Yu J, Dong S, Rushmere N K, Morgan B P, Abagyan R, Tomlinson S
Department of Pathology, New York University Medical Center, 550 First Avenue, New York, New York 10016, USA.
Biochemistry. 1997 Aug 5;36(31):9423-8. doi: 10.1021/bi970832i.
CD59 is a widely distributed membrane-bound glycoprotein that inhibits the formation of the cytolytic membrane attack complex (MAC) of complement on host cells. CD59 from different species varies in its capacity to inhibit heterologous complement, and this species selective function of CD59 contributes to the phenomenon of homologous restriction. Here, we demonstrate that human CD59 is not an effective inhibitor of rat complement, although rat CD59 inhibits rat and human complement equally well. By constructing human-rat CD59 chimeric proteins, we have mapped the residues important in conferring human CD59 species selectivity to two regions; 40-47 and 47-66 in the primary structure. Analysis of a model of the molecular surface of human CD59 revealed that residues 40-66 mapped to a region in the three-dimensional structure that surrounds residues previously identified as important for CD59 function.
CD59是一种广泛分布的膜结合糖蛋白，可抑制补体在宿主细胞上形成溶细胞性膜攻击复合物（MAC）。来自不同物种的CD59抑制异源补体的能力有所不同，CD59的这种物种选择性功能导致了同源限制现象。在此，我们证明人CD59不是大鼠补体的有效抑制剂，尽管大鼠CD59对大鼠和人补体的抑制效果同样良好。通过构建人-大鼠CD59嵌合蛋白，我们已将赋予人CD59物种选择性的重要残基定位到两个区域；一级结构中的40-47和47-66。对人CD59分子表面模型的分析表明，40-66位残基映射到三维结构中的一个区域，该区域围绕着先前确定对CD59功能重要的残基。
