Detecting Glucose Fluctuations in the Campylobacter jejuni N-Glycan Structure
| Autor: | Xiaoming Bian, Parastoo Azadi, Christine M. Szymanski, Kenneth K.-S. Ng, Richard L. Guerrant, David T. Bolick, Harald Nothaft, William G. Miller, Asif Shajahan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Glycan
Glycosylation Campylobacteriosis Enzyme-Linked Immunosorbent Assay medicine.disease_cause Biochemistry Campylobacter jejuni Article Microbiology Mice Residue (chemistry) Phagocytosis Polysaccharides Carbohydrate Conformation Escherichia coli medicine Animals Amino Acid Sequence Antiserum Aspartic Acid biology Immune Sera Campylobacter General Medicine medicine.disease biology.organism_classification carbohydrates (lipids) Glucose Carbohydrate Sequence biology.protein Molecular Medicine Glucosyltransferase Antibody Sequence Alignment |
| Zdroj: | ACS Chem Biol |
| ISSN: | 1554-8937 1554-8929 |
| Popis: | Campylobacter jejuni is a significant cause of human gastroenteritis worldwide and all strains express an N-glycan that is added to at least 80 different proteins. We characterized 98 C. jejuni isolates from infants from seven low- and middle-income countries and identified 4 isolates unreactive with our N-glycan-specific antiserum that was raised against the C. jejuni heptasaccharide composed of GalNAc-GalNAc-GalNAc(Glc)-GalNAc-GalNAc-diNAcBac. Mass spectrometric analyses indicated these isolates express a hexasaccharide lacking the glucose branch. Although all 4 strains encode the PglI glucosyltransferase (GTase), one aspartate in the DXDD motif was missing, an alteration also present in ~4% of all available PglI sequences. Deleting this residue from an active PglI resulted in a non-functional GTase when the protein glycosylation system was reconstituted in E. coli, while replacement with Glu/Ala was not deleterious. Molecular modelling proposed a mechanism for how the DXDD residues and the structure/length beyond the motif influences activity. Mouse vaccination with an E. coli strain expressing the full-length heptasaccharide produced N-glycan-specific antibodies and a corresponding reduction in Campylobacter colonization and weight loss following challenge. However, the antibodies did not recognize the hexasaccharide and were unable to opsonize C. jejuni isolates lacking glucose suggesting this should be considered when designing N-glycan based vaccines to prevent campylobacteriosis. |
| Databáze: | OpenAIRE |
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