NMR Spectroscopy Molecular Dynamics, and Conformation of a Synthetic Octasaccharide Fragment of the O-Specific Polysaccharide of Shigella Dysenteriae Type 1

Published

January 1, 2000

Author(s)

B Coxon, Fahriye N. Sari, G Batta, V Pozsgay

Abstract

A synthetic octasaccharide fragment of the O-polysaccharide from Shigella dysenteriae type 1 has been studied as its methyl glycoside derivative by one-dimensional and two-dimensional homonuclear and heteronuclear NMR spectroscopy. Complete ¹H and ¹³C NMR assignments have been generated for the octasaccharide derivative, namely methyl O-α-L-rhamnopyranosyl-(1 -> 2)-O-α-D-galactopyranosyl-(1 -> 3)-O-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-(1 -> 3)-O-α-L-rhamnopyranosyl-(1 -> 3)-O-α-L-rhamnopyranosyl-(1 -> 2)-O-α-D-galactopyranosyl-(1 -> 3)-O-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-(1 -> 3)-O-α-L-rhamnopyranoside. ¹³C spin-lattice relaxation times have also been measured for this derivative. An octasaccharide derivative containing one D-galactose residue with a specific ¹³C label at C-1 has been synthesized and used to measure interglycosidic ¹³C-¹H coupling by the 2D J-resolved ¹H NMR method. From the NMR data, three types of conformational restraints were developed; (a) 29 inter-residue, distance restraints, (b) 48 intra-residue, ring atom dihedral angle restraints, (c) one heteronuclear, inter-residue dihedral angle restraint. The use of these restraints in a restrained molecular dynamics computation with simulated annealing yielded a conformation resembling a short, irregular spiral, with methyl substituents on the exterior.

Citation

Carbohydrate Research

Volume

242

Issue

No. 1

Pub Type

Journals

Keywords

carbon-13 labeling, conformation, NMR Spectroscopy, octasaccharide, restrained molecular dynamics, Shigella dysenteriae type 1, simulated annealing, T-ROESY, TOCSY

Citation

Coxon, B. , Sari, F. , Batta, G. and Pozsgay, V. (2000), NMR Spectroscopy Molecular Dynamics, and Conformation of a Synthetic Octasaccharide Fragment of the O-Specific Polysaccharide of Shigella Dysenteriae Type 1, Carbohydrate Research (Accessed July 17, 2024)