Figure 8
From: A single active catalytic site is sufficient to promote transport in P-glycoprotein
BODIPY FL Vinblastine (VBL-BPY) binding to wild-type Pgp in permeabilized NIH 3T3 cells (a) and to Walker A mutant Pgps in permeabilized MDCK cells (b). Cells permeabilized by Staphylococcus alpha toxin (a) or Streptolysin O (b) were treated with different concentrations of CsA, ATP/Mg2++ vanadate (Vi) or AMP-PNP/Mg2+ followed by co-staining with VBL-BPY and 15D3-A647. The ratio of the VBL-BPY and 15D3-A647 fluorescence intensity was determined in pixels representing the plasma membrane, selected on the basis of 15D3-A647 fluorescence intensity exceeding the threshold of 300. Nucleotide-treated samples were compared to permeabilized ATP-depleted cells (0 mM nucleotide); the values are means ± SD of three independent experiments (***P < 0.001).
