Evaluation of the potential of dietary proteins as precursors of dipeptidyl peptidase (DPP)-IV inhibitors by an in silico approach

Synthetic inhibitors against the enzyme dipeptidyl peptidase (DPP)-IV, a serine protease implicated in the inactivation of incretin hormones, are currently used for the management of type 2 diabetes. The aim of the present study was to evaluate the potential of dietary proteins from various food commodities to serve as precursors of DPP-IV inhibitors by using an in silico approach. A total of 2256 fragments with peptide sequences matching those reported in the literature to present DPP-IV inhibitory activity were found in the 34 proteins that were investigated. Among those, Gly-Ala, Gly-Pro and Pro-Gly were the most frequently occurring sequences. Caseins from cow's milk and collagens from bovine meat and salmon appeared to be the richest potential sources of DPP-IV inhibitors, whereas proteins from oat showed lower occurrence frequency values. This study suggests that dietary proteins could be used for generating DPP-IV inhibitory peptides. (C) 2012 Elsevier Ltd. All rights reserved.