摘要
综合运用抑制动力学、荧光强度、表面疏水性分析和分子对接等方法研究表没食子儿茶素没食子酸酯(EGCG)对葡萄糖淀粉酶的抑制作用,及消化过程中葡萄糖淀粉酶结构的变化。结果表明,EGCG对葡萄糖淀粉酶的抑制属于混合竞争性抑制,以竞争抑制为主。随着EGCG质量浓度的升高,葡萄糖淀粉酶在425 nm处的荧光强度逐渐降低,荧光猝灭Stern-Volmer曲线的线性关系良好,荧光方式属于静态猝灭。随着EGCG质量浓度的增加,葡萄糖淀粉酶的表面疏水作用力逐渐降低。分子对接的结果表明,EGCG与葡萄糖淀粉酶非催化位点上的氨基酸结合。综上,EGCG与葡萄糖淀粉酶非催化位点的结合,影响催化位点与底物的结合,改变葡萄糖淀粉酶的结构,影响酶的表面疏水性,从而降低酶的催化效率。研究结果可为理解EGCG与葡萄糖淀粉酶的作用机制提供理论依据。
To investigate the inhibition mechanism of epigallocatechin gallate(EGCG)on glucoamylase and its effect on glucoamylase structure during the digestion process,the methods including inhibition kinetics,fluorescence intensity,surface hydrophobicity analysis and molecular docking were comprehensively adopted.It was shown that EGCG exhibited mixed competitive inhibition on glucoamylase with competitive inhibition as the main factor.As the mass concentration of EGCG increased,the fluorescence intensity of glucoamylase at 425 nm gradually decreased,and the linear relationship of the Stern-Volmer curve of fluorescence quenching was good,and the fluorescence quenching mode belonged to static quenching.With the increase in EGCG mass concentration,the surface hydrophobic interaction of glucoamylase gradually decreased.The molecular docking revealed that the EGCG was bound to amino acids on the non-catalytic site of glucoamylase.It was concluded that the binding of EGCG to the non-catalytic site of glucoamylase affected the binding of the catalytic site and substrate,changed the structure of glucoamylase,affected the hydrophobic interaction of glucoamylase,thus reduced the catalytic efficiency of glucoamylase.These findings provided theoretical basis for the understanding of the interaction mechanism between EGCG and glucoamylase.
作者
黄伟红
刘一
郑富明
HUANG Weihong;LIU Yi;ZHENG Fuming(Zhejiang Agricultural Technology Extension Center,Hangzhou 310020,China;College of Food and Health,Zhejiang A&F University,Hangzhou 311300,China;Suichang Yuanshi Health Agriculture Development Co.,Ltd.,Suichang 323300,Zhejiang,China)
出处
《浙江农业学报》
北大核心
2025年第9期1951-1957,共7页
Acta Agriculturae Zhejiangensis
基金
浙江农林大学人才启动项目(2024LFR006)。
