Thromb Haemost 2001; 86(06): 1501-1511
DOI: 10.1055/s-0037-1616755
Review Article
Schattauer GmbH

Crotalin, a vWF and GP Ib Cleaving Metalloproteinase from Venom of Crotalus atrox

Wen-Bin Wu
1   Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
,
Hui-Chin Peng
1   Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
,
Tur-Fu Huang
1   Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Received 08. Juni 2001

Accepted after resubmission 03. August 2001

Publikationsdatum:
12. Dezember 2017 (online)

Zoom Image

Summary

Binding of von Willebrand factor (vWF) to a variety of extracellular matrix (ECM) components and to platelet glycoprotein (GP) Ib-IX-V complex is important in mediating platelet adhesion and aggregation in the early stage of hemostasis. We previously purified a potent antithrombotic protein, named crotalin, functionally acting as a GP Ib antagonist (1). In this study, we further characterized crotalin as a P-I metalloproteinase with a molecular mass of 25 kDa as determined by gel filtration and two-dimensional SDS-PAGE. Crotalin is a vWF binding and cleaving metalloproteinase. In addition, crotalin cleaved platelet GP Ib as judged by flow cytometry and Western blotting. The multiple effects of crotalin on vWF and platelet GP Ib antagonized ristocetin-, but not collagen and thrombin-induced platelet aggregation, suggesting that its effect is specific. We also found that crotalin auto-proteolytically degraded to ~14 and ~10 kDa fragments in the presence of SDS. Interestingly, both degradation fragments, intact and reduced crotalin were able to bind vWF, suggesting the binding of crotalin to vWF is conformation-independent. In conclusion, the results presented further explain the potent antithrombotic effect of crotalin in vivo. In addition, the multiple effects of crotalin may be used as a tool to determine the binding motifs that are responsible for the vWF-ECMs or vWF-GP Ib interaction.