Abstract: The disclosure concerns a synthetic conjugate, methods of constructing this conjugate, and methods of using a conjugate of this type to replace naturally occurring proteins or inhibiting the reaction between a naturally occurring protein and a defined site of biological activity in a vertebrate.

Abstract: A method of inhibiting von Willebrand factor binding to human platelets induced with thrombin, ADP, or other stimuli has been developed. The administration of the small molecular weight peptide or the synthetic inhibitory molecule of the invention significantly inhibits thrombin or ADP-modified human platelets binding of von Willebrand factor, a plasma protein necessary for platelet interaction with blood vessels. The method of the invention is useful for inhibiting the formation of hemostatic platelet plugs and the initiation of thrombotic lesions. The blockage caused by hemostatic platelet plugs and the damage caused by thrombotic lesions are major factors in heart disease and stroke. The invention also includes a method of inducing the interaction of platelets with blood vessels by administration of a synthetic platelet reactive molecule.

Abstract: A method of inhibiting thrombin or ADP-induced human platelet aggregation by fibrinogen has been developed. The administration of the small molecular weight peptide or the synthetic inhibitory molecule of the invention significantly inhibits thrombin or ADP-modified human platelets binding of fibrinogen, a plasma protein necessary for platelet aggregation. The method of the invention is useful for inhibiting of the formation of hemostatic platelet plugs and of the initiation of thrombotic lesions. The blockage caused by hemostatic platelet plugs and the damage caused by thrombotic lesions are major factors in heart disease and stroke. The invention also includes a method of inducing the formation of thrombin or ADP-modified platelet aggregates by administration of a synthetic aggregating molecule which represents a functional substitute for fibrinogen.