Permeability properties of unilamellar vesicles containing choline plasmalogens and comparison with other choline glycerophospholipid species

✍ Scribed by A. Hermetter; F. Paltauf

• Book ID: 103037342
• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 482 KB
• Volume: 29
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(81)90053-0

✦ Synopsis

The rates of non-electrolyte and ion diffusion across bilayer membranes consisting of choline plasmalogens or of their alkyl and acyl analogs were studied. The influx of [~4C]glucose, 86Rb÷ and 3'C1-into small unilamellar vesicles made from a semisynthetic choline plasmalogen and from synthetic diacyl, alkylacyl and dialkyl analogs with comparable side chain compositions were measured. Rates of glucose and Rb ÷ diffusion are about equal in alkenylacyl-and diacyl-glyceropliosphocholine (GPC) bilayers, but are reduced in dialkyl-GPC membranes; the permeability coefficients correlate with the packing densities of the respective choline glycerophospholipids in monolayers at the air water interface. Rates of chloride diffusion are consistently higher in membranes formed from phospholipids containing alkenyl or alkyl ether bonds as compared to the diacyl analogs. Highest rates of C1-diffusion are observed with choline plasmalogen vesicles. The phospholipid side chain composition has little influence on C1-permeation, but glucose and Rb ÷ diffusion are markedly affected. Incorporation of cholesterol (30 mol%) into choline plasmalogen membranes reduces their solute permeability by approximately 70%. A similar effect is found with the other choline phospholipid analogs. Thus, the choline phospholipid-cholesterol interaction, as far as it is reflected in reduced bilayer permeability, is not influenced by the presence of the alkenylether bond of plasmalogens.