Linked Life Data

10080349

Source:http://linkedlifedata.com/resource/pubmed/id/10080349

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-6-23
pubmed:abstractText
The structures of several K49 PLA2 proteins have been determined and these differ as a group in several regions from the closely related D49 PLA2 enzymes. One outstanding difference is the presence of a high number of positively charged residues in the C-terminal region which combined with the overall high number of conserved lysine residues gives the molecule an interfacial adsorption surface which is highly positively charged compared to the opposite surface of the molecule. Although some nucleotide sequences have been reported, progress in obtaining active recombinant proteins has been slow. The K49 proteins exert several toxic activities, including myotoxicity, anticoagulation and edema formation. The most studied of these activities is myotoxicity. The myotoxicity induced by the K49 PLA2 proteins is histologically similar to that caused by the D49 PLA2 myotoxins, with some muscle fiber types possibly more sensitive than others. Whereas it is clear that the K49 PLA2 myotoxins lyse the plasma membrane of the affected muscle cell in vivo, the exact mechanism of this lysis is not known. Also, it is not known whether the toxin is internalized before, during or after the initial lysis or ever. The K49 PLA2 toxins lyse liposomes and cells in culture and in the latter, the PLA2 myotoxins exert at least two distinct mechanisms of action, neither of which is well-characterized. While the K49 PLA2 proteins are enzymatically inactive on artificial substrates, the toxins cause fatty acid production in cell cultures. Whether the fatty acid release is due to the enzymatic activity of the K49 PLA2 or stimulation of tissue lipases, is unknown. While there may be a role for fatty acid production in one mechanism of myotoxicity, a second mechanism appears to be independent of enzymatic activity. Although we are beginning to understand more about the structure of these toxins, we still know little about the precise mechanism by which they interact with the skeletal muscle cell in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0041-0101
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
411-45
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Lysine 49 phospholipase A2 proteins.
pubmed:affiliation
Department of Anatomy, Pathology and Pharmacology, Oklahoma State University, Stillwater 74078-0350, USA. carla@okway.okstate.edu
pubmed:publicationType
Journal Article, Review