Barre Annick, Borges Jean-Philippe, Rougé Pierre
Surfaces Cellulaires et Signalisation chez les Végétaux, UMR-CNRS 5546, Pôle de Biotechnologie végétale, 24, chemin de Borde Rouge, 31326 Castanet-Tolosan, France.
Biochimie. 2005 Jun;87(6):499-506. doi: 10.1016/j.biochi.2005.02.011. Epub 2005 Apr 2.
Three-dimensional models of the major vicilin allergens from peanut (Ara h 1), lentil (Len c 1) and pea (Pis s 1), were built by homology-based modelling from the X-ray coordinates of the structurally closely related soybean beta-conglycinin. All the allergen monomers exhibit the typical cupin motif made of two modules related by a pseudo-dyad axis. Each module consists of a beta-barrel core domain associated to a loop domain which mainly contains alpha-helices. The three cupin motifs are assumed to be arranged in a homotrimeric structure similar to that observed in beta-conglycinin, phaseolin or canavalin. Most of the sequential B-cell epitopes characterized on the C-terminus of the Ara h 1 allergen are well conserved in both Len c 1 and Pis s 1 allergens. They occupy very comparable areas on the molecular surface of the allergens and exhibit a similar three-dimensional conformation. This antigenic community readily accounts for the IgE-binding cross-reactivity commonly observed between the vicilin allergens from edible legume seeds. The clinical implication of this cross-reactivity is addressed for a definite diagnosis of legume seed allergy.
利用结构密切相关的大豆β-伴大豆球蛋白的X射线坐标，通过基于同源性的建模构建了花生（Ara h 1）、小扁豆（Len c 1）和豌豆（Pis s 1）中主要豌豆球蛋白过敏原的三维模型。所有过敏原单体均呈现出典型的“铜蛋白”基序，该基序由通过伪二元轴相关的两个模块组成。每个模块由一个与主要包含α-螺旋的环结构域相关的β-桶状核心结构域组成。假定这三个“铜蛋白”基序以类似于在β-伴大豆球蛋白、菜豆蛋白或刀豆球蛋白中观察到的同三聚体结构排列。在Ara h 1过敏原C端鉴定的大多数连续B细胞表位在Len c 1和Pis s 1过敏原中都高度保守。它们在过敏原分子表面占据非常相似的区域，并呈现出相似的三维构象。这种抗原共性很容易解释可食用豆类种子中豌豆球蛋白过敏原之间常见的IgE结合交叉反应性。这种交叉反应性的临床意义在豆类种子过敏的明确诊断中得到探讨。
