Conformational analysis of oligosaccharides

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 ... 

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. 

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. 

R. U. Lemieux and K. Bock, Arch. Biochem. Biophys., 221, 125 (1983). The Conformational Analysis of Oligosaccharides by H-NMR and HSEA Calculation. 

S. W. Homans and M. Forster, Glycobiology, 2, 143 (1992). Application of Restrained Minimization, Simulated Annealing and Molecular Dynamics Simulations for the Conformational Analysis of Oligosaccharides. 

A complete structural determination of chitin/chitosan, subsequent to its isolation and purification, involves the determination (the constituent of the two monosaccharides the molecular size the molecular size distribution the linkage positions between the monomer units their sequence and degree of heterogeneity and any preferred conformation of the molecule(s) present). NMR spectroscopy can be used for structural characterization and conformational analysis of oligosaccharides in solution (van Halbeek 1996, Chaplin 2000). Conformational changes accompanied with metal-binding were examined by means of C NMR spectroscopy (Saito et al. 1987a,b). 

Reviews have been published on progress over the last 20 years in computional methods for studying oligo- and poly-saccharide conformations in the solid state and in solution, and on the newer techniques of H-n.m.r. spectroscopy which have proved useful in the elucidation of oligosaccharide structures. A review and a symposium report have appeared on the conformational analysis of oligosaccharides in solution by n.m.r. methods combined with... 

Spin-lattice relaxation times, n.O.e. data, and chemical shifts have been applied to the conformational analysis of oligosaccharides by H -n.m.r. spectroscopy. Differences in values for similar protons in different oligosaccharides can be conformationally significant where is > 0.1 p.p.m., and may be attributed to specific inter-unit deshielding by oxygen atoms with which the proton is in a strong non-bonded interaction. A new method for sugar sequence... 

Hounsell EF (1995) H NMR in the structural and conformational analysis of oligosaccharides and glyco-conjugates. Progress in Nuclear Magnetic Resonance Spectroscopy 27 445-474. 

The applications of C H NOEs for the conformational analysis of oligosaccharides have thus far been quite limited. However, they have been measured at natural abundance in Neu5Aca2-6Gaipi-4Glc [41] and in C, H enriched GaipMGlc [51]. 

In recent years the value of long-range C C coupling constants for the conformational analysis of oligosaccharides has been realized [52-55, 56-58). A principal difficulty with the measurement of these parameters is the requirement for C-enriched material—imlike heteronuclear C- H measurements where the 1% natural abundance of C is not a substantial sensitivity barrier, 0.01% of... 

As an example of the use of some of the techniques described above in the conformational analysis of oligosaccharides, a case study of the solution properties of the trisaccharide Neu5Aca2-3Gaipi-4Glc will be described. 

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