title: Effect of the asymmetric Ca2+ distribution on the bilayer properties of phosphatidylcholine-sonicated vesicles.
abstract: The incorporation of Ca2+ in the inner volume of egg phosphatidylcholine vesicles increases the fluorescence anisotropy of a diphenylhexatriene probe. This increase is higher than for Na+ at the same normality. An effect of the same magnitude is induced by Ca2+ when using binary lipid mixture (dioleoylphosphatidylcholine and dipalmitoylphosphatidylcholine) as long as the mixture is maintained below the phase-transition temperature of the saturated species. The influence of Ca2+ may be explained by an asymmetric distribution of the saturated and unsaturated lipids between the internal and the external monolayers.
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP, La Plata, Argentina.
authors.forename: L S
authors.initials: LS
authors.lastname: Bakás
authors.forename: E A
authors.initials: EA
authors.lastname: Disalvo
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D004134:Dimyristoylphosphatidylcholine / Q000378:metabolism; D004161:Diphenylhexatriene; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D008051:Lipid Bilayers / Q000378:metabolism*; D008081:Liposomes; D010713:Phosphatidylcholines / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013010:Sonication
chemical_list: D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D004161:Diphenylhexatriene; D015060:1,2-Dipalmitoylphosphatidylcholine; D012964:Sodium; C017251:1,2-oleoylphosphatidylcholine; D002118:Calcium; D004134:Dimyristoylphosphatidylcholine