Interaction of (-)-epigallocatechin-3-gallate with human serum albumin: Fluorescence, Fourier transform infrared, circular dichroism, and docking studies
Interaction of (-)-epigallocatechin-3-gallate with human serum albumin: Fluorescence, Fourier transform infrared, circular dichroism, and docking studies
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DOI：
10.1002/prot.20995
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发表时间：
2006-08-01
影响因子：
2.9
通讯作者：
Dasgupta, Swagata
中科院分区：
文献类型：
--
作者：
Maiti, Tushar Kanti;Ghosh, Kalyan Sundar;Dasgupta, Swagata
(-)-表没食子儿茶素-3-没食子酸酯 (EGCG) 是绿茶的主要成分，据报道，其抗氧化特性可预防多种疾病。首次通过荧光、圆二色性 (CD)、傅里叶变换红外 (FTIR) 光谱和蛋白质-配体对接研究了 EGCG 与人血清白蛋白 (HSA) 的结合。我们观察到在 EGCG 存在下 HSA 的荧光发生猝灭。结合参数通过 Scatchard 图确定，结果与从修改的 Stern-Volmer 方程获得的结果一致。根据van't Hoff方程计算的热力学参数，发现焓变Delta H度和熵变Delta S度分别为-22.59和16.23 J/mol K。这些值表明，除了最初的疏水缔合外，复合物还通过范德华相互作用和氢键结合在一起。通过荧光光谱、CD 和 FTIR 实验以及对接研究获得的数据表明 EGCG 与位于 HSA 子结构域 IIa 和 IIIa 的残基结合。观察到残基 Trp 214、Arg 218、GIn 221、Asn 295 和 Asp 451 存在特异性相互作用。我们还观察了结合 EGCG 时相互作用残基的可及表面积的变化，以便更好地理解相互作用。
(-)-Epigallocatechin-3-gallate (EGCG), the major constituent of green tea has been reported to prevent many diseases by virtue of its antioxidant properties. The binding of EGCG with human serum albumin (HSA) has been investigated for the first time by using fluorescence, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, and protein-ligand docking. We observed a quenching of fluorescence of HSA in the presence of EGCG. The binding parameters were determined by a Scatchard plot and the results were found to be consistent with those obtained from a modified Stern-Volmer equation. From the thermodynamic parameters calculated according to the van't Hoff equation, the enthalpy change Delta H degrees and entropy change Delta S degrees were found to be -22.59 and 16.23 J/mol K, respectively. These values suggest that apart from an initial hydrophobic association, the complex is held together by van der Waals interactions and hydrogen bonding. Data obtained by fluorescence spectroscopy, CD, and FTIR experiments along with the docking studies suggest that EGCG binds to residues located in subdomains IIa and IIIa of HSA. Specific interactions are observed with residues Trp 214, Arg 218, GIn 221, Asn 295 and Asp 451. We have also looked at changes in the accessible surface area of the interacting residues on binding EGCG for a better understanding of the interaction.