title: Antigenicity and functional properties of β-lactoglobulin conjugated with fructo-oligosaccharides in relation to conformational changes.
abstract: Bovine β-lactoglobulin (β-LG) was conjugated with fructo-oligosaccharides (FOS) by Maillard reaction to investigate the relationship among antigenicity, functional properties, and conformational changes of β-LG. When comparing the antigenicity of β-LG conjugated with FOS at different ratios, the lowest antigenicity of β-LG was observed at a ratio of 1:4, which was about 7 times lower than that of the control β-LG. Thus, the ratio of 1:4 was chosen to conjugate β-LG with FOS, and the functional properties and conformational changes of β-LG-FOS conjugates were investigated. The functional properties (solubility, emulsifying ability, and emulsion stability) of β-LG were enhanced after conjugation with FOS. Furthermore, the molecular weight of β-LG increased from 18.4 to 19.9 kDa after conjugation with FOS, as evaluated by sodium dodecyl sulfate-PAGE and mass spectrometry. Partial unfolding of β-LG occurred after conjugation with FOS, as reflected by the quenching of fluorescence, the red-shift of fluorescence spectra, and the increase of β-strands, which may contribute to the decrease in antigenicity and the improvement of functional properties.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: J Z
authors.initials: JZ
authors.lastname: Zhong
authors.forename: Y J
authors.initials: YJ
authors.lastname: Xu
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: C M
authors.initials: CM
authors.lastname: Liu
authors.forename: S J
authors.initials: SJ
authors.lastname: Luo
authors.forename: Z C
authors.initials: ZC
authors.lastname: Tu
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004655:Emulsions; D004797:Enzyme-Linked Immunosorbent Assay; D005632:Fructose / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D013058:Mass Spectrometry; D009842:Oligopeptides / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D011487:Protein Conformation; D055550:Protein Stability; D012995:Solubility
chemical_list: D000941:Antigens; D004655:Emulsions; D009842:Oligopeptides; D009844:Oligosaccharides; C102983:beta-lactorphin; D005632:Fructose