PURIFICATION AND CHARACTERIZATION OF THE HUMAN PLATELET FIBRINOGEN RECEPTOR, GpIIb/IIIa COMPLEX

Platelet GpIIb/IIIa is a member of the integrin family of structurally related adhesion receptors, and adhesive proteins, such as fibrinogen. Ligand binding requires platelet activation by an agonist to convert the receptor to a state where it is capable to bind the ligand. In addition to this a modification, induction of the surface expression and ligand-binding function of an additional pool of GpIIb/ IIIa derived from α-granuler membranes and/or surface-connecting open canalicular system are established. Fibrinogen binding to platelets appears to be important for platelet aggregation. Platelet aggregation is essential for normal hemostasis and also plays a role in thrombosis. In this study, we purified GpIIb/IIIa on a single step from normal human platelets by GRGDSPaffinity chromatography. In addition, studies on the characterization of the binding properties to GIIb/ IIIa of the specific ligands were carried out with the purified GpIIb/IIIa complex.