title: Molecular determinants for the line tension of coexisting liquid phases in monolayers.
abstract: The line tension (λ) in biphasic membranes has been determined in monolayers and bilayers using a variety of techniques. In this work we present a novel approach to the determination of λ in monolayers with liquid/liquid phase coexistence, overcoming several of the drawbacks of current techniques. Using our method, we determined the line tension of liquid/liquid phases in binary mixtures of different lipids and a molecule similar to cholesterol but less oxidizable. We analyzed the effect of the hydrocarbon chain length and the polar head-group of the non-sterol lipid and found the latter to exert much more influence than the former. The presence of PE led to high λ values, PG to low values and PS and PC to intermediate values. The line tension showed a strong correlation with the critical packing parameter of the phospholipid. The spontaneous curvature displayed by the phases constituted by a particular lipid appears to be an important parameter for determining the line tension in mixed films.
authors.affiliation: Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Dpto. de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
authors.forename: Andrea Alejandra
authors.initials: AA
authors.lastname: Bischof
authors.forename: Natalia
authors.initials: N
authors.lastname: Wilke
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence; D056004:Molecular Dynamics Simulation; D044367:Phase Transition; D055672:Static Electricity; D013500:Surface Tension
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D008567:Membranes, Artificial; D002784:Cholesterol