Gogstad G O, Hagen I, Korsmo R, Solum N O
Biochim Biophys Acta. 1982 Mar 18;702(1):81-9. doi: 10.1016/0167-4838(82)90029-2.
Proteins released from stimulated platelets were compared to those of a well-defined preparation of alpha-granules and the soluble cytoplasm by crossed immunoelectrophoresis. Nearly all releasable proteins were detected in the alpha-granule, whereas the true proteins of the soluble cytoplasm were not released. The released glycoproteins interacted with lectins similarly to their alpha-granula-located counterparts. The alpha-granules were divided into soluble contents and membranes by ultrasonication followed by ultracentrifugation. The proteins of the soluble content corresponded to those released from the stimulated platelets. This observation was also supported by SDS-polyacrylamide gel electrophoresis. The results indicate that the bulk of the proteins released from stimulated platelets originate from the soluble content of the alpha-granules. Two major alpha-granule antigens as well as the myosin heavy chain were not released and recovered in the alpha-granule membrane. These results support the hypothetical exocytosis mechanism for the release of alpha-granule proteins from platelets.
通过交叉免疫电泳，将刺激血小板释放的蛋白质与明确界定的α-颗粒制剂和可溶性细胞质的蛋白质进行比较。几乎所有可释放的蛋白质都在α-颗粒中被检测到，而可溶性细胞质的真正蛋白质并未释放。释放的糖蛋白与凝集素的相互作用与其位于α-颗粒中的对应物相似。通过超声处理然后超速离心，将α-颗粒分为可溶性内容物和膜。可溶性内容物的蛋白质与刺激血小板释放的蛋白质相对应。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳也支持了这一观察结果。结果表明，刺激血小板释放的大部分蛋白质源自α-颗粒的可溶性内容物。两种主要的α-颗粒抗原以及肌球蛋白重链未释放，并在α-颗粒膜中回收。这些结果支持了血小板释放α-颗粒蛋白的假设性胞吐机制。
