In contrast to fibrinogen or fibrin, peptide and peptide mimetic binding to alpha does not cause outside-in signalling as judged by measurements of phosphatidylinositol 4,5-bisphosphate beta (GPIIb-IIIa) IIb 3

Binding of ligands, including RGD-containing peptides, to the platelet fibrinogen receptor, integrin alphaIIb beta3 has been reported to cause outside-in signals, which result in clustering of occupied receptors and changes in conformation of the receptor and its cytoplasmic tails. Thus, the peptides that are usually used as inhibitors may function as partial agonists. Binding of ligand, fibrinogen or polymerizing fibrin, to platelets with …