title: Lateral proton conduction in mixed monolayers of phosphatidylethanolamine and cetyltrimethylammonium bromide.
abstract: Proton conduction is known to be facilitated along phospholipid monolayers spread on aqueous phases. This property was monitored with mixed cetyltrimethylammonium bromide/phosphatidyl-ethanolamine monolayers. The film was shown to be metastable by surface pressure and fluorescence measurements. The detergent was leaving the interface for the bulk phase. Nevertheless, a fraction of the detergent remained in the lipid matrix, as shown by the binding of the fluorescent probe 8-anilino-1-naphthalensulfonate. Its dissociation constant decreased, and the nature of its binding site was affected, as shown by a shift of its emission spectrum. Apart from film expansion, the properties of the film were affected only at the water/membrane interface. Proton conduction was prevented only when the surface concentration of the detergent was larger than a critical value. Such an effect could be due either to the disruption in the continuity of the conducting hydrogen-bond network or to an electrostatic repulsion of the protons by the interface.
authors.affiliation: Centre de Recherches de Biochimie et de Génétique Cellulaires du CNRS, Toulouse, France.
authors.forename: B
authors.initials: B
authors.lastname: Gabriel
authors.forename: M
authors.initials: M
authors.lastname: Prats
authors.forename: J
authors.initials: J
authors.lastname: Teissié
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D003902:Detergents / Q000737:chemistry; D008563:Membrane Lipids / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011522:Protons; D013050:Spectrometry, Fluorescence; D013499:Surface Properties
chemical_list: D002593:Cetrimonium Compounds; D003902:Detergents; D008563:Membrane Lipids; D010714:Phosphatidylethanolamines; D011522:Protons; D000077286:Cetrimonium