Alpha-tocopherol interacts with natural micelle-forming single-chain phospholipids stabilizing the bilayer phase.
The effect of the association of alpha-tocopherol (vitamin E) with single chain or very asymmetric phospholipids has been studied by 31P nuclear magnetic resonance, Fourier transform infrared spectroscopy, and light microscopy. Our results demonstrate that alpha-tocopherol stabilizes and forms bilayer structures in systems composed of either 1-palmitoyl-sn-glycero-3-phosphocholine, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine, 1-O-hexadecyl-sn-glycero-3-phosphocholine, or 1,2-dipalmitoyl-sn-glycero-3- phosphocholine/1-palmitoyl-sn-glycero-3-phosphocholine, whereas in the absence of alpha-tocopherol all these systems produce micellar structures. The free hydroxyl group of alpha-tocopherol is shown to be important in stabilizing the bilayer structure by comparing the effects produced by an analog of alpha-tocopherol, alpha-tocopheryl acetate, which has the hydroxyl group blocked by an acetyl group. It is suggested that the complementary shapes of alpha-tocopherol and the asymmetric phospholipids may be the reason for the stabilization of the bilayer structure.
Salgado
J
J
Departamento de Bioquímica y Biología Molecular (A), Universidad de Murcia, Spain.
Villalaín
J
J
Gómez-Fernández
J C
JC
D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008823:Micelles; D008961:Models, Structural; D008968:Molecular Conformation; D010713:Phosphatidylcholines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D014810:Vitamin E / Q000737:chemistry*
D008051:Lipid Bilayers; D008823:Micelles; D010713:Phosphatidylcholines; D014810:Vitamin E