Linked Life Data

10978181

Source:http://linkedlifedata.com/resource/pubmed/id/10978181

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2000-9-28
pubmed:abstractText
Cholesterol is known to affect the activity of membrane-bound enzymes, including Na(+)/K(+)-ATPase. To gain insight into the mechanism of cholesterol's effect, we have used various hydrophobic fluorescent probes which insert into different regions of the membrane bilayer and report on the degree of hydration of their environment. Specifially, we have measured the generalized polarization of Laurdan and the lifetime of DPH and derivatives of DPH inserted into membranes from pig kidneys enriched in Na(+)/K(+)-ATPase. Spectral measurements were also carried out on these membranes after modification of their cholesterol content. The generalized polarization of Laurdan increased with increasing cholesterol, showing an abrupt modification at the native cholesterol content. The fluorescence lifetimes of DPH and the DPH derivatives were analyzed using a distribution model. The center value of these lifetime distributions and their widths also changed with increasing cholesterol. One DPH derivative, DPH-PC, showed a minimum value for the lifetime center at the native cholesterol concentration, whereas the other derivatives showed a maximum value for the lifetime center at that cholesterol concentration. DPH-PC is known to sense the protein-lipid interface, whereas the other derivatives sense the bulk lipid phase. These data suggest that hydration at the protein-lipid interface is maximal at the native cholesterol concentration as is the enzymatic activity. Hydration at the protein-lipid interface is therefore proposed to be required for activity. These results are in agreement with current models of membrane dynamics and thermodynamics of protein function.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10928-35
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Modulation of pig kidney Na+/K+-ATPase activity by cholesterol: role of hydration.
pubmed:affiliation
Istituto de Química, Universidad Catolica de Valparaiso, Av. Brasil 2950, Valparaíso, Chile.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't