原標(biāo)題：用過敏患者的血清來確定大豆球蛋白表位，可以發(fā)現(xiàn)許多豆類和堅果常見的共享表位
本研究主要描述了兩種相似大豆球蛋白亞基（Gly m 6）結(jié)合IgE的B細(xì)胞表位
?對位于大豆球蛋白六聚體暴露表面的大多數(shù)表位進(jìn)行三維建模
?與其它植物11S貯藏蛋白序列比較，發(fā)現(xiàn)一個顯性表位和多個共享表位
?不同植物家族的貯藏蛋白之間通常會共享常見的“熱點(diǎn)”表位
　　越來越多的西方飲食中增加了大豆的食用量，但最近有研究表明，普通人群中大豆過敏的患病率約為0.5%，在兒童中這一比例高達(dá)13%。
　　本研究采用2D凝膠電泳技術(shù)，研究6例大豆過敏成人血清與大豆蛋白免疫球蛋白E（IgE）結(jié)合的情況。使用包含大豆球蛋白A2和A3亞基主序列的合成肽來繪制IgE結(jié)合區(qū)域，同時利用生物信息學(xué)軟件來定位在大豆球蛋白六聚體模型上的假定表位。
　　我們通過篩選大豆過敏患者的血清，確定了主要貯藏蛋白Gly m 6的線性IgE結(jié)合表位。然后進(jìn)一步在三維硅膠模型中進(jìn)行定位分析，并與其他植物貯藏蛋白表位進(jìn)行比較。我們也利用網(wǎng)絡(luò)軟件來探究準(zhǔn)確預(yù)測表位的能力，但結(jié)果參差不齊。最終我們在大豆球蛋白A3（A3.1–A3.3）和A2（A2.1–A2.6）亞基中總共鑒定出9個IgE結(jié)合表位。
　　除一名患者的血清與四種不同的A2表位結(jié)合外，大部分患者的血清IgE僅與一或兩種表位結(jié)合。9個結(jié)合表位中的兩個表位（A3.2和A2.4）與先前確定的來自其他植物的11S球蛋白“熱點(diǎn)”表位區(qū)重疊。大多數(shù)表位被預(yù)測可暴露在大豆球蛋白六聚體的三維模型表面。對大豆球蛋白和其他植物球蛋白進(jìn)行氨基酸序列比對揭示了一個顯性“熱點(diǎn)”表位區(qū)，且該“熱點(diǎn)”區(qū)屬于已報道的四個“熱點(diǎn)”區(qū)。這項研究可能有助于對大豆過敏免疫治療和診斷的未來發(fā)展研究。


延伸閱讀
Molecular Immunology Volume 70, February 2016,Pages 125-133
Using patient serum to epitope map soybean glycinins reveals common epitopes shared with many legumes and tree nuts
https://doi.org/10.1016/j.molimm.2015.12.008
Abstract:
Highlights ? 
The IgE-binding B-cell epitopes of two similar soybean glycinin subunits (Gly m 6) are described. 
 ? Three-dimensional modeling of the glycinin hexamers located most epitopes on the exposed surfaces. 
 ? Comparison with other plant 11S storage protein sequences revealed one dominant and several shared epitopes. 
 ? Common epitope hot spots are often shared between plant storage proteins from diverse families.
Abstract
 Soybean consumption is increasing in many Western diets; however, recent reviews suggest that the prevalence of soy allergy can be as high as 0.5% for the general population and up to 13% for children. The immunoglobulin-E (IgE) binding of sera from six soy-sensitive adult human subjects to soybean proteins separated by 2D gel electrophoresis was studied. 
Synthetic peptide sets spanning the mature glycinin subunit A2 and A3 primary sequences were used to map the IgE-binding regions. Putative epitopes identified in this study were also localized on glycinin hexamer models using bioinformatics software. 
We identified linear IgE-binding epitopes of the major storage protein Gly m 6 by screening individual soy-sensitive patient sera. These epitopes were then further analysed by 3D in silico model localization and compared to other plant storage protein epitopes. Web-based software applications were also used to study the ability to accurately predict epitopes with mixed results. A total of nine putative IgE-binding epitopes were identified in the glycinin A3 (A3.1–A3.3) and A2 (A2.1–A2.6) subunits. 
Most patients' sera IgE bound to only one or two epitopes, except for one patient's serum which bound to four different A2 epitopes. Two epitopes (A3.2 and A2.4) overlapped with a previously identified epitope hot spot of 11S globulins from other plant species.  Most epitopes were predicted to be exposed on the surface of the 3D model of the glycinin hexamer. Amino acid sequence alignments of soybean acidic glycinins and other plant globulins revealed one dominant epitope hot spot among the four reported hot spots. This study may be helpful for future development of soy allergy immunotherapy and diagnosis.
All Authors:
Hanaa Saeed Christine Gagnon Elroy Cober Steve Gleddie
　　創(chuàng)建過敏性疾病的科研、科普知識交流平臺，為過敏患者提供專業(yè)診斷、治療、預(yù)防的共享平臺。