An in silico model to predict the potential of dietary proteins as sources of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides

An in silico approach was developed to predict the potential of 72 dietary proteins to act as a source of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides. The model takes 68 DPP- IV inhibitory peptides (having an IC50 value < 2000 μM) and the specific contribution of their amino acids into account. Bovine α-lactalbumin (α-La) and κ-casein (CN) displayed the highest protein coverage (PC, 43.9 %) and potency index (PI, 17.9 10-6 μM-1 g-1), respectively for DPP-IV inhibitory peptides. Sequence alignment of 39 DPP-IV inhibitory peptides having IC50’s < 200 μM revealed the frequent occurrence of Trp at the N-terminus and Pro at position 2. Canola, chicken egg, oat and wheat were identified as potential sources of DPP-IV inhibitory peptides. In silico approaches may assist in the selection of food proteins for the enzymatic release of DPP-IV inhibitory peptides. The results are relevant to the generation of biofunctional ingredients for glycaemic management.