Stuart G R, Lynch N J, Lu J, Geick A, Moffatt B E, Sim R B, Schwaeble W J
MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, UK.
FEBS Lett. 1996 Nov 18;397(2-3):245-9. doi: 10.1016/s0014-5793(96)01156-8.
C1q receptor (C1qR/collectin receptor) is located on many cell types. Binding of C1q to these cells elicits numerous responses. Protein sequencing has shown that C1qR is almost identical to calreticulin (CaR), an abundant multifunctional protein. Radioiodinated C1qR and CaR bind to C1q with identical characteristics. Three recombinant C1qR/CaR domains (N-, C-terminal domains and central P-domain) were expressed using the Thiofusion system, and used to study the interaction with C1q. Both the N- and P-domains were implicated in C1q binding. A region, termed the S-domain, spanning the N and P intersection was expressed, and showed concentration-dependent binding to C1q, demonstrating that the C1q binding site lies within this region.
C1q受体（C1qR/凝集素受体）存在于多种细胞类型上。C1q与这些细胞的结合引发众多反应。蛋白质测序表明，C1qR与钙网蛋白（CaR）几乎相同，钙网蛋白是一种丰富的多功能蛋白质。放射性碘化的C1qR和CaR以相同的特性与C1q结合。使用硫醇融合系统表达了三个重组C1qR/CaR结构域（N端结构域、C端结构域和中央P结构域），并用于研究与C1q的相互作用。N结构域和P结构域均参与C1q结合。表达了一个跨越N和P交界处的区域，称为S结构域，该区域显示出与C1q的浓度依赖性结合，表明C1q结合位点位于该区域内。
