title: Distribution of BODIPY-labelled phosphatidylethanolamines in lipid bilayers exhibiting different curvatures.
abstract: In this paper we have investigated the behaviour of newly synthesised mono-palmitoyl- and dipalmitoyl-phosphatidylethanolamine probes (abbreviated as mPE and dPE, respectively) labelled in the polar headgroup region by either the FL-BODIPY or the 564/570-BODIPY fluorophore and solubilised in lipid systems that exhibit different curvatures. Because of the bulky BODIPY-groups, the monoacyl-form derivatives have a conic-like shape, whereas that for the diacyl derivatives is rather cylindrical. A careful analysis of time-resolved resonance energy transfer experiments by means of analytical models as well as Monte Carlo simulations shows that the mPE derivatives have a comparable affinity to highly curved bilayer regions (torroidal pores formed by magainin-2 in lipid bilayers, or the rims of discoid bicelles) and to planar bilayer regions (i.e. the flat region of lipid bilayers and bicelles). Furthermore, the monoacyl-probes are as compared to the diacyl-probes effectively closer to each other in a lipid bilayer, while none of these probes seems to be randomly distributed. Self-aggregation is most efficiently induced by the larger aromatic 564/570-BODIPY chromophore, but it is suppressed when using the diacyl instead of the monoacyl-form, and/or by attaching BODIPY-groups to the acyl-chain.
authors: Department of Chemistry: Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden.
authors: Radek
authors: R
authors: Šachl
authors: Ilya
authors: I
authors: Mikhalyov
authors: Natalia
authors: N
authors: Gretskaya
authors: Agnieszka
authors: A
authors: Olżyńska
authors: Martin
authors: M
authors: Hof
authors: Lennart B-Å
authors: LB
authors: Johansson