Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: diarrhea [ICD11:
ME05.1 
, ICD11:
SA55 ];
cholera [ICD11:
1A00 , ICD11:
XN7N1 ]
NCBI PubMed ID: 20860010Journal NLM ID: 9504818Publisher: Chichester, UK: Wiley
Correspondence: banoubjo
dfo-mpo.gc.ca
Institutions: Department of Chemistry, Memorial University of Newfoundland, Saint John's, NL, Canada
We present the MALDI-TOF/TOF-MS analyses of various hapten-bovine serum albumin (BSA) neoglycoconjugates obtained by squaric acid chemistry coupling of the spacer-equipped, terminal monosaccharide of the O-specific polysaccharide of Vibrio cholerae O1, serotype Ogawa, to BSA. These analyses allowed not only to calculate the molecular masses of the hapten-BSA neoglycoconjugates with different hapten-BSA ratios (4.3, 6.6 and 13.2) but, more importantly, also to localize the covalent linkages (conjugation sites) between the hapten and the carrier protein. Determination of the site of glycation was based on comparison of the MALDI-TOF/TOF-MS analysis of the peptides resulting from the digestion of BSA with similar data resulting from the digestion of BSA glycoconjugates, followed by sequencing by MALDI-TOF/TOF-MS/MS of the glycated peptides. The product-ion scans of the protonated molecules were carried out with a MALDI-TOF/TOF-MS/MS tandem mass spectrometer equipped with a high-collision energy cell. The high-energy collision-induced dissociation (CID) spectra afforded product ions formed by fragmentation of the carbohydrate hapten and amino acid sequences conjugated with fragments of the carbohydrate hapten. We were able to identify three conjugation sites on lysine residues (Lys235, Lys437 and Lys455). It was shown that these lysine residues are very reactive and bind lysine specific reagents. We presume that these Lys residues belong to those that are considered to be sterically more accessible on the surface of the tridimensional structure. The identification of the y-series product ions was very useful for the sequencing of various peptides. The series of a- and b-product ions confirmed the sequence of the conjugated peptides.
hapten, Vibrio cholerae O1, BSA, neoglycoconjugate vaccine, MALDI-TOF/TOF-MS, MALDI-CID-TOF-TOF-MS/MS, protein carrier
Structure type: monomer
Location inside paper: p.1149, fig.1a, p.1157, fig.4
Aglycon: spacer-squaric acid
Trivial name: fragment of O-polysaccharide
Contained glycoepitopes: IEDB_130664
Methods: conjugation, MALDI-TOF/TOF MS, MALDI-CID-TOF/TOF MS/MS, SELDI-TOF MS
Enzymes that release or process the structure: tryptic digestion
Comments, role: terminal residue of O-antigen part; of structure (see RR: 25289); Vibrio cholerae O1 serotype Ogawa
Related record ID(s): 25289
NCBI Taxonomy refs (TaxIDs): 127906
Show glycosyltransferases
There is only one chemically distinct structure:
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