Oligosaccharides, conformational analysis

Table 1 Computational Protocol for Oligosaccharide Conformational Analysis" Step...

It is important to note that the results of JP R significantly influenced the thinking of subsequent researchers. In the interests of brevity I note here only the key papers of Tvaroska and Bleha [20, 21], which further demonstrated the utility of Fourier analysis, the particularly elegant paper in 1979 by Wolfe et al. [22], which refined many of the ideas laid out in JP R s prior work and extended its range of applicability, and the efforts of Thogersen et al. [23], who built upon the work of JP R in the construction of an empirical potential function for oligosaccharide conformational analysis. 

The conformational behaviour in solution of a dermatan-derived tetra-saccharide has been explored by means of NMR spectroscopy, especially by NOE-based conformational analysis. RDCs were also measured for the tetrasaccharide in a phage solution and interpreted in combination with restrained MD simulations. The RDC-derived data substantially confirmed the validity of the conformer distribution resulting from the NOE-derived simulations, but allowed an improved definition of the conformational behaviour of the oligosaccharides in solution, which show a moderate flexibility at the central glycosidic linkage. Differences in the shapes of the different species with the IdoA in skew and in chair conformations and in the distribution of the sulphate groups were also highlighted.28... 

Conformational analysis of oligosaccharides in solution by NMR is mainly based on hydrogen-hydrogen distance information obtained from the nuclear Overhauser effect (n.O.e.) ( ). Other independent NMR... 

Conformational Analysis of Oligosaccharides Reconciliation of Theory with Elxperiment J. P. Carvers D. MandeP, S. W. MichnickS A. Imberfy S and J. W. Brady ... 

This review presents a brief account on the conformation of biologically active oligosaccharides. Emphasis will be put on the conformational analysis of heterooligomers. The conformational preferences of some disaccharides will be included for reference purposes. Conformational aspects of homo-oligomers and homopolymers will not be discussed. 

Some important contributions to the conformational analysis of oligosaccharides have come from the determination of the structure of oligosaccharides which form complexes with protein. In this context the complex of lysozyme with chitohexaose [40] and the phosphorylase complex with maltoheptaose [41, 42] and maltopentaose [43] have been resolved to atomic resolution. 

The special problem of the conformational analysis — the orientation of the glycosylated 6-hydroxymethylgroups in these oligosaccharides — is of major importance because of the large differences in the global shape that are induced via conformational changes in this part of the molecule. 

Further developments in NMR were presented in Sydney (1980) on high-resolution NMR by J. F. G. Vliegenthart, and on two-dimensional NMR by L. D. Hall. More applications of conformational analysis were discussed by K. Bock (Vancouver 1982) on the conformations of oligosaccharides, by H. J. Jennings (Utrecht 1984), on the conformations of some polysaccharides, by I. Tvaroska (Stockholm 1988), on computational methods for determining conformations, and by Y. Kishi (Paris 1992) on the conformations of C-glycosyl compounds. 

Several applications of these couplings to the conformational analysis of various mono- and oligosaccharides have also been described.138 140 143 149 150 These applications incorporate both theoretical and experimental approaches toward determination of the conformation of saccharides in solution, a question still controversial because of the time-averaged character of the NMR data obtained (NOE and couplings) and the occurrence of conformational equilibria.3 Variations of Vc H values for maltose according to the solvent used have been observed,46 and... 

De Castro, C., Carannante, A., Lanzetta, R., Liparoti, V., Molinaro, A., Parrilli, M. Core oligosaccharide structure from the highly phytopathogenic Agrobacterium tumefaciens TT111 and conformational analysis of the putative rhamnan epitope. Glycobiology 16 (2006) 1272-1280. 

Thogersen H, Lemieux RU, Boch K, Meyer B (1982) Further justification for the exo-anomeric effect. Conformational analysis based on nuclear magnetic resonance spectroscopy of oligosaccharides. Can J Chem 60 44-57... 

Additional parameters for conformational analysis of oligosaccharides were derived by Imberty et al. [78],... 

S. W. Homans, A molecular mechanical force field for the conformational analysis of oligosaccharides comparison of theoretical and crystal structures of Man alpha 1-3Man beta l-4GlcNAc. Biochemistry, 29 (1990) 9110. 

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