Figure 2. Sub-proteomics of caveolin-enriched, DRM fractions.

HUVEC were fractionated by sucrose-gradient ultracentrifugation as described in the Experimental section and equal amounts of each fraction were analysed by SDS/PAGE, stained with (A) Coomassie Brilliant Blue (CBB) and immunoblotted for transferrin receptor (TfR) for PM, PDI for ER and CAV1 for caveolae. Molecular masses (in kDa) are indicated. DRM fractions 4 and 5 were further analysed by two-dimensional gel electrophoresis, followed by excision of protein spots and identification by MS as described. (B) A composite two-dimensional DRM map is depicted with protein names labelling (stretches of) identified proteins. Molecular masses and pI markers are indicated.