兔C4b结合蛋白α链的cDNA结构。与C4b结合的补体调节蛋白模块中保守的序列基序。

cDNA structure of rabbit C4b-binding protein alpha-chain. Preserved sequence motive in complement regulatory protein modules which bind C4b.

作者信息

García de Frutos P, Dahlbäck B

机构信息

Department of Clinical Chemistry, University of Lund, Malmö General Hospital, Sweden.

出版信息

Biochim Biophys Acta. 1995 Apr 4;1261(2):285-9. doi: 10.1016/0167-4781(95)00019-d.

DOI:10.1016/0167-4781(95)00019-d

PMID:7711074

Abstract

A full length cDNA clone for the alpha-chain of the rabbit complement regulatory protein C4b-binding protein (C4BP) was isolated from a liver cDNA library. The clone encoded an open reading frame of 597 amino acids, which included a signal peptide, eight short consensus repeats (SCR) and a carboxy terminal non-repeat region. Gel filtration of rabbit plasma and testing of fractions for factor I cofactor activity (C4BP-like) revealed two peaks of activity, the one with highest molecular weight corresponding in size to that of human C4b-binding protein. Comparison of the rabbit C4BP alpha-chain sequence with other SCR containing C3b/C4b binding proteins revealed highest sequence similarities between the second SCRs in C4BP from rabbit, human and murine species and SCRs at corresponding position in complement receptor 1 (CR1) whereas in decay accelerating factor (DAF), the third SCR was most similar. A conserved sequence motive was identified in these C4b-binding SCRs.

摘要

从兔肝脏cDNA文库中分离出兔补体调节蛋白C4b结合蛋白（C4BP）α链的全长cDNA克隆。该克隆编码一个597个氨基酸的开放阅读框，其中包括一个信号肽、八个短共有重复序列（SCR）和一个羧基末端非重复区域。对兔血浆进行凝胶过滤并检测各组分的I因子辅因子活性（类C4BP），结果显示有两个活性峰，分子量最高的那个峰的大小与人C4b结合蛋白的大小相对应。将兔C4BPα链序列与其他含有C3b/C4b结合蛋白的SCR进行比较，结果显示兔、人和鼠类物种C4BP中第二个SCR与补体受体1（CR1）相应位置的SCR之间的序列相似性最高，而在衰变加速因子（DAF）中，第三个SCR最为相似。在这些C4b结合SCR中鉴定出一个保守的序列基序。