Figure 2

Identification of haptoglobin by LC-MS/MS analysis and database searching. Proteins were excised from the corresponding gel spots and subjected to in-gel digestion. The resulting peptides were extracted from the gel and analyzed by LC-MS/MS. MS/MS data were searched against the human database by Spectrum Mill software to obtain protein identification information. Upper panel: the sequence coverage of haptoglobin by LC-MS/MS analysis. Ten tryptic peptides (sequence underlined) were matched to human haptoglobin by database searching. Lower panel: MS/MS spectra of two of the ten peptides: DIAPTLTLYVGK and VVLHPNYSQVDIGLIK. The peptide sequences were established by extensive b and y ions matched to sequence.