title: N-nervonoylsphingomyelin (C24:1) prevents lateral heterogeneity in cholesterol-containing membranes.
abstract: This study was conducted to explore how the nature of the acyl chains of sphingomyelin (SM) influence its lateral distribution in the ternary lipid mixture SM/cholesterol/1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), focusing on the importance of the hydrophobic part of the SM molecule for domain formation. Atomic force microscopy (AFM) measurements showed that the presence of a double bond in the 24:1 SM molecule in mixtures with cholesterol (CHO) or in pure bilayers led to a decrease in the molecular packing. Confocal microscopy and AFM showed, at the meso- and nanoscales respectively, that unlike 16:0 and 24:0 SM, 24:1 SM does not induce phase segregation in ternary lipid mixtures with DOPC and CHO. This ternary lipid mixture had a nanomechanical stability intermediate between those displayed by liquid-ordered (Lo) and liquid-disordered (Ld) phases, as reported by AFM force spectroscopy measurements, demonstrating that 24:1 SM is able to accommodate both DOPC and CHO, forming a single phase. Confocal experiments on giant unilamellar vesicles made of human, sheep, and rabbit erythrocyte ghosts rich in 24:1 SM and CHO, showed no lateral domain segregation. This study provides insights into how the specific molecular structure of SM affects the lateral behavior and the physical properties of both model and natural membranes. Specifically, the data suggest that unsaturated SM may help to keep membrane lipids in a homogeneous mixture rather than in separate domains.
authors.affiliation: Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Centro Cientifico Tecnológico La Plata, Consejo Nacional de Investigaciones Científicas y Tecnicas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina. Electronic address: smate@med.unlp.edu.ar.
authors.forename: Sabina
authors.initials: S
authors.lastname: Maté
authors.affiliation: Unidad de Biofísica-Centro Mixto, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
authors.forename: Jon V
authors.initials: JV
authors.lastname: Busto
authors.affiliation: Unidad de Biofísica-Centro Mixto, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
authors.forename: Aritz B
authors.initials: AB
authors.lastname: García-Arribas
authors.affiliation: Unidad de Biofísica-Centro Mixto, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Sot
authors.affiliation: Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Centro Cientifico Tecnológico La Plata, Consejo Nacional de Investigaciones Científicas y Tecnicas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
authors.forename: Romina
authors.initials: R
authors.lastname: Vazquez
authors.affiliation: Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Centro Cientifico Tecnológico La Plata, Consejo Nacional de Investigaciones Científicas y Tecnicas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Herlax
authors.affiliation: Groupe de spectrométrie de masse-APLIPID, Université Pierre et Marie Curie, Faculté de Médicine Pierre et Marie Curie, Paris, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Wolf
authors.affiliation: Departamento de Ciencias Biológicas. Facultad de Ciencias Exactas. Universidad Nacional de La Plata, La Plata, Argentina.
authors.forename: Laura
authors.initials: L
authors.lastname: Bakás
authors.affiliation: Unidad de Biofísica-Centro Mixto, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Bilbao, Spain.
authors.forename: Félix M
authors.initials: FM
authors.lastname: Goñi
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000737:chemistry; D000818:Animals; D002784:Cholesterol / Q000737:chemistry*; D004910:Erythrocyte Membrane / Q000737:chemistry; D006801:Humans; D007848:Laurates / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D055595:Mechanical Phenomena; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry; D011817:Rabbits; D012756:Sheep; D013109:Sphingomyelins / Q000737:chemistry*
chemical_list: D007848:Laurates; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D002784:Cholesterol; D015081:2-Naphthylamine; C017251:1,2-oleoylphosphatidylcholine; C065580:laurdan