Conformational changes in bovine α-lactalbumin and β-lactoglobulin evoked by interaction with C18 unsaturated fatty acid give insights into increased allergic potential

Bovine α-lactalbumin (BLA) and β-lactoglobulin (BLG) are the most common and severe food allergens in milk and can bind C18 unsaturated fatty acid (UFA) and change their bioactivities. This study aims to determine the effects of C18 UFA on the structures of BLA and BLG and their allergic properties, such as antigenicity and allergenicity. We reveal that C18 UFA can efficiently promote the gradual unfolding of the structure of BLA and BLG and increase their hydrophobicity. Moreover, the IgG binding ability and the expression of IgG-dependent activation marker CD200R3 on basophils were remarkably promoted after the C18 UFA treatment. Finally, we also observed that C18 UFA can enhance the IgE binding ability and the degranulation capacity of human basophil KU812 cells (intracellular Ca2+, histamine, β-Hex, and IL-6). Collectively, these results suggested that C18 UFA changed the structure of BLA and BLG, which contributed to their increased allergic potential.