食品科学 ›› 2020, Vol. 41 ›› Issue (3): 12-17.doi: 10.7506/spkx1002-6630-20181211-137

• 基础研究 • 上一篇    下一篇

鼠尾草酸对α-淀粉酶的抑制作用

王静,刁翠茹,王华丽,李祥,汪名春,王浩   

  1. (1.天津科技大学食品科学与工程学院,天津 300457;2.国家食品安全风险评估中心标准三部,北京 100022;3.安徽农业大学茶与食品科技学院,安徽 合肥 230036)
  • 出版日期:2020-02-15 发布日期:2020-02-26
  • 基金资助:
    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)

Inhibitory Mechanism of Carnosic Acid on Alpha-Amylase

WANG Jing, DIAO Cuiru, WANG Huali, LI Xiang, WANG Mingchun, WANG Hao   

  1. (1. College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China; 2. The Third Division of National Food Safety Standard, China National Center for Food Safety Risk Assessment, Beijing 100022, China; 3. College of Tea and Food Science and Technology, Anhui Agricultural University, Hefei 230036, China)
  • Online:2020-02-15 Published:2020-02-26

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。

关键词: α-淀粉酶, 鼠尾草酸, 抑制作用, 分子对接

Abstract: Inhibiting α-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 on α-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 of α-amylase was statically quenched by binding carnosic acid. Molecular docking results showed that carnosic acid binding to the active site of α-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 of α-amylase, eventually leading to a decrease in the catalytic activity of α-amylase.

Key words: α-amylase, carnosic acid, inhibitory effect, molecular docking

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