荧光光谱法研究黄豆苷原与牛血清白蛋白的相互作用  

Study on the interaction between BSA and Daidzein by fluorescence spectroscopy

作　　者：宋胜梅[1] 罗小芹[1] 徐茂田[1] 

机构地区：[1]商丘师范学院化学系河南省高校重点实验室培育基地,河南商丘476000

出　　处：《商丘师范学院学报》2011年第3期58-62,共5页Journal of Shangqiu Normal University

基　　金：国家自然科学基金资助项目(20775047)

摘　　要：用荧光光谱法在pH7.4的PBS中研究了黄豆苷原(Daidzein,Da)与牛血清白蛋白(bovine serum albu-min,BSA)的相互作用.结果表明Da可静态猝灭BSA的内源荧光,温度升高时受动态猝灭的影响变得明显.二者之间的结合位点数约为1.5,315 K、310 K,300 K和290 K时的表观结合常数分别为5.44×104L.mol-1,5.70×104L.mol-1,5.29×104L.mol-1和5.69×104L.mol-1.焓变为0.2969 kJ.mol-1,熵变为91.78为J.mol-1.K-1,各温度下的自由能变均小于零,热力学参数表明二者之间主要靠静电力发生作用,熵变对反应过程具有较大贡献,且反应是自发过程.同步荧光光谱表明Da的加入改变了BSA的构像,使色氨酸残基的微环境亲水性增强.本研究对于阐明Da与蛋白的相互作用机理具有借鉴意义.The interaction mechanism and mode of daidzein（Da） with bovine serum albumin（BSA） in pH 7.4 PBS were studied by fluorescence spectroscopy.The results showed that the intrinsic fluorescence of BSA could be quenched by Da and the possible mechanism is static quenching,and the dynamic quenching is significantly with temperature rising.Further more,the number of binding site is 1.5,and the apparent binding constants at 315 K,310 K,300 K and 290 K are 5.44×104 L·mol-1,5.70×104 L·mol-1,5.29×104 L·mol-1 and 5.69×104 L·mol-1,respectively.The thermodynamic parameters determined by the van＇t Hoff analysis,such as enthalpy change △H（0.2969 kJ·mol-1）,entropy change △S（91.78 J·mol-1·K-1）,and the free energy change（△G0） at the experimental temperature,indicated that the type of force is electrostatic force.Meanwhile entropy change plays mainly contribution to the reaction,and the process is spontaneous.Synchronous fluorescence spectra showed that the conformational of the BSA is changed and the microenvironment of tryptophan residues is more hydrophilic when Da was added.So this study could be significant for understanding the interaction mechanism between Da and proteins.

关 键 词：黄豆苷原 牛血清白蛋白 荧光光谱 

分 类 号：O657.32[理学—分析化学]