PMID: PMC4739677-2-3

 

    Legend: Gene, Sites

Title : Other O-glycoprotomic Studies on Complex Biofluids

Abstract :
  1. In the recent past efforts have been made to investigate the O-glycoproteome of different complex biological samples
  2. Halim et al., for instance, analyzed the O-glycoproteome of cerebrospinal fluid ( CSF ) using a sialic-acid capture-and-release protocol (30)
  3. This protocol is based on the sialic acid specific hydrazide capturing of periodate oxidized glycoproteins
  4. Upon tryptic digestion the protocol allows the acid hydrolysis of sialic acid glycosidic bonds in order to release and analyze (formerly) sialylated glycopeptides
  5. To focus on O-glycosylations the authors included a peptide N-glycosidase F ( PNGase F) sample pretreatment step to remove N-glycans
  6. The authors have used an automated CID-MS2 /-MS3 spectra search protocol for glycopeptide identification (Peptide-GalNAc-Gal) and have employed ECD and ETD to pinpoint the glycosylation sites
  7. In total they have identified 106 O-glycosylation sites and could pinpoint 67 of these
  8. The identified CSF O-glycopeptides belong to 49 different proteins and were predominately decorated with structures corresponding to core-1 mucin-type O-glycans
  9. In a previous study the same group has also investigated the human urinary N-and O-glycoproteome using the sialic-acid capture-and-release protocol (58)
  10. Unfortunately, the applied protocol does not allow the enrichment of nonsialylated glycoproteins nor does it give any information on the degree of sialylation of the attached O-glycan moieties
  11. This limits the applicability of this procedure, as the degree of O-glycan sialylation is a crucial determinant in the pathogenesis of a number of diseases (22)
  12. In another large-scale glycoproteomics study conducted by Hägglund et al. in 2007 human plasma proteins , derived from Cohn fraction IV of a plasma fractionation, were analyzed with respect to occupied N- and O-glycosylation sites (60)
  13. The analyzed Cohn fraction is supposed to contain mainly α-globulins, like plasminogen and haptoglobin , and is depleted from γ-globulins and serum albumin
  14. The authors have employed two different enzymatic deglycosylation strategies to pinpoint occupied N-glycosylation sites : ( 1) PNGase F + H218O; (2) endo-β-N-acetylglucosaminidases (Endo D and Endo H) + different exoglycosidases
  15. These two strategies were applied on HILIC enriched tryptic (glyco) peptides , that were fractionated by strong cation exchange chromatography and eventually measured by LC- ESI-MS/MS using high-energy CID
  16. The authors were able to identify 103 N-glycosylation sites as well as 23 O-glycosylation sites/regions derived from 61 and 11 human blood plasma proteins , respectively
  17. Unfortunately, the occupied O-glycosylation sites could not be pinpointed and no information on the glycan moiety could be deduced
  18. In 2012 Darula et al. reported on the O-glycoproteomic analysis of bovine serum (77)
  19. In this study the authors have combined different protein- and peptide-level prefractionation and enrichment strategies, including jacalin lectin affinity chromatography, mixed-mode chromatography, and electrostatic repulsion hydrophilic interaction chromatography (ERLIC) to enrich tryptic mucin-type O-glycopeptides
  20. After additional use of exoglycosidases to improve glycopeptide characterization, truncated glycopeptides were subjected to LC- ESI-MS/MS with HCD and ETD for automated peptide identification and glycosylation site determination
  21. Overall, the authors could identify and pinpoint 124 glycosylation sites in 51 proteins , including many O-glycosylation sites that have not been described before—unfortunately, though, at the expense of the intact glycan structure
  22. In a recent publication from Bai et al. an analytical workflow is presented, which allows the mapping of mucin-type O-glycosylation sites on glycoproteins present in human blood plasma (76)
  23. The authors have used jacalin lectin affinity chromatography to enriched tryptic O-glycopeptides (peptide\+GalNAc) which were treated with PNGase F and different exoglycosidases
  24. In this study 49 O-glycopeptides , belonging to 36 human blood plasma glycoproteins , were identified by LC- ESI-MS/MS (CID)
  25. Overall, the authors could assign 13 O-glycosylation sites unambiguously, of which nine sites have not been described before
Output (sent_index, trigger, protein, sugar, site):
  • 10. glycoproteins, , glycoproteins, -, -
  • 10. nonsialylated, , glycoproteins, -, -
  • 12. N-, , -, -, sites
  • 14. N-glycosylation, , -, -, sites
  • 16. N-glycosylation, , -, -, sites
  • 17. O-glycosylation, , -, -, sites
  • 19. O-glycopeptides, , -, -, O-glycopeptides
  • 20. glycopeptide, , -, -, glycopeptide
  • 20. glycopeptides, , -, -, glycopeptides
  • 20. glycosylation, , -, -, site
  • 21. O-glycosylation, , -, -, sites
  • 21. glycosylation, , -, -, sites
  • 22. O-glycosylation, , -, -, sites
  • 22. glycoproteins, , glycoproteins, -, -
  • 23. O-glycopeptides, , -, -, O-glycopeptides
  • 24. O-glycopeptides, , -, -, O-glycopeptides
  • 24. glycoproteins, , glycoproteins, -, -
  • 25. O-glycosylation, , -, -, sites
  • 3. glycoproteins, , glycoproteins, -, -
  • 4. glycopeptides, , -, -, glycopeptides
  • 4. sialylated, , -, -, glycopeptides
  • 6. glycopeptide, , -, -, glycopeptide
  • 6. glycosylation, , -, -, sites
  • 7. O-glycosylation, , -, -, sites
  • 8. O-glycopeptides, , -, -, O-glycopeptides
Output(Part-Of) (sent_index, protein, site):
  • 21. proteins, sites
  • 22. glycoproteins, sites
  • 8. CSF, O-glycopeptides
*Output_Site_Fusion* (sent_index, protein, sugar, site):

 

 

Protein NCBI ID SENTENCE INDEX