Unidad de Bioquímica, Departamento de Biotecnología, E.T.S. Ingenieros Agrónomos, UPM, Madrid, Spain.
Clin Exp Allergy. 2010 Sep;40(9):1422-30. doi: 10.1111/j.1365-2222.2010.03578.x.
Peach is the most important fruit related to food allergy in the Mediterranean area. Pru p 3, its lipid transfer protein, has been described as the principal allergen responsible for cross-reactivities with other foods and pollen and the severity of clinical symptoms. However, the involvement of other allergenic families cannot be ruled out. Thaumatin-like proteins (TLPs) have been described as food allergen in several fruits, such as apple, cherry, kiwi and banana, and pollen.
To identify members of the TLP family in peach fruit and to characterize putative allergens.
Through two-dimensional (2D) electrophoresis of peach extract and immunodetections with a pool of peach-allergic patients, IgE-binding spots were identified and the corresponding proteins purified and characterized as allergens by in vitro and in vivo assays. Three isoforms, belonging to the TLP family, were purified by different chromatographic systems and characterized by N-terminal amino acid sequences, molecular weight determination (MALDI) and enzymatic activity analysis (beta-1,3-gluconase test and inhibition growth of fungi). In the same way, their IgE-binding capacity and allergenic activity were tested by ELISA assays, basophil activation tests and skin prick tests (SPT).
Two peach-TLPs, Pru p 2.0101 and Pru p 2.0201, were identified as IgE-binding spots by 2D electrophoresis. Another peach-TLP, Pru p 2.0301, was cloned and produced as recombinant protein in a yeast system. The three isoforms were purified and characterized as TLPs by immunoblotting with anti-chestnut TLP antibodies and anti-plant N-asparagine complex glycan (anti-cross-reactive carbohydrate determinant). All of them showed beta-1,3-glucanase activity and inhibition of fungal growth. The three TLPs were recognized by around 50% of the sera from 31 patients analysed in ELISA experiments. All three gave a positive response to an SPT and/or in basophil activation experiments.
Three isoforms, belonging to the TLP family, were identified in peach as principal allergens. Their prevalence, observed in in vitro, ex vivo and in vivo analyses, suggests that they are important allergens and should therefore be included in the routine diagnosis of peach allergy, at least in the Mediterranean area.
桃是地中海地区与食物过敏最相关的最重要水果。其脂质转移蛋白 Pru p 3 已被描述为与其他食物和花粉发生交叉反应以及引发严重临床症状的主要过敏原。然而，也不能排除其他过敏原家族的参与。类硫氧还蛋白（TLPs）已被描述为几种水果（如苹果、樱桃、猕猴桃和香蕉）和花粉中的食物过敏原。
鉴定桃果实中 TLP 家族的成员并对其潜在过敏原进行鉴定。
通过桃提取物的二维电泳和一组桃过敏患者的免疫检测，鉴定 IgE 结合斑点，并用体外和体内试验对相应蛋白质进行纯化和鉴定为过敏原。通过不同的色谱系统对三种同工型进行纯化，并用 N 端氨基酸序列、分子量测定（MALDI）和酶活性分析（β-1,3-葡聚糖酶试验和抑制真菌生长）进行鉴定。同样，通过 ELISA 试验、嗜碱性粒细胞激活试验和皮肤点刺试验（SPT）测试它们的 IgE 结合能力和致敏活性。
通过 2D 电泳鉴定出两种桃 TLP，即 Pru p 2.0101 和 Pru p 2.0201，为 IgE 结合斑点。另一种桃 TLP，Pru p 2.0301，通过酵母系统克隆并产生重组蛋白。三种同工型均用抗栗 TLP 抗体和抗植物 N-天冬酰胺复合聚糖（抗交叉反应性碳水化合物决定簇）的免疫印迹进行鉴定，被鉴定为 TLPs。它们均具有β-1,3-葡聚糖酶活性并抑制真菌生长。在 ELISA 实验中分析的 31 名患者的血清中，约有 50%的血清识别出这三种 TLP。所有三种 TLP 在 SPT 和/或嗜碱性粒细胞激活实验中均呈阳性反应。
在桃中鉴定出三种同工型，它们属于 TLP 家族，是主要过敏原。在体外、离体和体内分析中观察到它们的普遍性表明它们是重要的过敏原，因此应将它们纳入桃过敏的常规诊断中，至少在地中海地区应如此。
