摘要
在模拟动物体生理条件和不同温度下,采用荧光、紫外光谱法研究溴酚蓝(BPB)与牛血清白蛋白(BSA)结合反应。用Stern-Volmer和Lineweaver-Burk方程分别处理试验数据,发现BSA与BPB发生反应,生成新的复合物,属于静态荧光猝灭。实验求出反应时复合物的形成常数K_(LB)、热力学参数与结合位点数,证明溴酚蓝与牛血清白蛋白的结合主要为静电作用力。位点竞争实验结果显示BPB与BSA的作用位置主要在BSA的Site I(sub-domainⅡA)位。通过同步荧光光谱和三维荧光光谱法,探讨BPB对BSA构象的影响,实验结果表明BPB使色氨酸残基所处微环境的极性减弱、疏水作用增强。本文为探讨BPB的染色机理、毒理效应和生物学效应提供了重要信息。
Under simulated physiological conditions of animals and at various temperatures, the bindingreaction of Bromophenol blue （BPB） to bovine serum albumin （BSA） was studied by fluorescence spec-trum and ultra-violet spectrum spectroscopy. The fluorescence quenching data were analyzed accordingto Stem-Volmer equation and Lineweaver-Burk double-reciprocal equation. The study show that BSA re-acted with BPB and formed a certain new compound, which belonged to static fluorescence quenching.The formation constants of the compound K LB, the thermodynamic parameters and the number of bind-ing sites were obtained. And the binding power between them is mainly the electrostatic acting force.Site marker competitive experiments showed that the binding of BPB to BSA primarily took place in siteI （sub-domain Ⅱ A）of BSA. The effect of BPB on the conformation of BSA was analyzed by synchro-nous fluorescence spectra and threedimensional fluorescence spectra, which indicates that the polaritymicroenvironment around Trp residues decreased, while hydrophobic forces increased. These provideimportant information for enucleating the dyeing mechanisms, the toxicity effects and biological effectsof BPB.
出处
《广西师范大学学报（自然科学版）》
CAS
北大核心
2014年第2期82-87,共6页
Journal of Guangxi Normal University:Natural Science Edition
基金
国家自然科学基金资助项目(21201023)
关键词
溴酚蓝
牛血清白蛋白
荧光猝灭光谱
三维荧光光谱
热力学参数
bromophenol blue
bovine serum albumin
fluorescence quenching spectrum
three dimension-al fluorescence spectrum
thermodynamic parameters
