The novel metalloproteinase atroxlysin-I from Peruvian Bothrops atrox (Jergón) snake venom acts both on blood vessel ECM and platelets

• Published in: Archives of biochemistry and biophysics Vol. 496; no. 1; pp. 9 - 20
• Main Authors: Sanchez, Eladio F., Schneider, Francisco S., Yarleque, Armando, Borges, Marcia H., Richardson, Michael, Figueiredo, Suely G., Evangelista, Karla S., Eble, Johannes A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-04-2010
• Subjects: Amino Acid Sequence; Animals; Atroxlysin; Blood Platelets - drug effects; Blood Platelets - metabolism; Blood Vessels - cytology; Blood Vessels - drug effects; Blood Vessels - metabolism; Bothrops; Extracellular Matrix - drug effects; Extracellular Matrix - metabolism; Fibrin - metabolism; Fibrinogen - metabolism; Fibronectins - metabolism; Hemorrhage - chemically induced; Hemostasis; Hemostasis - drug effects; Humans; Integrins - metabolism; Macroglobulins - metabolism; Metalloproteases - chemistry; Metalloproteases - metabolism; Metalloproteases - toxicity; Metalloproteinase; Molecular Sequence Data; Platelets; Snake venom; Snake Venoms - enzymology; Substrate Specificity; Snake venom; Atroxlysin; Metalloproteinase; Platelets; Hemostasis
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2010.01.010

We report the isolation and structure–function relationship of a 23
kDa metalloproteinase named atroxlysin-I from the venom of the Peruvian
Bothrops atrox (Jergón). Atroxlysin is a P-I metalloproteinase and contains 204 residues. Its proteolytic activity towards dimethylcasein is enhanced by Ca
+2 but inhibited by EDTA, dithiothreitol, excessive Zn
+2 and α2-macroglobulin. Unlike other structurally homologous P-I metalloproteinases, atroxlysin-I causes hemorrhages. To examine its hemorrhagic activity mechanistically, we studied its function
in vitro and
in vivo. It cleaved the Ala
14–Leu
15 and Tyr
16–Leu
17 bonds in oxidized insulin B-chain and specifically hydrolyzed the α-chains of fibrin(ogen) in a dose- and time-dependent manner. Atroxlysin-I cleaved plasma fibronectin and other extracellular matrix proteins (collagens I and IV) and the triple-helical fragment CB3 of collagen IV, but did not degrade laminin-111. Complementarily, the laminin and collagen binding integrins α
7β
1 and α
1β
1 were cleaved by atroxlysin. Even without catalytic activity atroxlysin-I inhibited collagen- and ADP-triggered platelet aggregation.