Related Experiment Video
Updated: Aug 8, 2026

Investigating von Willebrand Factor Pathophysiology Using a Flow Chamber Model of von Willebrand Factor-platelet String Formation
Published on: August 14, 2017
Releasing or expression modulating mediator involved in hemostasis by Berythractivase and Jararhagin (SVMPs)
Agostinho Luiz Maia Pereira1, Márcio Fritzen, Fernanda Faria
1Biochemistry and Biophysics Laboratory, Butantan Institute, Avenue Vital Brazil, 1500, Butantã, 05503-900 São Paulo/SP, Brazil.
Abstract:
PIII snake venom metalloproteases (SVMPs) are structurally related to ADAMs (a disintegrin and metalloprotease human family of proteins). Berythractivase and Jararhagin are PIII SVMPs with 69% homology with different hemostatic properties. In order to clarify these differences and further characterize the biological effects of these proteins, we compared the effect of both proteases on human umbilical vein endothelial cell (HUVEC) for evaluating the release and modulation of coagulation and fibrinolysis mechanisms as well as the expression of their correlated genes. We found that both proteins increase the von Willebrand factor liberation, but did not modulate gene expression. Berythractivase, differently from Jararhagin increased the expression of tissue factor. Our results showed that both SVMPs (Berythractivase and Jararhagin) activate HUVEC releasing or modulating mediators involved in hemostasis. Meanwhile, we can suggest through the up-regulation of TF gene that the studied SVMP acts in a specific manner, suggesting that Jararhagin has preferentially a local action, while Berythractivase can be assumed as a systemic pro-coagulant protein with activity on the surface of HUVECs.
Related Concept Videos
Regulation of Angiogenesis and Blood Supply
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized, and...
Vascular Spasm
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...

