title: Effect of average phospholipid curvature on supported bilayer formation on glass by vesicle fusion.
abstract: The adsorption of large unilamellar vesicles composed of various combinations of phosphatidylcholine, phosphatidylethanolamine (PE), monomethyl PE, and dimethyl PE (PE-Me2) onto a glass surface was studied using fluorescence microscopy. The average lipid geometry within the vesicles, described mathematically by the average intrinsic curvature, C(0,ave), was methodically altered by changing the lipid ratios to determine the effect of intrinsic curvature on the ability of vesicles to rupture and form a supported lipid bilayer. We show that the ability of vesicles to create fluid planar bilayers is dependent on C(0,ave) and independent of the identity of the component lipids. When the C(0,ave) was approximately -0.1 nm(-1), the vesicles readily formed supported lipid bilayers with almost full mobility. In contrast, when the C(0,ave) ranged from approximately -0.2 to approximately -0.3 nm(-1), the adsorbed vesicles remained intact upon the surface. The results indicate that the average shape of lipid molecules within a vesicle (C(0,ave)) is essential for determining kinetically viable reactions that are responsible for global geometric changes.
authors.affiliation: Department of Molecular and Cellular Medicine, The Texas A&M University System Health Science Center, College Station, Texas 77843, USA.
authors.forename: Chiho
authors.initials: C
authors.lastname: Hamai
authors.forename: Tinglu
authors.initials: T
authors.lastname: Yang
authors.forename: Sho
authors.initials: S
authors.lastname: Kataoka
authors.forename: Paul S
authors.initials: PS
authors.lastname: Cremer
authors.forename: Siegfried M
authors.initials: SM
authors.lastname: Musser
mesh_terms: D000042:Absorption; D005898:Glass / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008561:Membrane Fusion; D008856:Microscopy, Fluorescence; D008962:Models, Theoretical; D044367:Phase Transition; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; C483858:phosphatidylethanolamine