Fusion of sulfatide-containing vesicles of phosphatidylcholine.
Positively charged albumin is described as a 'useful tool' to induce both aggregation and fusion of phosphatidylcholine vesicles containing sulfatide. Techniques that include light-scattering, Sepharose chromatography, centrifugation, electron microscopy, trapped volume determination and scanning calorimetry demonstrate that extensive fusion occurs during aggregation when sulfatide concentrations are above 4-5 mol%. The rate of fusion increases with time for 1-2 h, then reaches a plateau. Fusion occurs extensively above the transition temperature of the phospholipid and is strongly inhibited by increasing concentration of vesicle cholesterol. The significance of both membrane fluidity and sulfatide-phospholipid organization in the fusion mechanism are discussed.
D055598:Chemical Phenomena; D002621:Chemistry; D008027:Light; D008560:Membrane Fluidity; D008561:Membrane Fusion; D008563:Membrane Lipids; D008854:Microscopy, Electron; D010713:Phosphatidylcholines; D012542:Scattering, Radiation; D012710:Serum Albumin, Bovine; D013433:Sulfoglycosphingolipids; D013816:Thermodynamics
D008563:Membrane Lipids; D010713:Phosphatidylcholines; D013433:Sulfoglycosphingolipids; D012710:Serum Albumin, Bovine