Grazing-Angle Neutron Diffraction Study of the Water Distribution in Membrane Hemifusion: From the Lamellar to Rhombohedral Phase
Abstract
The water distribution between lipid bilayers is important in understanding the role of the hydration force at different steps of the membrane fusion pathway. Here in this study, we used grazing-angle neutron diffraction to map out the water distribution in lipid bilayers transiting from a lamellar structure to the hemifusion “stalk” structure in a rhombohedral phase. Under osmotic pressure exerted by different levels of relative humidity, the lipid membrane sample was maintained in equilibrium at different lattices suitable for neutron diffraction. The D2O used to hydrate the lipid membrane sample stood out from the lipid in the reconstructed structure because of its much higher coherent neutron scattering length density. The density map indicates that water dissociated from the headgroup in the lamellar phase. In the rhombohedral phase, water was significantly reduced and was squeezed into pockets around the stalk. This study complements earlier structural studies by grazing-angle X-ray diffraction, which is sensitive to only the parts of the structure with high electron density (such as phosphors). The experiment also demonstrated that the recently developed time-of-flight small-angle neutron scattering beamline at the Spallation Neutron Source is suitable for grazing-angle neutron diffraction to provide the structures of large unit cells on themore »
- Authors:
-
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division, and Center for Structural Molecular Biology
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- OSTI Identifier:
- 1471910
- Grant/Contract Number:
- AC05-00OR22725
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Journal of Physical Chemistry Letters
- Additional Journal Information:
- Journal Volume: 9; Journal ID: ISSN 1948-7185
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 59 BASIC BIOLOGICAL SCIENCES; membrane fusion; hydration force; water; grazing-angle neutron diffraction
Citation Formats
Qian, Shuo, and Rai, Durgesh K. Grazing-Angle Neutron Diffraction Study of the Water Distribution in Membrane Hemifusion: From the Lamellar to Rhombohedral Phase. United States: N. p., 2018.
Web. doi:10.1021/acs.jpclett.8b01602.
Qian, Shuo, & Rai, Durgesh K. Grazing-Angle Neutron Diffraction Study of the Water Distribution in Membrane Hemifusion: From the Lamellar to Rhombohedral Phase. United States. https://doi.org/10.1021/acs.jpclett.8b01602
Qian, Shuo, and Rai, Durgesh K. Thu .
"Grazing-Angle Neutron Diffraction Study of the Water Distribution in Membrane Hemifusion: From the Lamellar to Rhombohedral Phase". United States. https://doi.org/10.1021/acs.jpclett.8b01602. https://www.osti.gov/servlets/purl/1471910.
@article{osti_1471910,
title = {Grazing-Angle Neutron Diffraction Study of the Water Distribution in Membrane Hemifusion: From the Lamellar to Rhombohedral Phase},
author = {Qian, Shuo and Rai, Durgesh K.},
abstractNote = {The water distribution between lipid bilayers is important in understanding the role of the hydration force at different steps of the membrane fusion pathway. Here in this study, we used grazing-angle neutron diffraction to map out the water distribution in lipid bilayers transiting from a lamellar structure to the hemifusion “stalk” structure in a rhombohedral phase. Under osmotic pressure exerted by different levels of relative humidity, the lipid membrane sample was maintained in equilibrium at different lattices suitable for neutron diffraction. The D2O used to hydrate the lipid membrane sample stood out from the lipid in the reconstructed structure because of its much higher coherent neutron scattering length density. The density map indicates that water dissociated from the headgroup in the lamellar phase. In the rhombohedral phase, water was significantly reduced and was squeezed into pockets around the stalk. This study complements earlier structural studies by grazing-angle X-ray diffraction, which is sensitive to only the parts of the structure with high electron density (such as phosphors). The experiment also demonstrated that the recently developed time-of-flight small-angle neutron scattering beamline at the Spallation Neutron Source is suitable for grazing-angle neutron diffraction to provide the structures of large unit cells on the order of a few nanometers, such as biomembrane structures.},
doi = {10.1021/acs.jpclett.8b01602},
journal = {Journal of Physical Chemistry Letters},
number = ,
volume = 9,
place = {United States},
year = {Thu Sep 20 00:00:00 EDT 2018},
month = {Thu Sep 20 00:00:00 EDT 2018}
}
Web of Science
Figures / Tables:
Figures / Tables found in this record: