Long‐range proton–carbon coupling constants in conformational analysis of oligosaccharides

Rundlöf, Torgny; Kjellberg, Alexandra; Damberg, Charlotta; Nishida, Toshiaki; Widmalm, Göran

doi:10.1002/(sici)1097-458x(1998110)36:11<839::aid-omr371>3.3.co;2-0

Cited by 20 publications

(48 citation statements)

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“…The solvent mixture contains 70% water, and a comparative study, in which long-range heteronuclear coupling constants have been measured in both water and the cryosolvent mixture, shows small changes, i.e., within the experimental error of the technique, in the 3 J C,H values for the oligosaccharides in the two solvents. 45 We interpret this observation as showing that, to a good approximation, the solvating properties of the mixed solvent are similar to those of water and that the choice of the cryosolvent is justified in order to facilitate the magneticfield-dependent studies. Furthermore, according to McCain and Markley 46,47 neither the overall molecular dimensions nor the pattern of internal motions varies for sucrose at concentrations of 0.1-1.0 M. Additionally, τ c for sucrose at 0.1 M aqueous solution is similar to that at the infinite dilution limit.…”

Section: Resultsmentioning

confidence: 99%

Motional Properties of Two Vicinally Disubstituted Trisaccharides As Studied by Multiple-Field Carbon-13 NMR Relaxation

et al. 1998

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Multiple-field carbon-13 NMR relaxation measurements have been performed on the two vicinally disubstituted trisaccharides -D- (2). Trisaccharide 1 has trans disubstitution of the terminal -glucosyl residues, while trisaccharide 2 has cis disubstitution. Carbon-13 T 1 and T 2 relaxation and NOE measurements were performed outside the extreme-narrowing regime at three temperatures 283, 303, and 323 K and four magnetic field strengths 6.3, 9.4, 11.7, and 14.1 T. The obtained relaxation rates and NOE factors, averaged for each sugar residue, were fitted to overall and internal correlation times and order parameters using the Lipari-Szabo "model-free" formalism. The 2,3-disubstituted O-methyl glycoside showed fairly high-order parameters, S 2 ≈ 0.9, for both trisaccharides at all three temperatures, while the terminal glucosyl residues of 1 and 2 showed lower and slightly temperature-dependent order parameters, S 2 ≈ 0.8. In 1, the terminal residues were found to have similar motional properties and an internal correlation time of ∼60 ps could be obtained from a simultaneous three-parameter fit at 303 K. Similar results were obtained for trisaccharide 2. This study shows that the branch-point residue displays more restricted mobility than the terminal residues in both trisaccharides and that internal motions can be detected for small oligosaccharides using NMR relaxation measurements and the Lipari-Szabo model-free formalism.

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Section: Resultsmentioning

confidence: 99%

Motional Properties of Two Vicinally Disubstituted Trisaccharides As Studied by Multiple-Field Carbon-13 NMR Relaxation

et al. 1998

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“…The measurements of transglycosidic 3 J CH coupling constants (Rundl€ of et al, 1998) were carried out using one-dimensional long-range experiments essentially as devised by Nishida et al (1995Nishida et al ( , 1996 employing 13 C site-selective excitation with a Gaussian-shaped pulse of 80-250 msec duration. The delay used for suppression of 1 J CH was set to (145 Hz) -1 and the time of the delay between excitation and coherence transfer, for evolution of the long-range coupling, was set by using nominal values of 8-16 Hz; an acquisition time of 3 sec, 4096-6144 transients and 32-64k data points were used.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility

et al. 2016

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SUMMARYThe macromolecular conformation of the constituent polysaccharides in lignocellulosic biomass influences their supramolecular interactions, and therefore their function in plants and their performance in technical products. The flexibility of glycosidic linkages from the backbone of hemicelluloses was studied by evaluating the conformational freedom of the φ and w dihedral angles using molecular dynamic simulations, additionally selected molecules were correlated with experimental data by nuclear magnetic resonance spectroscopy. Three types of b-(1?4) glycosidic linkages involving the monosaccharides (Glcp, Xylp and Manp) present in the backbone of hemicelluloses were defined. Different di-and tetrasaccharides with combinations of such sugar monomers from hemicelluloses were simulated, and free energy maps of the φ -w space and hydrogen-bonding patterns were obtained. The glycosidic linkage between Glc-Glc or Glc-Man (C-type) was the stiffest with mainly one probable conformation; the linkage from Man-Man or Man-Glc (M-type) was similar but with an increased probability for an alternative conformation making it more flexible, and the linkage between two Xyl-units (X-type) was the most flexible with two almost equally populated conformations. Glycosidic linkages of the same type showed essentially the same conformational space in both disaccharides and in the central region of tetrasaccharides. Different probabilities of glycosidic linkage conformations in the backbone of hemicelluloses can be directly estimated from the free energy maps, which to a large degree affect the overall macromolecular conformations of these polymers. The information gained contributes to an increased understanding of the function of hemicelluloses both in the cell wall and in technical products.

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“…Especially 3 J CH coupling constants follow the Karplus relation and build a more reliable tool for the determination of relative configurations as e.g. NOE connectivities, which often do not allow unambiguous conclusions [1][2][3][4][5][6][7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Analyses, extensions and comparison of three experimental schemes for measuring (nJCH+DCH)-couplings at natural abundance

Kobzar

Luy

2007

Journal of Magnetic Resonance

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Long‐range proton–carbon coupling constants in conformational analysis of oligosaccharides

Cited by 20 publications

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Motional Properties of Two Vicinally Disubstituted Trisaccharides As Studied by Multiple-Field Carbon-13 NMR Relaxation

Motional Properties of Two Vicinally Disubstituted Trisaccharides As Studied by Multiple-Field Carbon-13 NMR Relaxation

A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility

Analyses, extensions and comparison of three experimental schemes for measuring (nJCH+DCH)-couplings at natural abundance

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