分子量为3000的壳聚糖与牛血清白蛋白相互作用的研究

摘要

The interaction between in the range of 3000 the molecular weight of chitosan (CS)and bovine serum albumin (BSA)in vitro under simulative physiological conditions was investigated by fluorescence spectrum, ul-traviolet-visible absorption spectrometry and three-dimensional fluorescence spectra and circular dichroism (CD).It was shown that CS has a quite strong effect in quenching the fluorescence launching and enhance the UV absorption spectra of BSA. The maximum emission peak of BSA shifted to short wave for 8-10 nm.After the fluorescence quenching date was analyzed by Stern-Volmer equation,the results indicated that the reaction between bovine serum albumin and CS generated the new complex-system.The quenching belonged to static fluorescence quenching, with non-radiation energy transfer happening within single molecule. The binding con-stants KA(Kb) and thermodynamics parameters(ΔH ,ΔS ,ΔG )were calculated respectively according to equa-tion of fluorescence spectrometry and ultraviolet spectrometry at different temperatures.Based on thermody-namic data, the main reaction between CS and BSA were electrostatic force,but hydrophobic interaction can not be ignored.The effect of CS on the conformation of BSA was researched by synchronous fluorescence spectrom-etry and three-dimensional fluorescence spectra and circular dichroism, result in some micro-environmental and conformational changes of BSA molecules.%在模拟人体生理条件下，利用荧光光谱、圆二色谱、紫外-可见吸收光谱法和三维荧光法研究了3000分子量的壳聚糖(CS)与牛血清白蛋白(BSA)的相互作用.结果表明， CS对BSA的紫外吸收光谱具有增强作用，而对荧光光谱具有较强的荧光猝灭作用且峰位明显蓝移8~10nm.用Stern-Volmer方程分别对实验数据进行分析，得出结论， CS对BSA的荧光猝灭作用是属于静态荧光猝灭；与其反应生成了新的复合物，发生了分子内的非辐射能量转移；并求得相互作用过程的结合常数KA(Kb)和热力学参数(ΔG、ΔH、ΔS)，确定了它们之间的主要作用力是静电作用力，但疏水作用也不可忽略.圆二色谱、同步荧光光谱和三维荧光光谱法表明了CS对牛血清白蛋白的构象和所处的微环境发生了一定程度的变化.