Platelet glycoprotein Ib alpha chain (GPIbα) – von Willebrand factor (VWF) (GPIbα-VWF)

The interaction between Platelet glycoprotein Ib alpha chain (GPIbα) and von Willebrand factor (VWF) is a fundamental process in primary hemostasis and the pathogenesis of arterial thrombosis [1, 3]. GPIbα is the major ligand-binding subunit of the GPIb-IX-V complex on the platelet surface, while VWF is a large, multimeric glycoprotein that circulates in the blood and is stored in endothelial cells and platelets [3, 11]. Under high-shear stress conditions, such as those in stenosed or injured arteries, VWF undergoes a conformational transition from a globular to an elongated state, exposing its A1 domain to bind the N-terminal domain of GPIbα [11, 16]. This interaction facilitates the initial tethering and rolling of platelets on the vascular wall, which is a prerequisite for stable adhesion and subsequent thrombus growth [3, 15]. Abnormalities in this axis lead to significant clinical conditions, including bleeding disorders like von Willebrand disease and Bernard-Soulier syndrome, as well as thrombotic disorders like thrombotic thrombocytopenic purpura (TTP) [1, 18]. Therapeutic strategies targeting this interaction, including the approved nanobody caplacizumab and various experimental aptamers and antibodies, provide a targeted approach to preventing thrombosis with a potentially improved safety profile regarding bleeding compared to conventional antiplatelet agents [1, 7].

Other names

CD42bGP-Ib alphaFactor VIII-related antigenGPIb-VWF axisVWF-GPIb interaction

Inhibition of the protein-protein interaction between the von Willebrand factor A1 domain and the platelet glycoprotein Ib alpha N-terminal domain, thereby blocking platelet tethering and adhesion under high shear stress [1, 2, 4].