头孢美唑钠与BSA及纳米银-BSA体系相互作用的研究

摘要

纳米银与牛血清白蛋白(BSA)均匀混合形成纳米银-BSA体系,运用荧光光谱,紫外吸收光谱,同步荧光光谱研究了注射用头孢美唑钠(Cefmetazole Sodium for Injection,CS)与BSA及纳米银-BSA体系的相互作用.头孢美唑钠对BSA具有荧光猝灭作用,其猝灭方式为静态猝灭,求出了猝灭常数,结合常数及结合位点数.在295K和302K时用热力学方程处理实验数据,求得了热力学参数△H、△G、和△S,头孢美唑钠与BSA之间的作用力主要为氢键和范德华力.头孢美唑钠对BSA中色氨酸和酪氨酸残基均有影响.纳米银的存在不改变头孢美唑钠对BSA的猝灭方式,但猝灭常数、结合常数、热力学参数及作用力均发生变化,在短时间内,纳米银的加入对BSA构象未见明显影响.%The silver nanoparticles and bovine serum albumin( BSA) mixting formed the system of nanosilver-BSA. The interaction between cefmetazole sodium for injection(CS)and bovine serum albumin(BSA) without nanosilver or with nanosilver has been investigated by the fluorescence spectrometry,ultraviolet absorption spectrometry, sychronous fluorescence spectrometry. The fluorescence of BSA was quenched by CS,and the quenching mechanism of BSA was a static quenching process. The quenching data were analyzed according to Stern-Volmer equation,and the quenching constant,binding constant and binding sites were determined at different temperatures. After analyzing fluorescence quenching data by the thermodynamic equation,the value of thermodynamic param-eters( ΔH, ΔC and ΔS)were obtained. The binding force was mainly H-bond and Van der Waars. The CS had strong impact on the conformation of BSA. The quenching process of BSA was not changed by CS in the presence of nanosilver. But the quenching constant,binding constant,thermodynamic parameters and binding force varied with the concentration of nanosilver. The conformation of BSA was not affected by the silver nanoparticles in a short time.