Physiologic relevance of the membrane attack complex inhibitory protein CD59 in human seminal plasma: CD59 is present on extracellular organelles (prostasomes), binds cell membranes, and inhibits complement-mediated lysis.
Physiologic relevance of the membrane attack complex inhibitory protein CD59 in human seminal plasma: CD59 is present on extracellular organelles (prostasomes), binds cell membranes, and inhibits complement-mediated lysis.
复制标题
膜攻击复合物抑制性蛋白CD59在人类精液血浆中的生理相关性：CD59存在于细胞外细胞器（前列腺素）上，结合细胞膜，并抑制补体介导的裂解。
DOI：
10.1084/jem.177.5.1409
复制
发表时间：
1993-05-01
影响因子：
15.3
通讯作者：
Morgan, B P
中科院分区：
文献类型：
--
作者：
Rooney, I A;Atkinson, J P;Krul, E S;Schonfeld, G;Polakoski, K;Saffitz, J E;Morgan, B P
我们在这里证明了CD59，一种补体系统的膜攻击复合物（MAC）抑制剂，以至少20微克/毫升的浓度存在于无细胞精浆（SP）中。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、Western blotting和Edman降解分析表明，该蛋白SP CD59与从红细胞(E)膜中分离的CD59 （E CD59）相似，如果不是完全相同的话。与纯化的E - CD59一样，SP - CD59也具有糖基磷脂酰肌醇（GPI）锚点，并结合到异源细胞的膜上，抑制人MAC的裂解。这种现象不仅可以用纯化的SP - CD59孵育细胞，也可以用未分离的SP孵育细胞。此外，未分离SP中的CD59与洗涤后的精子结合，增加了其膜上蛋白质的含量。这种蛋白在明显存在于液相时保持其GPI锚点的机制引起了人们的兴趣，并被进一步研究。利用高速离心、高效液相色谱和电镜技术，我们发现所有可检测到的SP CD59都与囊泡胞外细胞器有关。这些细胞器被命名为“前列腺体”，先前已知存在于SP中，并与精子相互作用，尽管它们的功能尚不确定。异源E与前列腺小体的相互作用使细胞更能抵抗人mac的溶解。我们认为这些细胞器代表了一个CD59库，精子中丢失的蛋白质（可能是由于低水平的补体攻击或正常的膜周转）可以从这个库中得到补充。
We demonstrate here that CD59, an inhibitor of the membrane attack complex (MAC) of the complement system, is present in cell-free seminal plasma (SP) at a concentration of at least 20 micrograms/ml. Analyses by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and Edman degradation indicated that this protein, SP CD59, was similar, if not identical, to CD59 isolated from erythrocyte (E) membranes (E CD59). Like purified E CD59, SP CD59 also possesses a glycosyl phosphatidyl inositol (GPI) anchor and incorporates into the membranes of heterologous cells where it inhibits lysis by the human MAC. This phenomenon could be demonstrated not only if cells were incubated with purified SP CD59 but also if unfractionated SP were used. Further, CD59 in unfractionated SP bound to washed spermatozoa, increasing their membrane content of the protein. The mechanism by which this protein retains its GPI anchor while apparently present in the fluid phase is of interest and was further investigated. Using the techniques of high-speed centrifugation, fast performance liquid chromatography fractionation, and electron microscopy, we found that all detectable SP CD59 was associated with vesicular extracellular organelles. These organelles, named "prostasomes," were previously known to be present in SP and to interact with spermatozoa, although their function was uncertain. Interaction of heterologous E with prostasomes rendered the cells more resistant to lysis by human MACs. We propose that these organelles represent a pool of CD59 from which protein lost from spermatozoa, perhaps as a result of low level complement attack or of normal membrane turnover, can be replenished.