title: Ripple phase in asymmetric unilamellar bilayers with saturated and unsaturated phospholipids.
abstract: In a solution of phosphate-buffered saline (PBS), unilamellar bilayers with saturated phosphatidylcholines in one leaflet and negatively charged, unsaturated phospholipids in the other leaflet were observed in the ripple phase at room temperature using atomic force microscopy (AFM). This is the first observation of the ripple phase in asymmetric bilayers. Sodium and phosphate, components of PBS, were found to be necessary for the formation of the ripple structure in the asymmetric bilayers composed of dipalmitoylphosphatidylcholine (DPPC) and 1-palmitoyl-2-oleoylphosphatidylglycerol (POPG), demonstrating a dependency for specific ions for this phase. These results indicate that the two leaflets of a bilayer are closely coupled to give rise to such a long range and complicated morphology.
authors.affiliation: Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Czajkowsky
authors.forename: C
authors.initials: C
authors.lastname: Huang
authors.forename: Z
authors.initials: Z
authors.lastname: Shao
mesh_terms: D007477:Ions; D008051:Lipid Bilayers; D018625:Microscopy, Atomic Force; D010743:Phospholipids / Q000737:chemistry*
chemical_list: D007477:Ions; D008051:Lipid Bilayers; D010743:Phospholipids