Peanut allergies are among the most severe food allergies, and several allergenic proteins referred to as Ara h 1-Ara h 17 have been identified from peanut seeds. The molecular characterization of Ara h 1 (63 kDa), a glycosylated allergen, has almost been completed, and the occurrence of two homologous genes (clone 41B and clone P17) has been identified. In this study, we found a new variant of Ara h 1 i.e. 54 kDa, in which the N-terminal amino acid sequence was EGREGEQ-, indicating that the N-terminal domain of 63 kDa Ara h 1 had been removed. This new isoform was obtained from the run-through fraction of hydrophobic interaction chromatography while 63 kDa Ara h 1 was tightly bound to the hydrophobic resins, suggesting that the removal of the N-terminal domain resulted in extreme hydrophilic properties. We found that 63 kDa Ara h 1 occurs as higher order homo-oligomeric conformations such as decamer or nonamer, while 54 kDa Ara h 1 occurs exclusively as a homotrimer, indicating that the N-terminal domain of the 63 kDa molecule may be involved in higher order oligomerization. When antisera from peanut-allergic patients were treated with both the Ara h 1 molecules, the immunoglobulin E (IgE) antibodies in these sera reacted with each Ara h 1 molecule, suggesting that the C-terminal as well as the N-terminal domains of Ara h 1 contribute significantly to the epitope formations of this peanut glycoallergen. Furthermore, the glycoform analyses of N-glycans linked to 63 kDa and 54 kDa Ara h 1 subunits revealed that both typical high-mannose type and β-xylosylated type N-glycans are linked to the molecules. The cross-reactivity of IgE against Ara h 1 in the serum of one peanut allergy patient was completely lost by de-N-glycosylation, indicating the N-glycan of Ara h 1 was the sole epitope for the Ara h 1- specific IgE in the patient.

花生过敏是最严重的食物过敏之一，已从花生种子中鉴定出几种称为 Ara h 1-Ara h 17 的致敏蛋白。糖基化过敏原 Ara h 1 (63 kDa) 的分子表征已基本完成，并且已鉴定出两个同源基因（克隆 41B 和克隆 P17）的出现。在这项研究中，我们发现了 Ara h 1 的新变体，即. 54 kDa，其中N端氨基酸序列为EGREGEQ-，表明63 kDa Arah 1的N端结构域已被去除。这种新的异构体是从疏水相互作用色谱的贯穿部分获得的，而 63 kDa Arah 1 与疏水树脂紧密结合，这表明 N 末端结构域的去除导致了极端的亲水特性。我们发现 63 kDa Arah 1 以高阶同源寡聚体构象出现，例如十聚体或九聚体，而 54 kDa Arah 1 仅作为同源三聚体出现，表明 63 kDa 分子的 N 端结构域可能参与高阶低聚。当来自花生过敏患者的抗血清同时使用 Arah 1 分子进行治疗时，这些血清中的免疫球蛋白 E (IgE) 抗体与每个 Arah 1 分子发生反应，这表明 Arah 1 的 C 端和 N 端结构域对这种花生糖过敏原的表位形成有显着贡献。此外，糖型分析与 63 kDa 和 54 kDa Arah 1 亚基连接的 N-聚糖表明典型的高甘露糖型和 β-木糖基化型N-聚糖均与分子连接。一名花生过敏患者血清中IgE与Ara h 1的交叉反应因去-N-糖基化而完全丧失，表明Ara h 1的N-聚糖是Ara h 1-特异性IgE的唯一表位。患者。