Integrin alpha-IIb beta-3 (αIIbβ3)

Integrin alpha-IIb beta-3, commonly referred to as glycoprotein IIb/IIIa, is a heterodimeric transmembrane receptor expressed exclusively on the surface of platelets and megakaryocytes (UniProt P08514, P05106). It serves as the final common pathway for platelet aggregation by undergoing a conformational change upon platelet activation, which allows it to bind bivalent ligands such as fibrinogen and von Willebrand factor (StatPearls, 2023). This binding facilitates the cross-linking of adjacent platelets, leading to the formation of a stable thrombus. While essential for normal hemostasis, overactivation of this receptor is a key driver of arterial thrombosis, contributing to conditions like myocardial infarction and unstable angina (PubMed, PMID: 11091651). Therapeutic agents targeting this integrin, such as abciximab and tirofiban, are used in acute clinical settings to prevent ischemic events during coronary interventions. However, the use of these inhibitors is limited by a significant risk of bleeding and the potential for drug-induced thrombocytopenia (NIH, 2022). Deficiency or dysfunction of this receptor results in Glanzmann thrombasthenia, a rare inherited bleeding disorder.

Other names

Glycoprotein IIb/IIIaGP IIb/IIIaCD41/CD61ITGA2B/ITGB3Platelet membrane glycoprotein IIb/IIIa

Antagonist that competitively or non-competitively blocks the binding of fibrinogen and von Willebrand factor to the activated receptor complex, thereby preventing platelet cross-linking and aggregation (StatPearls, 2023; PubMed, PMID: 11091651).