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用紫外-可见和荧光光谱法研究Dy3+与牛血清白蛋白(BSA)的相互作用,同时采用同步和三维荧光法探索了Dy3+对BSA结构的影响。分析实验结果发现,Dy3+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红移5 nm~7 nm。用Stern-Volmer方程分别对实验数据进行分析,得出结论,Dy3+对BSA的荧光猝灭在Dy3+浓度小于1.212×10-5mol·L-1是生成复合物的静态猝灭,当Dy3+的浓度大于1.212×10-5mol·L-1是静态和动态荧光猝灭同时存在。并求得相互作用过程的静态结合常数K A(298 K;4.1×103L·mol-1,310 K;3.9×103L·mol-1)和结合位点数均为1。根据热力学函数判断出Dy3+主要通过疏水作用和静电引力进入BSA亚结构的空腔中。同步荧光光谱法和三维荧光光谱法表明了Dy3+对牛血清白蛋白的构象和微环境都有影响。
The interaction between Dy3 + and bovine serum albumin (BSA) was studied by UV-Vis and fluorescence spectroscopy. The effect of Dy3 + on the structure of BSA was also explored by synchronous and three-dimensional fluorescence methods. The experimental results show that Dy3 + has a strong fluorescence quenching effect on the fluorescence spectrum of BSA with obvious enhancement of the UV absorption spectrum and the peak position is obviously shifted by 5 nm ~ 7 nm. The Stern-Volmer equation was used to analyze the experimental data respectively. It was concluded that the fluorescence quenching of Dy3 + to BSA is a static quenching of the complex when the concentration of Dy3 + is less than 1.212 × 10-5mol·L-1. When the concentration of Dy3 + 1.212 × 10-5mol·L-1 is both static and dynamic fluorescence quenching. The static binding constants K A (298 K; 4.1 × 103 L · mol-1,310 K; 3.9 × 103 L · mol-1) and the number of binding sites were all 1 for the interaction process. According to the thermodynamic function, it is found that Dy3 + mainly enters the cavity of BSA substructure through hydrophobic interaction and electrostatic attraction. Synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy showed that Dy3 + had an influence on the conformation and microenvironment of bovine serum albumin.