ABSTRACT
Studying membrane dynamics requires the application of sophisticated physicochemical techniques, on preferably simple model systems. For this reason many investigations have been performed using model membranes of synthetic phospholipids. Protein dynamics can also be studied in these systems after reconstituting selected membrane proteins into the lipid model bilayers. Due to the anisotropic nature of the phospholipid bilayer with the polar head groups exposed to athe surrounding water and the apolar fatty acyl chains being located in the interior of the bilayer, the reorientational motions are not isotropic. FT-IR and Raman spectroscopy are suitable for the determination of equilibrium conformational characteristics of lipid molecules in their different phases. As lipid molecules do not have strongly fluorescing groups, a fluorescent label has to be bound covalently to the lipid molecule. Fluorescent probe can be introduced into the lipid bilayer. Dynamics of lipid molecules in binary lipid mixtures have not been studied in the same detail as pure lipids or lipid-cholesterol mixtures.
