Linked Life Data

11467945

Source:http://linkedlifedata.com/resource/pubmed/id/11467945

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
2001-7-24
pubmed:abstractText
The effects of phospholipid acyl chain length (n(c)), degree of acyl chain saturation, and cholesterol on Na,K-ATPase reconstituted into liposomes of defined lipid composition are described. The optimal acyl chain length of monounsaturated phosphatidylcholine in the absence of cholesterol was found to be 22 but decreased to 18 in the presence of 40 mol % cholesterol. This indicates that the hydrophobic matching of the lipid bilayer and the transmembrane hydrophobic core of the membrane protein is a crucial parameter in supporting optimal Na,K-ATPase activity. In addition, the increased bilayer order induced by both cholesterol and saturated phospholipids could be important for the conformational mobility of the Na,K-ATPase changing the distribution of conformations. Lipid fluidity was important for several parameters of reconstitution, e.g., the amount of protein inserted and the orientation in the liposomes. The temperature dependence of the Na,K-ATPase as well of the Na-ATPase reactions depends both on phospholipid acyl chain length and on cholesterol. Cholesterol increased significantly both the enthalpy of activation and entropy of activation for Na,K-ATPase activity and Na-ATPase activity of Na,K-ATPase reconstituted with monounsaturated phospholipids. In the presence of cholesterol the free energy of activation was minimum at a lipid acyl chain length of 18, the same that supported maximum turnover. In the case of ATPase reconstituted without cholesterol, the minimum free energy of activation and the maximum turnover both shifted to longer acyl chain lengths of about 22.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8842-51
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Modulation of Na,K-ATPase and Na-ATPase activity by phospholipids and cholesterol. I. Steady-state kinetics.
pubmed:affiliation
Department of Biophysics, University of Aarhus, DK-8000 Denmark. fc@biophys.au.dk
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't