光谱法与分子对接法研究山柰酚对牛血清白蛋白二级结构的影响  

Effect of kaempferol on secondary structure of bovine serum albumin:spectroscopy and molecular docking method

作　　者：林锐[1] 李悦[2] 裘兰兰[1] 何华[2,3] 李丽丽[2] 何佳[2] 

机构地区：[1]盐城卫生职业技术学院,江苏盐城224005 [2]中国药科大学分析化学教研室,江苏南京210009 [3]天然药物活性组分与功效国家重点实验室中国药科大学,江苏南京210009

出　　处：《化学研究与应用》2014年第6期797-803,共7页Chemical Research and Application

基　　金：盐城卫生职业技术学院青年基金项目(20114105)资助;大学生创新药物研制能力提高项目(J1030830)资助

摘　　要：采用分子对接技术和同步荧光光谱法、红边激发荧光位移法(REES法)及圆二色谱法(CD)共同研究了山柰酚与牛血清白蛋白(BSA)在pH7.40的缓冲溶液中的相互作用。分子对接的结果表明,山柰酚的B环插入到BSA的ⅡA结构域中的疏水腔内,与色氨酸残基(Trp212)的距离为12.96,维系药物与蛋白质的主要作用力为疏水作用。通过荧光光谱法测得二者之间相互作用力主要为疏水性相互作用,结合位点为1,与分子模拟结果一致。同步荧光光谱及REES法的研究表明,发生相互作用的过程中BSA的色氨酸残基处于运动受限的微环境中,而适当增加山柰酚的浓度能够改变色氨酸微环境的流动性,进而对BSA的构象产生一定影响;同时,圆二色谱的定量计算结果也表明,一定浓度的山柰酚与BSA的相互作用引起了α-螺旋含量的显著降低,从11.91%降低到1.67%,对BSA的二级结构产生一定影响。The interaction between kaempferol and bovine serum albumin（ BSA） was investigated by molecular docking technology, fluorescence spectroscopy,red edge excitation shift（REES）method and circular dichroism（CD）together to explore the mechanism of interaction under simulated physiological condition. The result of molecular docking indicated that kaempferol can bind with BSA in the hydrophobic pocket of sub-domain IIA with hydrophobic force as the main acting force and the distance with Trp212 is 12. 96？. The thermodynamic parameters showed that the binding power between kaempferol and BSA is mainly driven by the elec-trostatic force which showing no difference with the Molecular Docking Method. The transformation of micro-environment around a-mino acid residues was observed by the spectra of synchronous fluorescence and REES method qualitatively which shows that the Trp residues located in the limited micro-environment and the fluidity may start to change with the increased concentration of kaempferol in the complex. Furthermore,the spectra of CD were employed to research the change of the secondary structure of BSA quantitatively through the assay of α-helix which dropped from 11. 91%to 1. 67%during the interaction.

关 键 词：光谱法 分子对接 山柰酚 牛血清白蛋白 相互作用 

分 类 号：O657.3[理学—分析化学]