title: Preparation and characterization of unilamellar vesicles from cholate-phospholipid micelle treated with cholestyramine.
abstract: Cholestyramine, a well-known bile-salt sequestrant, can be used effectively to remove cholate or deoxycholate from a solution of phosphatidylcholine-bile salt mixed micelle. Upon removal of the bile salt, unilamellar phospholipid vesicles form essentially instantaneously. Cholestyramine resin could be pelleted and removed from the vesicle solution after a low speed centrifugation. Based on phosphate analyses, the recovery of vesicles was approximately 60% of the starting material. The average diameter of these vesicles, as estimated by gel exclusion chromatography on sephacryl S-1000 beads and by trapped volume measurement using [3H]sucrose, ranged between 85 to 121 nm. Phosphatidylethanolamine, cholesterol, or n-alkane such as tetradecane can be incorporated into the vesicles without any selective loss; however, selective loss was experienced when negatively charged phospholipid species such as phosphatidylglycerol or phosphatidylserine was included in vesicle formation.
mesh_terms: D002792:Cholestyramine Resin; D019826:Cholic Acid; D002793:Cholic Acids; D008081:Liposomes / Q000302:isolation & purification*; D008823:Micelles; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids
chemical_list: D002793:Cholic Acids; D008081:Liposomes; D008823:Micelles; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D002792:Cholestyramine Resin; D019826:Cholic Acid