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黄曲霉毒素G1与人血清白蛋白的结合机理及分子对接_论文

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86? 2017, Vol.38, No.05 食品科学 ※基础研究 黄曲霉毒素G1与人血清白蛋白的结合 机理及分子对接 钟 红,王佳曼,马 良*,江 涛 (西南大学食品科学学院,重庆 400715) 摘? 要:在模拟人体血液pH 7.4的条件下,用分子对接及其荧光光谱、3D荧光、圆二色谱等方法研究黄曲霉毒素G1 (aflatoxin G1,AFG1) 与人血清白蛋白(human serum albumin,HSA)的相互作用。结果发现,根据双对数方程 得出AFG1与HSA结合反应猝灭机制为静态猝灭,4 个温度条件下结合常数数量级均为104,结合位点数近似为1。通 过分子对接和热力学参数计算,AFG1结合在HSA的ⅠB疏水腔中,二者结合力主要为疏水作用和氢键。通过研究体内 金属离子对AFG1-HSA反应的影响,Fe3+、Mg2+能增大AFG1对HSA的亲和力,而Zn2+、Cu2+、Mn2+离子则能大大降 低AFG1与HSA的亲和力。基于F?rster’s能量转移,二者反应距离为3.26 nm。3D荧光结果显示,二者的结合反应使HSA 生色团氨基酸残基疏水性增加,二级结构发生改变;圆二色谱结果表明,加入AFG1使得HSA的α-螺旋含量增加。 关键词:黄曲霉毒素G1;人血清白蛋白;光谱;分子对接;结合反应 Binding Mechanism and Molecular Docking between A?atoxin G1 and Human Serum Albumin ZHONG Hong, WANG Jiaman, MA Liang*, JIANG Tao (College of Food Science, Southwest University, Chongqing 400715, China) Abstract: The interaction between the mycotoxin aflatoxin G1 (AFG1) and human serum albumin (HSA) was investigated by molecular docking, fluorescence spectroscopy, 3D fluorescence spectrum, and circular dichroism (CD) under simulated physiological conditions (pH 7.4). According to the double logarithmic equation, the major binding mechanism between AFG1 and HSA was a static quenching process. At four different temperatures, the magnitude of binding constants was 104 and the number of binding sites was approximate to 1. Through the molecular docking and the calculation of thermodynamic B hydrophobic cavity, and hydrophobic interaction and hydrogen bonding parameters, the binding site of AFG1 was in the Ⅰ were the major forces in the binding process. By studying the effect of metal ions on AFG1-HSA reaction, the affinity of AFG1 to HSA could be increased by Mg2+ and Fe3+ but greatly reduced by Zn2+, Mn2+ and Cu2+. The binding distance between AFG1 and HSA was calculated to be 3.26?nm based on F?rster’s non-radiation energy transfer theory. The 3D florescence spectra revealed that the microenvironment of amino acid residues became more hydrophobic after the binding reaction. CD spectra revealed that the conformation of HSA was changed during the binding reaction as shown by an increase in α-helix. Key words: aflatoxin G1 (AFG1); human serum albumin (HSA); spectrum; molecular docking; binding interaction DOI:10.7506/spkx1002-6630-201705014 中图分类号:R994.4 引文格式: 钟红 , 王佳曼 , 马良 , 等 . 黄曲霉毒素 G 1与人血清白蛋白的结合机理及分子对接 [J]. 食品科学 , 2017, 38(5): 86-91. DOI:10.7506/spkx1002-6630-201705014. http://www.spkx.net.cn ZHONG Hong, WANG Jiaman, MA Liang, et al. Binding mechanism and molecular docking between aflatoxin G1 and human s


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