光谱及电化学方法研究大黄酸与牛血清白蛋白的相互作用

摘要

采用荧光光谱、紫外光谱和圆二色光谱法并结合电化学方法,研究了大黄酸与牛血清白蛋白之间的相互作用.结果表明:大黄酸对牛血清白蛋白有较强的荧光猝灭作用且为静态猝灭,并计算得出不同温度下其结合常数(KA)与结合位点数(n)分别为:3.67×105,0.95(298 K)；2.60×104,0.83(309 K).由热力学参数确定它们间的作用力主要是静电引力,并依据F(o)rster能最转移理论求得其结合距离为3.28 nm,同步荧光光谱及圆二色谱表明大黄酸对牛血清白蛋白的构象产生影响.%The interaction between rhein and bovine serum albumin(BSA) was studied by UV-Visible, fluorescence spectroscopy and circular dichroism in conjunction with electrochemical method. The results indicated that rhein has a powerful ability to quench the albumin's fluorescence in a static mode. The binding constants(KA) and binding site numbers (n) obtained at different temperatures were 3. 67X 105, 0. 99 (298 K) and 2. 60× 104, 0. 83 (309 K) respectively. According to the thermodynamic parameters the main sorts of binding force of rhein-BSA was fixed as electrostatic. The distance between donor and acceptor in rhein-BSA was 3. 28 nm based on the Fdrster energy transfer theory. Results of the circular dichroism and synchronous fluorescence show that the binding can cause conformation change of BSA.