Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: paratyphoid fever [ICD11:
1A08 
, ICD11:
XN0UV ];
infection due to Salmonella paratyphi [ICD11:
XN0UV ];
infection due to Salmonella enterica [ICD11:
XN5VC ]
The structure was elucidated in this paperNCBI PubMed ID: 2566578Publication DOI: 10.1016/j.carres.2014.12.002Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: francesca.micoli
novartis.com
Institutions: Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa, Novartis Vaccines Institute for Global Health, Via Fiorentina 1, I-53100 Siena, Italy, Department of Life Sciences, Blg. C11, Universita di Trieste, via L. Giorgieri 1, 34127 Trieste, Italy
Salmonella paratyphi A is increasingly recognized as a common cause of enteric fever cases and there are no licensed vaccines against this infection. Antibodies directed against the O-polysaccharide of the lipopolysaccharide of Salmonella are protective and conjugation of the O-polysaccharide to a carrier protein represents a promising strategy for vaccine development. O-Acetylation of S. paratyphi A O-polysaccharide is considered important for the immunogenicity of S. paratyphi A conjugate vaccines. Here, as part of a programme to produce a bivalent conjugate vaccine against both S. typhi and S. paratyphi A diseases, we have fully elucidated the O-polysaccharide structure of S. paratyphi A by use of HPLC-SEC, HPAEC-PAD/CD, GLC, GLC-MS, 1D and 2D-NMR spectroscopy. In particular, chemical and NMR studies identified the presence of O-acetyl groups on C-2 and C-3 of rhamnose in the lipopolysaccharide repeating unit, at variance with previous reports of O-acetylation at a single position. Moreover HR-MAS NMR analysis performed directly on bacterial pellets from several strains of S. paratyphi A also showed O-acetylation on C-2 and C-3 of rhamnose, thus this pattern is common and not an artefact from O-polysaccharide purification. Conjugation of the O-polysaccharide to the carrier protein had little impact on O-acetylation and therefore should not adversely affect the immunogenicity of the vaccine.
O-polysaccharide, O-acetylation, bacterial polysaccharide structure, Salmonella paratyphi A
Structure type: polymer chemical repeating unit
Location inside paper: p.111, table 1, native OPS
Compound class: O-polysaccharide
Contained glycoepitopes: IEDB_130422,IEDB_130701,IEDB_136035,IEDB_136105,IEDB_136906,IEDB_137472,IEDB_141794,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_151528,IEDB_152206,IEDB_174034,IEDB_190606,IEDB_225177,IEDB_885823,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_7,SB_72
Methods: GLC-MS, NMR-2D, GLC, Smith degradation, de-O-acetylation, composition analysis, NMR-1D, HR-MAS NMR, conjugation, HPLC-SEC, HPAEC-PAD/CD
Comments, role: NMR data of the aLRhap3Ac residue (R'): 1H: 5.09 4.21 5.19 3.88 4.06 1.36; 13C: 102.3 68.9 73.4 78.6 68.9 18.1, of the aLRhap2Ac residue (R''): 1H: 5.10 5.20 4.19 3.63 4.02 1.37; 13C: 99.6 73.5 68.2 81.5 68.8 18.0, and of the 2,3)aDManp(1- (M/M' and M''): 1H: 5.18 4.02/4.03 4.05 4.05 3.96 ~3.83, 13C: 100.7/100.3 79.7/79.4 77.8 67.0 74.2 61.2.
Related record ID(s): 30660, 30843
NCBI Taxonomy refs (TaxIDs): 54388
Show glycosyltransferases
NMR conditions: in D2O at 303 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
3,4,3 aXParp 100.2 67.6 35.1 70.4 69.9 17.2
3,4 aDManp 100.3 79.4 77.8 67.0 74.2 61.2
3 aLRhap 102.6 71.1 69.8 82.1 68.7 17.7
6 70%aDGlcp 99.6 72.0 73.8 70.1 72.9 61.3
aDGalp 101.7 68.4 77.9 69.5 72.0 61.7
3,2 20%Ac 174.1 21.6
3,3 30%Ac 173.9 21.1
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
3,4,3 aXParp 5.04 3.83 1.71 3.38 3.72 1.23
3,4 aDManp 5.30 4.03 4.05 4.05 3.96 3.83
3 aLRhap 5.04 4.08 3.97 3.55 3.93 1.32
6 70%aDGlcp 4.95 3.56 3.73 3.42 3.66 3.76-3.87
aDGalp 5.24 3.95 3.96 4.05 4.07 3.69-3.79
3,2 20%Ac - 2.18
3,3 30%Ac - 2.20
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
3,4,3 aXParp 100.2/5.04 67.6/3.83 35.1/1.71 70.4/3.38 69.9/3.72 17.2/1.23
3,4 aDManp 100.3/5.30 79.4/4.03 77.8/4.05 67.0/4.05 74.2/3.96 61.2/3.83
3 aLRhap 102.6/5.04 71.1/4.08 69.8/3.97 82.1/3.55 68.7/3.93 17.7/1.32
6 70%aDGlcp 99.6/4.95 72.0/3.56 73.8/3.73 70.1/3.42 72.9/3.66 61.3/3.76-3.87
aDGalp 101.7/5.24 68.4/3.95 77.9/3.96 69.5/4.05 72.0/4.07 61.7/3.69-3.79
3,2 20%Ac 21.6/2.18
3,3 30%Ac 21.1/2.20
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
|---|
| 3,4,3 | aXParp | 5.04 | 3.83 | 1.71 | 3.38 | 3.72 | 1.23 |
| 3,4 | aDManp | 5.30 | 4.03 | 4.05 | 4.05 | 3.96 | 3.83 |
| 3 | aLRhap | 5.04 | 4.08 | 3.97 | 3.55 | 3.93 | 1.32 |
| 6 | 70%aDGlcp | 4.95 | 3.56 | 3.73 | 3.42 | 3.66 | 3.76
3.87 |
| | aDGalp | 5.24 | 3.95 | 3.96 | 4.05 | 4.07 | 3.69
3.79 |
| 3,2 | 20%Ac |
| 2.18 | |
| 3,3 | 30%Ac |
| 2.20 | |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
|---|
| 3,4,3 | aXParp | 100.2 | 67.6 | 35.1 | 70.4 | 69.9 | 17.2 |
| 3,4 | aDManp | 100.3 | 79.4 | 77.8 | 67.0 | 74.2 | 61.2 |
| 3 | aLRhap | 102.6 | 71.1 | 69.8 | 82.1 | 68.7 | 17.7 |
| 6 | 70%aDGlcp | 99.6 | 72.0 | 73.8 | 70.1 | 72.9 | 61.3 |
| | aDGalp | 101.7 | 68.4 | 77.9 | 69.5 | 72.0 | 61.7 |
| 3,2 | 20%Ac | 174.1 | 21.6 | |
| 3,3 | 30%Ac | 173.9 | 21.1 | |
|
There is only one chemically distinct structure:
Found 
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(later renamed to: Salmonella enterica ssp. enterica sv. paratyphi A (NVGH307))