ISSN:
1432-1017
Keywords:
Lipid diffusion
;
free volume
;
excimers
;
pressure
;
model membranes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Physics
Notes:
Abstract The translational diffusion of pyrene, pyrene butyric acid and pyrene decanoic acid has been determined in phosphatidylcholine bilayers of different chain length and under pressure up to 200 bars. In the liquid crystalline phase and at a given temperature the diffusion decreases with increasing chain length. At a constant reduced temperature, T red (about 10 K above the transition temperature), long chain lipids exhibit the fastest diffusion which is in disagreement with hydrodynamic models but favours free volume models for diffusion in lipid bilayers. The volume of activation, V act, calculated from the decrease of the diffusion coefficient with pressure, ∂ln D/∂P, depends on lipid chain length. V act decreases with decreasing lipid chain length at a given temperature, T=65°C, and increases at the reduced temperature. These results are again in agreement with the dependence of the diffusion on lipid chain length and therefore with the free volume model.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00293258
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