Table II.
Fragment ions detected in Q-TOF after tryptic digest of 1-FEH IIb, with calculated matches to theoretical digest of virtual cDNA derived protein, and confirmation of identity by tandem MS/MS sequencing
| Observed Mass | Charge State | Calculated Mass (Presumptive1-FEH IIb Fragment Ion) | MS/MS Sequence (from N to C Terminus) |
|---|---|---|---|
| 415.2 | 2+ | 415.19 [T21+2H]2+ | 278 SFFDDAK 284 |
| 417.25 | 2+ | 417.22 [T41+2H]2+ | 467 SEEISLR 473 |
| 481.3 | 2+ | 481.26 [T37+2H]2+ | 427 VFQNQLGR 434 |
| 499.3 | 2+ | 499.26 [T36+2H]2+ | 419 EQSAIFFR 426 |
| 530.8 | 2+ | 530.78 [T1+2H]2+ | 1 QQIQQPYR 8 |
| 542.8 | 2+ | 542.79 [T5+2H]2+ | 107 QVQDLAWPK 115 |
| 559.8 | 2+ | 559.79 [T25+2H]2+ | 306 GWAGLQSFPR 315 |
| 602.8 | 2+ | 602.82 [T47+2H]2+ | 530 NAAFVVDQNVK 540 |
| 829.4 | 2+ | 829.43 [T42+2H]2+ | 474 NLIDHSIIESFGAGGK 489 |
| 921.95 | 2+ | 921.94 [T40+2H]2+ | 450 SNIDTTSYGAFVDIDPK 466 |
| 1,066.5 | 2+ | No match | T6 N-linked glycopeptide:116 NLSDPFLR 123 (Deoxyhexose)1 (Pentose)1 (Man)3 (GlcNAc)2 |
Glycosylation sites NX(S/T) are presented in bold. The position of the fragments in the mature 1-FEH IIb protein are indicated.