Figure 5

The combination of Bad and Noxa BH3 peptides provided synergism in the induction of MOMP in mitochondria dominantly protected by Mcl-1 protein. 2LMP mitochondria were pre-treated with buffer alone or recombinant Mcl-1 protein at 200 nM before being permeablized by Bim BH3 peptide alone, Bim BH3 peptide together with Bad or Noxa BH3 peptides at indicated concentrations, Bad and Noxa BH3 peptides simultaneously without the presence of Bim BH3 peptide (A). Mitochondrial isolated from MDA-MB-436 cell line were permeabilized by different concentrations of Bim, Bad or Noxa BH3 peptides alone or Bad and Noxa BH3 peptides simultaneously at indicated concentrations (B). Mitochondrial isolated from MDA-MB-453 cell line were permeabilized by different concentrations of Bim, Bad or Noxa BH3 peptides alone or Bad and Noxa BH3 peptides simultaneously at indicated concentrations (C). The presence of Bcl-2, Bcl-xL or Mcl-1 proteins on mitochondria isolated from MDA-MB-436, 2LMP and MDA-MB-453 cells was shown (D). Mitochondrial pellets (P) and supernatants (S) were carefully separated and mixed with sample buffer, and equivalent portions were subjected to SDS-PAGE and Western blot analysis for the indicated proteins. Results are representative of three independent experiments. N*: Noxa BH3 peptide.