荧光光谱法研究全氟辛酸与牛血清白蛋白的相互作用

Interaction of perfluorooctanoic acid (PFOA) with bovine serum albumin (BSA) by fluorescence spectroscopy

在模拟生理条件下(pH7.4),采用荧光光谱研究环境污染物全氟辛酸(PFOA)与牛血清白蛋白(BSA)的相互作用.结果表明,PFOA对BSA有荧光静态猝灭作用.PFOA与BSA在温度277,298,310K的反应结合常数分别为1.06×105,7.12×104,5.68×104L/mol;在BSA上有1个PFOA的结合位点,该位点更接近于色氨酸残基.由反应的热力学可推断PFOA与BSA的相互作用力主要是静电引力和疏水作用力.与PFOA结合后,BSA分子构象发生变化,色氨酸残基附近疏水性增强,蛋白质分子结构趋于折叠状态;而酪氨酸残基附近亲水性增强,蛋白质分子结构趋于松散状态.

The interaction between perfluorooctanoic acid （PFOA） and bovine serum albumin （BSA） in physiological buffer （pH7.4） was investigated by fluorescence quenching techniques.The results showed that PFOA could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure.The binding constants （K） of PFOA with BSA at 277K,298K and 310K were 1.06×105,7.12×104 and 5.68×104 L/mol respectively,and the binding site （n） on BSA for PFOA was 1.The thermodynamic parameters indicated that the interaction of PFOA with BSA was driven mainly by electrostatic and hydrophobic forces.The results of synchronous fluorescence spectra showed that binding of PFOA can induce conformational changes in BSA.