C5b-9 dimer: isolation from complement lysed cells and ultrastructural identification with complement-dependent membrane lesions.
C5b-9 dimer: isolation from complement lysed cells and ultrastructural identification with complement-dependent membrane lesions.
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DOI：
10.1084/jem.149.2.448
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发表时间：
1979-02-01
期刊：
影响因子：
--
通讯作者：
Müller-Eberhard HJ
中科院分区：
文献类型：
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作者：
Biesecker G;Podack ER;Halverson CA;Müller-Eberhard HJ
从人补体裂解的细胞膜中提取补体的膜攻击复合物（MAC），并将其性质与液相复合物SC_（5 b-9）进行比较。十二烷基硫酸钠聚丙烯酰胺凝胶电泳和免疫化学分析，两个分离的复合物具有相同的亚基组成，除了MAC缺乏S-蛋白。提取和分离的MAC的沉降系数和分子量分别为33.5 S和1.7 x 10（6）道尔顿，而SC 5 b-9的沉降系数和分子量分别为23 S和1.0 x 10（6）道尔顿。由于MAC的分子量大约是C5 b-0的两倍（800，000道尔顿），因此MAC被认为是C5 b- 9的二聚体。在特定的条件下，33.5 S二聚体可以转化为23 S单体而不解离亚基。MAC具有补体产生的超微结构膜损伤的特征性电子显微镜外观和尺寸。SC 5 b-9具有与病变形态不同的不同超微结构。分离的MAC可以重新纳入磷脂双分子层，并假定在所得的脂质囊泡的表面上的典型的补体病变的方向和外观。
The membrane attack complex (MAC) of complement was extracted from the membranes of cells lysed by human complement and its properties were compared with those of the fluid phase complex SC5b-9. Upon sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunochemical analysis, the two isolated complexes had identical subunit compositions, except that the MAC lacked the S-protein. The sedimentation coefficient and molecular weight of the extracted and isolated MAC were, respectively, 33.5 S and 1.7 x 10(6) daltons, compared to 23 S and 1.0 x 10(6) dalton for SC5b-9. Because the molecular weight of the MAC is approximately two times greater than that of C5b-0 (800,000 daltons), the MAC is considered the dimer of C5b- 9. Under specified conditions, the 33.5 S dimer could be converted to the 23 S monomer without dissociation of subunits. The MAC had the electron microscopic appearance and dimensions that are characteristic for the complement produced ultrastructural membrane lesions. SC5b-9 had a different ultrastructure that is dissimilar to the morphology of the lesions. The isolated MAC could be reincorporated into phospholipid bilayers and assumed on the surface of the resultant lipid vesicles the orientation and appearance of typical complement lesions.