J Investig Allergol Clin Immunol. 2015;25(1):47-54.
The allergenic potential of proteins can be altered under various physicochemical conditions. Glutathione (GSH) is a reducing agent that is used as an antioxidant in food products. We aimed to characterize the natural folding of peach proteins and test the allergenicity of reduced and natural Pru p 3, the major peach allergen.
Pru p 3 was purified from peach, and its conformation was analyzed by means of circular dichroism. Using a thiol fluorescent probe, reduced proteins were detected in fresh peach. GSH-reduced Pru p 3 was tested in vitro for T-cell proliferation and in vivo using skin prick testing.
GSH-reduced Pru p 3 produced variable skin prick reactions in peach-allergic patients. The proliferative response of peripheral blood mononuclear cells from allergic patients to reduced Pru p 3 tended to be less intense, whereas secretion of the cytokines IFN-γ, IL-5, and IL-10 was comparable. In a pool of sera from peach-allergic patients, reduction hardly impaired IgE-binding. Moreover, the stability of reduced Pru p 3 to gastrointestinal digestion was similar to that of the natural form.
GSH can at least transiently reduce Pru p 3. We found that the effect of reduction on the allergenicity of Pru p 3 varied. Therefore, as an additive, GSH does not seem to eliminate the risk of reactions for peach-allergic patients.
蛋白质的变应原性可在各种物理化学条件下发生改变。谷胱甘肽（GSH）是一种还原剂，被用作食品中的抗氧化剂。我们旨在对桃蛋白的天然折叠进行特征描述，并测试还原型和天然的 Pru p 3（主要的桃过敏原）的变应原性。
从桃中纯化 Pru p 3，并通过圆二色性分析其构象。使用硫醇荧光探针，检测新鲜桃中的还原型蛋白。在体外使用 Pru p 3 进行 T 细胞增殖试验，并用皮试进行体内试验。
GSH 还原的 Pru p 3 在桃过敏患者中引起了不同程度的皮肤点刺反应。过敏患者外周血单个核细胞对还原型 Pru p 3 的增殖反应倾向较弱，而 IFN-γ、IL-5 和 IL-10 的分泌则相当。在一组桃过敏患者的血清中，还原几乎不影响 IgE 结合。此外，还原型 Pru p 3 对胃肠道消化的稳定性与天然形式相似。
GSH 至少可以暂时还原 Pru p 3。我们发现还原对 Pru p 3 变应原性的影响存在差异。因此，作为添加剂，GSH 似乎不会消除桃过敏患者发生反应的风险。
