title: Lipid exchange and flip-flop in solid supported bilayers.
abstract: Inter- and intrabilayer transfer of phospholipid molecules was investigated by neutron reflectometry. The structure of solid supported lipid bilayers exposed to a solution of isotopically labeled vesicles was monitored as a function of temperature, time, and vesicle concentration. Lipid interbilayer exchange was shown to be the time limiting process, while lipid intrabilayer movement, the so-called flip-flop, was too fast to be visualized within the experimental acquisition time. The exchange process was characterized by an Arrhenius-like behavior and the activation energy of the process was concentration-independent. The results are discussed and compared extensively with the literature available on the topic.
authors.affiliation: Institut Laue-Langevin , 6, rue Jules Horowitz, 38042, Grenoble CEDEX 9, France.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Gerelli
authors.forename: Lionel
authors.initials: L
authors.lastname: Porcar
authors.forename: Lucia
authors.initials: L
authors.lastname: Lombardi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Fragneto
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D008958:Models, Molecular; D010743:Phospholipids / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids