MAGIC-ANGLE-SPINNING C-13-NMR SPIN-LATTICE RELAXATION STUDY OF THE LOCATION AND EFFECTS OF ALPHA-TOCOPHEROL, UBIQUINONE-10 AND UBIQUINOL-10IN UNSONICATED MODEL MEMBRANES

Alpha-Tocopherol, ubiquinone-10 and ubiquinol-10 have been studied by high resolution magic angle samples spinning C-13-nuclear magnetic res onance in egg yolk phosphatidylcholine multilamellar vesicles model me mbranes in order to assess their location and the induced perturbation s on this model system. Alpha-Tocopherol is placed in such a position that it is in close contact with the head group of the phospholipid an d exposed to the solvent. In this position it significantly perturbs t he phospholipid head group, the 5a-CH3 and the 7a-CH3 groups being the closest parts to the membrane surface. On the other hand, ubiquinol-1 0 perturbs the membrane surface more than ubiquinone-10, but neither c ompound significantly changed the phospholipid head group conformation .