Potential allergenicity response to structural modification of irradiated bovine α-lactalbumin

Bovine α-lactalbumin (α-La) is a major food allergen found in milk and is characterized by high conformational stability because of its four disulfide bridges and being calcium bound. This study aimed to describe the influence of gamma irradiation on the structure and potential allergenicity of α-La. The prepared α-La was irradiated at doses of 1-10 kGy. The changes in structure were characterized through SDS-PAGE, circular dichroism spectroscopy, ultraviolet absorption spectroscopy, and fluorescence spectroscopy. The potential allergenicity of the irradiated α-La was evaluated in vitro through IgG/IgE inhibition ELISA and the human basophil KU812 degranulation assay. The results showed that the secondary and tertiary structures of α-La significantly changed and caused extensive protein denaturation and aggregation. IgG and IgE binding properties remarkably decreased, and the degranulation capacity of basophils weakened. The results suggested that structural damage of α-La induced by irradiation significantly reduces the potential allergenicity of α-La.