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

• Basic Research • Previous Articles     Next Articles

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

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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