Quasielastic Light Scattering Studies of Micelle Formation and Cholesterol Precipitation in Model Bile Solutions

Quantitative Examination of the Simple Micelle–Mixed Micelle Coexistence for the Taurocholate–Lecithin System by GP-HPLC

“…It is noteworthy that essentially the same mixed micelle TC peak could be detected after the injection of a L suspension (i.e., L vesicles), is consistent with that for TC simple micelles but somewhat which was the case when the injected TC concentration was larger than values from other studies under similar conditions zero. This finding suggests that the phase transition between where n values in the range of 4 to 6 have been reported L vesicles and TC-L mixed micelles is very rapid compared (18)(19)(20). One may speculate on possible reasons for this to the elution times involved.…”

Cholesterol Binding to Simple Micelles in Aqueous Bile-Salt–Cholesterol Solutions

“…A previous study showed 10% positive deviations from After equilibration, duplicate 100-ml samples of the solution were taken for Ch concentration determination using a Henry's law in TC-Ch solution (10). Furthermore, it was confirmed that the uptake of Ch by the silicone film is a scintillation counter (Beckman Instruments Inc., Irvine, tions, the primary simple TC micelles cannot associate further into large rodlike aggregates (secondary micelles) (5,16). Funasaki et al (27) proposed a stepwise aggregation model; however, the resulting aggregation constant (3.18 mM 01 ) of k 6 was much higher than the aggregation constants (1.2 1 10 03 to 4.2 1 10 01 mM 01 ) other than k 6 , indicating that simple TC micelles with n equal to 6 were dominant in the solution.…”

“…Figure 2 shows that, although the TC molecule used contains nearly constant in aqueous solution even when the total TC concentration increased from 80 to 300 mM. Mazer et al three hydroxyl groups (3a, 7a, and 12a) relative to the two hydroxyl groups in TCDC (3a and 7a) and TUDC (3a and (1, 2, 14, 16) conducted quasielastic light-scattering studies for particle size measurement of simple TC micelles at dif-7b), the 7b-hydroxyl group in TUDC is almost in parallel with the taurine group, thus causing higher hydrophilicity ferent concentrations of TC solutions containing 0.15 M NaCl and obtained a constant hydrodynamic radius (Ç10 (lower hydrophobicity) (1,16,17). Nevertheless, due to the three hydroxyl groups, TCDC is more hydrophobic than Å ).…”

“…Other experiments also showed that the effective hydrophobic surface area, estimated by measuring the surface pressure and surface potential, corresponds precisely to the hydrophobicity and solubilization capacity of each bile salt (7,19). As mentioned above, the hydrophobicity of bile salts increases in the order TUDC õ TC õ TCDC (1,16,17 [6] bile-salt-Ch systems.…”

“…This is likely because Ch, and TCDC-Ch systems. For convenience, the following TCDC is more hydrophobic than TC, which in turn is more equations, derived from mass action and mass balance laws, hydrophobic than TUDC, as determined previously by high-are used for calculation performance liquid chromatography (1,16,17). Hence, the K S1 and K S2 values obtained for simple TC and TCDC micelles suggest that, in contrast to the behavior of simple TC micelles, simple TCDC micelles with one Ch molecule exhibit much more hydrophobicity than unbound simple TCDC micelles, although the precise location of Ch in the simple TCDC micelle is not known.…”