Identification of a novel α-amylase inhibitory activity peptide from quinoa protein hydrolysate

alpha-Amylase inhibitory activity plays an important role in reducing blood glucose. Food-derived alpha-amylase in-hibitors have attracted significant attention due to their safety. This study obtained peptides displaying alpha-amylase inhibitory activity from pepsin hydrolysate of quinoa protein concentrates. Gel filtration chroma-tography revealed that the <1 kDa component exhibited significant alpha-amylase inhibitory capability, while the purified component was identified via mass spectrometry identification. Six peptides with alpha-amylase inhibitory activity were selected, wherein the inhibitory ability of the peptide MMFPH was 66.41 % higher than the others. Molecular docking indicated that the peptide MMFPH residues restricted the alpha-amylase activity by binding to the active alpha-amylase site. The molecular interaction experiments showed that the peptides and alpha-amylase were in a fast-binding and slow-dissociation mode, allowing the small peptides produced via quinoa protein digestion to bind more rapidly to alpha-amylase, thus preventing a rise in blood glucose in vivo.

Automated summary

This study extracted peptides from quinoa protein that can reduce blood glucose levels by inhibiting the activity of alpha-amylase. Among these peptides, MMFPH exhibited the highest inhibitory capability. Molecular docking experiments revealed that MMFPH bound to the active site of alpha-amylase, inhibiting its activity. These findings suggest that the small peptides produced during quinoa protein digestion can quickly bind to alpha-amylase, thus reducing blood glucose levels.