Von Willebrand Factor

Thrombomodulin, also known as BDCA-3, is a glycosylated transmembrane protein present on the surface of vascular endothelial cells. Thrombomodulin is a high-affinity receptor for thrombin, a key protein in the coagulation cascade. Formation of the thrombomodulin-thrombin complex blocks the thrombin dependent conversion of fibrinogen to fibrin and also catalyzes the activation of protein C. Active protein C is able to proteolytically inactivate enhancers of the coagulation cascade.

Human Von Willebrand Factor (factor VIII R: Ag) is a 270 kDa multimeric plasma gylcoprotein. Important in the maintenance of hemostasis, it mediates platelet adhesion to injured vessel walls and serves as a carrier and stabilizer for coagulation factor VIII. The Von Willebrand factor has functional binding domains to platelet glycoprotein Ib, glycoprotein IIb/IIIa, collagen and heparin. The factor is synthesized by endothelial cells and is also present in platelets and megakaryocytes.