人表皮生长因子受体在大肠杆菌菌膜上功能性表达

Functional Expression of Human Epidermal Growth Factor Receptor (EGF-R) in Membrane of E.coli.

为将人表皮生长因子 (EGF)受体膜外第Ⅲ功能区 (hEGF RⅢ )表达于大肠杆菌菌膜上 ,重组构建了EGF RⅢ表达载体 ,并转化获得大肠杆菌表达株 .放射性受体分析发现12 5I EGF可与表达菌特异性结合 ,其特异性结合量随反应的时间和温度而变化 ,Scatchard分析显示表达菌表达单一亲和性受体 ,其解离常数为 3 0× 1 0 - 11mol/L ,每个细菌约有 738个结合位点 .免疫电镜显示EGF

An E.coli strain which could express domain Ⅲ of the extracellular region of the human EGF R(EGF RⅢ) in its membrane had been obtained. The results of EGF receptor radiobinding assay showed that 125 I EGF could bind specifically to the intact bacterial body, the amount of specific binding varied with the time and temperature of the reaction. The data of Scatchard analysis indicated that the number of the human EGF RⅢ expressed in the bacteria was about 738 sites/cell, and its dissociation constant was about 3 0×10 -11 mol/L. The sites of the bacteria to which EGF bound were discovered mainly on its membrane by immunoelectronmicroscopy .