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Selected Publication:

Sokolowski, T; Haselhorst, T; Scheffler, K; Weisemann, R; Kosma, P; Brade, H; Brade, L; Peters, T.
(1998): Conformational analysis of a Chlamydia-specific disaccharide alpha-Kdo-(2-->8)-alpha-Kdo-(2-->O)-allyl in aqueous solution and bound to a monoclonal antibody: observation of intermolecular transfer NOEs.
J Biomol NMR. 1998; 12(1):123-133 FullText FullText_BOKU

Abstract:
The disaccharide alpha-Kdo-(2 --> 8)-alpha-Kdo (Kdo: 3-deoxy-D-manno-oct-2-ulosonic acid) represents a genus-specific epitope of the lipopolysaccharide of the obligate intracellular human pathogen Chlamydia. The conformation of the synthetically derived disaccharide alpha-Kdo-(2 --> 8)-alpha-Kdo-(2 --> O)-allyl was studied in aqueous solution, and complexed to a monoclonal antibody S25-2. Various NMR experiments based on the detection of NOEs (or transfer NOEs) and ROEs (or transfer ROEs) were performed. A major problem was the extensive overlap of almost all H-1 NMR signals of alpha-Kdo-(2 --> 8)-alpha-Kdo-(2 --> O)-allyl. To overcome this difficulty, HMQC-NOESY and HMQC-trNOESY experiments were employed. Spin diffusion effects were identified using trROESY experiments, QUIET-trNOESY experiments and MINSY experiments. It was found that protein protons contribute to the observed spin diffusion effects. At 800 MHz, intermolecular trNOEs were observed between ligand protons and aromatic protons in the antibody binding site. From NMR experiments and Metropolis Monte Carlo simulations, it was concluded that alpha-Kdo-(2 --> 8)-alpha-Kdo-(2 --> O)-allyl in aqueous solution exists as a complex conformational mixture. Upon binding to the monoclonal antibody S25-2, only a limited range of conformations is available to alpha-Kdo-(2 --> 8)-alpha-Kdo-(2 --> O)-allyl. These possible bound conformations were derived from a distance geometry analysis using transfer NOEs as experimental constraints. It is clear that a conformation is selected which lies within a part of the conformational space that is highly populated in solution. This conformational space also includes the conformation found in the crystal structure. Our results provide a basis for modeling studies of the antibody-disaccharide complex.
Authors BOKU Wien:
Kosma Paul
Find related publications in this database (using NML MeSH Indexing)
Antibodies, Monoclonal -
Antigen-Antibody Complex -
Carbohydrate Conformation -
Chlamydia - chemistry
Disaccharides - chemistry
Epitopes - chemistry
Humans - chemistry
Lipopolysaccharides - chemistry
Models, Molecular - chemistry
Nuclear Magnetic Resonance, Biomolecular - methods
Solutions - methods
Water - methods

Find related publications in this database (Keywords)
HMQC-trNOESY
Kdo
monoclonal antibody
QUIET-trNOESY
trNOESY
trROESY


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