Purification of caveolin-enriched membrane fraction from CHO-CD36 cells and identification the colocalization of caveolin and CD36 proteins. Purification of the caveolin-enriched membrane fraction was as described in Materials and Methods. A: Coomassie blue staining of protein profile from purification fractions. Lane 1, whole cell lysate (80 μg); lane 2, post nuclear supernatant (60 μg), lane 3, Optiprep gradient fraction (30 μg), and lane 4, caveolin-enriched membrane fraction (20 μg). The same amount of proteins (30 μg) from each fraction as in Panel A was analyzed with Western blots by anti-CD36 antibody (B) and anti-caveolin antibody(C).