[Lipid asymmetry and alpha-tocopherol distribution in outer and inner monolayers of bilayer lipid membranes]

Using chemical modification of aminophospholipids (phosphatidylethanolamine, PEA; phosphatidylserin, PS), the location of these phospholipids and their fatty acids has been studied in the inner and outer monolayers of unilayer liposomes. It has been shown that both PEA and PS were located predominantly in the inner monolayer and contained most of the polyenoic fatty acid residues. alpha-tocopherol incorporated into these liposomes was also located predominantly in the inner monolayers. In the liposomes, prepared from a single phospholipid (dioleoylphosphatidylcholine) no asymmetrical distribution of incorporated alpha-tocopherol was observed.