Savage B, Saldívar E, Ruggeri Z M
Roon Research Center for Arteriosclerosis and Thrombosis, Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, La Jolla, California 92037, USA.
Cell. 1996 Jan 26;84(2):289-97. doi: 10.1016/s0092-8674(00)80983-6.
We have identified two distinct mechanisms initiating the adhesion of flowing platelets to thrombogenic surfaces. The intergrin alpha IIb beta 3 promotes immediate arrest onto fibrinogen but is fully efficient only at wall shear rates below 600-900 s-1, perhaps because of a relatively slow rate of bond formation or low resistance to tensile stress. In contrast, glycoprotein Ib alpha binding to immobilized von Willebrand factor (vWF) appears to have fast association and dissociation rates as well as high resistance to tensile stress, supporting slow movement of platelets in continuous contact with the surface even at shear rates in excess of 6000 s-1. This eventually allows activated alpha IIb beta 3 to arrest platelets onto vWF under conditions not permissive of direct binding to fibrinogen. The coupling of these different functions may be crucial for thrombogenesis.
我们已经确定了两种不同的机制来启动流动的血小板与血栓形成表面的粘附。整合素αIIbβ3促进血小板立即黏附到纤维蛋白原上，但仅在壁面剪切速率低于600 - 900 s-1时才完全有效，这可能是由于键形成速率相对较慢或抗张应力较低。相比之下，糖蛋白Ibα与固定化的血管性血友病因子（vWF）结合似乎具有快速的结合和解离速率以及高抗张应力，这支持血小板即使在超过6000 s-1的剪切速率下也能与表面持续接触并缓慢移动。这最终使得活化的αIIbβ3在不允许直接结合纤维蛋白原的条件下将血小板黏附到vWF上。这些不同功能的耦合可能对血栓形成至关重要。
