Stricker R B, Reyes P T, Corash L, Shuman M A
J Clin Invest. 1987 Jun;79(6):1589-94. doi: 10.1172/JCI112993.
We previously identified a 210,000-mol-wt platelet glycoprotein (GP 210) that is missing from Bernard-Soulier platelets, and found that an antibody against GP 210 inhibits ristocetin-induced platelet agglutination. We now show by immunoblotting that GP 210 binds heat-aggregated rabbit and human IgG, as well as keyhole limpet hemocyanin (KLH)-anti-KLH and ovalbumin (OA)-anti-OA immune complexes. Immune complex binding to GP 210 was preserved on chymotrypsin-treated platelets that lacked glycoprotein Ib (GP Ib). In contrast, ristocetin-induced platelet agglutination resulted in disappearance of immunologically detectable GP 210 and loss of immune complex binding, even though GP Ib remained intact. Purified Fc fragments inhibited binding of anti-GP 210 antibody to intact platelets and to GP 210 on immunoblots. The Fc fragments also blocked immune complex binding to GP 210. Conversely, anti-GP 210 antiserum and F(ab)2 fragments inhibited binding of fluorescein-labeled Fc fragments to intact platelets. We conclude that GP 210 functions as a platelet Fc receptor.
我们之前鉴定出一种210,000道尔顿分子量的血小板糖蛋白（GP 210），伯纳德-索利尔血小板中缺失该蛋白，并且发现抗GP 210抗体可抑制瑞斯托霉素诱导的血小板凝集。我们现在通过免疫印迹法表明，GP 210可结合热聚集的兔和人IgG，以及钥孔戚血蓝蛋白（KLH）-抗KLH和卵清蛋白（OA）-抗OA免疫复合物。在缺乏糖蛋白Ib（GP Ib）的经胰凝乳蛋白酶处理的血小板上，免疫复合物与GP 210的结合得以保留。相比之下，瑞斯托霉素诱导的血小板凝集导致免疫可检测的GP 210消失以及免疫复合物结合丧失，即便GP Ib保持完整。纯化的Fc片段可抑制抗GP 210抗体与完整血小板以及免疫印迹上GP 210的结合。Fc片段还可阻断免疫复合物与GP 210的结合。相反，抗GP 210抗血清和F(ab)2片段可抑制荧光素标记的Fc片段与完整血小板的结合。我们得出结论，GP 210作为血小板Fc受体发挥作用。
