State Key Laboratory of Food Science and Technology, School of Food Science and Technology , Jiangnan University , Wuxi 214122 , People's Republic of China.
Department of Food Science and Engineering, College of Light Industry and Food Engineering , Nanjing Forestry University , Nanjing 210037 , People's Republic of China.
J Agric Food Chem. 2019 Jun 5;67(22):6313-6323. doi: 10.1021/acs.jafc.9b00569. Epub 2019 May 22.
Gliadins are major allergens responsible for wheat allergies. Food processing is an effective strategy to reduce the allergenicity of gluten. In the present study, we determined the secondary and tertiary structures of gluten and gliadins treated by chemical, physical, and enzymatic means through FTIR, surface hydrophobicity, intrinsic fluorescence spectra, and UV absorption spectra. The results showed that the three treatments of phosphorylation and alcalase and papain hydrolyses significantly changed the conformational structures of gliadins, especially the secondary structure. Then, the potential allergenicity of the phosphorylated and alcalase and papain hydrolyzed gliadins were further characterized, and we observed a significant decrease in the allergenicity through the results of the index of spleen, serum total IgE, gliadin-specific IgE, histamine, and serum cytokine concentrations. An elevation of Th17 cells, the absence of Treg cells, and an imbalance in Treg/Th17 are associated with allergy. On the basis of the expression levels of related cytokines and key transcription factors, we also confirmed that phosphorylation and alcalase and papain hydrolysis could effectively reduce the allergenicity of gliadins by improving the imbalance of both Th1/Th2 and Treg/Th17 in the spleens of sensitized mice. This study suggested that the changes in conformational structure contribute to gliadin hyposensitization and that phosphorylation and alcalase and papain hydrolysis may be promising strategies for the production of wheat products with low allergenicity.
麦醇溶蛋白是引起小麦过敏的主要过敏原。食品加工是降低面筋致敏性的有效策略。在本研究中，我们通过傅里叶变换红外光谱（FTIR）、表面疏水性、内源荧光光谱和紫外吸收光谱，确定了化学、物理和酶处理对面筋和麦醇溶蛋白二级和三级结构的影响。结果表明，磷酸化、碱性蛋白酶和木瓜蛋白酶水解三种处理方法显著改变了麦醇溶蛋白的构象结构，特别是二级结构。然后，进一步对磷酸化和碱性蛋白酶及木瓜蛋白酶水解麦醇溶蛋白的潜在致敏性进行了表征，通过脾指数、血清总 IgE、麦醇溶蛋白特异性 IgE、组氨酸和血清细胞因子浓度的结果观察到致敏性显著降低。Th17 细胞升高、Treg 细胞缺失以及 Treg/Th17 失衡与过敏有关。基于相关细胞因子和关键转录因子的表达水平，我们还证实磷酸化和碱性蛋白酶及木瓜蛋白酶水解可以通过改善致敏小鼠脾脏中 Th1/Th2 和 Treg/Th17 的失衡，有效降低麦醇溶蛋白的致敏性。本研究表明，构象结构的变化有助于麦醇溶蛋白低致敏性，磷酸化和碱性蛋白酶及木瓜蛋白酶水解可能是生产低致敏性小麦产品的有前途的策略。
