title: In silico and in vitro analyses of the angiotensin-I converting enzyme inhibitory activity of hydrolysates generated from crude barley (Hordeum vulgare) protein concentrates.
abstract: Angiotensin-I-converting enzyme (ACE-I) plays a key role in control of hypertension, and type-2 diabetes mellitus, which frequently co-exist. Our current work utilised in silico methodologies and peptide databases as tools for predicting release of ACE-I inhibitory peptides from barley proteins. Papain was the enzyme of choice, based on in silico analysis, for experimental hydrolysis of barley protein concentrate, which was performed at the enzyme's optimum conditions (60 °C, pH 6.0) for 24 h. The generated hydrolysate was subjected to molecular weight cut-off (MWCO) filtration, following which the non-ultrafiltered hydrolysate (NUFH), and the generated 3 kDa and 10 kDa MWCO filtrates were assessed for their in vitro ACE-I inhibitory activities. The 3 kDa filtrate (1 mg/ml), that demonstrated highest ACE-I inhibitory activity of 70.37%, was characterised in terms of its peptidic composition using mass spectrometry and 1882 peptides derived from 61 barley proteins were identified, amongst which 15 peptides were selected for chemical synthesis based on their predicted ACE-I inhibitory properties. Of the synthesized peptides, FQLPKF and GFPTLKIF were most potent, demonstrating ACE-I IC50 values of 28.2 μM and 41.2 μM respectively.
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland; School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland.
authors.forename: Nirupama
authors.initials: N
authors.lastname: Gangopadhyay
authors.affiliation: Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Ireland.
authors.forename: Kieran
authors.initials: K
authors.lastname: Wynne
authors.affiliation: Teagasc Food Research Centre, Moorepark, Cork, Ireland.
authors.forename: Paula
authors.initials: P
authors.lastname: O'Connor
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: Eimear
authors.initials: E
authors.lastname: Gallagher
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland.
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Brunton
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland. Electronic address: dilip.rai@teagasc.ie.
authors.forename: Dilip K
authors.initials: DK
authors.lastname: Rai
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: Maria
authors.initials: M
authors.lastname: Hayes
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D003198:Computer Simulation; D001467:Hordeum / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D006973:Hypertension / Q000188:drug therapy; D013058:Mass Spectrometry; D010206:Papain / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry*; D011492:Protein Hydrolysates / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010455:Peptides; D010940:Plant Proteins; D011492:Protein Hydrolysates; D007703:Peptidyl-Dipeptidase A; D010206:Papain
keywords: ACE-I inhibition; Barley proteins; IC(50); In silico; Mass spectrometry; Peptides