Structural properties of the glycoplasmanylinositol anchor phospholipid of the complement membrane attack complex inhibitor CD59.
Structural properties of the glycoplasmanylinositol anchor phospholipid of the complement membrane attack complex inhibitor CD59.
复制标题
补体膜攻击复合物抑制剂 CD59 的糖原肌醇锚定磷脂的结构特性。
DOI：
10.1111/j.1365-2249.1992.tb03012.x
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发表时间：
1992
影响因子：
4.6
通讯作者：
Medof,ME
中科院分区：
文献类型：
--
作者：
Ratnoff,WD;Knez,JJ;Prince,GM;Okada,H;Lachmann,PJ;Medof,ME
CD 59是aulidine C5 b-9通道形成的膜调节因子，对磷脂酰肌醇特异性磷脂酶C（PI-PLC）的切割表现出可变的敏感性，PI-PLC是一种从细胞表面释放糖肌醇磷脂（GPI）锚定蛋白的酶。为了确定CD 59的GPI锚定磷脂是否与衰变加速因子（decay-accelerating factor，DIF）的GPI锚定磷脂相似，以及其结构的变化是否是其可变酶敏感性的基础，在纯化后原位比较了红细胞、多形核细胞和单核白细胞上表达的两种蛋白的GPI锚定。PI-PLC处理的细胞的流式细胞术分析显示，作为酶浓度的函数，两种蛋白质的平行细胞类型特异性释放。碱/羟胺处理的蛋白质（从[125 I]-表面标记的细胞中亲和纯化）的非变性PAGE分析提供了以下证据：（i）GPI锚定酰化的比例相当，和（ii）红细胞中的碱抗性而不是碱敏感性脂质取代基。这些研究结果表明，区别阵发性睡眠性血红蛋白尿症II型和III型红细胞的差异C5 b-9敏感性并不来自具有替代GPI锚定磷脂结构的CD 59分子的表达。
CD59, the membrane regulator of aulologous C5b-9 channel formation, exhibits variable sensitivity to cleavage by phosphatidylinositol-specific phospholipase C (PI-PLC), an enzyme that releases glyco-inositolphospholipid (GPI)-anchored proteins from cell surfaces. To determine whether the GPI-anchor phospholipid of CD59 is similar to that of decay-accelerating factor (DAF) and whether variation in its structure underlies its variable enzyme susceptibility, the GPI anchors of the two proteins expressed on erythrocytes, polymorphonuclear and mononuclear leucocytes were comparedin situand after purification. Flow cytometric analyses of PI-PLC-treated cells showed parallel cell type specific release of both proteins as a function of enzyme concentration. Non-denaturing PAGE analyses of alkaline/hydroxylamine-treated proteins (affinity-purified from [125I]-surface-labelled cells) provided evidence for (i) comparable proportions of GPI-anchor acylation, and (ii) alkali-resistant rather than alkali-sensitive lipid substituents in erythrocytes. These findings argue that the differential C5b-9 sensitivity that distinguishes paroxysmal nocturnal haemoglobinuria II and III erythrocytes does not derive from expression of CD59 molecules with alternative GPI-anchor phospholipid structures.