PHYS 246 |
| Cell membranes have complex lipid compositions, including an asymmetric distribution of phospholipids between the opposing leaflets of the bilayer. While it has been demonstrated that the lipid composition of the outer leaflet of the plasma membrane is sufficient for the formation of raft-like liquid-ordered phase domains, the influence that such domains may have on the lipids and proteins of the inner leaflet remains unknown. We built asymmetric planar supported bilayers with similar lipid compositions as found in plasma membranes. FLIC microscopy has been used to measure lipid asymmetry as a function of time and to measure rates of lipid flip-flop in supported bilayers. Lipid diffusion in asymmetric bilayers with coexisting liquid phases has been measured by single molecule fluorescence tracking. We demonstrate the impact of different lipid phases in one leaflet on the diffusion of lipids in different phases in the adjacent leaflet. |
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Physical Chemical Foundations of Biological Membrane Phenomena
1:20 PM-5:00 PM, Tuesday, 12 September 2006 Grand Hyatt San Francisco -- Merced, Oral
Division of Physical Chemistry |