Identification of the bacterial protein GroEL from infected
lung tissue. (A) Total protein coverage attained for GroEL from LC-MS/MS data generated from the LCM tryptic digestion. The peptide sequence YVASGMNPMDLK is boxed in red. (B) CID MSMS spectra of 1356.6, which matched GroEL peptide YVASGMNPMDLK, with a mass deviation of −1.8 ppm. (C) Fragment b and y ions that matched predicted b and y ions are highlighted in blue and red, respectively. Graphed below is the observed mass deviation from predicted mass for each matched fragment ion.