FIGURE 6.
Triply charged ion showing phosphorylation of phosducin-like protein at one of three consecutive serines, Ser18–Ser20. A: Collison-induced dissociation (CID) of the +3 charged parent ion at m/z 854, chosen automatically in information-dependant acquisition mode. This species represents the same phosphopeptide as in Figure 5. Again, the y8 ion excludes phosphorylation at Ser25. B: CID of the same parent ion chosen by hand for LC-MS/MS.