title: Susceptibility of milk protein-derived peptides to dipeptidyl peptidase IV (DPP-IV) hydrolysis.
abstract: In silico digestion of milk protein-derived peptides with gastrointestinal enzyme activities was used to predict the release of peptides with a Pro residue at position 2 from the N terminus. These peptides are known to act as preferred dipeptidyl peptidase IV (DPP-IV) substrates. Five casein-derived synthetic peptides (Ile-Pro-Ile-Gln-Tyr, Leu-Pro-Leu-Pro-Leu, Tyr-Pro-Tyr-Tyr, Leu-Pro-Tyr-Pro-Tyr and Ile-Pro-Ile) and a casein (CasH), whey (WPH) and lactoferrin hydrolysate (LFH) generated with gastrointestinal enzymes were incubated with DPP-IV at 37 °C for 18 or 24h. Peptide breakdown was evident following incubation with DPP-IV. Different modes of DPP-IV inhibition were observed depending on the test compound. Ile-Pro-Ile-Gln-Tyr, Tyr-Pro-Tyr-Tyr and Leu-Pro-Tyr-Pro-Tyr were substrate-, Leu-Pro-Leu-Pro-Leu and CasH were prodrug- while WPH and LFH were true DPP-IV inhibitors. These results are relevant for the bioactivity and bioavailability of functional foods targeting DPP-IV inhibition with potential blood glucose regulatory properties in humans.
authors.affiliation: Department of Life Sciences and Food for Health Ireland (FHI), University of Limerick, Limerick, Ireland.
authors.forename: Alice B
authors.initials: AB
authors.lastname: Nongonierma
authors.forename: Richard J
authors.initials: RJ
authors.lastname: FitzGerald
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D019295:Computational Biology; D004063:Digestion; D018819:Dipeptidyl Peptidase 4 / Q000737:chemistry / Q000378:metabolism*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000737:chemistry / Q000378:metabolism*; D005103:Expert Systems; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism; D007781:Lactoferrin / Q000737:chemistry / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D011492:Protein Hydrolysates / Q000737:chemistry / Q000378:metabolism; D055550:Protein Stability; D059748:Proteolysis; D034421:Sus scrofa; D000067816:Whey Proteins
chemical_list: D002364:Caseins; D054873:Dipeptidyl-Peptidase IV Inhibitors; D016166:Free Radical Scavengers; D008894:Milk Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; D011492:Protein Hydrolysates; D000067816:Whey Proteins; D018819:Dipeptidyl Peptidase 4; D007781:Lactoferrin
keywords: Antioxidant; Bioactive peptides; Dipeptidyl peptidase IV inhibitors; Milk; Prodrug-type inhibition; Substrate-type inhibition