苯基锡系列化合物与牛血清白蛋白相互作用的光谱研究  

Spectral studies on interaction of phenyltin series compounds with bovine serum albumin

作　　者：张朝红[1] 邓丽娜[1] 韩文明[1] 沈曼莉[1] 王君[2] 

机构地区：[1]辽宁大学环境系,辽宁沈阳110036 [2]辽宁大学化学系,辽宁沈阳110036

出　　处：《渤海大学学报（自然科学版）》2008年第2期97-104,共8页Journal of Bohai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(No:30570342);辽宁省教育厅自然科学基金资助项目(No:05L154)

摘　　要：采用光谱法研究了苯基锡化合物(一苯基锡(MPT),二苯基锡(DPT)和三苯基锡(TPT))与牛血清白蛋白(BSA)的相互作用。结果显示,三种苯基锡化合物与BSA均有不同程度的相互作用,紫外-可见(UV-vis)光谱表现为增色效应,荧光光谱表现为猝灭效应,圆二色(CD)光谱表现为特征峰的振幅减小和峰位位移。Stern-Volmer方程计算表明三种苯基锡化合物对BSA的荧光猝灭方式均为静态猝灭,并得出在25℃和37℃时的结合位点数(n)和平衡常数(K)。比较发现,随着温度升高,n和K均有所下降。根据能量转移理论,计算了三种苯基锡化合物与BSA相互作用的结合距离(r)和能量转移效率(E)。结果表明,三种r均小于7nm,且r的大小顺序为MPT-BSA,DPT-BSA和TPT-BSA。通过热力学研究判断出三种苯基锡化合物与BSA相互作用的方式和类型,MPT与BSA的作用方式为范德华力和配位作用,TPT与BSA的作用方式主要是范德华力,而DPT与BSA的作用方式主要为疏水作用。同步荧光光谱研究表明,三种苯基锡化合物对BSA分子构象及色氨酸和酪氨酸残基的微区均有不同程度的影响,但对色氨酸微区的影响较大。The interactions of the phenyltin compounds （monophenyltin （MPT）, diphenyltin （DPT） and triphenyltin （TPT）） with bovine serum albumin （BSA） were studied by spectral methods. The results showed that three kinds of phenyltin compounds could all interact with BSA to different degrees. It was found that the hyperchromic effects, fluorescence quenching effects and amplitude decrease and shift of the characteristic peaks occured in ultraviolet-visible （UV--vis）, fluorescence and circle dichromism （CD） spectra, respectively. Through the Stern -- Volmer equations, the quenching processes of BSA caused by three kinds of phenyltin compounds were proved to be the static quenching. And the binding site number （n） and equilibrium constant （K） at 25 （C and 37 （C were also obtained, respectively. It was observed that with increasing temperature, n and K all decreased slightly. The binding distance （r） and energy transfer efficiency （E） between phenyltin compounds and BSA were calculated according to energy transfer theory. The results showed that allr＇s were less than 7.0 nm, and the order was MPT--BSA （ DPT--BSA （ TPT--BSA. Through the research on thermodynamic, the mode and types of the interaction between phenyltin compounds and BSA were concluded. They belonged to Van der Waals force and coordination action between MPT and BSA, Van der Waals force between TPT and BSA, and hydrophobic action between DPT and BSA. Synchronous fluorescence spectra showed that the conformation of BSA molecule and microenvironment of the tryptophan and tyrosine residues were influenced by three kinds of phenyltin compounds to different degrees. But the effects on the tryptophan microenvironment were obvious.

关 键 词：苯基锡化合物 牛血清白蛋白(BSA) 相互作用 光谱法 

分 类 号：Q523[生物学—生物化学] O657.3[理学—分析化学]