Fig. 4.

Human ASBT (hASBT) is associated with DI fractions of human ileal brush-border membrane vesicles (BBMVs). A: human ileal BBMVs were treated with MβCD in the presence or the absence of 1.25 mM cholesterol or with vehicle alone and solubilized with Triton X-100, and then DS and DI fractions were isolated as described in materials and methods. Equal amounts of proteins (~80 μg) from DI and DS fractions were separated by electrophoresis on 10% polyacrylamide gel and then analyzed by Western blotting for ASBT and actin expression. B: blots were scanned, and the densities of the bands were determined by densitometric analysis. y-Axis indicates the density of DI fractions from the Optiprep gradient. Data are expressed as arbitrary units with control set as 100% and are means ± SE of 4 separate experiments. *P < 0.05 compared with control.