info:eu-repo/semantics/article
A prothrombin activator from Bothrops erythromelas (jararaca-da-seca) snake venom: characterization and molecular cloning
Fecha
2003-01Registro en:
Silva, Márcia B.; Schattner, Mirta Ana; Ramos, Celso R. R.; Junqueira de Azevedo, Inácio L. M.; Guarnieri, Míriam C.; et al.; A prothrombin activator from Bothrops erythromelas (jararaca-da-seca) snake venom: characterization and molecular cloning; Portland Press; Biochemical Journal; 369; 1-2003; 129-139
0264-6021
1470-8728
CONICET Digital
CONICET
Autor
Silva, Márcia B.
Schattner, Mirta Ana
Ramos, Celso R. R.
Junqueira de Azevedo, Inácio L. M.
Guarnieri, Míriam C.
Lazzari, María Ángela
Sampaio, Claudio A. M.
Pozner, Roberto Gabriel
Ventura, Janaina S.
Ho, Paulo L.
Chudzinski Tavassi, Ana M.
Resumen
A novel prothrombin activator enzyme, which we have named 'berythractivase', was isolated from Bothrops erythromelas (jararaca-da-seca) snake venom. Berythractivase was purified by a single cation-exchange-chromatography step on a Resource S (Amersham Biosciences) column. The overall purification (31-fold) indicates that berythractivase comprises about 5% of the crude venom. It is a single-chain protein with a molecular mass of 78 kDa. SDS/PAGE of prothrombin after activation by berythractivase showed fragment patterns similar to those generated by group A prothrombin activators, which convert prothrombin into meizothrombin, independent of the prothrombinase complex. Chelating agents, such as EDTA and o-phenanthroline, rapidly inhibited the enzymic activity of berythractivase, like a typical metalloproteinase. Human fibrinogen Aα-chain was slowly digested only after longer incubation with berythractivase, and no effect on the β- or γ-chains was observed. Berythractivase was also capable of triggering endothelial proinfiammatory and procoagulant cell responses, von Willebrand factor was released, and the surface expression of both intracellular adhesion molecule-1 and E-selectin was up-regulated by berythractivase in cultured human umbilical-vein endothelial cells. The complete berythractivase cDNA was cloned from a B. erythromelas venom-gland cDNA library. The cDNA sequence possesses 2330 bp and encodes a preproprotein with significant sequence similarity to many other mature metalloproteinases reported from snake venoms. Berythractivase contains metalloproteinase, desintegrin-like and cysteine-rich domains. However, berythractivase did not elicit any haemorrhagic response. These results show that, although the primary structure of berythractivase is related to that of snake-venom haemorrhagic metalloproteinases and functionally similar to group A prothrombin activators, it is a prothrombin activator devoid of haemorrhagic activity. This is a feature not observed for most of the snake venom metalloproteinases, including the group A prothrombin activators.