Ultrasound-assisted proteolysis of pea protein: Structural and peptidomic modulation to enhance α-glucosidase inhibitory activity.

With the increasing prevalence of diabetes mellitus, naturally derived α-glucosidase inhibitory peptides have garnered growing attention. Most studies have focused on preparation efficiency and bioactivity outcomes, while the structural mechanisms governing peptide release remain poorly understood. In this study, ultrasound-assisted proteolysis of pea protein was employed to elucidate how structural modifications regulate α-glucosidase inhibitory activity. Although ultrasonication reorganized protein conformations, subsequent pepsin hydrolysis promoted a more ordered and compact structure, resulting in a superior inhibition (IC50 = 2.17 mg/mL) than acidic protease hydrolysis. Medium-molecular-weight fractions (3-10 kDa) and α-helix-rich structures favored inhibitory expression, highlighting the importance of compact conformations. Peptidomic analysis combined with machine learning and molecular docking identified phenylalanine and glycine as key residues mediating inhibition via π interactions and hydrogen bonding. These findings emphasized the structural basis for the release of α-glucosidase inhibitory peptide and provided rational guidance for the targeted and efficient production of hypoglycemic ingredients and nutraceuticals.