Linked Life Data

6215062

Source:http://linkedlifedata.com/resource/pubmed/id/6215062

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1982-12-18
pubmed:abstractText
The Ca2+-pumping ATPase from human erythrocyte membranes, purified by the method previously reported [Niggli, V., Penniston, J. T., & Carafoli, E. (1979) J. Biol. Chem. 254, 9955-9958], was freed of minor impurities by extensive washing while bound to the calmodulin-Sepharose column. The pure enzyme showed a single band of Mr 138000, which contained no stainable carbohydrate. The enzyme retained calmodulin-stimulable ATPase activity; with appropriate assay conditions, an activity of 21.2 mumol/(mg x min) was obtained. Amino acid analysis showed that the ATPase had a larger proportion of polar amino acids than do other integral membrane proteins. Despite this, the ATPase showed a tendency to form dimers and higher aggregates even in the presence of sodium dodecyl sulfate and urea. The enzyme required Mg2+ but showed little activity unless a second ion was added. With regard to this second ion, the enzyme responded to alkaline earth metal ions in the order Ca2+ greater than Sr2+ much greater than Ba2+. It was highly specific for ATP and was stimulated by Na+ or K+; in all of these properties it resembled the enzyme in unfractionated membranes. Limited proteolysis using trypsin yielded, at short times, many fragments of various molecular weights; continued proteolysis resulted in two trypsin-resistant fragments of Mr 81000 and 33500. Analysis of the time course of proteolysis indicated that the ATPase existed in two or more conformations that had differing susceptibilities to proteolysis. It is suggested that these correspond to active and inactive conformers of the enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4511-6
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Molecular properties of calcium-pumping ATPase from human erythrocytes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't