Reconstruction of platelet proteins into phospholipid vesicles. Functional proteoliposomes.

Platelet membrane glycoproteins IIb and IIIa were reconstituted into liposomes containing phosphatidylcholine. The reconstituted vesicles bound antiplatelet antibodies and showed specific binding to thrombin-activated platelets. Prostacyclin, a known inhibitor of thrombin-activated platelet aggregation, inhibited the binding of the proteoliposomes to thrombin-activated platelets. The reconstituted vesicles also specifically bound 125I-labeled fibrinogen. This binding was insensitive to ADP but dependent on calcium ions. These data indicate that platelet glycoproteins IIb and IIIa have been successfully reconstituted into phospholipid vesicles such that their behavior is similar to that in intact platelets.