TNS探针检测中心蛋白与DNA结合后的构象变化  

Conformation changes of centrin binding to DNA detected by TNS probe

作　　者：张文龙 胡颖媛 薛美昭 杨斌盛[2] ZHANG Wenlong;HU Yingyuan;XUE Meizhao;YANG Binsheng(College of Chinese Medicine and Food Engineering,Shanxi University of Chinese Medicine,Jinzhong 030619,China;Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education,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,晋中030619 [2]山西大学分子科学研究所,化学生物学与分子工程教育部重点实验室,太原030006

出　　处：《分析试验室》2023年第2期209-216,共8页Chinese Journal of Analysis Laboratory

基　　金：山西省自然科学基金项目(201901D211532);山西省教育厅基金项目(2020L0416);山西中医药大学科研基金项目(2020BK09)资助。

摘　　要：中心蛋白(centrin)通过构象变化吸引多种修复因子到DNA损伤位点,参与核苷酸切除修复的识别过程,利用荧光探针可以研究蛋白质的构象变化。本研究以2-对甲苯胺基-6-萘磺酸(TNS)为探针,应用光谱法探究了八肋游仆虫中心蛋白N-端半分子(N-EoCen)与小牛胸腺DNA(CT-DNA)作用后的构象变化。结果表明,N-EoCen可以与CT-DNA形成复合物,复合物的形成使得蛋白的构象发生变化,疏水腔暴露。Ca^(2+)与N-EoCen配位后,有利于N-EoCen与CT-DNA的结合,会进一步诱导蛋白中疏水性氨基酸残基的暴露。本文研究结果为今后研究中心蛋白在核苷酸切除修复的识别过程中的分子机制提供了理论基础,并且为TNS作为探针应用于检测蛋白质与其他生物大分子的作用提供了参考。Centrin attracts multiple repair factors to DNA damage sites through conformation changes to participate in the recognition process of nucleotide excision repair.The conformation changes of proteins can be studied using fluorescent probes.In this study,the conformation changes of N-terminal domain of Euplotes octocarinatus centrin(N-EoCen)after interaction with calf thymus DNA(CT-DNA)were investigated by 2-ptoluidinylnaphthalene-6-sulfonate(TNS)fluorescence probe.The results showed that N-EoCen could form complex with CT-DNA.The conformation of N-EoCen changed and hydrophobic cavity was exposed upon the formation of N-EoCen-CT-DNA complex.The coordination of Ca^(2+)with N-EoCen was conductive to the binding of N-EoCen and CT-DNA,which further induced the exposure of hydrophobic amino acid residues in teh protein.The results of this study provided a theoretical basis for further research on the molecular mechanism of centrin in the recognition process of nucleotide excision repair,and a reference for the application of TNS as a probe to detect the interactions between protein and other biological macromolecules.

关 键 词：中心蛋白 小牛胸腺DNA(CT-DNA) 探针 构象 

分 类 号：O657.3[理学—分析化学] O629.7[理学—化学]