Fig. 7. Saline washing of mitochondria selectively suppresses autocatalysis of Bak conformation change. (A) Conventional (designated `unwashed') and saline-washed (`washed') mitochondria were prepared from the same cell homogenate. tBid-induced Bak conformation change (black symbols) and cytochrome c release (white symbols) were measured as in Fig. 6. The Bak data were best-fitted according to equation 1 (see Materials and Methods) to yield the f and c values given. These values were then used to obtain the best fits for the cytochrome c data according to equation 2 (see Materials and Methods) to give the curves shown and the a values given. (B) SDS-PAGE gels (Coomassie stained) and Bak immunoblots of the washed and unwashed mitochondrial preparations. Arrows show bands that were reduced in the washed preparation.