光谱法研究头孢尼西钠与牛血清白蛋白的相互作用

目的 运用荧光和紫外光谱法,在不同的温度下去探讨头孢尼西钠(CS)与牛血清白蛋白(BSA)的相互作用.方法 用Stern-Volmer、Lineweaver-Burk和双对数方程计算了速率常数(Kq)、猝灭常数(Ksv)、静态荧光猝灭缔合常数(KLB)、结合位点数(n)和有效结合常数(Kb).结果 CS能结合BSA.由于生成CS-BSA复合物,头孢尼西钠对BSA的猝灭是静态猝灭机制.热力学参数表明是一个自发过程,其作用力类型主要为静电作用力.BSA的亚螺旋域ⅡA是主要结合位置,离酪氨酸残基更近.有药物负协同作用.同步荧光光谱法表明CS能改变BSA的色氨酸和酪氨酸残基的微环境.结论 CS与BSA发生了静态相互作用,有一个结合位点,为CS的临床研究提供重要的参考依据.

On the interaction between cefonicid sodium and bovine serum albumin by spectrometry

Obiective To explore the interaction of cefonicid sodium(CS) with bovine serum albumin(BSA) by fluorescence and absorption spectroscopy. Methods The rate constant(Kq), quenching constant(Ksv), static fluo-rescence quenching association constant(KLB),binding site number(n) and binding constant(Kb) were calculated using Stern-Volmer, Lineweaver-Burk and double logarithm equations. Results CS was able to bind to BSA. The probable quenching mechanism of BSA by CS was mainly static quenching due to the formation of a CS-BSA com-plex. The results of thermodynamic parameters indicated that electrostatic force plays the main role in the binding process and the binding process was spontaneous. There was a single class of binding site for the BSA with CS. The primary binding site for CS was located at sub-domainⅡA of BSA and near by tyrosine residue. There was almost some negative cooperative effect. The results obtained from synchronous fluorescence showed that CS could change the microenvironment of Tyrand Trp residues of BSA. Conclusion The interaction between CS and BSA is dynam-ic. There is a single class of binding site for the BSA with CS. The obtained results provide references for its clini-cal application.