Structural and functional characterization of myotoxin I, a Lys49 phospholipase A2 homologue from the venom of the snake Bothrops atrox
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| Autores: | , , , |
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| Formato: | artículo original |
| Fecha de Publicación: | 2004 |
| Descripción: | A new myotoxin was isolated from the venom of Bothrops atrox from Colombia. B. atrox myotoxin I is a homodimer, with a subunit molecular mass of 13,826, and a pI of 8.9. Its complete nucleotide sequence was obtained by cDNA cloning, indicating a mature product of 122 residues that belongs to the family of Lys49 phospholipase A2 (PLA2) homologues, a subgroup of catalytically inactive proteins within the group IIA. Accordingly, the toxin was devoid of phospholipase and anticoagulant activities, in vitro. In mice, it induced conspicuous local myonecrosis, edema, and a systemic interleukin-6 response. In vitro, it was cytolytic upon myoblasts, and weakly bactericidal. The toxin showed highest homology with other Lys49 PLA2s, both in its primary and three-dimensional modeled structure, although with an evident difference in the C-terminal region. Unlike Lys49 proteins of American crotalids having 121 residues, this toxin presents an insertion (Asn) between positions 118 and 119. Despite several substitutions within the C-terminal region 115–129 between B. atrox myotoxin I and B. asper myotoxin II, antibodies against synthetic peptide 115–129 of the latter were strongly cross-reactive to the former, indicating the antigenic conservation of this site, known to be critical for the membrane-damaging activities of Lys49 myotoxins. |
| País: | Kérwá |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Kérwá |
| OAI Identifier: | oai:kerwa.ucr.ac.cr:10669/29513 |
| Acceso en línea: | http://www.sciencedirect.com/science/article/pii/S0041010104001837 https://hdl.handle.net/10669/29513 |
| Palabra clave: | Myotoxin Phospholipase A2 Lys49 Bothrops Snake venom |