桔皮苷与牛血清白蛋白相互作用的研究

Studies of interaction between hesperidin and bovine serum albumin by fluorescence quenching method

运用荧光光谱、紫外光谱法研究了桔皮苷与牛血清白蛋白(BSA)的相互作用。桔皮苷分子与BSA作用导致BSA内源荧光猝灭,猝灭机理主要为静态猝灭,并存在非辐射能量转移。测定了不同温度下该反应的结合常数、结合位点数及结合热力学参数。结果表明:桔皮苷与BSA之间主要为氢键或范德华作用力,作用过程是一个熵增加、自由能降低的自发分子间作用过程;测得了供体与受体间结合距离r和能量转移效率E;并用同步荧光技术考察了桔皮苷对BSA构象的影响。

The interaction between hesperidin and bovine serum albumin （BSA） was investigated using fluorescence and UV/ Vis. The experimental results showed that the fluorescence quenching of BSA by hesperidin is a result of the formation of hesperidin BSA complex; both static quenching and nonradiative energy transferring were confirmed to result in the fluorescence quenching. The binding site number n, apparent binding constant KA and corresponding thermodynamic parameters were measured at different temperatures. The process of binding hesperidin molecule on BSA was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrogen bonds and van der Waals interactions play a major role in stabilizing the complex. The binding distance r and energy transfer efficiency E between hesperidin and BSA were obtained according to fluorescence resonance energy transfer. The effect of hesperidin on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.