Purification and Characterization of Bovine β-Lactoglobulin Variants A and B (Characterization of Bovine β-Lactoglobulin Variants)

β-Lactoglobulin is a major allergen in whey, which have more than 9 variants. Among them, variants A and B are the most predominant forms in bovine milk. In this study, variants A and B were purified by combining gel filtration chromatography with anion-exchange chromatography for the first time. The purity of variants A and B were 96.2% and 94.3%, and the variants yield was 35.56% from the whey. The structure characterization has been monitored by the Circular dichroism spectrometry, Fourier transform infrared spectroscopy and Fluorescence spectroscopy. IgG binding of variants was evaluated by Western blotting which proved both keep well and β-Lactoglobulin B had a stronger ability. The substitution Val of Ala in β-Lactoglobulin B decreased its hydrophobic packing. In short, β-Lactoglobulin B had a stronger antigenicity but smaller hydrophobic packing than that of A.