Linked Life Data

6151948

Source:http://linkedlifedata.com/resource/pubmed/id/6151948

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1985-3-27
pubmed:abstractText
An acid-stable phosphoprotein was formed in a microsomal membrane fraction isolated from bovine aortic smooth muscle in the presence of Mg2+ + ATP and Ca2+. The microsomes also showed Ca2+ uptake activity. The Ca2+ dependence of phosphoprotein formation and of Ca2+ uptake occurred over the same range of Ca2+ concentration (1-10 microM), and resembled similar findings from rabbit skeletal microsomes. The molecular weight of the phosphorylated protein, estimated by SDS-gel electrophoresis, was approximately 105,000. The phosphoprotein was labile at alkaline pH, and its decomposition was accelerated by hydroxylamine. Half-maximum incorporation of 32P in the presence of 10 microM Ca2+ occurred at 60 nM ATP. The calcium-dependent phosphoprotein formation was not affected by 5 mM NaN3, but was inhibited in a dose-dependent fashion by ADP with a 50% inhibition occurring at 180 microM. Fifty mM MgCl2 was required for the maximal phosphorylation. The rate of phosphoprotein decomposition after adding 2 mM EGTA was accelerated by varying the Mg2+ concentration from 10 microM to 3 mM. Alkaline pH (9.0) slowed the rate of phosphoprotein decay. Optimal Ca2+-dependent phosphoprotein occurred at 15 degrees C over a broad pH range (6.4 to 9.0). The activation energy of EGTA-induced phosphoprotein decomposition was 25.6 kcal/mol between 0 and 16 degrees C and 14.6 kcal/mol between 16 and 30 degrees C. The phosphoprotein formed by aortic microsomes was thus quite similar to the acid-stable phosphorylated intermediate of the Ca2+-transport ATPase of sarcoplasmic reticulum from skeletal and cardiac muscle. These data suggest that the Ca2+-dependent phosphoprotein is a reaction intermediate of the Ca2+,Mg2+-ATPase of the aortic microsomes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
96
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1365-74
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:6151948-Adenosine Diphosphate, pubmed-meshheading:6151948-Adenosine Triphosphate, pubmed-meshheading:6151948-Animals, pubmed-meshheading:6151948-Aorta, pubmed-meshheading:6151948-Biological Transport, Active, pubmed-meshheading:6151948-Ca(2+) Mg(2+)-ATPase, pubmed-meshheading:6151948-Calcium, pubmed-meshheading:6151948-Calcium-Transporting ATPases, pubmed-meshheading:6151948-Cattle, pubmed-meshheading:6151948-Hydrogen-Ion Concentration, pubmed-meshheading:6151948-Hydrolysis, pubmed-meshheading:6151948-Hydroxylamines, pubmed-meshheading:6151948-Intracellular Membranes, pubmed-meshheading:6151948-Magnesium, pubmed-meshheading:6151948-Magnesium Chloride, pubmed-meshheading:6151948-Microsomes, pubmed-meshheading:6151948-Muscle, Smooth, Vascular, pubmed-meshheading:6151948-Phosphoproteins, pubmed-meshheading:6151948-Temperature
pubmed:year
1984
pubmed:articleTitle
Ca2+,Mg2+-ATPase of microsomal membranes from bovine aortic smooth muscle. Identification and characterization of an acid-stable phosphorylated intermediate of the Ca2+,Mg2+-ATPase.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't