title: Amyloid β-peptide insertion in liposomes containing GM1-cholesterol domains.
abstract: Neuronal membrane damage is related to the early impairments appearing in Alzheimer's disease due to the interaction of the amyloid β-peptide (Aβ) with the phospholipid bilayer. In particular, the ganglioside GM1, present with cholesterol in lipid rafts, seems to be able to initiate Aβ aggregation on membrane. We studied the thermodynamic and structural effects of the presence of GM1 on the interaction between Aβ and liposomes, a good membrane model system. Isothermal Titration Calorimetry highlighted the importance of the presence of GM1 in recruiting monomeric Aβ toward the lipid bilayer. Light and Small Angle X-ray Scattering revealed a different pattern for GM1 containing liposomes, both before and after interaction with Aβ. The results suggest that the interaction with GM1 brings to insertion of Aβ in the bilayer, producing a structural perturbation down to the internal layers of the liposome, as demonstrated by the obtained electron density profiles.
authors.affiliation: National Research Council, Institute of Biostructure and Bioimaging, Via Gaifami 18, Catania, Italy.
authors.forename: Maria Carmela
authors.initials: MC
authors.lastname: Nicastro
authors.affiliation: National Research Council, Institute of Biophysics, Via Ugo La Malfa 153, 90146 Palermo, Italy; Department of Physics and Chemistry, Università di Palermo, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Spigolon
authors.affiliation: National Research Council, Institute of Biophysics, Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Librizzi
authors.affiliation: National Research Council, Institute of Biophysics, Via De Marini, 6, 16149 Genova, Italy.
authors.forename: Oscar
authors.initials: O
authors.lastname: Moran
authors.affiliation: Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Ortore
authors.affiliation: National Research Council, Institute of Biophysics, Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Bulone
authors.affiliation: National Research Council, Institute of Biophysics, Via Ugo La Malfa 153, 90146 Palermo, Italy.
authors.forename: Pier Luigi San
authors.initials: PL
authors.lastname: Biagio
authors.affiliation: National Research Council, Institute of Biophysics, Via Ugo La Malfa 153, 90146 Palermo, Italy. Electronic address: rita.carrotta@pa.ibf.cnr.it.
authors.forename: Rita
authors.initials: R
authors.lastname: Carrotta
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002784:Cholesterol / Q000737:chemistry*; D005677:G(M1) Ganglioside / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D016229:Amyloid beta-Peptides; D008081:Liposomes; D005677:G(M1) Ganglioside; D002784:Cholesterol
keywords: Aβ-membrane interaction; Double layer perturbation; Isothermal titration calorimetry; Small angle X-ray scattering