黄曲霉毒素G1与人血清白蛋白的结合机理及分子对接.pdf

862017,o1.38,NO.05
品科学
※基础硏究
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
良*,江海
西南大学食品科学学院,重庆400715)
辆要:在模拟人体血液pH74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G
( aflatoxin G,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10,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AFGr-HSA反应的影响,Fe+、Mg3“能增大AFG,对HSA的亲和力,而zn+、C、Mm2+离子则能大大降
低AFG1与HSA的亲和力。基于F6 rster's能量转移,二者反应距离为326nm。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AFG,使得HSA的α-螺旋含量增加。
关键词:黄曲釋毒素G1;人血清白蛋白:光谱:分子对接;结合反应
Binding Mechanism and Molecular Docking between Aflatoxin G, and Human Serum Albumin
ZHONG Hong, WANG Jiaman, MA Liang *, JIANG Tao
(College of Food Science, Southwest University, Chongging 400715, China)
Abstract: The interaction between the mycotoxin aflatoxin G(AFG, )and human serum abumin(HSA)was investigated
by molecular docking, fluorescence spectroscopy, 3D fluorescence spectrum, and circular dichroism(CD)under simulated
physiological conditions(PH. 4).According to the double logarithmic equation, the major binding mechanism between
AFG and HSA was a static quenching process. At four different temperatures, the magnitude of binding constants was 10
and the number of binding sites was approximate o 1. Through the molecular docking and the calculation of thermodynamic
parameters, the binding site of AFG, was in the IB hydrophobic cavity, and hydrophobic interaction and hydrogen bonding
were the major forces in the binding process. By studying the effect of metal ions on AFG -HSA reaction, the affinity of
AFG, to HSA could be increased by Mg and Fe"but greatly reduced by Zn, Mn"and Cu*". The binding distance between
AFG and HSA was calculated to be 3. 26 nm based on Forsters 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 a-helix
Key words: aflatoxin G, (AFG, human serum albumin(HSA); spectrum; molecular docking; binding interaction
DO:10.7506/pkx1002-6630-201705014
中图分类号:R994.4
文献标志码
文章编号:1002-66030(2017)05-008606
引文格式
钟红,王佳曼,马良,等.黄曲霉毒素G1与人血清白蛋白的结合机理及分子对接[.食品科学,2017,38(5):86-9
DOE: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 G and
human serum albumin J]. Food Science, 2017, 38(5): 86-91.(in Chinese with English abstract)DO]: 10.7506/spkx1002
6630-201705014.http://www.spkx.net.cn
黄曲霉毒素G1( aflatoxin G1,AFG1)是由黄曲霉产生的主要次级代谢产物之一,主要污染花生、大豆等
( Aspergilus flavus)和寄生曲霉( Aspergilus parasiticus)大宗粮油作物。粮油产品产生的黄曲霉毒素中AFG
收稿日期:2016-09-10
基金项目:国家重点基础研究发展计划(973计划)项目(2013CB127803);国家自然科学基金青年科学基金项目(31301476)
作者简介:钟红(1991-),女,硕士研究生,研究方向为食品安全与质量控制。E-mail:62544156gq.com
通信作者:马良(1979-),女,副教授,博士,研究方向为食品安全与食品检测技术。E-mail:zhyhmle@163.com
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