Identification of the IgE-binding epitope in ω-5 gliadin, a major allergen in wheat-dependent exercise-induced anaphylaxis
Identification of the IgE-binding epitope in ω-5 gliadin, a major allergen in wheat-dependent exercise-induced anaphylaxis
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DOI：
10.1074/jbc.m311340200
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发表时间：
2004-03-26
影响因子：
4.8
通讯作者：
Dekio, S
中科院分区：
文献类型：
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作者：
Matsuo, H;Morita, E;Dekio, S
小麦依赖性运动诱发的过敏反应 (WDEIA) 是一种严重的 IgE 介导的过敏反应，由摄入小麦和接下来几个小时内的剧烈体育锻炼相结合引起。在小麦蛋白中，omega-5 麦醇溶蛋白是快速 omega-麦醇溶蛋白的成分之一，据报道是过敏反应的主要过敏原。在这项研究中，我们使用衍生纤维素膜上合成的重叠肽阵列检测了 omega-5 麦醇溶蛋白一级序列中的 IgE 结合表位。来自四名患有 WDEIA 的患者的血清具有针对快速 omega-麦醇溶蛋白的特异性 IgE，用于探测膜。在 omega-5 麦醇溶蛋白的一级序列中检测到 7 个表位：QQIPQQQ、QQLPQQQ、QQFPQQQ、QQSPEQQ、QQSPQQQ、QQYPQQQ 和 PYPP。通过使用15名患者的血清，发现其中4个：QQIPQQQ、QQFPQQQ、QQSPEQQ和QQSPQQQ为显性表位。 QQIPQQQ 和 QQFPQQQ 的突变分析表明，Gln(1)、Pro(4)、Gln(5)、Gln(6) 和 Gln(7) 位点的氨基酸对于 IgE 结合至关重要。除了 WDEIA 的诊断和免疫治疗技术之外，这些结果还将为开发更安全的小麦产品提供有用的工具。
Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a severe IgE-mediated allergic reaction provoked by the combination of wheat-ingestion with intensive physical exercise over the next few hours. Among wheat proteins, omega-5 gliadin, which is one of the components of fast omega-gliadin, has been reported as a major allergen in the anaphylaxis. In this study, we detected IgE-binding epitopes within the primary sequence of omega-5 gliadin using arrays of overlapping peptides synthesized on derivatized cellulose membranes. Sera from four patients with WDEIA having specific IgE to the fast omega-gliadin were used to probe the membrane. Seven epitopes, QQIPQQQ, QQLPQQQ, QQFPQQQ, QQSPEQQ, QQSPQQQ, QQYPQQQ, and PYPP, were detected within the primary sequence of omega-5 gliadin. By using sera of 15 patients, 4 of them, QQIPQQQ, QQFPQQQ, QQSPEQQ, and QQSPQQQ, were found to be dominant epitopes. Mutational analysis of the QQIPQQQ and QQFPQQQ indicated that amino acids at positions Gln(1), Pro(4), Gln(5), Gln(6), and Gln(7) were critical for IgE binding. These results will provide a useful tool for developing safer wheat products in addition to diagnostic and immunotherapy techniques for WDEIA.