利用IgE交叉识别和蛋白结构比较定位2S白蛋白的过敏原表位

食物过敏是FAO/WHO认定的全球性食品安全问题之一，但对于食物过敏的物质基础，过敏原表位的定位，我们仍缺乏有力手段。本研究利用交叉过敏中的IgE交叉识别，结合蛋白结构比较，建立过敏原表位定位的新方法，在全蛋白上实现2S白蛋白的过敏原表位定位。取多个花生、坚果过敏患者的血清IgE交叉识别多种2S白蛋白过敏原，依据IgE识别将蛋白分组。利用计算机模拟技术比较各组蛋白结构，找到被相同血清IgE识别的，2S白蛋白过敏原的共同结构。经界面形貌算法、氢氘交换核磁共振等检验，明确共同结构与IgE识别的关系，实现过敏原表位定位。本研究将批量定位2S白蛋白家族的过敏原表位，为它们的脱敏加工指示靶点。研究建立的过敏原表位定位新方法，同步、准确定位多种蛋白的多个表位，这将大幅提高过敏原结构研究的效率，加速深化人们对食物过敏物质基础的认知。

The prevalence of food allergy has been increasing over the past few decades in line with other allergic diseases. But we have difficult in localizing the epitopes of allergens, the physical basis of food allergen, especially the conformational epitopes. Based on the cross-reactivity of peanut and tree nuts allergens, we are intended to localize the epitopes of 2S albumins by combining wet experiments and computer simulations. Because of the specificity of Ig E, there must be domain(s) of same property in the proteins that induced the cross-recognition. .In this research, 2S albumins, from peanut or tree nuts including Ara h 2, Ara h 6, Cor a 14, Jug r 1, Car i 1, Ana o 3, Pis v 1, Ber e 1 and so on, would be divided in groups according the serum IgE recognition. All protein recognized by a same IgE was grouped together, and their specific structure in common (with certain physical and chemical properties) would be found using Swiss-model and molecular dynamics software. Among the common structures, those that were also found in proteins out of this group would be deducted. The remained structures should be those that recognized by serum IgE, namely, possib IgE binding epitopes. The possible epitopes of all IgE could be marked on these allergens when there is..These possible epitopes could be tested by binding interface profiling approach. Using structure-based interface profiles, we can predict the protein-protein binding affinity change, according the mutation on the interface. So if we got the right structure of IgE recognizing and binding, this change would match the result actual measurement, while we performed the actual measurement by biolayer interferometry. Moreover, Hydrogen/deuterium exchange memory NMR can also reveal structural epitopes involved in IgE cross-reactivity, which would also help in testing the role of those common structure. Those structures passed the tests could be regarded as epitopes of allergen..Hopefully, we will develop a new strategy for precise location of allergen epitopes in batch. The new method of epitope location would promote the study on mechanism of food allergy for its physical basis. Localizing the epitopes of 2S albumin would help finding target sites of peanut and tree nut in desensitization processing.