Fig. 4.
Isolation of caveolin-enriched, detergent-insoluble microdomains from type 1 astrocytes. Detergent-insoluble complexes were isolated from type 1 astrocytes and from lung tissue as described in Materials and Methods.A, Equal amounts of protein (20 μg/lane) were separated by SDS-PAGE and processed for immunoblot analysis using anti-caveolin mAb C060. In type 1 astrocytes, only the α isoform of caveolin-1 is detected (lanes 1, 2represent two separate astrocyte preparations). In complexes isolated from lung, both the α and β isoforms of caveolin-1 are detected (lane 3). B, C, Equal volumes of fractions collected across the gradient were resolved by SDS-PAGE and processed for immunoblot analyses using anti-caveolin mAb 2234 or anti-caveolin affinity-purified polyclonal antibody. The mAb 2234 recognizes a single faint band, predominantly located in fraction 5 (B; only 7 of the 11 fractions are shown), whereas the polyclonal antibody recognizes a single band that, although peaks in fraction 5, is detected in multiple fractions (C). Molecular mass × 10−3 is indicated vertically; fraction number is indicated horizontally.