Taxonomic group: bacteria / Firmicutes
(Phylum: Firmicutes)
NCBI PubMed ID: 36354960Publication DOI: 10.1021/jacs.2c05953Journal NLM ID: 7503056Publisher: American Chemical Society
Correspondence: Jian Yin <jianyin
jiangnan.edu.cn>
Institutions: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Lihu Avenue 1800, Wuxi, Jiangsu 214122, P. R. China, Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Muhlenberg 1, Potsdam 14476, Germany, Wuxi School of Medicine, Jiangnan University, Lihu Avenue 1800, Wuxi, Jiangsu 214122, P. R. China
Shigella is the second most common etiologic pathogen responsible for childhood acute diarrhea. An anti-Shigella vaccine is still eagerly awaited due to the increasing drug resistance of this pathogen. The Shigella O-antigen is a promising vaccine target. To identify the immune epitopes of the glycan, the first total synthesis of Shigella dysenteriae serotype 10 O-antigen tetrasaccharide containing a (S)-4,6-O-pyruvyl ketal was completed. The 1,2-trans-β-glycosylation & C2 epimerization and conformational locking strategies facilitated the construction of two 1,2-cis-β-glycosidic linkages. The reactivities of both the glycosyl donor and acceptor were improved by adding electron-donating benzyl groups, enabling an efficient assembly of the tetrasaccharide. The (S)-4,6-O-pyruvyl ketal was introduced at the final stage due to its influence on the glycosylation stereospecificity and efficiency. In addition, (R)-4,6-O-pyruvylated and nonpyruvylated tetrasaccharides and three further fragments were synthesized. Glycan microarray screening revealed that the tetrasaccharide repeating unit is the key antigenic epitope of the O-antigen. Moreover, the (S)-4,6-O-pyruvyl ketal is an essential structural feature of this antigen for designing carbohydrate-based vaccines against S. dysenteriae serotype 10. The comparison of the (S)-4,6-O-pyruvylated glycan and its (R)-epimer will set an example for biological evaluation of other bacterial glycans containing pyruvyl ketals.
synthesis, serotype, O-antigen, glycosylation, vaccine
Structure type: oligomer
Location inside paper: Fig. 1, B. anthracis SCWPs
Aglycon: (1->4) cell wall polysaccharide
Trivial name: secondary cell wall polysaccharide
Compound class: cell wall polysaccharide (SCWPs)
Contained glycoepitopes: IEDB_135813,IEDB_137340,IEDB_141807,IEDB_151531,IEDB_885813
Methods: 13C NMR, 1H NMR, NMR-2D, TLC, chemical synthesis, chemical methods, UV, RP-HPLC, HR-ESI-MS, microarray binding assays
Comments, role: terminal unit of secondary cell wall polysaccharide of B. anthracis
Related record ID(s): 8533, 21134, 21135, 21136, 21137
NCBI Taxonomy refs (TaxIDs): 1392
Show glycosyltransferases
There is only one chemically distinct structure:
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