人B细胞系Raji细胞ClqR的特性

Characterization of theClq Receptor on the Human B LymphocyteLine,Raji

应用Ｃｅｌｌ－ＥＬＩＳＡ、ＦＡＣＳ、ＲＢＡ及ＷＢ等技术，对人Ｂ细胞系Ｒａｊｉ细胞ＣｌｑＲ的特性进行了研究。Ｒａｊｉ细胞可结合外源Ｃｌｑ，其与ＦＩＴＣ－ＣｌｑＲ的结合可为过量未标记Ｃｌｑ所阻断。在生理离子强度（Ｉ０，１５）和温度（３７℃）条件下，￣（１２５）Ｉ－Ｃｌｑ与细胞的结合呈特异、剂量依赖、可饱和及可逆性；反应于５０～６０ｍｉｎ达平衡，服从假一级动力学；达平衡时Ｃｌｑ结合位点数／细胞为１．６×１０￣６，Ｋａ值８．５×１０￣６／ｍｏｌ，ｎＨ０．９４７３。Ｒａｊｉ细胞ＣｌｑＲ识别的是Ｃｌｑ的胶原样区。抗人ＣｌｑＲ抗体１１２识别Ｒａｊｉ细胞，与约７０ＫＤ的膜蛋白分子反应。

By means of Cell-ELIsA,FACS,RBA and WB,the Clq receptor(ClqR ) on a human B lym- phocyte line, Raji, was characterized. Raji cells were able to bind exogenous Clq and the binding of FLTC-Clqto the cells was blocked by an excess of unlabelled Clq. Rajicells bound monomeric￣(125)I-Clq in a specific, dos- e-dependent,saturable and reversible manner under physiologic ionic strength(10.15) and temperature(37℃)conditions. Maximum Clq binding was achieved in 50 60minutes and the reaction followed pseudo-first-or-der kinetics. At equilibrium,1.6 ×10￣6molecules of Clq bound per cell with an equilibrium constant(Ka) of 8.5×10￣6/mol and a Hill coefficient(nH)of 0.9473. It was via its collagen-like region that Clq bound to Rajicell receptors;The anti-ClqR antibody 112 recognized a membrane protein of 70KD on Raji cells.