Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1986-1-6
pubmed:abstractText
Rigor complexes between actin and myosin have been shown to cause increased binding of Ca2+ to troponin C. A similar effect of force-generating crossbridges has been suggested as an explanation for the coupling between load and activation which has been observed in skeletal and cardiac muscle. The goal of this study was to test the hypothesis that Ca2+-troponin affinity during crossbridge cycling is load-dependent. Ca2+-binding to detergent-extracted rabbit psoas fibres was measured during ATP-induced force generation and in the relaxed state. To compare Ca2+ binding in the latter two states it was necessary to establish conditions in which ATP-induced force could be regulated independently of free Ca2+ concentration. Such conditions were obtained by the use of either the ATPase inhibitor sodium vanadate or the substitution of MgITP for MgATP as an energy source. This study showed that in the presence of MgATP (or MgITP) the amount of Ca2+ bound to the myofilaments at a given free Ca2+ concentration was independent of the force generated. Thus force per se is not a determinant of Ca2+-troponin affinity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0142-4319
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
477-86
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
The binding of calcium to detergent-extracted rabbit psoas muscle fibres during relaxation and force generation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.