Ligand-Binding Assays: Fibrinogen

The fibrinogen receptor on platelets is glycoprotein (GP) IIb/IIIa, also known as α_IIb β₃ . This receptor can bind to immobilized fibrinogen in its resting state. Binding to soluble fibrinogen, however, requires activation of the receptor. This can occur due to inside-out signaling in response to a platelet agonist such as ADP, or directly by agents such as manganese. The interaction between GPIIb/IIIa and fibrinogen is essential in the formation of platelet aggregates (1 ,2 ).