Plow E F, McEver R P, Coller B S, Woods V L, Marguerie G A, Ginsberg M H
Blood. 1985 Sep;66(3):724-7.
Fibrinogen, fibronectin, von Willebrand factor, and thrombospondin are four large glycoproteins that bind to thrombin-stimulated platelets and influence cellular adhesive functions. The effects of five monoclonal antibodies that react with platelet membrane glycoproteins (GP) IIb and/or IIIa on the binding of these four molecules to stimulated platelets were assessed. Tab and PMI-1, antibodies recognizing GPIIb, had no effect, whereas 10E5 and 2G12, antibodies that immunoprecipitate both GPIIb and IIIa in the presence of calcium, inhibited binding of all four ligands by greater than 85%. T10, an antibody specific for the GPIIb-IIIa complex, produced partial inhibition (60% to 80%) of the binding of each ligand. Inhibitory antibodies were effective in the same dose range for all four proteins and also inhibited binding of fibrinogen, fibronectin, and von Willebrand factor to receptors fixed in an induced state (thrombin-stimulated platelets fixed with paraformaldehyde). Thrombospondin did not bind to these fixed cell preparations. The results suggest that these four adhesive proteins have a related mechanism of binding to thrombin-stimulated platelets. This related mechanism may entail the sharing of some, but not necessarily all, binding sites for the four ligands or a proximal relationship between these binding sites.
纤维蛋白原、纤连蛋白、血管性血友病因子和血小板反应蛋白是四种大型糖蛋白，它们可与凝血酶刺激的血小板结合并影响细胞黏附功能。评估了五种与血小板膜糖蛋白（GP）IIb和/或IIIa反应的单克隆抗体对这四种分子与刺激血小板结合的影响。识别GPIIb的抗体Tab和PMI-1没有作用，而10E5和2G12这两种在有钙存在时能免疫沉淀GPIIb和IIIa的抗体，可抑制所有四种配体的结合，抑制率超过85%。T10是一种对GPIIb-IIIa复合物具有特异性的抗体，对每种配体的结合产生部分抑制（60%至80%）。抑制性抗体对所有四种蛋白质在相同剂量范围内均有效，并且还抑制纤维蛋白原、纤连蛋白和血管性血友病因子与以诱导状态固定的受体（用多聚甲醛固定的凝血酶刺激血小板）的结合。血小板反应蛋白不与这些固定的细胞制剂结合。结果表明，这四种黏附蛋白与凝血酶刺激的血小板结合具有相关机制。这种相关机制可能需要这四种配体共享一些但不一定是全部的结合位点，或者这些结合位点之间存在近端关系。
