title: Behavior of giant vesicles with anchored DNA molecules.
abstract: We study changes in curvature and elastic properties of lipid membranes induced by anchoring of long hydrophilic polymers at low polymer surface concentrations (corresponding to the mushroom regime). The effect of anchored polymers on the membrane spontaneous curvature is characterized by monitoring the changes in the fluctuation spectra and the morphology of giant unilamellar vesicles. The polymers used in our study are fluorescently labeled and biotinylated lambda-phage DNA molecules which bind to biotinylated giant unilamellar vesicles via a biotin-avidin-biotin linkage. By varying the amount of biotinylated lipid in the membrane, we control the surface concentration of anchors. At low anchor concentrations, the spontaneous curvature of the membrane increases linearly with the DNA concentration. The linear increase is consistent with theoretical predictions for polymer surface concentrations in the mushroom regime. At higher anchor concentrations, which should still belong to the mushroom regime, the vesicles undergo budding transitions. In this latter regime, the bud size is used to estimate the polymer-induced membrane curvature.
authors: Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany.
authors: Vesselin
authors: V
authors: Nikolov
authors: Reinhard
authors: R
authors: Lipowsky
authors: Rumiana
authors: R
authors: Dimova
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D021962:Membrane Microdomains / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D009690:Nucleic Acid Conformation
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D004247:DNA