Linked Life Data

2109907

Source:http://linkedlifedata.com/resource/pubmed/id/2109907

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-5-31
pubmed:abstractText
Pa-11, a phospholipase A2 isolated from the venom of an Australian elapid snake Pseudechis australis, was chemically modified and its enzymic, neuromuscular and lethal activities were studied. Carboxymethylation of Met-8 gave a derivative with 2% of the enzymic activity and less than 3% of the lethal activity of native Pa-11; it had about 5% of the original ability to block directly and indirectly stimulated mouse phrenic nerve-hemidiaphragm preparations. Nitrophenylsulfenylation of tryptophanyl residues at positions 31 and 69 caused loss of all activities. Amidination of all 14 lysyl residues gave a derivative with 41% and 16% of the enzymic and lethal activities, respectively, but with less than 5% of the original neuromuscular blocking activity. Mono-carbamoylation of lysyl residues at positions 58, 63, 81 and 85 was achieved. The most abundant derivative, 58-carbamoyl-lysine Pa-11 was enzymically 130% and lethally 100% as active as native Pa-11, but it had only about 20% of the native's neuromuscular activity in vitro. 63-Carbamoyl-lysine Pa-11 had 10% of the enzymic and 20% of the lethal activities, respectively; however, it retained at least 50% of its ability to block neuromuscular transmission in vitro, while losing most of its activity to block directly stimulated muscle contractions. 81- and 85-Carbamoyl derivatives have the same enzymic and lethal activities as the original protein, but the 85 derivative had less than 10% of the native neuromuscular activity. Hence, modifications of lysine residues at positions 58, 63 and 85 seem to be particularly significant in altering the neuromuscular, but not enzymic, activity of Pa-11, perhaps by altering the ability of the toxin to bind to its target on nerve and muscle membranes. Modification at position 63 appeared to lead to a dissociation of effects on neuromuscular transmission and directly on muscle cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0041-0101
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
107-17
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Effects of chemical modifications of Pa-11, a phospholipase A2 from the venom of Australian king brown snake (Pseudechis australis), on its biological activities.
pubmed:affiliation
Department of Chemistry, Faculty of Science, Tohoku University, Sendai, Japan.
pubmed:publicationType
Journal Article