PMID: PMC4084840-1-5

 

    Legend: Gene, Sites

Title : Non-CanonicalN-Glycosylation

Abstract :

1. Consistent with our observation that glycosylationwas present at N274 based on PNGaseF/18O labeling (N >D/18O), we also detected four high-mannose glycoforms ofthe NVVFVIDK peptide , including M5, M6,M7, and M8 glycoforms in recombinant ITIH4 , and M5 and M6 glycoformsin serum-derived ITIH4
2. The CID spectrum of serum-derived glycopeptideNVVFVIDK + M6 (Figure 2B) is representativeof CID MS/MS spectra from both serum and recombinant ITIH4 and offersdefinitive evidence of glycosylation at this noncanonical site
3. Thespectrum contains oxonium ions including [HexNAc + H]1+ at m/z 204, [Hex-Hex + H]1+ at m/z 325, [HexNAc-Hex\+ H]1+ at m/z 366, and[HexNAc-Hex-Hex + H]1+ at m/z 528 consistent with a high-mannose glycan and a strong peptide b- and y-ion series (b2-b5 and y2-y6) leading to a confidentassignment
4. In addition, a series of glycopeptide Y ions including[NVVFVIDK + HexNAc2Hex1 + 2H]2+ at m/z 751.33, [NVVFVIDK+ HexNAc2Hex2 + 2H]2+ at m/z 832.34, [NVVFVIDK + HexNAc2Hex3 + 2H]2+ at m/z 913.41, [NVVFVIDK + HexNAc2Hex4 + 2H]2+at m/z 994.47, and [NVVFVIDK + HexNAc2Hex5 + 2H]2+ at m/z 1075.43,consisting of the intact peptide and partially fragmented glycan,and B ions including [HexNAc1Hex3 + H]1+ at m/z 690.19, [HexNAc1Hex6 + H]1+ at m/z 1176.35 consisting of the fragmented glycan, are alsopresent in the spectrum
5. ITIH4 glycopeptides from the recombinant ITIH4 demonstrate a greater variety of the high-mannose glycoforms(M5-M8) (Table 3), but the glycoforms in serumare limited to high-mannose forms as well

Output (sent_index, trigger, protein, sugar, site):

• 2. glycosylation, , -, -, site
• 3. b-, , -, -, y2-y6
• 4. glycopeptide, , -, -, glycopeptide
• 5. glycopeptides, , ITIH4, -, glycopeptides

Output(Part-Of) (sent_index, protein, site):

• 1. ITIH4, M6-M7
• 5. ITIH4, glycopeptides

*Output_Site_Fusion* (sent_index, protein, sugar, site):

• 3. -, -, y2-y6

 

Protein	NCBI ID	SENTENCE INDEX