光谱法研究尼泊金乙酯钠与牛血清白蛋白的相互作用

摘要

Under simulated physiological conditions(pH= 7.40), the interaction of ethylparaben sodium (EPS) with bovine serum albumin(BSA) has been studied by fluorescence spectrum,UV-vis absorption spectrum and synchronous fluorescence spectroscopy at different temperatures. The experi-ments indicated that the fluorescence of BSA was quenched by EPS and the quenching mechanism was a static quenching procedure by generating EPS-BSA complexes. The binding constants of EPS-BSA system at the temperatures of 291 K and 310 K were 3.23×106and 3.63×105L·mol-1respectively via double-logarithm regression equation. The binding-sites were 0.99 and 0.84,respectively. The thermo-dynamic parameters (ΔH,ΔS) of EPS-BSA system were obtained by thermodynamical formulas under different temperatures. The binding power of EPS-BSA systems were mainly hydrogen bond and Van der Waals force from ΔH<0 and ΔS<0. The synchronous fluorescence spectra showed that EPS had an effect on the conformation of BSA structures. The important reference information for the toxicological and biological effects of EPS was provided by this study.%在模拟生理条件下(pH=7.40),应用荧光光谱、吸收光谱和同步荧光光谱法探讨了不同温度下尼泊金乙酯钠(Ethylparaben Sodium,EPS)与牛血清白蛋白(Bovine Serum Albumin,BSA)相互作用的机制.荧光光谱和吸收光谱分别表明:尼泊金乙酯钠对BSA内源荧光有明显猝灭作用,属于静态猝灭,二者的猝灭作用是由于尼泊金乙酯钠与BSA形成基态复合物导致的.运用双对数方程求得291、310 K时的结合常数分别为3.23×106、3.63×105L·mol-1,结合位点数分别为0.99和0.84.运用热力学方程得出热力学参数(ΔH,ΔS),通过ΔH<0,ΔS<0可知二者之间的作用力主要是氢键或范德华力.同步荧光光谱表明尼泊金乙酯钠对BSA结构的构象会产生影响.本研究为EPS的毒理和生物学效应提供了重要的参考信息.