PHYS 656 |
| Micro domains form during the phase transition in synthetic membranes composed of single phospholipids or of a mixture of phospholipids with different transition temperature. The fluctuations in size and time of micro domains have not been studied extensively. We describe novel results obtained using the Laurdan fluorescence probe that report on the local water penetration in the membrane. The system studied are giant unilamellar vesicles that are well visible under the microscope. Both the excitation and the emission spectrum of Laurdan are affected by the surrounding packing of the lipids. Using a two-photon microscope and the recently described scanning fluorescence correlation spectroscopy technique we were able to study the onset of phase separation. We also describe how the phases in the two lamellae of the membrane get coupled over time. A surprising result of our studies is the relatively large micro heterogeneity of the lipid liquid phase. |
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Physical Chemical Foundations of Biological Membrane Phenomena
1:20 PM-5:00 PM, Thursday, 14 September 2006 Grand Hyatt San Francisco -- Merced, Oral
Division of Physical Chemistry |