矢车菊-3-O-葡萄糖苷与牛血清白蛋白相互作用的光谱学研究

应用紫外吸收光谱、荧光光谱和同步荧光光谱法研究了矢车菊-3-O-葡萄糖苷与牛血清白蛋白(BSA)的相互作用,结果表明:矢车菊-3-O-葡萄糖苷能使BSA发生内源荧光猝灭,属静态猝灭机理。25℃和30℃下,矢车菊-3-O-葡萄糖苷与BSA的静态猝灭速率常数分别为3.7×104 L.mol-1,4.1×104 L.mol-1,结合常数为1.1×105 L.mol-1,1.5×105 L.mol-1,结合位点数为1。根据Fòrster非辐射能量转移机理,矢车菊-3-O-葡萄糖苷与BSA之间的作用距离约为5.6 nm,能量转移效率为0.085。热力学分析表明矢车菊-3-O-葡萄糖苷与BSA存在疏水相互作用,矢车菊-3-O-葡萄糖苷对BSA构象影响较小。

SPECTROSCOPIC STUDY ON INTERACTION OF CYANIDN - 3 - O - GLUCOSIDE CHLORIDE WITH BOVINE SERUM ALBUMIN

The interaction of Cyanidin-3-O-glucoside chloride with bovine serum albumin(BSA) was studied by UV absorption spectroscopy fluorescence spectroscopy and synchronous fluorescence spectroscopy in the work.The results showed that Cy-3-O-Glu could induce an endogenous fluorescence quenching of BSA under a mechanism of static quenching.The quenching rate constants at 25℃and 30℃ were determined to be 3.7×104 L·mol-1,4.1×104 L·mol-1,respectively;the binding constants 1.1×105 L·mol-1,1.5×105 L·mol-1,respectively.The number of binding site of the static quenching was calculated.According to the theory of Fòrster nonradiative energy transfer the interacting distance of Cy-3-O-Glu and BSA was estimated to be 5.62nm nm with an efficiency of 0.0851.By analysis of thermodynamic parameters,the binding of Cy-3-O-Glu with BSA was mainly attributed to the hydrophobic interaction.The Cy-3-O-Glu had only a slight influence on the BSA conformation by the fluorescence spectra.