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Titolo:
EFFECT OF LIPID STRUCTURE ON THE DIPOLE POTENTIAL OF PHOSPHATIDYLCHOLINE BILAYERS
Autore:
CLARKE RJ;
Indirizzi:
MAX PLANCK INST BIOPHYS,DEPT BIOPHYS CHEM,KENNEDYALLEE 70 D-60596 FRANKFURT GERMANY
Titolo Testata:
Biochimica et biophysica acta. Biomembranes
fascicolo: 2, volume: 1327, anno: 1997,
pagine: 269 - 278
SICI:
0005-2736(1997)1327:2<269:EOLSOT>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
MEMBRANE PROBE RH421; CHARGE-SHIFT PROBES; NEURONAL-ACTIVITY; WATER INTERFACE; VESICLES; NEURITE; MODEL; DYES; SENSITIVITY; MONOLAYERS;
Keywords:
VOLTAGE-SENSITIVE DYE; DIPOLE POTENTIAL; LIPID VESICLE; FLUORESCENCE; LIPID PACKING; LIPID SATURATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
50
Recensione:
Indirizzi per estratti:
Citazione:
R.J. Clarke, "EFFECT OF LIPID STRUCTURE ON THE DIPOLE POTENTIAL OF PHOSPHATIDYLCHOLINE BILAYERS", Biochimica et biophysica acta. Biomembranes, 1327(2), 1997, pp. 269-278

Abstract

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 unsaturatedphosphatidylcholines. 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 ofthe 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 lengthof 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. (C) 1997 Elsevier Science B.V.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 09:26:30