PMID: PMC4739677-2-5

 

    Legend: Gene, Sites

Title : Glycopeptide Enrichment Via HILIC

Abstract :

1. Glycopeptides are usually under-represented in a peptide mixture, because of the glycan microheterogeneity
2. In a tryptic digest of a typical glycoprotein only about 2% to 5% of the peptides are glycopeptides (78)
3. In addition, the ionization efficiency of glycopeptides is significantly lower compared with their nonglycosylated counterparts, thus making the efficient and selective enrichment of glycopeptides key to most glycoproteomics workflows
4. The use of HILIC based glycopeptide enrichment methods has proven to be a vital tool in glycoproteomics because of their broad glycan specificity, reproducibility and compatibility with mass spectrometry
5. In a previous report by Zauner et al. it could be shown, that Proteinase K-generated glycopeptides can be separated into earlier eluting O-glycopeptides and later eluting N-glycopeptides using HILIC (32)
6. Based on this publication we have employed HILIC for the selective enrichment and fractionation of human blood plasma O-glycopeptides
7. Here of particular importance is the removal of highly abundant nonglycosylated peptides derived from albumin and other major (glyco-) proteins
8. Careful manual inspection of CID- MS2 fragment spectra of the acquired HILIC fractions revealed the efficient enrichment of glycopeptides - and indeed the presence of solely mucin-type core-1 O-glycosylated glycopeptides
9. N-glycopeptides were not detected, as they were expected to be present in the late eluting HILIC wash fractions because of their generally higher hydrophilicity compared with the most commonly found forms of mucin-type O-glycopeptides (non-, mono- and disialylated core-1 and -2 O-glycopeptides )

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

• 2. glycopeptides, , -, -, glycopeptides
• 2. glycopeptides, , -, -, peptides
• 2. glycoprotein, , glycoprotein, -, -
• 3. glycopeptides, , -, -, glycopeptides
• 4. glycopeptide, , -, -, glycopeptide
• 5. N-glycopeptides, , -, -, N-glycopeptides
• 5. O-glycopeptides, , -, -, O-glycopeptides
• 5. glycopeptides, , -, -, glycopeptides
• 6. O-glycopeptides, , -, -, O-glycopeptides
• 7. nonglycosylated, , -, -, peptides
• 8. O-glycosylated, , -, -, glycopeptides
• 8. glycopeptides, , -, -, glycopeptides
• 9. N-glycopeptides, , -, -, N-glycopeptides
• 9. O-glycopeptides, , -, -, O-glycopeptides
• 9. disialylated, , -, -, O-glycopeptides

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

• 5. Proteinase, glycopeptides

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

 

Protein	NCBI ID	SENTENCE INDEX