Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Joint Inst. for Neutron Sciences, Oak Ridge, TN (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Joint Inst. for Neutron Sciences, Oak Ridge, TN (United States)
Joint Inst. for Neutron Sciences, Oak Ridge, TN (United States)
Julich Research Centre (Germany). Julich Centre for Neutron Science (JCNS)
We found that the lipid raft hypothesis presents insight into how the cell membrane organizes proteins and lipids to accomplish its many vital functions. Yet basic questions remain about the physical mechanisms that lead to the formation, stability, and size of lipid rafts. Thus, much interest has been generated in the study of systems that contain similar lateral heterogeneities, or domains. In the current work we present an experimental approach that is capable of isolating the bending moduli of lipid domains. This is accomplished using neutron scattering and its unique sensitivity to the isotopes of hydrogen. Combining contrast matching approaches with inelastic neutron scattering, we isolate the bending modulus of ~13 nm diameter domains residing in 60 nm unilamellar vesicles, whose lipid composition mimics the mammalian plasma membrane outer leaflet. Importantly, the bending modulus of the nanoscopic domains differs from the modulus of the continuous phase surrounding them. Moreover, from additional structural measurements and all-atom simulations, we also determine that nanoscopic domains are in-register across the bilayer leaflets. Taken together, these results inform a number of theoretical models of domain/raft formation and highlight the fact that mismatches in bending modulus must be accounted for when explaining the emergence of lateral heterogeneities in lipid systems and biological membranes.
Nickels, Jonathan D., et al. "Mechanical Properties of Nanoscopic Lipid Domains." Journal of the American Chemical Society, vol. 137, no. 50, Sep. 2015. https://doi.org/10.1021/jacs.5b08894
Nickels, Jonathan D., Cheng, Xiaolin, Mostofian, Barmak, Stanley, Christopher, Lindner, Benjamin, Heberle, Frederick A., Perticaroli, Stefania, Feygenson, Mikhail, Egami, Takeshi, Standaert, Robert F., Smith, Jeremy C., Myles, Dean A. A., Ohl, Michael, & Katsaras, John (2015). Mechanical Properties of Nanoscopic Lipid Domains. Journal of the American Chemical Society, 137(50). https://doi.org/10.1021/jacs.5b08894
Nickels, Jonathan D., Cheng, Xiaolin, Mostofian, Barmak, et al., "Mechanical Properties of Nanoscopic Lipid Domains," Journal of the American Chemical Society 137, no. 50 (2015), https://doi.org/10.1021/jacs.5b08894
@article{osti_1265834,
author = {Nickels, Jonathan D. and Cheng, Xiaolin and Mostofian, Barmak and Stanley, Christopher and Lindner, Benjamin and Heberle, Frederick A. and Perticaroli, Stefania and Feygenson, Mikhail and Egami, Takeshi and Standaert, Robert F. and others},
title = {Mechanical Properties of Nanoscopic Lipid Domains},
annote = {We found that the lipid raft hypothesis presents insight into how the cell membrane organizes proteins and lipids to accomplish its many vital functions. Yet basic questions remain about the physical mechanisms that lead to the formation, stability, and size of lipid rafts. Thus, much interest has been generated in the study of systems that contain similar lateral heterogeneities, or domains. In the current work we present an experimental approach that is capable of isolating the bending moduli of lipid domains. This is accomplished using neutron scattering and its unique sensitivity to the isotopes of hydrogen. Combining contrast matching approaches with inelastic neutron scattering, we isolate the bending modulus of ~13 nm diameter domains residing in 60 nm unilamellar vesicles, whose lipid composition mimics the mammalian plasma membrane outer leaflet. Importantly, the bending modulus of the nanoscopic domains differs from the modulus of the continuous phase surrounding them. Moreover, from additional structural measurements and all-atom simulations, we also determine that nanoscopic domains are in-register across the bilayer leaflets. Taken together, these results inform a number of theoretical models of domain/raft formation and highlight the fact that mismatches in bending modulus must be accounted for when explaining the emergence of lateral heterogeneities in lipid systems and biological membranes.},
doi = {10.1021/jacs.5b08894},
url = {https://www.osti.gov/biblio/1265834},
journal = {Journal of the American Chemical Society},
issn = {ISSN 0002-7863},
number = {50},
volume = {137},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2015},
month = {09}}
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 696https://doi.org/10.1016/j.nima.2012.08.059