MALDI-MS data of P-gp peptides (HPLC signal 2) after one Edman coupling step with phenylisothiocyanate
| MALDI-MS | PTC Residues Incorporated3-a | Sequence | Unmodified Peptide Molecular Mass3-b | Dexniguldipine Incorporation3-b | Number of Lysine Residues |
|---|---|---|---|---|---|
| m/z | aa | Da | |||
| 8137 | 5 | 468–527 | 7418 | + | 4 |
| 6224 | 3–4 | 620–670 | 5735 | – | 3 |
| 5514 | 2 | 620–666 | 5228 | – | 3 |
| 618–659 | + | 3 |
MALDI mass spectrometric analysis of the [3H]B9209-005–bound P-gp peptide (fraction of HPLC signal 2 in Fig. 6) after first Edman coupling procedure. For the Edman coupling, the lyophilized HPLC fraction was incubated with 5% PITC for 4 h at 30°C. The ion signals in the spectrum are labeled with the average mass and the number of phenylthiocarbamoyl (PTC) groups that are incorporated (compare Fig. 7).