Linear IgE-epitope mapping and comparative structural homology modeling of hazelnut and English walnut 11S globulins
Linear IgE-epitope mapping and comparative structural homology modeling of hazelnut and English walnut 11S globulins
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DOI：
10.1016/j.molimm.2009.06.020
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发表时间：
2009-09-01
影响因子：
3.6
通讯作者：
Roux, Kenneth H.
中科院分区：
文献类型：
--
作者：
Robotham, Jason M.;Hoffman, Gregg G.;Roux, Kenneth H.
对核桃和榛子的过敏反应可能很严重。 11 S 球蛋白（豆蛋白）已被确定为这些以及其他坚果和种子中的重要过敏原。在这里，我们鉴定了核桃和榛子 11 S 球蛋白的线性 IgE 结合表位，并生成 3D 11 S 球蛋白模型来绘制表位的位置，以便与其他过敏同源物进行比较。线性 IgE 表位作图是通过固相重叠 15 个氨基酸肽进行的，用来自过敏性人类血清的 IgE 进行探测。鉴定出几种对患者 IgE 具有反应性的核桃 (Jug r 4) 和榛子 (Cor a 9) 11S 球蛋白肽。与腰果 (Ana o 2)、花生 (Ara h 3) 和大豆 G1 (Gly m 6.0101) 和 G2 (Gly m 6.0201) 过敏同源物的比较比对揭示了几个共有的过敏“热点”。根据大豆甘氨酸的原子结构进行同源建模。坚果和花生同源物之间的表面图比较揭示了对 IgE 引发和结合可能很重要的结构基序，并表明，与预测相反，反应性表位广泛分布在整个单体亚基的内部和外部，包括被四级亚基关联封闭的区域。这些发现揭示了可能对该蛋白质类别的过敏性和交叉反应性很重要的结构特征。 (C) 2009 Elsevier Ltd. 保留所有权利。
Allergic reactions to walnuts and hazelnuts can be serious. The 11 S globulins (legumins) have been identified as important allergens in these and other nuts and seeds. Here we identify the linear IgE-binding epitopes of walnut and hazelnut 11 S globulins, and generate 3D 11 S globulin models to map the locations of the epitopes for comparison to other allergenic homologues. Linear IgE-epitope mapping was performed by solid-phase overlapping 15-amino, acid peptides probed with IgE from pooled allergic human sera. Several walnut (Jug r 4) and hazelnut (Cor a 9) 11S globulin peptides with reactivity to patient IgE were identified. Comparative alignment with cashew (Ana o 2), peanut (Ara h 3), and soybean G1 (Gly m 6.0101) and G2 (Gly m 6.0201) allergenic homologues revealed several shared allergenic 'hot spots'. Homology modeling was performed based on the atomic structure of the soybean glycinin. Surface map comparisons between the tree nut and peanut homologues revealed structural motifs that could be important for IgE elicitation and binding and show that, contrary to predictions, the reactive epitopes are widely distributed throughout the monomeric subunits, both internally and externally, including regions occluded by quaternary subunit association. These findings reveal structural features that may be important to allergenicity and cross-reactivity of this protein class. (C) 2009 Elsevier Ltd. All rights reserved.