B. Purified wild-type (WT) or mutant (G179I or T182I) Bax protein of the indicated concentration was incubated with the Bax-/-/Bak-/- mitochondria in the absence or presence of tBid protein. The proteins released from and those remaining in the mitochondria were separated and analyzed by SDS-PAGE and immunoblotting with antibody specific to either cytochrome c or Smac. n = 2. 