采用紫外、荧光和圆二色光谱研究了秋水仙碱与人血清白蛋白之间的相互作用。结果发现秋水仙碱使人血清白蛋白的紫外吸收增强,特征荧光峰猝灭,并且随温度升高猝灭常数KSV降低。求算了不同温度下秋水仙碱与人血清白蛋白相互作用的平衡常数与结合位点数。根据Van’t Hoff方程计算出ΔH=-11.66kJ·mol^-1,ΔS=51.507 J.(mol·K)^-1,得出二者之间的作用力主要是静电作用力。圆二色光谱测得加入秋水仙碱后人血清白蛋白的α-螺旋降低,二级结构改变,表明秋水仙碱对人血清白蛋白的荧光猝灭机制属于形成配合物所引起的静态猝灭。
The binding reaction of colchicine with human serum albumin(HSA) was studied by UV-Vis absorption, fluorescence and circular dichroism spectrometry. The results indicated that colchicine led to the increase in UV absorption and the quenching of intrinsic fluorescence of HSA. As the temperature increased, the quenching constant Ksv decreased. The binding constants and the numbers of the binding sites of the interaction between colchicine and HSA at different temperatures were obtained. The thermodynamic parameters, enthalpy change (AH) and entropy change (AS), were calculated to be -11.66 kJ·mol^-1 and 51. 507 J(mol·K)^-1 respectively according to Van't Hoff equation, which suggested that the main binding force between colchicine and HSA was static interaction. The protein conformation was altered(CD date) with decreasing of a-helices in the presence of colchicine. The results showed that the quenching mechanism of the combination of colchicine with human serum albumin was a static quenching procedure.