Figure 3. Representative MS/MS spectra of Akt and ERK1/2 peptides obtained from the co-IP complex.

MS/MS analysis of the doubly charged ion at m/z 912.46 or 798.90 originated from the peptide segment Y[26]–[39]K of Akt (a), or A[193–205]K of ERK1/2 (b), respectively. The sequence of the peptide was assigned with a single letter abbreviation based on the fragment ions observed for the peptide segments. N-terminal b ions and C-terminal y ions resulting from the amide bond cleavage are labeled. * denotes the addition of 145.0198 Dalton due DSP-crosslinking.