The membrane attack mechanism of complement. Verification of a stable C5-9 complex in free solution.
The membrane attack mechanism of complement. Verification of a stable C5-9 complex in free solution.
复制标题
补体的膜攻击机制。在自由溶液中验证稳定的C5-9复合物。
DOI：
10.1084/jem.138.2.438
复制
发表时间：
1973-08-01
影响因子：
15.3
通讯作者：
Muller-Eberhard, H J
中科院分区：
文献类型：
--
作者：
Kolb, W P;Muller-Eberhard, H J
补体C5至C9的膜攻击机制先前已被假定为在靶细胞表面上与计算的摩尔重量为995，000的稳定十分子复合物缔合。现已证明，由C5、C6、C7、C8和C9组成的可溶性和稳定的复合物是通过经典或替代途径激活补体的结果。其沉降系数为22.5S，分子量为100万道尔顿，在pH 8.6时作为α-球蛋白电泳迁移。稳定且可溶的C5 b-9复合物不能与红细胞结合，并且没有明显的细胞溶解活性。然而，由于C9的部分不饱和结合位点，它可以结合额外的C9，从而作为C9裂解EAC 1 -8的抑制剂。这些结果支持了补体的膜结合攻击系统代表C5 b-9的稳定的十分子组装的概念。与游离溶液中的类似物不同，膜结合复合物具有细胞溶解活性。
The membrane attack mechanism of complement, C5 to C9, has previously been postulated to associate on the target cell surface to a stable decamolecular complex with a calculated mol wt of 995,000. A soluble and stable complex consisting of C5, C6, C7, C8, and C9 has now been demonstrated to arise as a consequence of complement activation by the classical or alternate pathway. It has a sedimentation coefficient of 22.5S and a mol wt of 1 million daltons, and it migrates on electrophoresis at pH 8.6 as an α-globulin. The stable and soluble C5b-9 complex cannot bind to erythrocytes and has no demonstrable cytolytic activity. However, due to partially unsaturated binding sites for C9, it can bind additional C9 and thus function as an inhibitor of lysis of EAC1-8 by C9. These results support the concept according to which the membrane-bound attack system of complement represents a stable, decamolecular assembly of C5b-9. Unlike its analogue in free solution, the membrane-bound complex is cytolytically active.