title: Probing Intermolecular Interactions in Phospholipid Bilayers by Far-Infrared Spectroscopy.
abstract: Fast thermal fluctuations and low frequency phonon modes are thought to play a part in the dynamic mechanisms of many important biological functions in cell membranes. Here we report a detailed far-infrared study of the molecular subpicosecond motions of phospholipid bilayers at various hydrations. We show that these systems sustain several low frequency collective modes and deduce that they arise from vibrations of different lipids interacting through intermolecular van der Waals forces. Furthermore, we observe that the low frequency vibrations of lipid membrane have strong similarities with the subpicosecond motions of liquid water and suggest that resonance mechanisms are an important element to the dynamics coupling between membranes and their hydration water.
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina , 98122 Messina, Italy.
authors.forename: Giovanna
authors.identifier: 0000-0002-3548-3255
authors.initials: G
authors.lastname: D'Angelo
authors.affiliation: Institute for Physical Chemistry II, Ruhr-University Bochum , 44801 Bochum, Germany.
authors.forename: Valeria
authors.initials: V
authors.lastname: Conti Nibali
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina , 98122 Messina, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Crupi
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina , 98122 Messina, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rifici
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina , 98122 Messina, Italy.
authors.forename: Ulderico
authors.initials: U
authors.lastname: Wanderlingh
authors.affiliation: Dipartimento di Fisica, Università degli Studi di Perugia , 06123 Perugia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Paciaroni
authors.affiliation: Dipartimento di Fisica, Università degli Studi di Perugia , 06123 Perugia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sacchetti
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina , 98122 Messina, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Branca
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D010743:Phospholipids / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; D014867:Water