Taxonomic group: bacteria / Chlamydiae
(Phylum: Chlamydiae)
Associated disease: infection due to Chlamydia psittaci [ICD11:
XN4S7 
]
NCBI PubMed ID: 20022906Journal NLM ID: 9104124Publisher: IRL Press at Oxford University Press
Correspondence: sml
fz-borstel.de
Institutions: Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
Chlamydiae contain a rough type lipopolysaccharide (LPS) of 3-deoxy-α-D-manno-oct-2-ulopyranosonic acid residues (Kdo). Two Kdo trisaccharides, 2.8/2.4- and 2.4/2.4-linked, and a branched 2.4[2.8]2.4-linked Kdo tetrasaccharide occur in Chlamydiaceae. While the 2.8/2.4-linked trisaccharide contains a family-specific epitope, the branched Kdo oligosaccharide occurs only in Chlamydophila psittaci and antibodies against it will be useful in human and veterinarian diagnostics. To overcome the generation of cross-reactive antibodies that bind with high affinity to a dominant epitope formed by 2.4/2.4-linked Kdo, we immunized mice with a synthetic 2.4[2.8]-linked branched Kdo trisaccharide and used phage display of scFv to isolate recombinant antibody fragments (NH2240-31 and SAG506-01) that recognize the branched Kdo oligosaccharide with a K(D) of less than 10 nM. Importantly, although these antibodies used germline genes coding for an inherited Kdo recognition site they were able clearly to distinguish between 2.4[2.8]2.4- and 2.4/2.4-linked Kdo. Sequence determination, binding data, and X-ray structural analysis revealed the basis for the improved discrimination between similar Kdo ligands and indicated that the alteration of a stacking interaction from a phenylalanine residue in the center of the combining site to a tyrosine residue facing away from the center favours recognition of branched 2.4[2.8]2.4-linked Kdo residues. Immunofluorescence tests of infected cell monolayers using this antibody show specific staining of C. psittaci elementary bodies that allow it to be distinguished from other pathogenic chlamydiae.
carbohydrate, Kdo, antibody, Chlamydia, specificity
Structure type: oligomer
Location inside paper: p.462, fig.1B
Aglycon: lipid A-BSA
Contained glycoepitopes: IEDB_130650,IEDB_130659,IEDB_150901
Methods: X-ray, ELISA, serological methods, genetic methods, surface plasmon resonance (SPR), immunofluorescence analyses, fluorescence microscopy
Biological activity: comparison of antibody combining sites
Biosynthesis and genetic data: genetic data
3D data: 3D data
Related record ID(s): 25254, 25652, 25653
NCBI Taxonomy refs (TaxIDs): 83554Reference(s) to other database(s): GTC:G27503UD, GlycomeDB:
5830
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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(later renamed to: Chlamydia psittaci)