Linked Life Data

9271269

Source:http://linkedlifedata.com/resource/pubmed/id/9271269

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-9-18
pubmed:abstractText
A fluorescent ratio method utilizing styrylpyridinium dyes has recently been suggested for the measurement of the membrane dipole potential. Up to now only qualititative measurements have been possible. Here the fluorescence excitation ratio of the dye di-8-ANEPPS has been measured in lipid vesicles composed of a range of saturated and unsaturated phosphatidylcholines. It has been found that the fluorescence ratio is inversely proportional to the surface area occupied by the lipid in its fully hydrated state. This finding allows, by extra- and interpolation, the packing density to be estimated of phosphatidylcholines for which X-ray crystallographic data are not yet available. Comparison of the fluorescence data with literature data of the dipole potential from electrical measurements on monolayers and bilayers allows a calibration curve to be constructed, so that a quantitative determination of the dipole potential using di-8-ANEPPS is possible. It has been found that the value of the dipole potential decreases with increasing unsaturation and, in the case of unsaturated lipids, with increasing length of the hydrocarbon chains. This effect can be explained by the effects of chain packing on the spacing between the headgroups. In addition to the effects of lipid structure on membrane fluidity, these measurements demonstrate the possibility of a direct electrical mechanism for lipid regulation of protein function, in particular of ion transport proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
1327
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
269-78
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Effect of lipid structure on the dipole potential of phosphatidylcholine bilayers.
pubmed:affiliation
Department of Biophysical Chemistry, Max-Planck-Institut für Biophysik, Frankfurt am Main, Germany. clarker@kennedy.biophys.mpg.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't