文献类型：期刊文献

中文题名：EGCG-Cu络合物与牛血清蛋白相互作用研究

英文题名：Study on binding of EGCG-Cu complex to bovine serum albumin

作者：张亮亮[1] 徐曼[1] 胡新宇[1] 汪咏梅[1]

第一作者：张亮亮

机构：[1]江苏省生物质能源与材料重点实验室,中国林业科学研究院林产化学工业研究所,南京210042

年份：2017

卷号：2

期号：5

起止页码：46-50

中文期刊名：林业工程学报

外文期刊名：Journal of Forestry Engineering

收录：CSTPCD;;北大核心:【北大核心2014】；

基金：国家重点研发计划(2017YFD0601000);江苏省生物质能源与材料重点实验室基本科研业务费项目(JSBEM-S-201707)

语种：中文

中文关键词：表没食子儿茶素没食子酸酯(EGCG);牛血清白蛋白(BSA);荧光猝灭法;Stern-Volmer方程

外文关键词：EGCG; BSA; fluorescence spectroscopy; Stern-Volmer equation

分类号：Q614.33

摘要：表没食子儿茶素没食子酸酯(EGCG)为茶叶中主要活性成分之一,具有抑制细胞增殖,诱导细胞凋亡,抑制肿瘤血管生成等多种生理活性功能。EGCG能够与蛋白质及金属离子形成络合物,从而影响其各种生理活性功能。笔者利用荧光猝灭法分别研究了EGCG及其Cu(Ⅱ)络合物(EGCG-Cu)与牛血清白蛋白(BSA)的相互作用,并分析了Cu(Ⅱ)的存在对EGCG与BSA相互作用的影响。利用Stern-Volmer曲线分析了EGCG及其Cu(Ⅱ)络合物分别与BSA络合反应中不同的荧光猝灭机理,采用Stern-Volmer方程及不同Stern-Volmer修正方程计算得到3种不同反应体系中EGCG与BSA相互作用的结合常数。结果表明:随EGCG和EGCG-Cu络合物样品浓度的增加,BSA出现典型的荧光猝灭现象,表明EGCG和EGCG-Cu络合物均与BSA发生了相互作用。反应溶液中Cu(Ⅱ)的存在会改变EGCG与BSA的相互作用形式,并降低EGCG与BSA相互作用的结合常数。此外,EGCG与Cu(Ⅱ)络合后能够提高EGCG与BSA之间的结合常数。研究结果可为深入分析EGCG在体内的各种生理活性功能提供参考。
Epigallocatechin-3-gallate （EGCG）, the major polyphenolic constituent of green tea, has a variety of biological functions in vitro, including the inhibition of cell proliferation, induction of cell cycle arrest or apoptosis, and inhibition of tumor angiogenesis and vascular tumor growth. The potential chelating activity of EGCG for metal ions, especially transitional metal ions, has significant effects on the bioactivity of EGCG. Binding interactions between EGCG and its copper complex and bovine serum albumin （BSA） were investigated through fluorescence spectroscopy in this study. The effect of copper on the interaction between EGCG and BSA was also analyzed. The different quenching mechanisms in the binding interaction were studied and the binding constants of EGCG, EGCG-Cu（ Ⅱ ） to BSA were obtained by using different modified Stern-Volmer equations. The results showed that, when EGCG and EGCG-Cu（ Ⅱ） were added to the BSA solution, the fluorescence was quenched, indicating that interactions happened between EGCG, EGCG-Cu（Ⅱ） and BSA. The fluorescence intensity gradually decreased with the increasing concen- tration of EGCG with an obvious red-shift of the maximum of BSA. When EGCG was continuously added to BSA solution containing Cu（Ⅱ ） at pH 7.4, the fluorescence of BSA decreased. There was no spectral shift when the EGCG was added to BSA containing Cu（ Ⅱ ）, indicating that the mode of EGCG-BSA interaction is expected to be altered by Cu（ Ⅱ）. Additionally, the binding constant between EGCG and BSA increased significantly after EGCG was mod- ified by Cu（ Ⅱ ） to form EGCG-Cu（ Ⅱ） complex. Our results suggest that after chelating with copper, the interaction mode of EGCG with BSA is altered and this could have various implications on its other physicochemical activities.