Table 1.
Sites of HNE Modification on Recombinant CDK2 Identified by LC-MS/MSa
| peptide | residue modified | XCorr | observed m/z | charge | mass error (ppm) | peptide start-stop | observed spectra |
|---|---|---|---|---|---|---|---|
| ELNH*PPNIVK | His60 | 3.15 | 611.3672 | 2 | 0.33 | 57–65 | 3 |
| LLDVIH*TENK | His71 | 3.12 | 670.3999 | 2 | 0.15 | 66–75 | 4 |
| DLK*PQNLLINTEGAIK | Lys129 | 3.55 | 642.3870 | 3 | 0.00 | 127–142 | 2 |
| TYTH*EVVTLWYR | His161 | 3.18 | 863.4668 | 2 | 0.17 | 158–169 | 8 |
| SLLSQMLH*YDPNKR | His268 | 3.45 | 620.6743 | 3 | 0.32 | 261–273 | 2 |
| AALAH*PFFQDVTK | His283 | 2.13 | 534.9724 | 3 | 0.37 | 279–291 | 7 |
| PVPH*LR | His295 | 1.89 | 438.7900 | 1 | 1.82 | 292–298 | 4 |
Recombinant CDK2 was modified in vitro with 30 μM HNE and analyzed for sites of HNE adduction by tandem mass spectrometry in three independent experiments. Modified residues are indicated by an asterisk. Data shown in the table represent the adducted peptides with the lowest mass error.