title: Gastrointestinal Endogenous Protein-Derived Bioactive Peptides: An in Vitro Study of Their Gut Modulatory Potential.
abstract: A recently proposed paradigm suggests that, like their dietary counterparts, digestion of gastrointestinal endogenous proteins (GEP) may also produce bioactive peptides. With an aim to test this hypothesis, in vitro digests of four GEP namely; trypsin (TRYP), lysozyme (LYS), mucin (MUC), serum albumin (SA) and a dietary protein chicken albumin (CA) were screened for their angiotensin-I converting (ACE-I), renin, platelet-activating factor-acetylhydrolase (PAF-AH) and dipeptidyl peptidase-IV inhibitory (DPP-IV) and antioxidant potential following simulated in vitro gastrointestinal digestion. Further, the resultant small intestinal digests were enriched to obtain peptides between 3-10 kDa in size. All in vitro digests of the four GEP were found to inhibit ACE-I compared to the positive control captopril when assayed at a concentration of 1 mg/mL, while the LYS < 3-kDa permeate fraction inhibited renin by 40% (±1.79%). The LYS < 10-kDa fraction inhibited PAF-AH by 39% (±4.34%), and the SA < 3-kDa fraction inhibited DPP-IV by 45% (±1.24%). The MUC < 3-kDa fraction had an ABTS-inhibition antioxidant activity of 150 (±24.79) µM trolox equivalent and the LYS < 10-kDa fraction inhibited 2,2-Diphenyl-1-picrylhydrazyl (DPPH) by 54% (±1.62%). Moreover, over 190 peptide-sequences were identified from the bioactive GEP fractions. The findings of the present study indicate that GEP are a significant source of bioactive peptides which may influence gut function.
authors.affiliation: The Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. Lakshdavewn@gmail.com.|Teagasc, The Irish Agricultural and Food Development Authority, Food BioSciences Department, Ashtown, Dublin 15, Ireland. Lakshdavewn@gmail.com.
authors.forename: Lakshmi A
authors.initials: LA
authors.lastname: Dave
authors.affiliation: Teagasc, The Irish Agricultural and Food Development Authority, Food BioSciences Department, Ashtown, Dublin 15, Ireland. Maria.Hayes@teagasc.ie.
authors.forename: Maria
authors.initials: M
authors.lastname: Hayes
authors.affiliation: Instituto de Agroquı́mica y Tecnologı́a de Alimentos (CSIC), Avenida Agustín Escardino 7, 46980 Paterna, Valencia 46002, Spain. lemoso@iata.csic.es.
authors.forename: Leticia
authors.initials: L
authors.lastname: Mora
authors.affiliation: The Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. Carlos.Montoya@massey.ac.nz.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Montoya
authors.affiliation: The Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. P.MMoughan@massey.ac.nz.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Moughan
authors.affiliation: The Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. S.M.Rutherfurd@massey.ac.nz.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Rutherfurd
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000037:antagonists & inhibitors / Q000378:metabolism; D000418:Albumins / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D001713:Biphenyl Compounds / Q000737:chemistry / Q000378:metabolism; D002645:Chickens; D018819:Dipeptidyl Peptidase 4 / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D009077:Mucins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009113:Muramidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000378:metabolism; D010851:Picrates / Q000737:chemistry / Q000378:metabolism; D012083:Renin / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D000092502:Renin Inhibitors
chemical_list: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000418:Albumins; D000975:Antioxidants; D001713:Biphenyl Compounds; D018819:Dipeptidyl Peptidase 4; D009077:Mucins; D009113:Muramidase; D010455:Peptides; D007703:Peptidyl-Dipeptidase A; D010851:Picrates; D012083:Renin; D000092502:Renin Inhibitors; C004931:1,1-diphenyl-2-picrylhydrazyl; C526684:PLA2G7 protein, human
keywords: angiotensin-I converting enzyme (ACE-I) inhibition; antioxidant peptides; dipeptidyl peptidase IV inhibition; gut non-dietary proteins; lysozyme; renin inhibition; serum albumin