Ca2+-mediated association of glycoprotein G (thrombinsensitive protein, thrombospondin) with human platelets.

摘要: Washed human platelets suspended in buffers containing either 1.8 mM Ca2+ and 0.49 Mg2+ or 1 EDTA were treated with alpha-thrombin to induce secretion. Glycoprotein G, a major glycoprotein alpha-granules, was quantitatively secreted from activated the EDTA-containing buffer but remained platelet presence of Mg2+. Addition that caused G bind platelets. To determine if is expressed on membrane surface platelet, rapidly labeled by method employing lactoperoxidase-catalyzed iodination. Although barely detected unstimulated platelets, labveling min after thrombin treatment showed became one prominent proteins. These findings show an alpha-granule protein, glycoproteins thrombin-activated its binding dependent divalent cations.