Figure 4.

Structural identification of the m/z 9198 peak cluster. A. Peptide mapping of the m/z 9198 marker. MS spectrum of the m/z 9198 tryptic digest in the gel eluate. All peptides were sequenced with tandem MS using Q-TOF for confirmation. Results from the MASCOT search for protein identification include start and end positions of the peptide sequence starting from the amino acid terminal of the whole protein, the observed m/z, transformed to its experimental mass (Mr(expt)), the calculated mass (Mr(calc)) from the matched peptide sequence, as well as their mass difference (Delta), the number of missed cleavage sites for trypsin (Miss), the estimate Z-score and its significance, and the peptide sequence. B. Matched amino acid sequence of the m/z 9198 marker (in grey: amino acid sequence sequenced by Q-TOF MS), haptoglobin alpha-1 chain and the corresponding N-terminus of haptoglobin-related-protein (in grey: amino acid substitutions between haptoglobin and haptoglobin-related-protein) [24].