Fig. 1. The levels of stress response proteins are increased in both total and purified mitochondrial extracts from H₂O₂-induced apoptotic cells. Comparison of protein expression levels in total cellular (A) and purified mitochondrial extracts (B) of untreated (control) and H₂O₂-treated wild-type S. cerevisiae cells. Selected regions of the 2-D gel (isoelectric point/molecular mass) are shown enlarged and the position of altered protein spots are marked with an arrowhead. Putative protein fragments are marked with an asterisk. The apparent isoelectric points and molecular masses of the proteins were calculated with Melanie 3.0 (GeneBio) using identified proteins with known parameters as references.