FIGURE 7.

Tests for a direct interaction between purified human caveolin 1 and purified human Na,K-ATPase. A, pull-down assay. Western blotting of unbound, wash I and II, and elution fractions probed with anti-caveolin 1 (see “Methods”) (n = 2). B and C, blue native gel. B, Coomassie-stained. C, Western blot probed with anti-caveolin 1. Lane 1, markers; lane 2, 5 μg of purified human Na,K-ATPase plus purified caveolin (3 μg), a molar ratio of 3:1 (caveolin/Na,K-ATPase). C, as in lanes 1–3 of B, probed with anti-caveolin 1 antibody (n = 6).