Line Tension Controls Liquid-Disordered + Liquid-Ordered Domain Size Transition in Lipid Bilayers

Rebecca D Usery; Thais A Enoki; Sanjula P Wickramasinghe; Michael D Weiner; Wen-Chyan Tsai; Mary B Kim; Shu Wang; Thomas L Torng; David G Ackerman; Frederick A Heberle; John Katsaras; Gerald W Feigenson

doi:10.1016/j.bpj.2017.02.033

Line Tension Controls Liquid-Disordered + Liquid-Ordered Domain Size Transition in Lipid Bilayers

Biophys J. 2017 Apr 11;112(7):1431-1443. doi: 10.1016/j.bpj.2017.02.033.

Authors

Affiliations

¹ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York.
² Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York; Department of Biochemistry and Biophysics at the University of Pennsylvania, Philadelphia, Pennsylvania.
³ Department of Physics, Cornell University, Ithaca, New York.
⁴ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York; Department of Medicine, Baylor College of Medicine, Houston, Texas.
⁵ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York; Harvard Medical School Library of Integrated Network-based Cellular Signatures Center and Laboratory of Systems Pharmacology, Harvard University, Boston, Massachusetts.
⁶ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York; Department of Biochemistry, Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire.
⁷ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York; Scientific Computing, Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia.
⁸ Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee; The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee.
⁹ Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee.
¹⁰ Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York. Electronic address: gwf3@cornell.edu.

Abstract

To better understand animal cell plasma membranes, we studied simplified models, namely four-component lipid bilayer mixtures. Here we describe the domain size transition in the region of coexisting liquid-disordered (Ld) + liquid-ordered (Lo) phases. This transition occurs abruptly in composition space with domains increasing in size by two orders of magnitude, from tens of nanometers to microns. We measured the line tension between coexisting Ld and Lo domains close to the domain size transition for a variety of lipid mixtures, finding that in every case the transition occurs at a line tension of ∼0.3 pN. A computational model incorporating line tension and dipole repulsion indicated that even small changes in line tension can result in domains growing in size by several orders of magnitude, consistent with experimental observations. We find that other properties of the coexisting Ld and Lo phases do not change significantly in the vicinity of the abrupt domain size transition.

MeSH terms

Biophysical Phenomena*
Electron Spin Resonance Spectroscopy
Lipid Bilayers / chemistry*
Molecular Dynamics Simulation
Neutron Diffraction
Phase Transition*
Scattering, Small Angle

Substances

Lipid Bilayers

Abstract

MeSH terms

Substances

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