1. Line Tension Controls Liquid-Disordered + Liquid-Ordered Domain Size Transition in Lipid Bilayers
- Author
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Michael D. Weiner, Thais A. Enoki, Frederick A. Heberle, Mary B. Kim, Wen-Chyan Tsai, Gerald W. Feigenson, Sanjula P. Wickramasinghe, David G. Ackerman, Rebecca D. Usery, Shu Wang, John Katsaras, and Thomas Torng
- Subjects
0301 basic medicine ,Phase transition ,Membranes ,Orders of magnitude (temperature) ,Tension (physics) ,Chemistry ,Cell Membrane ,Lipid Bilayers ,Biophysics ,03 medical and health sciences ,Molecular dynamics ,Crystallography ,Dipole ,030104 developmental biology ,Membrane Microdomains ,Chemical physics ,Lipid bilayer ,Order of magnitude ,Line (formation) - 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.
- Published
- 2017