Jin Tengchuan, Guo Feng, Chen Yu-Wei, Howard Andrew, Zhang Yu-Zhu
Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616, United States.
Mol Immunol. 2009 May;46(8-9):1796-804. doi: 10.1016/j.molimm.2009.01.023. Epub 2009 Feb 28.
The prevalence of food allergy has increased dramatically in recent years. Tremendous research progress has been made in understanding the pathophysiological mechanisms of allergy and in identifying and characterizing food allergens. Peanut is a major food allergen source and Ara h 3 is a major peanut allergen. Using overlapping short peptides, several linear IgE-binding epitopes in Ara h 3 have been defined before. However, the structure of Ara h 3 of the native allergen is not clear and information on conformational epitopes is lacking. Structural characterization of allergens is required for understanding the allergenicity of food allergens and for the development of immunotherapeutic agents. Previously, we have reported the crystallization of Ara h 3 purified from raw peanut. Here we report the crystal structure of Ara h 3 at 1.73A resolution. Mapping of the previously defined linear epitopes on the crystal structure of Ara h 3 indicated that linear epitopes with more solvent exposure were those indicated by the literature to react with more patient sera. The structure of Ara h 3 may be used to assess the importance of conformational epitopes in further investigations.
近年来，食物过敏的患病率急剧上升。在了解过敏的病理生理机制以及鉴定和表征食物过敏原方面已经取得了巨大的研究进展。花生是主要的食物过敏原来源，而Ara h 3是主要的花生过敏原。此前已通过重叠短肽确定了Ara h 3中的几个线性IgE结合表位。然而，天然过敏原Ara h 3的结构尚不清楚，且缺乏关于构象表位的信息。了解食物过敏原的致敏性以及开发免疫治疗药物需要对过敏原进行结构表征。此前，我们报道了从生花生中纯化的Ara h 3的结晶情况。在此，我们报告了Ara h 3在1.73埃分辨率下的晶体结构。将先前确定的线性表位映射到Ara h 3的晶体结构上表明，溶剂暴露更多的线性表位与文献中显示的能与更多患者血清发生反应的表位一致。Ara h 3的结构可用于在进一步研究中评估构象表位的重要性。
