Differential effects of conjugated linoleic acid isomers on the biophysical and biochemical properties of model membranes

摘要: Conjugated linoleic acids (CLA) are known to exert several isomer-specific biological effects, but their mechanisms of action unclear. In order determine whether the physicochemical effects CLA on membranes play a role in we synthesized phosphatidylcholines (PCs) with 16:0 at sn-1 position and one four isomers (trans 10 cis 12 (A), trans 9 11 (B), (C), (D)) sn-2, determined biophysical properties monolayers bilayers. The surface areas PCs two natural (A C) were similar all pressures, they differed significantly presence cholesterol, PC-A condensing more than PC-C. Liposomes similarly showed increased binding cholesterol compared PC-C liposomes. liposomes less permeable carboxyfluorescein PC double bonds (B) highest affinity lowest permeability. CLA-PCs stimulated lecithin-cholesterol acyltransferase activity by 2-fold, whereas unnatural (B D) inhibitory. These results suggest that differences A C may partly contribute effects.