摘要
抑制α-淀粉酶的活性可以有效降低餐后血糖浓度升高,故本实验从抑制率、抑制类型、荧光猝灭效应及分子模拟几个方面出发研究鼠尾草酸对α-淀粉酶的抑制作用。结果显示,鼠尾草酸对α-淀粉酶有较为显著的抑制作用,半数抑制浓度为1.12 mg/mL,以可逆的竞争性方式抑制α-淀粉酶的活性。荧光猝灭实验结果表明,鼠尾草酸与α-淀粉酶结合后使α-淀粉酶的荧光特性发生静态猝灭。分子对接结果显示鼠尾草酸与α-淀粉酶作用后没有催化底物生成新的产物,而是形成可逆的酶-抑制剂复合物,引起变构调节,从而扰乱了α-淀粉酶的构象动力学,最终导致酶催化活性降低。
Inhibitingα-amylase activity could effectively reduce the increase in the postprandial blood glucose level.The purpose of this study was to investigate the inhibitory kinetics and mechanism of carnosic acid onα-amylase.Results showed that carnosic acid exhibited potent inhibitory activity with a half maximal inhibitory concentration(IC50)of 1.12 mg/mL in a reversible and competitive manner.Fluorescence quenching experiments revealed that the fluorescence ofα-amylase was statically quenched by binding carnosic acid.Molecular docking results showed that carnosic acid binding to the active site ofα-amylase did not result in the formation of any new products but in the formation of a reversible enzyme-inhibitor complex,which triggered allosteric regulation to perturb conformational dynamics ofα-amylase,eventually leading to a decrease in the catalytic activity ofα-amylase.
作者
王静
刁翠茹
王华丽
李祥
汪名春
王浩
WANG Jing;DIAO Cuiru;WANG Huali;LI Xiang;WANG Mingchun;WANG Hao(College of Food Science and Engineering,Tianjin University of Science and Technology,Tianjin 300457,China;The Third Division of National Food Safety Standard,China National Center for Food Safety Risk Assessment,Beijing 100022,China;College of Tea and Food Science and Technology,Anhui Agricultural University,Hefei 230036,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第3期12-17,共6页
Food Science
基金
国家自然科学基金青年科学基金项目（31701550）
天津市科技计划项目（17KPHDSF00120）
