光谱法研究稀土离子钇(Ⅲ)与牛血清白蛋白的相互作用

Study on Interaction of Y^(3+) and Bovine Serum Albumin by Spectrometry

用荧光光谱和紫外-可见吸收光谱研究了稀土金属离子Y3+与牛血清白蛋白(BSA)的相互作用。实验结果发现:Y3+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20～25 nm。用Stern-Volmer方程分别对实验数据进行分析,得出结论:Y3+对BSA的荧光猝灭作用是属于静态荧光猝灭,Y3+与BSA反应生成了新的复合物,发生了分子内的非辐射能量转移。求得相互作用过程的结合常数(KA)和热力学参数(ΔΗ、ΔS、ΔG),确定了它们之间的主要作用力是范德华力、氢键等,但静电作用力也不可忽略。同步荧光光谱法表明Y3+对牛血清白蛋白的构象有影响。

The interaction between rare earth ion Y^3＋ and bovine serum albumin（BSA） was studied by fluorescence spectrum and ultraviolet-visible absorption spectrometry.It was shown that Y3＋ has a quite strong effect to quench the fluorescence launching and enhance the UV absorption spectra of BSA.The maximum emission peak of BSA shifted to short wave by 20～25 nm.After the fluorescence quenching date was analyzed by Stern-Volmer equation,the results indicated that the reaction between bovine serum albumin and Y3＋ generated the new complex-system.The quenching belonged to static fluorescence quenching,with non-radiation energy transfer happening within single molecule.The binding constants（KA） and thermodynamics parameters（ΔΗ,ΔS,ΔG） were calculated according to equation of fluorescence spectrometry at different temperatures.Based on thermodynamic data,the main reaction between Y^3＋ and BSA was van der Waals force and hydrogen bond,but electrostatic force can not be ignored.The effect of rare earth ion Y^3＋ on the conformation of BSA was researched by synchronous fluorescence spectrometry.