Linked Life Data

2940236

Source:http://linkedlifedata.com/resource/pubmed/id/2940236

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1986-7-7
pubmed:abstractText
Myosin was rapidly prepared from the slime mould, Physarum polycephalum to a high level of homogeneity (greater than 95%), in a high yield (about 10 mg/100 g tissue) and in a phosphorylated state (about 5 mol phosphate/mol of 500,000 Mr myosin). Actin activated the Mg-ATPase activity of this myosin in the absence of Ca2+ about 30-fold, and this actin-activated ATPase activity was reduced to about 20% of the original activity when Ca2+ concentration was increased to 50 microM, i.e., the actin-myosin-ATP interactions show Ca-inhibition. The Ca2+ concentration giving half-maximum inhibition was 1-3 microM. The Ca-inhibition was clearly observed at physiological concentrations of Mg2+ but was obscured at both lower and higher concentrations of Mg2+. The Ca-inhibitory effect on ATP hydrolysis by actomyosin reconstituted from skeletal actin and Physarum myosin was quick and reversible. Ca-binding measurement showed that myosin bound Ca2+ with half-maximal binding at 2 microM Ca2+ and maximum binding of 2 mol per mol myosin, indicating that Ca2+ may inhibit the ATPase activity by binding to myosin. The involvement of this myosin-linked regulatory system in the Ca2+ -control of cytoplasmic streaming is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1433-46
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The inhibitory Ca2+-regulation of the actin-activated Mg-ATPase activity of myosin from Physarum polycephalum plasmodia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't