Meng Xuanyi, Li Xin, Wang Xinkang, Gao Jinyan, Yang Hao, Chen Hongbing
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R. China.
School of Food Science & Technology, Nanchang University, Nanchang 330031, P.R. China.
Food Funct. 2016 Jul 13;7(7):3102-10. doi: 10.1039/c6fo00400h.
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.
牛α-乳白蛋白（α-La）是牛奶中一种主要的食物过敏原，因其具有四个二硫键且与钙结合而具有高度的构象稳定性。本研究旨在描述γ射线辐照对α-La结构和潜在致敏性的影响。制备的α-La以1-10 kGy的剂量进行辐照。通过SDS-PAGE、圆二色光谱、紫外吸收光谱和荧光光谱对结构变化进行表征。通过IgG/IgE抑制ELISA和人嗜碱性粒细胞KU812脱颗粒试验在体外评估辐照后α-La的潜在致敏性。结果表明，α-La的二级和三级结构发生显著变化，导致蛋白质广泛变性和聚集。IgG和IgE结合特性显著降低，嗜碱性粒细胞的脱颗粒能力减弱。结果表明，辐照诱导的α-La结构损伤显著降低了α-La的潜在致敏性。
