title: Imaging phase separation in model lipid membranes through the use of BODIPY based molecular rotors.
abstract: In order to fully understand the dynamics of processes within biological lipid membranes, it is necessary to possess an intimate knowledge of the physical state and ordering of lipids within the membrane. Here we report the use of three molecular rotors based on meso-substituted boron-dipyrrin (BODIPY) in combination with fluorescence lifetime spectroscopy to investigate the viscosity and phase behaviour of model lipid bilayers. In phase-separated giant unilamellar vesicles, we visualise both liquid-ordered (Lo) and liquid-disordered (Ld) phases using fluorescence lifetime imaging microscopy (FLIM), determining their associated viscosity values, and investigate the effect of composition on the viscosity of these phases. Additionally, we use molecular dynamics simulations to investigate the orientation of the BODIPY probes within the bilayer, as well as using molecular dynamics simulations and fluorescence correlation spectroscopy (FCS) to compare diffusion coefficients with those predicted from the fluorescence lifetimes of the probes.
authors.affiliation: Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. m.kuimova@imperial.ac.uk nicholas.brooks@imperial.ac.uk.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Dent
authors.forename: Ismael
authors.initials: I
authors.lastname: López-Duarte
authors.forename: Callum J
authors.initials: CJ
authors.lastname: Dickson
authors.forename: Niall D
authors.initials: ND
authors.lastname: Geoghegan
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Cooper
authors.forename: Ian R
authors.initials: IR
authors.lastname: Gould
authors.forename: Rob
authors.initials: R
authors.lastname: Krams
authors.forename: James A
authors.initials: JA
authors.lastname: Bull
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Brooks
authors.forename: Marina K
authors.initials: MK
authors.lastname: Kuimova
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D004058:Diffusion; D008051:Lipid Bilayers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D013050:Spectrometry, Fluorescence; D053835:Unilamellar Liposomes / Q000737:chemistry; D014783:Viscosity
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D008051:Lipid Bilayers; D053835:Unilamellar Liposomes