title: Re-formation of fibrils from hydrolysates of β-lactoglobulin fibrils during in vitro gastric digestion.
abstract: In this study, in vitro digestion of β-lactoglobulin (β-Lg) fibrils and the re-formation of fibril-like structures after prolonged enzymatic hydrolysis (up to 48 h) were investigated using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), thioflavin T fluorescence photometry, and transmission electron microscopy (TEM). Pure β-Lg fibrils that had been formed by heat treatment at pH 2.0 were rapidly hydrolyzed by pepsin in the simulated gastric fluid (pH 1.2), and some new peptides that were suitable for further fibril formation were produced. TEM showed that the new fibrils were long and straight but thinner than the original fibrils, and both TEM and MALDI-MS indicated that the peptides in the new fibrils were shorter/smaller than the peptides in the original fibrils. The formation of new fibrils was found to be affected more by pH than by enzyme activity or temperature.
authors.affiliation: Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
authors.forename: Libei
authors.initials: L
authors.lastname: Bateman
authors.forename: Aiqian
authors.initials: A
authors.lastname: Ye
authors.forename: Harjinder
authors.initials: H
authors.lastname: Singh
mesh_terms: D004063:Digestion; D005753:Gastric Mucosa / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D066298:In Vitro Techniques; D007782:Lactoglobulins / Q000737:chemistry* / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D010434:Pepsin A / Q000378:metabolism; D011492:Protein Hydrolysates / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007782:Lactoglobulins; D011492:Protein Hydrolysates; D010434:Pepsin A