Linked Life Data

12127577

Source:http://linkedlifedata.com/resource/pubmed/id/12127577

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2002-7-19
pubmed:abstractText
In order to analyze its structure-function relationships, the complete amino acid sequence of myotoxin II from Atropoides (Bothrops) nummifer from Costa Rica was determined. This toxin is a Lys49-type phospholipase A(2) (PLA(2)) homologue, devoid of catalytic activity, structurally belonging to class IIA. In addition to the Asp49 --> Lys change in the (inactive) catalytic center, substitutions in the calcium-binding loop suggest that its lack of enzymatic activity is due to the loss of ability to bind Ca(2+). The toxin occurs as a homodimer of basic subunits of 121 residues. Its sequence has highest similarity to Lys49 PLA(2)s from Cerrophidion, Trimeresurus, Bothrops and Agkistrodon species, which form a subfamily of proteins that diverged early from Asp49 PLA(2)s present in the same species, as shown by phylogenetic analysis. The tertiary structure of the toxin was modeled, based on the coordinates of Cerrophidion godmani myotoxin II. Its exposed C-terminal region 115-129 shows several differences in comparison to the homologous sequences of other Lys49 PLA(2)s, i.e. from Agkistrodon p. piscivorus and Bothrops asper. Region 115-129 of the latter two proteins has been implicated in myotoxic activity, on the basis of the direct membrane-damaging of their corresponding synthetic peptides. However, peptide 115-129 of A. nummifer myotoxin II did not exert toxicity upon cultured skeletal muscle cells or mature muscle in vivo. Differences in several amino acid residues, either critical for toxicity, or influencing the conformation of free peptide 115-129 from A. nummifer myotoxin II, may account for its lack of direct membrane-damaging properties.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1357-2725
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Elsevier Science Ltd.
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1268-78
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Structural characterization and phylogenetic relationships of myotoxin II from Atropoides (Bothrops) nummifer snake venom, a Lys49 phospholipase A(2) homologue.
pubmed:affiliation
Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't