Fig. 3. Mapping of the processing site at the C-terminus of TgMIC6 by identification of the peptide EEGSGHAGAIA by MS/ESI. After in-gel digestion of MIC6Ty, the tryptic peptides were bound to Poros R2 and Poros oligoR3 material. In the eluate from the R3 column, a doubly charged peptide ion matching the mass of the peptide EEGSGHAGAIA (m/z = 499.9) was detected. This peptide was fragmented and major fragment peaks are assigned to a b^o series with the C-terminal peptide sequence AGAIA. Two additional peaks labelled as y₉ and y₁₀ are consistent with the two N-terminal amino acids EE. The amino acid sequence conservation around the cleavage site in TgMIC2, TgMIC6, TgMIC12 and PbTRAP is depicted below, with the tryptic peptide of MIC6 in bold.