Identification and molecular docking of a novel antidiabetic peptide from protamex-camel milk protein hydrolysates against α-amylase and DPP-IV

Antidiabetic peptides were identified from camel milk protein hydrolysates, and their inhibitory activities against α-amylase and dipeptidyl peptidase-IV (DPP-IV) were determined. The possible binding mechanism between the enzymes and the peptide was elucidated through molecular docking. Camel milk proteins were hydrolyzed using protamex, and the hydrolysates were divided into three fractions (>10, 3–10, and <3 kDa) through ultrafiltration. Fraction <3 kDa was more effective at inhibiting α-amylase and DPP-IV and was purified through gel chromatography and identified through LC-MS/MS. In total, 20 peptides were considered as potential bioactive peptides, mainly derived from β-casein. The novel peptide QEPVPDPVRGL exhibited the most potent antidiabetic activity and spontaneously interacted with α-amylase and DPP-IV through hydrogen bonds, salt bridges, and pi-alkyl, thereby occupying their active cavities. This study indicated that camel milk protein hydrolysates are good sources of peptides with antidiabetic potential.