s^(-1),4.1665×10^(12) L·mol^(-1)·s^(-1),we can speculate that the quenching method is static quenching.According to F rster’s non-radiative energy transfer mechanism,the binding distance r=4.8 nm and energy transfer efficiency E=0.5793 between the donor and receptor were calculated,indicating the existence of non radiative energy transfer between DBR and BSA.By calculating the thermodynamic parameters of the system,it is shown thatΔH<0,ΔS<0,ΔG<0,indicating that the types of the two forces are hydrogen bonding and van der Waals forces.In addition,with the addition of DBR,the conformation of BSA has changed.Theα-spiral structure has decreased from 60.55%to 58.5%.Electrochemical analysis shows that non-electroactive supramolecular compounds form.The molecular docking simulation results speculate that DBR molecules have entered the hydrophobic cavity of BSA molecules,and their binding sites are located in the domainⅠA subdomain.
作者
闫恳
张燕燕
卞在东
张辉兰
黄鹏
倪佳
黄和平
YAN Ken;ZHANG Yanyan;BIAN Zaidong;ZHANG Huilan;HUANG Peng;NI Jia;HUANG Heping(School of Pharmacy,Anhui University of Chinese Medicine,Hefei 230038;Anhui Provincial Key Laboratory of TCM Research and Development,Hefei 230012)
出处
《分析科学学报》
CAS
CSCD
北大核心
2024年第3期337-343,共7页
Journal of Analytical Science
基金
安徽省高校自然科学研究项目(KJ2020A0422)。
关键词
1
8-二川芎嗪基大黄酸
牛血清白蛋白
光谱法
电化学法
分子对接
1,8-Ditetramethylpyrazine based rhein
Bovine serum albumin
Spectroscopy
Electrochemical method
Macromolecular docking
