Solubilization of multilamellar liposomes of egg yolk lecithin by the bile salt sodiumtaurodeoxycholate and the effect of cholesterol--a rapid-ultrafiltration study.
The solubilization of multilamellar egg yolk lecithin liposomes by sodiumtaurodeoxycholate in aqueous phase was studied by ultrafiltration as a function of time, bile salt and cholesterol concentration. The corresponding equilibrium states were analysed. Complete solubilization was achieved at total bile salt/lecithin molar mixing ratios of approximately 5. The minimum ratio to start solubilization was 0.1, corresponding to a free bile salt concentration of only 5% of the critical micelle concentration (CMC). Mean equilibrium constants for the partition of bile salts between non-filterable aggregates and filterable mixed micelles and also the free bile salt concentration were determined. Sodiumtaurodeoxycholate had a higher affinity for small mixed micelles than for lamellar mixed aggregates especially in the presence of cholesterol, which reduces the degree and rate of the solubilization process. A non-homogeneous distribution of bile salts in the lipid phase was detected at low bile salt concentrations.
Müller
K
K
Institut für Röntgenfeinstrukturforschung der Osterreichischen, Akademie der Wissenschaften, Graz, Austria.
Schuster
A
A
D001647:Bile Acids and Salts / Q000378:metabolism*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002784:Cholesterol / Q000494:pharmacology*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives*; D004530:Egg Yolk / Q000032:analysis*; D007700:Kinetics; D008081:Liposomes / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism*; D012995:Solubility; D013657:Taurodeoxycholic Acid / Q000378:metabolism*; D014462:Ultrafiltration / Q000379:methods
D001647:Bile Acids and Salts; D008081:Liposomes; D010713:Phosphatidylcholines; D003840:Deoxycholic Acid; D013657:Taurodeoxycholic Acid; D002784:Cholesterol