title: Phospholipid dependence of calcium ion effects on electrophoretic mobilities of liposomes.
abstract: Electrophoretic light scattering (ELS) and depolarization of fluorescence have been used to determine the effect of membrane fluidity on the binding of Ca2+ to liposomes. ELS was used to measure the electrophoretic mobilities of the liposomes. Fluorescence depolarization was used to determine membrane fluidity. Zero to 30 mol% phosphatidylserine (PS) was incorporated into liposomes containing, as bulk phospholipids, one of the following: dimyristoyl-phosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC), egg phosphatidylcholine (PC), or hydrogenated egg phosphatidylcholine (H egg PC). The binding of Ca2+ to the liposomes appears to be influenced by membrane fluidity. Liposomes containing bulk phospholipids whose phase transition temperature is higher than the experimental temperature exhibit enhanced binding of CA2+.
mesh_terms: D002118:Calcium; D004586:Electrophoresis / Q000379:methods; D008081:Liposomes; D008560:Membrane Fluidity; D010713:Phosphatidylcholines; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D002118:Calcium