View Generic Document: Phase Behavior of Mixed Lipid Bilayered System
Citation:
Rodriguez-Rivera, Veronica (2005). Phase Behavior of Mixed Lipid Bilayered System. National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce..
Lipid mixtures of short and long amphiphile chains self-assemble in water to form a great variety of structures. The morphology of these structures include phases composed of
extended flexible bilayer membrane that may display order by stacking with a periodicity as in the anisotropic lamellar phase, or they may also form bilayered miscelles (or bicelles), bilayered
disks formed of a long lipid chain with their edges stabilized by short chain lipid, with diameter of a few hundred angstroms. The lipid mixtures have a great potential in the study of membrane
proteins and peptides. These mixtures imitate the physical properties of biological membranes and they are stable over a wide range of temperatures, pH and ionic strength. By having a detailed
description of the morphology of the lipid mixtures and understanding their phases will help increase their use in various structural biology techniques. Our goal was to study the effect on
transition between the bicelle to lamellar phase by changing the concentration of lipid in the solution. Each sample consisted of molar ratios of DHPC:DMPC:DMPG of 0.2:1:0.067. The concentration of
lipid was of 20%, 10% and 5%. The 20% sample has a liquid to gel phase transition temperature of near 25°C. The lamellar phase forms above 25°C. By lowering the sample’s concentration and by an
isotropic substitution of H2O by D2O, we found some intriguing results: the liquid to gel phase transition and lamellar phase temperature shifted. SANS, reflectometry and crossed polarizers were
use to study the transition between the bicelle to lamellar phase. With these results, the structure of the phase boundary between the bicelles and lamellar morphology was better understood and
characterized.
Publisher
National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce.
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View Generic Document: Phase Behavior of Mixed Lipid Bilayered System 