Study on Isolation, Identification and Activity of Novel α-Glucosidase Inhibitory Peptide Derived from Dahe Black Pig Ham

Protein degradation during fermentation and maturation of Dahe black pig ham results in abundant bioactive peptides. In order to investigate whether there were α-glucosidase inhibitory peptides in Dahe black pig ham and its activity, ham peptides of different molecular masses were prepared by ultrafiltration separation, and α-glucosidase inhibition rate was used as an index to identify, screen and study the activity of peptides in Dahe black pig ham by peptidomics combined with bioinformatics analysis. The results showed that the peptide of Dahe black pig ham with molecular weight less than 3 kDa had good α-glucosidase inhibitory activity. A total of 143 peptides were identified from Dahe black pig ham, mainly derived from myosin, troponin and β-enolase. The further screened peptide IEEALGDK showed a good α-glucosidase inhibitory activity (IC₅₀=1.42 mg/mL). The results of BIOPEP-UWM search revealed that the peptide IEEALGDK was a novel bioactive peptide. Peptide stability studies have shown that the IEEALGDK peptide has good thermal stability, acid and alkali resistance and gastrointestinal digestive stability. Molecular docking results showed that the peptide IEEALGDK mainly exerted its active effects by occupying the active residue sites of α-glucosidase, Arg594, Arg727, Arg799 and Arg467 through hydrogen bonding and hydrophobic interactions. The IEEALGDK peptide derived from Dahe black pig ham had good α-glucosidase inhibitory activity and the study aimed to provide a theoretical support for the further development and use of the Dahe black pig ham peptide.