Linked Life Data

6539330

Source:http://linkedlifedata.com/resource/pubmed/id/6539330

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1984-7-2
pubmed:abstractText
F-actin at steady state in the presence of ATP partially depolymerized to a new steady state upon mechanical fragmentation. The increase in critical concentration with the number concentration of filaments has been quantitatively studied. The data can be explained by a model in which the preferred pathway for actin association-dissociation reactions at steady state in the presence of ATP involves binding of G-actin . ATP to filaments, ATP hydrolysis, and dissociation of G-actin . ADP which is then slowly converted to G-actin . ATP. As a consequence of the slow exchange of nucleotide on G-actin, the respective amounts of G-actin . ATP and G-actin . ADP coexisting with F-actin at steady state depend on the filament number concentration. G-actin coexisting with F-actin at zero number concentration of filaments would then consist of G-actin . ATP only, while the critical concentration obtained at infinite number of filaments would be that for G-actin . ADP. Values of 0.35 and 8 microM, respectively, were found for these two extreme critical concentrations for skeletal muscle actin at 20 degrees C, pH 7.8, 0.1 mM CaCl2, 1 mM MgCl2, and 0.2 mM ATP. The same value of 8 microM was directly measured for the critical concentration of G-actin . ADP polymerized in the presence of ADP and absence of ATP, and it was unaffected by fragmentation. These results have important implications for experiments in which critical concentrations are compared under conditions that change the filament number concentrations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6274-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
The critical concentration of actin in the presence of ATP increases with the number concentration of filaments and approaches the critical concentration of actin.ADP.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.