Figure 8.

Tryptic phosphopeptides: effect of extra phosphate and basic residues on elution in SCX. Sample and conditions (see Figure 6): (Bottom) Peptides with one phosphate group and a Lys/Arg residue at the C-terminus, including peptides with additional basic residues and with segments corresponding to the number of peptides terminating in Arg or Lys residues. (Top) Peptides with additional phosphate groups and basic residues as indicated. The units in the Y-axis are the number of phosphopeptides in the tallest bar in each histogram.