Comparison of MOMP induction by different BH3 peptides and the abilities to repress Bim BH3 peptide-induced MOMP by different anti-apoptotic Bcl-2 family proteins. 2LMP mitochondria were isolated and permeabilized by different BH3 peptide and ABT-737 at indicated concentrations (A). 2LMP mitochondria were pre-treated with buffer alone or recombinant Bcl-2, Bcl-xL, or Mcl-1 proteins at indicated concentration before being permeablized by Bim BH3 peptide (B). Mitochondrial pellets (P) and supernatants (S) were carefully separated and mixed with sample buffer, and equivalent portions were subjected to SDS-PAGE and Western blotting analysis for Cytochrome C and Smac/Diablo. Results are representative of three independent experiments.