Table I

Analysis of the frequency and normalized overall intensity of b-ions compared with y-ions in MALDI-CID spectra of Lys-N- and Lys-C-derived peptides

The percent intensity is the intensity of all b-ions divided by the sum of intensity of all b- and y-ions.

b-ion vs. y-ionLys-N (211 peptides)Lys-C (220 peptides)
No prolineProline-containingNo prolineProline-containing
Frequency (%)84754648
Intensity (%)9471 (81a)5043
  • a After subtracting the intensity of y-ions with an N-terminal proline.