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

Journal Article · Sat Apr 01 00:00:00 EDT 2017 · Biophysical Journal

DOI:https://doi.org/10.1016/j.bpj.2017.02.033· OSTI ID:1432720

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

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. Lastly, 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.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1432720
• Alternate ID(s): OSTI ID: 1351775; OSTI ID: 1398313
• Journal Information: Biophysical Journal, Journal Name: Biophysical Journal Vol. 112 Journal Issue: 7; ISSN 0006-3495
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES