Nimpf J, Wurm H, Kostner G M
Thromb Haemost. 1985 Aug 30;54(2):397-401.
The interaction of beta 2-glycoprotein-I (beta 2-G-I), a plasma constituent of unknown function, with blood platelets was studied. The following results were obtained: 1) beta 2-G-I binds to washed human platelets isolated by centrifugation (WP) at one kind of specific, saturable binding sites. The dissociation constant was found to be approx. 1 X 10(-6) M. In the presence of physiological concentrations of Ca++ (2.5 mM), this specific binding is markedly reduced. Unspecific binding of beta 2-G-I to platelets, however, is not influenced by Ca++. Platelets prepared by gel filtration (GFP), differing in their in vitro aggregability from WP, exhibit no specific binding of beta 2-G-I. Binding to GFP is also not induced by activation with thrombin, collagen or ADP. beta 2-G-I causes significant alteration of the ADP-induced aggregation of GFP. Aggregation induced by thrombin, collagen, arachidonic acid or PAF-acether, however is not altered by beta 2-G-I. It is suggested, that pelleting during centrifugation causes irreversible rearrangements in the membrane of platelets.
研究了功能未知的血浆成分β2-糖蛋白I（β2-G-I）与血小板的相互作用。得到了以下结果：1）β2-G-I在一种特异性、可饱和的结合位点与通过离心分离的洗涤人血小板（WP）结合。发现解离常数约为1×10^(-6)M。在生理浓度的Ca++（2.5 mM）存在下，这种特异性结合明显减少。然而，β2-G-I与血小板的非特异性结合不受Ca++的影响。通过凝胶过滤制备的血小板（GFP），其体外聚集性与WP不同，不表现出β2-G-I的特异性结合。用凝血酶、胶原蛋白或ADP激活也不会诱导与GFP的结合。β2-G-I会显著改变GFP的ADP诱导聚集。然而，凝血酶、胶原蛋白、花生四烯酸或血小板活化因子诱导的聚集不受β2-G-I的影响。有人认为，离心过程中的沉淀会导致血小板膜发生不可逆的重排。
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