Abstract
Lateral organization of lipids in the cell membrane appears to be an ancient feature of the cell, given the existence of lipid rafts in both eukaryotic and prokaryotic cells. Currently seen as platforms for protein partitioning, we posit that lipid rafts are capable of playing another role: stabilizing membrane physical properties over varying temperatures and other environmental conditions. Membrane composition defines the mechanical and viscous properties of the bilayer. The composition also varies strongly with temperature, with systematic changes in the partitioning of high and low melting temperature membrane components. In this way, rafts function as buffers of membrane physical properties, progressively counteracting environmental changes via compositional changes; i.e., more high melting lipids partition to the fluid phase with increasing temperature, increasing the bending modulus and viscosity, as thermal effects decrease these same properties. To provide an example of this phenomenon, we have performed neutron scattering experiments and atomistic molecular dynamics simulations on a phase separated model membrane. The results demonstrate a buffering effect in both the lateral diffusion coefficient and the bending modulus of the fluid phase upon changing temperature. This demonstration highlights the potentially advantageous stabilizing effect of complex lipid compositions in response to temperature and potentially other membrane destabilizing environmental conditions.
Original language | English |
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Pages (from-to) | 2050-2056 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry B |
Volume | 123 |
Issue number | 9 |
DOIs | |
State | Published - Mar 7 2019 |
Bibliographical note
Publisher Copyright:© 2019 American Chemical Society.
Funding
The authors would like to acknowledge the extraordinary technical support of Malcolm Cochran. R.J.A., S.H., and M.C.R. were supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and McMaster University. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05- 00OR22725. This research also used resources of the Ohio Supercomputer Center (OSC) provided to X.C. This research also used resources of the Compute and Data Environment for Science (CADES) provided to M.D.S. M.D.S. was partially supported by ORNL Laboratory Directed R&D (LDRD) project 8294. J.K. is supported through the Scientific User Facilities Division of the Department of Energy (DOE) Office of Science, sponsored by the Basic Energy Science (BES) Program, DOE Office of Science, under Contract No. DEAC05-00OR22725. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The authors would like to acknowledge the extraordinary technical support of Malcolm Cochran. R.J.A., S.H., and M.C.R. were supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and McMaster University. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This research also used resources of the Ohio Supercomputer Center (OSC) provided to X.C. This research also used resources of the Compute and Data Environment for Science (CADES) provided to M.D.S. M.D.S. was partially supported by ORNL Laboratory Directed R&D (LDRD) project 8294. J.K. is supported through the Scientific User Facilities Division of the Department of Energy (DOE) Office of Science, sponsored by the Basic Energy Science (BES) Program, DOE Office of Science, under Contract No. DEAC05-00OR22725. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.
Funders | Funder number |
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Basic Energy Science | |
CADES | |
DOE Office of Science | |
Data Environment for Science | |
ORNL Laboratory Research and Development Program | |
U.S. Department of Energy | |
Office of Science | DE-AC05-00OR22725 |
Basic Energy Sciences | |
Oak Ridge National Laboratory | |
Laboratory Directed Research and Development | 8294 |
Cades Foundation | |
McMaster University | |
Natural Sciences and Engineering Research Council of Canada |