Multi-component modeling of quasielastic neutron scattering from phospholipid membranes

Journal Article · Wed May 07 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4872167· OSTI ID:22252944

D’Angelo, G.; Branca, C.; Trimarchi, A.; Rifici, S.; Finocchiaro, D. ^[1]; Conti Nibali, V. ^[2]; Crupi, C. ^[3]; Ollivier, J. ^[4]; Middendorf, H. D. ^[5]

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1. Dipartimento di Fisica e Scienze della Terra, University of Messina, I-98166 Messina (Italy)
2. Institute for Physical Chemistry II, Ruhr-University Bochum, Bochum (Germany)
3. IPCF-V.le F. Stagno D’Alcontres, n. 37, Messina 98158 (Italy)
4. Institut Laue-Langevin, 6 rue J. Horowitz, BP 156, F-38042 Grenoble (France)
5. Clarendon Laboratory, University of Oxford, Oxford (United Kingdom)

We investigated molecular motions in the 0.3–350 ps time range of D{sub 2}O-hydrated bilayers of 1-palmitoyl-oleoyl-sn-glycero-phosphocholine and 1,2-dimyristoyl-sn-glycero-phosphocholine in the liquid phase by quasielastic neutron scattering. Model analysis of sets of spectra covering scale lengths from 4.8 to 30 Å revealed the presence of three types of motion taking place on well-separated time scales: (i) slow diffusion of the whole phospholipid molecules in a confined cylindrical region; (ii) conformational motion of the phospholipid chains; and (iii) fast uniaxial rotation of the hydrogen atoms around their carbon atoms. Based on theoretical models for the hydrogen dynamics in phospholipids, the spatial extent of these motions was analysed in detail and the results were compared with existing literature data. The complex dynamics of protons was described in terms of elemental dynamical processes involving different parts of the phospholipid chain on whose motions the hydrogen atoms ride.

• OSTI ID: 22252944
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 17 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
HYDROGEN
LIQUIDS
MEMBRANES
NEUTRON REACTIONS
PHOSPHOLIPIDS
QUASI-ELASTIC SCATTERING
SIMULATION
SPECTRA