光谱法研究加替沙星与牛血清白蛋白的相互作用

Study of the interaction between Gatifloxacin and Bovine Serum Abulmin by spectrometry

采用荧光光谱和紫外吸收光谱法研究牛血清白蛋白与加替沙星的相互作用机制.由荧光光谱可知加替沙星对牛血清白蛋白有猝灭作用;用Stern-Volmer方程求得在17℃和25℃温度下它们的结合常数分别为1.14×107L·mol-1和6.30×106L·mol-1,结合位点数分别为1.46和1.44;用热力学方程处理实验数据得到结合反应的相关参数(25℃):ΔH=53.46 kJ·mol-1,ΔG=-38.79 kJ·mol-1,ΔS=49.24 J·K-1·mol-1;并用三维荧光光谱和同步荧光光谱探讨加替沙星对牛血清白蛋白构象的影响.实验结果表明,加替沙星对牛血清白蛋白的猝灭方式为静态猝灭,它们间的主要作用力为静电作用.

The mechanism of interaction between gatifloxacin（GTF） and bovine serum abulmin（BSA） was investigated with ultraviolet absorbance spectra and fluorescence spectra. The fluorescence spectra showed that the fluorescence intensity of BSA was quenched by GTF. According to Stem-Volmer equation, their binding constants are 1. 14 × 10^7 and 6. 3 × 10^6, and the numbers of bingding sites are 1. 46 and 1. 44, respectively, at 17℃and 25℃. After analyzing and disposing the data of the experiment by thermodynamic equation, the corresponding thermodynamic parameters（25℃ ） （ △H=53. 46 kJ · mol^-1 , AG= - 38. 79 kJ · mol^-1 ,△S=49. 24 J · K^-1 · mol^-1 ） were obtained At the same time, the effect of GTF on the conformation of BSA was analyzed using three-dimensional fluorescence spectrometry and synchronous fluorescence spectrometry. The experiments proved that the quenching belonged to static fluorescence quenching, and the main dominant sort of binding force was electro-static interaction.