Two Novel Peptides in Soybeans as Inhibitors of Α-Amylase and Α-Glucosidase: Virtual Screening and Identification

Abstract

Soybean peptides (SPs) have bioactivities of enzyme inhibition that are beneficial to human health, but their mechanism is not clear. This study aimed to identify peptide fragments in SPs simultaneously inhibit α-amylase and α-glucosidase, and to explore their enzyme inhibition mechanism. The inhibitory activity of SPs against the enzymes was determined firstly. And, two octapeptides, LDQTPRVF and SRNPIYSN, were identified at the first time by using HPLC-QTOF-MS/MS and virtual screening. Molecular simulation results showed that hydrogen bonds and π–π bonds were the key factors, and N-terminal (Leu & Ser) and C-terminal (Phe) of peptide were important inhibiting sites. Both octapeptides were synthesized, and their IC50 values were 3.08 and 5.58 mM for α-amylase, and 2.52 and 4.57 mM for α-glucosidase, respectively. This study provided evidence for SPs as a potential inhibitor of α-amylase and α-glucosidase in special dietary foods.

Keywords: Soybean peptides, α-Amylase, α-Glucosidase, Molecular docking, Inhibition activity