Characterization of the extent of internal motions in oligosaccharides

• Published in: Biochemistry (Easton) Vol. 32; no. 47; pp. 12715 - 12724
• Main Authors: Rutherford, T. J, Partridge, J, Weller, C. T, Homans, S. W
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 30.11.1993
• Subjects: Biological and medical sciences; Carbohydrate Conformation; Carbohydrate Sequence; Carbon Isotopes; Computer Simulation; Conformational dynamics in molecular biology; Disaccharides - chemistry; Fundamental and applied biological sciences. Psychology; Magnetic Resonance Spectroscopy; Mannose - chemistry; Molecular biophysics; Molecular Sequence Data; Motion; Oligosaccharides - chemistry; Ribonucleases - chemistry; Water - chemistry; Synthetic product; Oligosaccharide; Conformational dynamics; Thermodynamic parameter; Molecular dynamics method; NMR spectrometry; Disaccharide
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi00210a021

A detailed investigation has been undertaken on the extent and nature of torsional fluctuations about the glycosidic linkage of the model disaccharide Man alpha 1-3Man alpha 1-OMe. In particular, we sought to determine whether the three nuclear Overhauser effects and the two long-range heteronuclear 3JCH spin coupling constants measurable across the glycosidic linkage were consistent with a single conformation or multiple conformations about that linkage. Within experimental error, we have found that these five parameters can be interpreted in terms of a single, rigid geometry. Alternatively, the data are also consistent with a model in which the glycosidic torsional angles exhibit significant but restricted fluctuations about the global minimum energy conformation. Evidence from restrained molecular dynamics simulations both in vacuo and with explicit inclusion of solvent water and from 13C relaxation measurements upon an oligomannose glycan in covalent association with protein suggests that the latter model is the most accurate representation of the conformational behavior of oligosaccharides in solution.