Preparation and identification of novel DPP-IV inhibitory peptides from Musculus senhousei: Peptidomic analysis, molecular simulation, and validation

Bioactive peptides have been considered effective alternatives for the treatment of type 2 diabetes targeting the dipeptidyl peptidase-IV (DPP-IV). In this study, novel DPP-IV inhibitory peptides were prepared and identified from Musculus senhousei through two-stage chromatographic purification, peptidomic analysis, in silico screening, and validation. Furthermore, molecular simulation was employed to analyze the interaction from a molecular perspective. Results showed that Musculus senhousei hydrolysate produced by 8 h Neutrase hydrolysis exhibited the significant DPP-IV inhibitory activity. Purification and identification led to the discovery of 387 peptide sequences. A total of 11 novel peptides with potential DPP-IV inhibitory activity were screened in silico. Further synthesis and validation of peptide activity showed that LTWR and DPF significantly inhibit DPP-IV in a competitive inhibitory manner, with IC50 values of 1788.67 ± 28.13 and 1399.73 ± 27.15 μM, respectively. Results from molecular docking and dynamic simulations indicated that peptides LTWR and DPF could tightly bind to the catalytic site of DPP-IV through hydrogen-bond and hydrophobic interaction. These findings suggested that Musculus senhousei could serve as a natural source of bioactive peptides for potential treatment of type 2 diabetes.