Direct comparison of elastic incoherent neutron scattering experiments with molecular dynamics simulations of DMPC phase transitions
Neutron scattering techniques have been employed to investigate 1,2-dimyristoyl-sn -glycero-3-phosphocholine (DMPC) membranes in the form of multilamellar vesicles (MLVs) and deposited, stacked multilamellar-bilayers (MLBs), covering transitions from the gel to the liquid phase. Neutron diffraction...
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| Main Authors: | , , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
27 April 2016
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| In: |
The European physical journal. E, Soft matter
Year: 2016, Volume: 39, Issue: 4 |
| ISSN: | 1292-895X |
| DOI: | 10.1140/epje/i2016-16048-y |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1140/epje/i2016-16048-y
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| Author Notes: | Bachir Aoun, Eric Pellegrini, Marcus Trapp, Francesca Natali, Laura Cantù, Paola Brocca, Yuri Gerelli, Bruno Demé, Michael Marek Koza, Mark Johnson, and Judith Peters |
| Summary: | Neutron scattering techniques have been employed to investigate 1,2-dimyristoyl-sn -glycero-3-phosphocholine (DMPC) membranes in the form of multilamellar vesicles (MLVs) and deposited, stacked multilamellar-bilayers (MLBs), covering transitions from the gel to the liquid phase. Neutron diffraction was used to characterise the samples in terms of transition temperatures, whereas elastic incoherent neutron scattering (EINS) demonstrates that the dynamics on the sub-macromolecular length-scale and pico- to nano-second time-scale are correlated with the structural transitions through a discontinuity in the observed elastic intensities and the derived mean square displacements. Molecular dynamics simulations have been performed in parallel focussing on the length-, time- and temperature-scales of the neutron experiments. They correctly reproduce the structural features of the main gel-liquid phase transition. Particular emphasis is placed on the dynamical amplitudes derived from experiment and simulations. Two methods are used to analyse the experimental data and mean square displacements. They agree within a factor of 2 irrespective of the probed time-scale, i.e. the instrument utilized. Mean square displacements computed from simulations show a comparable level of agreement with the experimental values, albeit, the best match with the two methods varies for the two instruments. Consequently, experiments and simulations together give a consistent picture of the structural and dynamical aspects of the main lipid transition and provide a basis for future, theoretical modelling of dynamics and phase behaviour in membranes. The need for more detailed analytical models is pointed out by the remaining variation of the dynamical amplitudes derived in two different ways from experiments on the one hand and simulations on the other. |
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| Item Description: | Gesehen am 18.08.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1292-895X |
| DOI: | 10.1140/epje/i2016-16048-y |