title: Nanoroughness Strongly Impacts Lipid Mobility in Supported Membranes.
abstract: In vivo lipid membranes interact with rough supramolecular structures such as protein clusters and fibrils. How these features whose size ranges from a few nanometers to a few tens of nanometers impact lipid and protein mobility is still being investigated. Here, we study supported phospholipid bilayers, a unique biomimetic model, deposited on etched surfaces bearing nanometric corrugations. The surface roughness and mean curvature are carefully characterized by AFM imaging using ultrasharp tips. Neutron specular reflectivity supplements this surface characterization and indicates that the bilayers follow the large-scale corrugations of the substrate. We measure the lateral mobility of lipids in both the fluid and gel phases by fluorescence recovery after patterned photobleaching. Although the mobility is independent of the roughness in the gel phase, it exhibits a 5-fold decrease in the fluid phase when the roughness increases from 0.2 to 10 nm. These results are interpreted with a two-phase model allowing for a strong decrease in the lipid mobility in highly curved or defect-induced gel-like nanoscale regions. This suggests a strong link between membrane curvature and fluidity, which is a key property for various cell functions such as signaling and adhesion.
authors.affiliation: Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Blachon
authors.affiliation: Doctoral School for Science and Technology, Platform for Research in NanoSciences and Nanotechnology, Campus Pierre Gemayel, Lebanese University , Fanar-Metn BP 90239 Beirut, Lebanon.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Harb
authors.affiliation: CNRS, INSA de Lyon, LaMCoS, UMR5259, Université de Lyon , 69621 Lyon, France.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Munteanu
authors.affiliation: Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Piednoir
authors.affiliation: Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Fulcrand
authors.affiliation: Université de Strasbourg, Institut Charles Sadron , UPR22, CNRS, 67034 Strasbourg Cedex 2, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Charitat
authors.affiliation: Institut Laue-Langevin , 71 Avenue des Martyrs, F-38042 Grenoble, France.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Fragneto
authors.affiliation: Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Pierre-Louis
authors.affiliation: CINaM-CNRS, Aix-Marseille Université , UMR7325, 13288 Marseille, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Tinland
authors.affiliation: Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France.
authors.forename: Jean-Paul
authors.identifier: 0000-0003-0528-8819
authors.initials: JP
authors.lastname: Rieu
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010316:Particle Size; D010743:Phospholipids / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids