Barrier characteristics of membrane model systems containing unsaturated phosphatidylethanolamines

✍ Scribed by P.C. Noordam; C.J.A. van Echteld; B. de Kruijff; A.J. Verkleij; J. de Gier

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 751 KB
• Volume: 27
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(80)90037-7

✦ Synopsis

The barrier characteristics of membrane model systems containing unsaturated phosphatidylethanolamines have been investigated. (1) At increasing temperatures 18: Ic/18: lcphosphatidylethanolamine liposomes lose their permeability barrier for K* as a consequence of the transition from a lamellar to a hexagonal orientation as detected by ~1P-NMR and freeze-fracturing electron microscopy. (2) Introduction of 18:lc/18:lc-phosphatidyleholine in the 18:1 e/18:1 c-phosphatidylethanolamine lipid system stabilizes the bilayer structure and the permeability barrier for K ÷ and glucose while cholesterol destabilizes. (3) Upon heating of the investigated 18:1 c/18:1 e-phosphatidylcholine-I 8:1 e] 18:1 c-phosphatidylethanolamine-(cholesterol) mixtures, structures are formed which give rise to isotropie 3~P-NMR signals and which on the basis of freeze-fracture pictures are interpreted as sponge-like structures. Lowering the temperature results in restoration of the barrier function of the lipid structures.