富勒醇与血清白蛋白相互作用的光谱学研究

摘要

Fluorescence spectroscopy and UV-Vis absorption spectrometry assays were used to investigate the interaction mecha-nism of Fullerols and human serum albumin and bovine serum albumin under different temperature.The results revealed that Ful-lerols was capable of quenching SA's fluorescence in both static modes.Binding constant values,binding site numbers and ther-modynamics parameters of fixation reaction between Fullerols and serum albumin under different temperature were obtained with measurement and numeration.On the basis of thermodynamics data,the interaction forces of serum albumin after binding with Fullerols were mainly hydrophobic force.The binding strength of Fullerols and BSA was remarkably greater than that of Ful-lerols and HSA.Binding constants of Fullerols and BSA affected by temperature displayed dominant when bound to HSA.The binding sites of Fullerols and BSA were slightly larger.Then modes and mechanisms were observed by means of quenching mech-anism analysis and molecular docking simulation method.Using AlignX amino acid Sequence Analys it was found that similarity of amino acid sequence of the two proteins were higher.Besides,significant difference in some small sequence fragments was ob-served.The distinctness was mostly in the vicinity of 160 and 185 of amino acid sequence,which proved that presumably affected the key sites of mode between the two proteins and Fullerols.%采用荧光光谱法和紫外-可见吸收光谱法研究了不同温度下富勒醇与血清白蛋白的相互作用机理,研究结果表明,富勒醇对人和牛血清白蛋白的内源荧光有明显的猝灭作用,猝灭过程均为静态猝灭,并测定和计算得到不同温度下富勒醇与血清白蛋白反应的结合常数(K HSA(273 K——)1.546×104,K HSA(293 K——)1.513×104;K BSA(273 K——)13.920×104,K BSA(293 K——)939.500×104)、结合位点数(n HSA(293 K——)0.9522;n BSA(293 K——)1.3762).通过结合反应的热力学数据分析,推测出富勒醇与血清白蛋白之间主要靠疏水作用结合;富勒醇与BSA结合强度明显大于富勒醇与HSA的结合强度,BSA的结合常数受温度影响更大;人和牛血清白蛋白在273和293 K的结合位点数在0.901→1.376之间,BSA与富勒醇结合位点数略大于HAS.同时采用分子模拟对接方法,预测富勒醇对牛血清白蛋白的结合部位和作用方式;通过AlignX序列分析法得到BSA与HSA的氨基酸序列相似度较高,在序列160和185附近氨基酸序列差异性较大,推测这是影响两种蛋白质之间与富勒醇作用方式的关键位点.