title: Structural characterization of liposomes made of diether archaeal lipids and dipalmitoyl-L-α-phosphatidylcholine.
abstract: The physicochemical properties of binary lipid mixtures of diether C(25,25) lipids and dipalmitoyl-L-α-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C(25,25) lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50 °C, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC liposomes, while at higher temperatures, the impact of the long isoprenoid chains on the membrane stability becomes more pronounced. Photon correlation spectroscopy and transmission electron microscopy show that mixed liposomes do not fuse or aggregate, even after 41 days at 4 °C.
authors.affiliation: University of Ljubljana, Slovenia.
authors.forename: Dejan
authors.initials: D
authors.lastname: Gmajner
authors.forename: Pegi Ahlin
authors.initials: PA
authors.lastname: Grabnar
authors.forename: Magda Tušek
authors.initials: MT
authors.lastname: Znidarič
authors.forename: Jasna
authors.initials: J
authors.lastname: Strus
authors.forename: Marjeta
authors.initials: M
authors.lastname: Sentjurc
authors.forename: Nataša Poklar
authors.initials: NP
authors.lastname: Ulrih
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D001105:Archaea / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D005454:Fluorescence Polarization; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry* / Q000648:ultrastructure*; D010539:Permeability; D013696:Temperature
chemical_list: D008055:Lipids; D008081:Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine