硝酸咪康唑与牛血清白蛋白作用的热力学特征研究

在模拟动物体生理条件和不同温度下,用荧光猝灭光谱、同步荧光光谱、三维荧光光谱和紫外可见吸收光谱等,研究了不同温度下硝酸咪康唑(Miconazole Nitrate,MIN)与牛血清白蛋白(BSA)相互作用的光谱行为。用Stern-Volmer方程、Lineweav-er-Burk双倒数方程和热力学方程等处理实验数据,得到在16～37℃温度范围内的作用常数KLB及热力学参数;发现MIN与BSA可结合形成具有一定结构的复合物,其荧光猝灭作用更符合静态猝灭作用特征,作用力可能主要是静电力;同时探讨了MIN对BSA构象的影响。为研究MIN的治病机制和生物学效应等提供了重要信息。

Studies on the Thermodynamics Features of the Interaction between Miconazole Nitrate and Bovine Serum Albumin

Under the imitated physiological condition of animals and different temperatures,the interaction of miconazole nitratel(MIN) to bovine serum albumin(BSA) was studied by means of the fluorescence quenching spectrum,synchronous fluorescence spectrum,three-dimensional fluorescence spectrum and ultro-violet spectrum.The average value of bonding constant(K_(LB):2.077×10~4 L·mol~(-1)),thermodynamic parameters (△H~θ:-13.23 kJ·mol~(-1),△G~θ:-24.74 kJ·mol~(-1),△S~θ:38.41 J·K~(-1)) and number of bonding sites(0.9167) were obtained. It has been proved that BSA interacted with miconazole nitrate and form a new compound by analyzing the fluorescence quenching data by Stern-Volmer equation,Lineweaver-Burk equation and thermodynamic equation, and the decrease of fluorescence of BSA was caused by a static quenching mechanism possibly owing to the electrostatic forces between BSA and MIN. The comformational modification of BSA was also investigated. It would provide important information for the study of the mechanism of disease and the biological effects.