基于荧光光谱法分子动力学模拟探究葛根素与β-乳球蛋白的结合机制  

Exploration of the Binding Mechanism between Puerarin andβ-Lactoglobulin Using Fluorescence Spectroscopy and Molecular Dynamics Simulation

作　　者：马波[1,2] 李蓉 徐傲[2] 段文杰 黄业传 MA Bo;LI Rong;XU Ao;DUAN Wenjie;HUANG Yechuan(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;College of Food and Biology,Jingchu University of Technology,Jingmen 448000,China;Hubei Xianzhiling Foods Corporation,Jingmen 448000,China)

机构地区：[1]西南科技大学生命科学与工程学院,四川绵阳621010 [2]荆楚理工学院食品与生物学院,湖北荆门448000 [3]湖北仙之灵食品有限公司,湖北荆门448000

出　　处：《食品科学》2025年第7期34-42,共9页Food Science

基　　金：湖北省科技计划项目(2022BEC031)。

摘　　要：本实验通过荧光光谱法、分子对接技术、分子动力学模拟对葛根素(puerarin,PUE)与β-乳球蛋白(β-lactoglobulin,β-lg)的结合机制进行探究。荧光光谱分析结果表明,PUE通过静态猝灭有效猝灭了β-lg的荧光,在25、35、45℃条件下的结合常数分别为7.24×10^(4)、1.34×10^(5)、2.18×10^(5) L/mol,结合位点数分别为1.02、1.18、1.15,因此可知只有一个或一类结合位点。同步荧光和三维荧光光谱分析结果表明PUE与β-lg结合过程中导致β-lg的微环境极性增加,疏水作用力减弱。分子对接结果显示PUE结合在β-lg的疏水腔内,与β-lg的6个氨基酸残基形成疏水作用力,5个氨基酸残基形成短氢键。分子动力学结果显示复合物中β-lg的均方根误差(root mean square deviation,RMSD)、回旋半径、溶剂可及表面积分别为(0.17±0.02)nm、(1.47±0.01)nm、(88.94±2.05)nm^(2),游离的β-lg RMSD、回旋半径、溶剂可及表面积分别为(0.22±0.03)nm、(1.48±0.01)nm、(90.09±1.73)nm^(2),此外复合物中β-lg的均方根波动值同样低于游离的β-lg,表明PUE/β-lg复合物在分子层面有更好的稳定性。本研究初步揭示了PUE和β-lg的结合机制,对于增加PUE的生物利用度有一定的参考意义。The binding mechanism of puerarin(PUE)toβ-lactoglobulin(β-lg)was investigated by fluorescence spectroscopy,molecular docking,and molecular dynamics simulation.The fluorescence spectroscopy results showed that PUE statically quenched the fluorescence ofβ-lg.At 25,35,and 45℃,the binding constants were 7.24×10^(4),1.34×10^(5),and 2.18×10^(5) L/mol,and the numbers of binding sites were 1.02,1.18,and 1.15,respectively,indicating there was only one binding site or class of binding sites.Synchronous fluorescence and three-dimensional fluorescence spectroscopy indicated that the binding of PUE toβ-lg resulted in an increase in the polarity of the microenvironment ofβ-lg,thereby weakening the hydrophobic force.Molecular docking results showed that PUE bound to the hydrophobic cavity ofβ-lg,forming hydrophobic interactions with six amino acid residues ofβ-lg and short hydrogen bonds with five amino acid residues.The molecular dynamics results showed that the root mean square deviation(RMSD),radius of gyration(Rg),and solvent accessible surface area(SASA)of the complex were(0.17±0.02)nm,(1.47±0.01)nm,and(88.94±2.05)nm^(2),and those ofβ-lg were(0.22±0.03)nm,(1.48±0.01)nm,and(90.09±1.73)nm^(2),respectively.The root mean square fluctuation(RMSF)of the complex was lower than that ofβ-lg,suggesting that the PUE/β-lg complex has better stability at the molecular level.This study is of reference significance for increasing the bioavailability of PUE.

关 键 词：葛根素 Β-乳球蛋白 荧光光谱 分子动力学模拟 非共价相互作用 

分 类 号：TS201.2[轻工技术与工程—食品科学]