Young J D, Rosse W F, Hasselkus-Light C S
Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, N.Y. 10021.
Biochem Biophys Res Commun. 1990 Jan 30;166(2):648-52. doi: 10.1016/0006-291x(90)90858-k.
The 65 kDa C8-binding protein or homologous restriction factor (C8bp/HRF) protects cells from complement (C)-mediated lysis by binding to C8 and abrogating lytic channel formation. Human C8bp/HRF is shown here to be immunologically related to human C8 and C9 and to murine lymphocyte poreforming protein (PFP, perforin). Polyclonal antibodies raised against purified C8, C9 and perforin react with C8bp/HRF. The antigenic epitopes shared by these four proteins are limited to cysteine-rich or disultide bridge-masked domains. Only complement proteins or perforin that have been disulfide-reduced elicit the production of cross-reactive antibodies when used as immunogens. Analogously, only C8bp/HRF that has been disulfide-reduced reacts with these antibodies. These results suggest that C8bp/HRF may belong to the complement/perforin supergene family. The function of homologous domains shared by these four proteins remains to be elucidated.
65 kDa C8结合蛋白或同源限制因子（C8bp/HRF）通过与C8结合并消除溶细胞通道的形成，保护细胞免受补体（C）介导的溶解。本文显示，人C8bp/HRF在免疫上与人C8和C9以及小鼠淋巴细胞穿孔素（PFP，穿孔素）相关。针对纯化的C8、C9和穿孔素产生的多克隆抗体与C8bp/HRF发生反应。这四种蛋白质共有的抗原表位仅限于富含半胱氨酸或二硫键掩盖的结构域。只有经过二硫键还原的补体蛋白或穿孔素用作免疫原时，才会引发交叉反应性抗体的产生。类似地，只有经过二硫键还原的C8bp/HRF才会与这些抗体发生反应。这些结果表明，C8bp/HRF可能属于补体/穿孔素超基因家族。这四种蛋白质共有的同源结构域的功能仍有待阐明。
