Fig. 6. GAPDH is extensively fragmented in 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 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. The apparent isoelectric points and molecular masses of the proteins were calculated with Melanie 3.0 (GeneBio) using identified proteins with known parameters as a reference. Putative protein fragments are marked with an asterisk. Tdh3p fragments are numbered 1 to 4. For each Tdh3p and Tdh2p fragment, matched peptides obtained after trypsin digestion and used for identification of the proteins, as well as the amino acids specific for Tdh3p and Tdh2p, are shown in Fig. S1 in supplementary material.