Figure 5.

Bilayer affinity of sterol in the presence of the ceramide analogs in complex bilayers. The affinity of CTL (2 mol %) for unilamellar vesicles composed of POPC, POPC/PSM/CHL (60/30/10 or 75/15/10 mol %), and POPC/PSM/Cer/CHL (60/15/15/10 mol %) was deduced from the equilibrium partitioning of CTL between the vesicles (40 μM final lipid concentration) and mβCD at 23°C (solid circles) and 37°C (open circles). Sterol affinity was defined as the molar fraction partition coefficient K_x ± SD for duplicate measurements as previously described (47).