光谱法、量热法以及分子对接研究槲皮素与中心蛋白的相互作用  

Study on the interaction between Centrin and Quercetin by spectroscopic methodologies, calorimetric and molecular docking

作　　者：张文龙 石恩娴[2] 胡颖媛 裴科 任蕾 杨斌盛[3] ZHANG Wen-long;SHI En-xian;HU Ying-yuan;PEI Ke;REN Lei;YANG Bin-sheng(College of Chinese Medicine and Food Engineering,Shanxi University of Chinese Medicine,Jinzhong 030619,China;Department of Pharmacy,Shanxi Medical University,Taiyuan 030001,China;Institute of Molecular Science,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西中医药大学中药与食品工程学院,山西晋中030619 [2]山西医科大学药学院,山西太原030001 [3]山西大学分子科学研究所,山西太原030006

出　　处：《分子科学学报》2023年第2期127-134,共8页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(81703704);山西省应用基础研究计划资助项目(201901D211532);山西省教育厅资助项目(2020L0416);山西中医药大学科研基金资助项目(2020BK09)。

摘　　要：通过光谱法、等温滴定量热法(ITC)以及分子对接等技术研究了八肋游仆虫中心蛋白N端分子(N-EoCen)与槲皮素(Quercetin,Q)之间的相互作用以及Q对N-EoCen构象的影响.结果表明,在室温下Hepes(pH=7.4)缓冲溶液中,Q可以与N-EoCen以物质的量比1∶1结合于N-EoCen的第二个EF-hand的E,F螺旋之间,条件结合常数约为104L·mol^(-1),复合物的形成是放热的过程,Q与N-EoCen之间存在氢键、疏水作用以及范德华力等多种作用.Q与N-EoCen中酪氨酸残基(Tyr72)的结合距离为1.54 nm.复合物的形成使得蛋白的构象发生变化,α-helix含量减少.本文的研究成果对于进一步了解中心蛋白分子识别多样性的结构基础,以及相关药物的研发具有参考价值.Quercetin(Q), a flavonoid, is widely found in a variety of fruits and vegetables, Chinese herbal medicine and beverages. Q can regulate multiple signaling pathways through multiple targets, exhibiting a wide range of biological activities. For example, it has been reported that Q can bind to calmodulin as an inhibitor and participate in regulating tumor promoters, but the thermodynamic parameters of the binding between Q and calmodulin have not been reported. Therefore, further research on Q and related proteins is conducive to understanding its metabolic mechanism. In order to explore the binding mechanism between Quercetin(Q) and N-terminal domain of Euplotes octocarinatus centrin(N-EoCen) and the influence of Q on the conformation change of N-EoCen, the interaction of N-EoCen and Q was characterized by using different methods including various spectroscopic techniques, isothermal titration calorimetry analysis(ITC) and molecular docking. The results indicate that Q could form complex with N-EoCen in molar ratio 1∶1, and the conditional binding constant is about 10^(4) L·mol^(-1) in 10 mmol·L^(-1) Hepes solution(pH=7.4) at room temperature as shown by ITC and fluoresence spectroscopy. The enthalpy change associated with Q binding to N-EoCen is negative, indicative of an exothermic process. There are hydrogen bonding, hydrophobic interaction and van der Waals force between them according to the obtained outcome. The distance between Q and tyrosine residue(Tyr72) in N-EoCen is 1.54 nm calculated by F9ster′s energy transfer theory. Besides, molecular docking was used to simulate the binding mode of N-EoCen and Q, Q could bind to the E and F helix of the second EF-hand of N-EoCen. The experimental results are consistent with the molecular docking results. Finally, circular dichroism(CD) and three-dimensional fluorescence spectroscopy experiments reveal that the formation of N-EoCen-Q complex results in a conformational change of protein. In more detail, the content of α-helix of protein decreases. The study

关 键 词：八肋游仆虫中心蛋白N端分子 槲皮素 复合物 构象 

分 类 号：O657[理学—分析化学]