Title : Inter-α-trypsin Inhibitor Heavy Chain H2
Abstract :
- For the H2 heavy chain of the Inter-alpha-trypsin inhibitor a c-terminal cluster of mono- and disialylated mucin-type core 1 O-glycans ( Thr666, Ser673, Thr675 and Thr691 ) has been described in literature (58, 60, 66, 67)
- These previously reported O-glycosylated sites , except for the site T666, could be confirmed by the present study, albeit solely with monosialylated T-antigens
- ETD spectra of the O-glycopeptide 689ESPPPHV696 (m/z 507.153+/760.242+) enabled a clear identification of the occupied O-glycosylation site Thr666
- This finding is supported, in particular, by a signal detected in the doubly charged species at m/z 1287.411+ which corresponds to a z+16 ion (supplemental Fig
- S6)
- Remarkably, the CID-MS2 spectrum of the O-glycopeptide 669WANPPPV677 (m/z 760.923+) revealed that both O-glycosylation sites, Ser673 and Thr675 , are occupied by a monosialylated T-antigen (supplemental Fig
- S7)
- Moreover, the spectrum features signals indicating the presence of hexose rearrangement products, that is the transfer of an additional hexose either to the glycan or the peptide moiety, as described earlier (68, 69)
- The occurrence of these artifacts necessitates the careful interpretation of CID glycopeptide fragment spectra
Output (sent_index, trigger,
protein,
sugar,
site):
- 1. O-glycans, , -, -, Thr666, Ser673, Thr675 and Thr691
- 1. Ser673, , -, -, Thr666, Ser673, Thr675 and Thr691
- 3. O-glycopeptide, , -, -, O-glycopeptide
- 3. O-glycosylation, , -, -, site Thr666
- 6. O-glycopeptide, , -, -, O-glycopeptide
- 6. O-glycosylation, , -, -, sites, Ser673 and Thr675
- 6. occupied, , -, -, sites, Ser673 and Thr675
- 9. glycopeptide, , -, -, glycopeptide
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 1. -, -, Thr666, Ser673, Thr675 and Thr691
- 3. -, -, site Thr666
- 6. -, -, sites, Ser673 and Thr675