葛杏莉，贾　弦，汪　鑫，齐　炎，夏彩芬

(湖北工程学院 化学与材料科学学院，湖北 孝感 432000)

光谱法研究羧甲基壳聚糖与牛血清白蛋白的相互作用

葛杏莉，贾弦，汪鑫，齐炎，夏彩芬*

(湖北工程学院 化学与材料科学学院，湖北 孝感 432000)

摘要:采用荧光光谱法、紫外光谱法、红外光谱法和圆二色谱法研究了羧甲基壳聚糖(CMCS)与牛血清白蛋白(BSA)的相互作用过程及机理。研究结果表明，CMCS对BSA的内源荧光有猝灭作用，且为静态猝灭；紫外光谱分析表明，CMCS与BSA分子发生了相互作用，形成了基态复合物；圆二色谱和红外光谱分析结果表明，CMCS与BSA中肽键发生作用，α-helix结构含量发生改变，使BSA二级结构发生变化；三维荧光的实验结果表明，当在BSA中加入CMCS后，分子全局的内源荧光强度明显降低；同步荧光和位点竞争实验结果表明，CMCS与BSA 的结合位点更接近于色氨酸残基，结合部位为Site I。

关键词：羧甲基壳聚糖；牛血清白蛋白；荧光光谱法；圆二色谱法；紫外光谱法

中图分类号：O636.1

文献标志码：码：A

文章编号：号：2095-4824(2015)03-0005-07

收稿日期：2015-03-25

基金项目：湖北工程学院生物质资源转化利用湖北省协同创新中心项目(XTCX041)

作者简介：葛杏莉(1962-)，女，湖北通城人，湖北工程学院化学与材料科学学院实验师。

通讯作者夏彩芬(1979-)，女，湖北武汉人，湖北工程学院化学与材料科学学院讲师，博士，本文。

Abstract：The interaction process and mechanism between carboxymethyl chitosan (CMCS) and bovine serum albumin (BSA) are investigated by means of fluorescent spectrometry, ultraviolet spectroscopy, infrared spectroscopy, and circular dichroism (CD). And it is found that the fluorescence quenching of BSA accorded with the CMCS concentration-dependent. And the Stern-Volmer curve of the fluorescence quenching of BSA by CMCS shows that the mechanism is mainly static quenching. The UV indicates that the BSA molecules are combined with the CMCS, forming a complicated ground-state. The analytical results with the CD and infrared spectroscopy indicate that the peptide bonds within the CMCS and the BAS are affected each other and the α-helix content of BSA is changed with CMCS by CD, leading to the changes of secondary structure in the BSA. The experimental result with three-dimension fluorescence shows that the strength of overall intrinsic fluorescence is significantly reduced when the CMCS is added into the BAS. The results with the synchronous fluorescence and the site competition suggest that the binding sites between the CMCS and the BSA are more close to tryptophan residues, where the binding sites are located at Site I.

贾弦(1991-)，女，湖北荆州人，湖北工程学院化学与材料科学学院学生。

羧甲基壳聚糖(CMCS)是壳聚糖的高级衍生物之一。近年来，由于羧甲基壳聚糖在药物载体体系、组织工程及生物改良支架等方面具有广泛的应用前景，已成为发展迅速的一种生物医用材料[1-3]。……