Quantitation of peptides by their fragments
The peptide at m/z 652.0 (M + 3H)3+ in Fig. 4B was fragmented in the Leu-d0 and Leu-d3 form. Intensities and ratios are listed for a number of fragment ions.
| Ion | Peptide label | m/z | Intensity | Observed ratio |
|---|---|---|---|---|
| b2 | Leu-d0 | 171.1 | 127 | 10.0 |
| Leu-d3 | 171.1 | 1264 | ||
| y5 | Leu-d0 | 568.3 | 243 | 9.1 |
| Leu-d3 | 571.3 | 2221 | ||
| y6 | Leu-d0 | 639.4 | 117 | 11.1 |
| Leu-d3 | 642.4 | 1297 | ||
| y10 | Leu-d0 | 1095.6 | 19 | 10.8 |
| Leu-d3 | 1104.6 | 206 |