Figure 5 of Giblin, Mol Vis 2013; 19:267-280.


Figure 5. The numbers of tandem mass (MS/MS) spectra are shown for the 2 -SH group-containing peptides of water-soluble nuclear βB2-crystallin. A shows total counts for each of the 2 peptides containing an −SH group; B shows peptides containing protein-bound glutathione (PSSG) expressed as per −SH peptide; and C shows peptides containing protein-bound cysteine (PSSC) expressed as per −SH peptide. Open bars are counts from age-matched controls and solid black bars are counts after 30 treatments of the animals with hyperbaric oxygen. There is a different vertical scale for A, compared to those for B and C, which are identical. The counts in panel A correspond to a soluble protein sample of 0.4 mg. A shows that peptides for each of the 2 cysteine residues showed a slight O2-induced decrease in number of counts. The majority of control and O2-induced PSSG was shown by residue C67 (B). Note that this single residue of βB2 produced the highest levels of control and O2-induced PSSG, compared to the other 11 crystallins (see Figure 1B). Residue C67 produced relatively little control or O2-induced PSSC (C), compared to the amounts observed for PSSG (B).