Figure 3.

Fluorescence-based determination of the CMC and aggregation number of CHOBIMALT micelles. A. Observed fluorescence from 10 μM 8-ANS as a function the CHOBIMALT concentration. B. Expansion of the low [CHOBIMALT] region of (A). C. Plots of the reciprocal of the relative fluorescence intensity from 3A versus the concentration of CHOBIMALT create a breakpoint that leads to estimate of CHOBIMALT’s apparent critical micellar concentration (roughly 3 μM). D. Fluorescence intensity from 250 nM 8-ANS as a function of the CHOBIMALT concentration in water only or in 10 mM Na-phosphate, 100mM NaCl, pH 7. Apparent CMCs of 4.0 ± 0.1 mM and 4.2 ± 0.2 mM were derived, respectively. E. Fluorescence from 1 nM pyrene as a function of the concentrations of CHOBIMALT, cholesterol, and DDM. In the case of CHOBIMALT the inflection points for the two sigmoidal transitions were determined to be 70 nM and 3 μM. F. Calibration of coumarin-153 partitioning between solution and CHOBIMALT micelles using 1 and 5 μM coumarin-153. G. Fluorescence quenching of pyrene as a function of the concentration of coumarin-153 quencher, at either 0.1% (1 mM) or 0.5% (5 mM) CHOBIMALT. From the slopes of the linear fits to these data micelle concentrations were extracted that permitted estimation of the aggregation numbers for CHOBIMALT micelles at 0.1% and 0.5% total concentrations (185 ± 35 and 222 ±11, respectively). Samples were in pure water. H. Same as F except that solutions contained 10 mM phosphate buffer, pH 7 and 100 mM NaCl. In this case aggregation numbers were determined to be 200 ± 20 at 0.1% CHOBIMALT and 228 ± 25 at 0.5%.