title: Lamellar gel (lβ) phases of ternary lipid composition containing ceramide and cholesterol.
abstract: Lipid lateral segregation into specific domains in cellular membranes is associated with cell signaling and metabolic regulation. This phenomenon partially arises as a consequence of the very distinct bilayer-associated lipid physico-chemical properties that give rise to defined phase states at a given temperature. Until now lamellar gel (Lβ) phases have been described in detail in single or two-lipid systems. Using x-ray scattering, differential scanning calorimetry, confocal fluorescence microscopy, and atomic force microscopy, we have characterized phases of ternary lipid compositions in the presence of saturated phospholipids, cholesterol, and palmitoyl ceramide mixtures. These phases stabilized by direct cholesterol-ceramide interaction can exist either with palmitoyl sphingomyelin or with dipalmitoyl phosphatidylcholine and present intermediate properties between raft-associated phospholipid-cholesterol liquid-ordered and phospholipid-ceramide Lβ phases. The present data provide novel, to our knowledge, evidence of a chemically defined, multicomponent lipid system that could cooperate in building heterogeneous segregated platforms in cell membranes.
authors: Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
authors: Jon V
authors: JV
authors: Busto
authors: Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
authors: Aritz B
authors: AB
authors: García-Arribas
authors: Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
authors: Jesús
authors: J
authors: Sot
authors: Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, E-30080/Murcia, Spain.
authors: Alejandro
authors: A
authors: Torrecillas
authors: Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, E-30080/Murcia, Spain.
authors: Juan C
authors: JC
authors: Gómez-Fernández
authors: Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
authors: Félix M
authors: FM
authors: Goñi
authors: Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain. Electronic address: alicia.alonso@ehu.es.
authors: Alicia
authors: A
authors: Alonso
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D002518:Ceramides / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D013109:Sphingomyelins / Q000737:chemistry
chemical_list: D002518:Ceramides; D005782:Gels; D008051:Lipid Bilayers; D013109:Sphingomyelins; D015060:1,2-Dipalmitoylphosphatidylcholine; C097760:N-palmitoylsphingosine; D002784:Cholesterol