人FcεRIα亚基细胞外区的原核表达及其和IgE结合的机制

Procaryotic expression of human FceR I a subunit extracellular domain and its binding mechanism with IgE

应用两种不同的表达系统对FceR I α亚基的细胞外区进行克隆和表达,表达产物经纯化后用免疫斑点杂交法检测其与IgE结合的能力,探索IgE与其高亲和力受体FceR I α亚基的细胞外区结合的机制。结果两种体系均成功表达出FceRI α亚基的细胞外区,pBAD/gⅢA表达的FceR I α亚基的细胞外区能与IgE结合,而PQE30表达的FeaR I α亚基的细胞外区不能与IgE结合。提示FccR I α亚基的细胞外区已足够和IgE结合,无需β、γ亚基的存在,其所具有的一定的空间构型和二硫键的形成在与IgE结合时是必需的,而糖基化位点在与IgE的结合时是非必需的。

Human FceR I a subunit extracellular domain was cloned and expressed with 2 different expressing systems and Dot blot was used to detect its biological activity to bind with IgE,providing reference for binding mechanism of human FceR I a subunit extracellular domain with IgE. It was shown that FceR I a subunit extracellular domain from pBAD/g I A expressing system could bind with IgE, but the one from PQE30 expressing system could not bind with IgE. It is suggested that FceR I a subunit extracellular domain alone is sufficient to bind with IgE without P and Y subunit. The proper space configuration and disulfide bond of FceR I a subunit is necessary for binding with IgE, but its glycosylation is unnecessary.