title: Stalk formation as a function of lipid composition studied by X-ray reflectivity.
abstract: We have investigated the structure and interaction of solid-supported multilamellar phospholipid bilayers in view of stalk formation as model systems for membrane fusion. The multi-component bilayers were composed of ternary and quaternary mixtures, containing phosphatidylcholines, phosphatidylethanolamines, sphingomyelin, cholesterol, diacylglycerol, and phosphatidylinositol. Analysis of the obtained electron density profiles and the pressure-distance curves reveals systematic changes in structure and hydration repulsion. The osmotic pressure needed to induce stalk formation at the transition from the fluid lamellar to the rhombohedral phase indicates how membrane fusion properties are modified by bilayer composition.
authors.affiliation: Department of Physics, Hashemite University, 13115 Zarqa, Jordan. Electronic address: zkhattari@hu.edu.jo.
authors.forename: Ziad
authors.initials: Z
authors.lastname: Khattari
authors.affiliation: Institut für Röntgenphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Köhler
authors.affiliation: Institut für Röntgenphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Yihui
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institut für Röntgenphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Aeffner
authors.affiliation: Institut für Röntgenphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany. Electronic address: tsalditt@gwdg.de.
authors.forename: Tim
authors.initials: T
authors.lastname: Salditt
mesh_terms: D000465:Algorithms; D002784:Cholesterol / Q000737:chemistry; D004075:Diglycerides / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D008561:Membrane Fusion; D008563:Membrane Lipids / Q000737:chemistry; D008954:Models, Biological; D008956:Models, Chemical; D015394:Molecular Structure; D009997:Osmotic Pressure; D044367:Phase Transition; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010716:Phosphatidylinositols / Q000737:chemistry; D013109:Sphingomyelins / Q000737:chemistry; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D004075:Diglycerides; D008051:Lipid Bilayers; D008055:Lipids; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D013109:Sphingomyelins; D002784:Cholesterol
keywords: Membrane fusion; Multi-component lipid bilayer; Stalk structure; X-ray reflectivity