Isolation and characterization of myotoxin II from Atropoides (Bothrops) nummifer snake venom, a new Lys49 phospholipase A2 homologu
artículo original
Fecha
2000Autor
Angulo Ugalde, Yamileth
Olamendi Portugal, Timoteo
Possani, Lourival D.
Lomonte, Bruno
Metadatos
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Myotoxic phospholipases A2 of class II are commonly found in the venoms of crotalid snakes. As an approach to
understanding their structure±activity relationship, diverse natural variants have been characterized biochemically
and pharmacologically. This study describes a new myotoxic phospholipase A2 homologue, isolated from the venom
of Atropoides (Bothrops ) nummifer from Costa Rica. A. nummifer myotoxin II is a basic protein, with an apparent
subunit molecular mass of 16 kDa, which migrates as a dimer in sodium dodecylsulfate-polyacrylamide gel
electrophoresis under nonreducing conditions. It is strongly recognized by antibodies generated against Bothrops
asper myotoxin II, by enzyme-immunoassay. The toxin induces rapid myonecrosis upon intramuscular injection in
mice (evidenced by an early increase in plasma creatine kinase activity), and signicant edema in the footpad assay.
It also displays cytolytic activity upon cultured murine endothelial cells. The toxin (up to 50 ug) has no detectable
phospholipase A2 activity on egg yolk phospholipids, and does not show an anticoagulant effect on sheep platelet-
poor plasma in vitro. N-terminal sequence determination (53 amino acid residues) demonstrated that A. nummifer
myotoxin II is a new Lys49 variant of the family of myotoxic, class II phospholipases A2. Sequence comparison
with other phospholipases A2 revealed Asn53 as a novel substitution. In addition, this myotoxin is the first Lys49
variant presenting Asn in its N-terminus. Consequently, these fndings suggest that neither Ser1 or Lys53, usually
found in this family of proteins, are essential amino acid residues for their myotoxic, cytolytic, or edema-inducing
effects
External link to the item
10.1016/S1357-2725(99)00099-0Colecciones
- Microbiología [1171]