Interaction of phosphatidylcholine liposomes and plasma lipoproteins with sheep erythrocyte membranes. Preferential transfer of phosphatidylcholine containing unsaturated fatty acids.
The interaction of sheep erythrocyte membranes with phosphatidylcholine vesicles (liposomes) or human plasma lipoproteins is described. Isolated sheep red cell membranes were incubated with liposomes containing [14C]phosphatidylcholine or [3H]phosphatidylcholine in the presence of EDTA. A time-dependent uptake of phosphatidylcholine into the membranes could be observed. The content of this phospholipid was increased from 2 to 5%. The rate of transfer was dependent on temperature, the amount of phosphatidylcholine present in the incubation mixture and on the fatty acid composition of the liposomal phosphatidylcholine. A possible adsorption of lipid vesicles to the membranes could be monitored by adding cholesteryl [14C]oleate to the liposomal preparation. As cholesterylesters are not transferred between membranes [1], it was possible to differentiate between transfer of phosphatidylcholine molecules from the liposomes into the membranes and adsorption of liposomes to the membranes. The phosphatidylcholine incorporated in the membranes was isolated, and its fatty acids were analysed by gas chromatography. It could be shown that there was a preferential transfer of phosphatidylcholine molecules containing two unsaturated fatty acids.
D000818:Animals; D002250:Carbon Radioisotopes; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D006801:Humans; D007700:Kinetics; D008074:Lipoproteins / Q000097:blood*; D008081:Liposomes; D010713:Phosphatidylcholines / Q000097:blood*; D012756:Sheep; D013329:Structure-Activity Relationship
D002250:Carbon Radioisotopes; D005231:Fatty Acids, Unsaturated; D008074:Lipoproteins; D008081:Liposomes; D010713:Phosphatidylcholines