Departament of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain.
Clin Exp Allergy. 2009 Dec;39(12):1929-36. doi: 10.1111/j.1365-2222.2009.03382.x.
Patients allergic to mustard are frequently sensitized to peach.
To identify and analyse new yellow mustard allergens that could be involved in IgE cross-reactivity.
Sera from mustard-allergic patients with symptoms to peach were studied. Mass spectrometry analyses provided sequences of IgE-reactive proteins. cDNAs encoding Sin a 3 and Sin a 4 were amplified by polymerase chain reaction, cloned and sequenced. The recombinant allergens were obtained in Pichia pastoris and Escherichia coli, respectively, and used for ELISA, immunoblotting and inhibition experiments. Sequence alignment was used to identify common IgE epitopes.
Sin a 3- and Sin a 4-specific cDNAs encode for mature proteins of 92 and 131 amino acids that belong to nsLTP and profilin protein families, respectively. Sin a 3 and Sin a 4 showed 54% and 80% identity with allergenic nsLTP from peach and profilin from melon, respectively. Both recombinant allergens were IgE-reactive in ELISA and immunoblotting. Peach pulp and peel, and melon extracts nearly abolished the IgE binding to recombinant Sin a 3 or recombinant Sin a 4 in immunoblotting.
Sin a 3 (nsLTP) and Sin a 4 (profilin) were identified as new mustard allergens and showed IgE cross-reactivity with fruits such as peach or melon, respectively. The knowledge of these two allergens will contribute towards better understand with cross-reactivity between mustard and other plant food allergens, and their availability will provide physicians with useful tools for molecular diagnosis.
对芥末过敏的患者常对桃过敏。
鉴定和分析可能参与 IgE 交叉反应的新的黄色芥末过敏原。
研究了对桃有症状的芥末过敏患者的血清。质谱分析提供了 IgE 反应蛋白的序列。通过聚合酶链反应扩增编码 Sin a 3 和 Sin a 4 的 cDNA，克隆并测序。分别在毕赤酵母和大肠杆菌中获得重组过敏原，并用于 ELISA、免疫印迹和抑制实验。序列比对用于鉴定共同的 IgE 表位。
Sin a 3 和 Sin a 4 特异性 cDNA 编码成熟蛋白，分别为 92 和 131 个氨基酸，属于 nsLTP 和丝状蛋白家族。Sin a 3 和 Sin a 4 与桃和瓜的过敏原 nsLTP 和丝状蛋白分别具有 54%和 80%的同源性。重组过敏原在 ELISA 和免疫印迹中均具有 IgE 反应性。桃果肉和果皮以及瓜提取物在免疫印迹中几乎完全抑制了重组 Sin a 3 或重组 Sin a 4 与 IgE 的结合。
Sin a 3（nsLTP）和 Sin a 4（丝状蛋白）被鉴定为新的芥末过敏原，分别与桃或瓜等水果表现出 IgE 交叉反应性。对这两种过敏原的了解将有助于更好地理解芥末与其他植物性食物过敏原之间的交叉反应性，并且它们的可用性将为医生提供分子诊断的有用工具。
