Using Molecular Docking to Investigate the Alpha-amylase Inhibitory Activity of Bitter Peptides RK7 and KQ7 Derived from Yak Cheese

Abstract

In this study, the physicochemical properties of two bitter peptides derived from yak cheese, RPKHPIK (RK7) and KVLPVPQ (KQ7) were calculated by using online bioinformatics tools such as ExPASy-ProtParam, Innovagen, and Pep-Draw. Molecular docking was used to elucidate the mechanism of the inhibitory effect of the two peptides on α-amylase and their α-amylase inhibitory activity was determined. The results showed that the molecular masses of RK7 and KQ7 were 875.07 and 779.98 Da, and their hydrophobicity were 42.86% and 71.42%, respectively. Molecular docking showed that His305, Glu233, Trp59 and Trp58 in α-amylase played an important role in binding to RK7 and KQ7. Furthermore, Asp197, Glu233 and Asp300 were the key amino acids for the activity of α-amylase. The half maximal inhibitory concentration (IC50) of RK7 and KQ7 against α-amylase were 0.45 and 0.86 mg/mL, respectively. The findings of this study provide new evidence for the study of α-amylase inhibitory peptides.

Keywords

• yak cheese; bitter peptide; α-amylase inhibitory activity; molecular docking; mechanism of action