分子对接法和光谱法研究BRCA1^(846-871)及其五突变肽与RAD51^(181-200)相互作用  

Interactions of RAD51^(181-200) with BRCA1^(846-871) mutants by molecular docking and spectral methods

作　　者：符林娜 曹孟杰 赵东欣[1] 卢奎[1,2] FU Linna;CAO Mengjie;ZHAO Dongxin;LU Kui(School of Chemistry and Chemical Engineering,Henan University of Technology,Zhengzhou 450001,Henan,China;School of Chemical Engineering and Food Science,Zhengzhou University of Technology,Zhengzhou 450044,Henan,China)

机构地区：[1]河南工业大学化学化工学院,河南郑州450001 [2]郑州工程技术学院化工食品学院,河南郑州450044

出　　处：《化学研究》2021年第2期95-102,F0003,共9页Chemical Research

基　　金：国家自然科学基金项目(21572046)。

摘　　要：影响RAD51蛋白的修复功能,可有效改善肿瘤细胞对化疗药物的耐受性。利用计算机模拟BRCA1^(846-871)关键肽段五个活性位点的突变,通过分子对接法筛选出与RAD51^(181-200)相互作用较强的9条五突变肽。采用固相合成法合成目标多肽,利用反相高效液相色谱(RP-HPLC)技术分离、纯化得到纯度大于93%的纯品肽,电喷雾电离质谱(ESI-MS)技术进行表征。通过荧光光谱法和圆二色光谱法(CD)研究BRCA1^(846-871)及其五突变肽与RAD51^(181-200)的相互作用。荧光谱图显示,除P6外,其余配体均与受体RAD51^(181-200)发生静态猝灭。在室温下,P1(4.17×10^(4) L·mol^(-1))、P4(7.61×10^(4) L·mol^(-1))和P5(1.19×10^(4) L·mol^(-1))与受体RAD51^(181-200)结合较强。圆二色光谱图显示,P1、P4和P5使受体RAD51^(181-200)的α-螺旋结构含量降低非常明显,从60.5%分别下降为35.7%、36.3%和36.4%,BRCA1^(846-871)、P3、P6和P9对受体α-螺旋结构含量影响较小,从60.5%分别下降为56.3%、55.6%、55.6%和54.6%,而P2、P7和P8对受体α-螺旋结构含量几乎不产生影响。综合光谱分析结果可知,配体P4与受体RAD51^(181-200)的相互作用最强。The BRCA1 protein maintains genomic stability,and its mutation affects the repair function of the RAD51 protein,which can cause tumor cells to develop drug resistance.Therefore,BRCA1 protein was mutated and the interaction of fragment BRCA1^(846-871) and RAD51^(181-200) was studied.Nine five-mutant peptides with strong interaction with RAD51 were selected by computer aided design.These mutant peptides were obtained by solid-phase peptide synthesis(SPPS)method.All peptides were purified and characterized by RP-HPLC and ESI-MS.Fluorescence spectrogram and CD results showed that BRCA1 fragment ligands changed the secondary structure of the RAD51^(181-200).Fluorescence spectroscopy results showed that P1(4.17×10^(4) L·mol^(-1)),P4(7.61×10^(4) L·mol^(-1))and P5(1.19×10^(4) L·mol^(-1))were strongly bound to RAD51^(181-200) fragment receptor.CD Pro results showed that the secondary structure of RAD51^(181-200) induced by P1,P4 and P5 decreased from 60.5%to 35.7%,36.3% and 36.4%,respectively.The secondary structure of RAD51^(181-200) induced by BRCA1^(846-871),P3,P6 and P 9 decreased from 60.5%to 56.3%,55.6%,55.6%and 54.6%,respectively while P2,P7 and P8 had little effect on the secondary structure of RAD51^(181-200).Comparing all spectral data,P4 has the most significant interaction with RAD51^(181-200).

关 键 词：BRCA1 分子对接 荧光光谱 圆二色光谱 

分 类 号：O657.3[理学—分析化学] O641.3[理学—化学]