Von Willebrand factor

• OMIM: 193400

• MGI: 98941

The von Willebrand factor (vWF ) is a protein that plays as a carrier protein of blood coagulation factor VIII an important role in hemostasis and after Erik Adolf von Willebrand ( 1870-1949 ), a Finnish internists, was named.

The von Willebrand factor is of megakaryocytes, but especially formed by the endothelial cells that form the inner wall of a blood vessel ( the intima ). Furthermore, it is in the α - granules of platelets ( thrombocytes). If there is a plan view of the inner wall of the endothelium, the underlying proteins of the vascular wall to be exposed, including Collagens. At this the von Willebrand factor can bind. Certain cellular elements of the blood, the blood platelets ( thrombocytes), on their surface via a docking site to which can bind von Willebrand factor. This is called von Willebrand receptor glycoprotein Ib or / designated V / IX. Thus, the von Willebrand factor creates a bridge between the platelets and the injured vessel wall. An already adherent platelet vWF can bind via glycoprotein IIb and IIIa.

The von Willebrand factor thus has a direct effect on the cellular hemostasis. In the plasmatic clotting he is not directly involved, since it is not necessary for the formation of fibrin. Due to its function as a carrier and protective protein for coagulation factor VIII leads a lack of von Willebrand factor or a defect in its protein structure through this direct interaction but to impairment of plasmatic hemostasis (see Willebrand syndrome and von Willebrand disease).