食盐对β-乳球蛋白与花青素结合及其分子动力学的影响  

Molecular dynamics study of salt on the binding ofβ-lactoglobulin to anthocyanins

作　　者：管思彤 胡霄 黄业传 GUAN Sitong;HU Xiao;HUANG Yechuan(College of Food and Biology,Jingchu University of Technology,Jingmen,Hubei 448000,China;Characteristic Food Function Mining and Comprehensive Utilization Research Center,Jingchu University of Technology,Jingmen,Hubei 448000,China)

机构地区：[1]荆楚理工学院食品与生物学院,湖北荆门448000 [2]荆楚理工学院特色食品功能挖掘与综合利用研究中心,湖北荆门448000

出　　处：《食品与机械》2025年第2期33-40,共8页Food and Machinery

基　　金：湖北省大学生创新创业训练计划项目(编号:S202411336027);湖北省科技计划项目(编号:2022BEC031)。

摘　　要：[目的]探究食盐浓度对蛋白与小分子物质间结合的影响。[方法]分别以β-乳球蛋白和花青素作为目标蛋白和小分子,采用分子动力学模拟研究在5种食盐浓度下(0,0.25,0.50,0.75,1.00 mol/L)两者的结合规律和蛋白结构变化。[结果]花青素主要结合在β-乳球蛋白疏水腔处。在150 ns的分子动力学模拟中,各食盐浓度下蛋白结构均较稳定,其与小分子的结合也比较平稳;但随NaCl浓度的增加,蛋白间氢键、疏水表面积和α-螺旋均有所降低,同时β-折叠在0.75 mol/L的食盐浓度下有所增加。两者的结合自由能先随食盐浓度的增加而增加,在0.50 mol/L达到最大值后逐渐下降,1.00 mol/L时甚至远低于对照组,主要是由于在1.00 mol/L的食盐浓度下,范德华力、氢键作用和疏水作用力同时减弱引起的,小分子在蛋白的结合位置也从疏水腔内部向表面靠近。[结论]食品体系中食盐的添加量会显著影响蛋白与植物小分子的结合,进而可能影响到蛋白的性质和小分子物质的生物活性。[Objective]To investigate the effects of different NaCl concentrations on the binding of proteins to small molecules.[Methods]Theβ-lactoglobulin and anthocyanin were selected as the target protein and small molecule,respectively.Molecular dynamics simulations were conducted to study the binding patterns and protein structural changes under five NaCl concentrations(0,0.25,0.50,0.75,and 1.00 mol/L).[Results]Anthocyanin mainly bound to the hydrophobic cavity ofβ-lactoglobulin.In the 150 ns molecular dynamics simulations,the protein structure remained stable at each NaCl concentration,and its binding with the small molecule was steady.However,with the increase in NaCl concentration,the hydrogen bonds between proteins,hydrophobic surface area,andα-helix content decreased,while theβ-sheet content increased within the 0.75 mol/L NaCl concentration range.The binding free energy of the two components first increased with NaCl concentration,reached a maximum at 0.50 mol/L,and then gradually decreased.At 1.00 mol/L,it was even much lower than the control group,mainly due to the simultaneous weakening of van der Waals forces,hydrogen bonding,and hydrophobic interactions under 1.00 mol/L NaCl.Small molecules also moved from the interior of the hydrophobic cavity toward the surface at the protein binding site.[Conclusion]The amount of NaCl added in the food system significantly affects the binding of proteins to small plant molecules,which may further affect the properties of proteins and the biological activity of small molecules.

关 键 词：NACL 花青素 Β-乳球蛋白 分子动力学 

分 类 号：TS2[轻工技术与工程—食品科学与工程]