全氟辛酸与血清蛋白分子间作用的紫外-荧光光谱分析法建立及理论模建研究

摘要

Study on the establishment of intermolecular interaction between perfluorooctanoic acid(PFOA)and human serum protein(HSA)and its theoretical modeling.Fluorescence spectrums combined with ultraviolet spectrum have been studied the intermolecular interaction between PFOA and HSA to obtain PFOA-HSA ultraviolet-fluorescence spectrum features.The UV-fluorescence characteristic spectra showed that PFOA regularly decreased the UV absorption and fluorescence intensity of HSA, and the maximum emission wavelength of HSA caused obvious blue shift,which indicated that there was intermolecular interac-tion between PFOA and HSA.The binding constants between PFOA and HSA were obtained by analyzing spectrum experiments data,which indicated the medium intermolecular interaction between PFOA and HSA.On the basis of Van't Hoff equation to analyze spectrum experiments datas to attain the thermodynamic parameters of the intermolecular interaction between PFOA and HSA.The obtained thermodynamic parameters were Δ H> 0,ΔS> 0,ΔG< 0,which indicated that the main forces between HSA and PFOA were hydrophobic force and hydrogen bond by Ross theories,and the intermolecular interaction between HSA and PFOA was spontaneous process.Synchronous fluorescence spectrum revealed that the intermolecular interaction of PFOA and HSA resulted in a change in the microdomain conformation of the serum protein molecule,which changed the conformational domain of the tryptophan residue.In this paper,the polarizing factor M was proposed to quantitatively characterize the interac-tion between PFOA and HSA by fluorescence polarization spectroscopy.Based on spectral data analysis,the theoretical model of the interaction between PFOA and HSA was established,The theoretical model results showed that the intermolecular interac-tion of PFOA and HSA occured mainly in the HSA active site Ⅰ region and the intermolecular interaction between HSA and PFOA was a spontaneous process.The results of spectral experiments were basically consistent with the theoretical modeling re-sults.These data can provide a useful reference for a comprehensive understanding of the intermolecular interactions between bi-ological macromolecules and perfluorinated compounds and the study of microscopic toxicological mechanisms.%全氟辛酸(PFOA)与血清蛋白(SA)分子间作用分析法的建立及理论模建研究.荧光光谱结合紫外光谱法研究PFOA与血清蛋白(HSA)分子间作用,获得PFOA-HSA分子间作用的紫外-荧光特征谱,紫外-荧光特征谱表明PFOA规律性降低了HSA紫外吸收和荧光强度,HSA最大发射波长明显发生蓝移,表明PFOA与HSA发生了分子间作用,根据双对数回归曲线方程得到结合常数,定量说明PFOA与 HSA之间存在中等强度的分子间作用力.Van't Hoff方程分析光谱数据得到 HSA与 PFOA分子间作用的热力学参数 Δ H>0,Δ S>0,Δ G<0,依据Ross理论分析PFOA与HSA分子间作用,表明二者主要通过疏水作用力和氢键发生分子间作用,并且HSA与PFOA之间的分子间作用是自发过程.同步荧光光谱解析出PFOA与HSA的分子间作用导致血清蛋白分子的微区构象发生改变,使色氨酸残基位域构象发生改变.建议偏振因子 M,通过荧光偏振光谱,定量表征PFOA与HSA分子间作用.基于光谱数据分析,建立了PFOA与HSA分子间作用的理论模型,模建结果说明PFOA与 HSA的分子间作用主要发生在 HSA活性位点Sudlow's sites I,HSA与PFOA分子间作用是自发过程.光谱实验与理论模建结果基本一致,可为全面了解生物大分子与全氟化合物之间的分子间作用以及研究微观毒理机制提供有益参考.