The Structure of Molecules Containing Cyclohexane or Pyranose Rings.

Hassel, O.; Ottar, B.; Roald, B.; Linnasalmi, Annikki; Laukkanen, Pentti

doi:10.3891/acta.chem.scand.01-0929

Cited by 160 publications

(69 citation statements)

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“…This conclusion agrees with molecular dynamics simulations [21, 511 and calculated populations for the three staggered Table 2). The destabilizing contribution of the Hassel-Ottar effect [53] apparently outweighs the energy gain due to hydrogen bonding and seems to be responsible for the low population of the gg rotamer.…”

Section: Calculated With Eqn Rij = R K L ( O K L / O T J ) 1 'mentioning

confidence: 99%

Three‐dimensional structure of the oligosaccharide terminus of globotriaosylceramide and isoglobotriaosylceramide in solution

Poppe

Dąbrowski

Lieth

et al. 1990

European Journal of Biochemistry

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Spatial structures of the oligosaccharide parts of globotriaosylceramide, Gal(al-4)Gal(fll-4)Glc(fl1-1)Cer (Cer = ceramide) and isoglobotriaosylceramide, Gal(al-3)Gal(/3l-4)Glc(/l1-1)Cer were investigated in (C2H3)2S0 solution by means of laboratory and rotating frame NOE, hydroxyl protons being used as long-range sensors defining the distance constraints. Both oligosaccharides were found to exist in more than one conformation interconverting rapidly on the NMR time scale. The conformation of the Gal(al-4)Gal(~1-4)Glc/3 trisaccharide dissolved in 2 H 2 0 appeared to be the same as that of the corresponding part of the glycosphingolipid in (C2H3)2S0 solution.Globotriaosylceramide Gal(~1-4)Glc(/31 -l)Cer; I] and isoglobotriaosylceramide Gal(/ll-4)Glc(fl1-1)Cer; 21 belong to the globo series of glycosphingolipids found in many different mammalian tissues [I]. The former was recognized as an antigen of the P blood group system, whilst 2 was found to be associated with malignant neoplasms [I, 21. Recent findings have shown that the Gal(a1-4)GalB segment of many glycosphingolipids can act as an attachment site for bacteria, bacterial toxins and viruses [3,4]. The importance of the three-dimensional (3D) structure of this epitope in relation to its biological role has been highlighted [3,4] and a detailed conformational investigation of the corresponding disaccharide, galabiose, has been published [5].The spatial structure of oligosaccharides can be determined, in principle, from experimental data (NOE, coupling constants, chemical shifts) and/or from theoretical calculations. Since the latter are still far from being able to deliver unequivocal solutions, experimental approaches remain the main source of structural information. It must be realized, however, that an experimentally derived conformation does not necessarily correspond to a single state, but may result rather as an average of many, or even an infinite number, of states [6, 71. Apart from possible, but not very likely, radical progress in computational methods, reliable verification of one-state vs multiple-state conformational models requires a Correspondence to J. Dabrowski, Max-Planck-Institut fur Medizinische Forschung, Jahnstrasse 29, D-6900 Heidelberg, Federal Republic of Germany Abbreviations. Cer, ceramide; COSY, correlation spectroscopy; ID, 2D and 3D. one-, two-and three-dimensional; DANTE, delays alternating with nutations for tailored excitation; FID, free induction decay; GESA, geometry of saccharides programme; HOHAHA spectroscopy, homonuclear Hartmann-Hahn spectroscopy; HSEA, hardsphere exo-anomeric method; ROE, rotating frame nuclear Overhauser effect; ROESY, 2D ROE spectroscopy; TOCSY, total correlation spectroscopy ; TPPI, time-proportional phase incrementation. greater number of experimentally based constraints, in fact more than can presently be obtained with the aid of NMR spectroscopy. In particular, NOE contacts, which are found to be abundant and highly effective as constraints in the conformational analysis of proteins, oligopeptid...

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Section: Calculated With Eqn Rij = R K L ( O K L / O T J ) 1 'mentioning

confidence: 99%

Three‐dimensional structure of the oligosaccharide terminus of globotriaosylceramide and isoglobotriaosylceramide in solution

Poppe

Dąbrowski

Lieth

et al. 1990

European Journal of Biochemistry

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“…The forbidden orientation was only observed in special cases where it is stabilized by intramolecular hydrogen bonding. This conformational factor was first recognized by Hassel & Ottar (1947). It is more generally referred to as the peri interaction or the 1,3-syndiaxial interaction.…”

Section: Introductionmentioning

confidence: 99%

Crystallographic studies of carbohydrates

Jeffrey¹

1990

Acta Crystallogr B Struct Sci

150

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The monosaccharides which constitute the monomer units of many important industrial and biological macromolecules are well represented among the 2000 crystal structures of the carbohydrate class 45 of the Cambridge Structural Database. There are few examples of crystal structure analyses of the corresponding acids, but many of their calcium salts and calcium salt complexes. With the exception of the disaccharides and cyclodextrins, the oligosaccharides are not well represented, with less than ten trisaccharides, one tetrasaccharide and one hexasaccharide-iodide complex. Two important conformational factors are the Hassel-Ottar effect and the anomeric effect, both of which have been studied using crystallographic data. Hydrogen bonding is ubiquitous in carbohydrate crystals and generally involves all the hydroxyls as both donors and acceptors, and some of the ring and glycosidic oxygens as acceptors. These hydrogen bonds tend to form finite or infinite chains. In hydrates, these chains are linked through the water molecules to form networks. Cyclic hydrogen-bond systems are observed in the cyclodextrins. Long-chain alkylated carbohydrates provide a large class of thermotropic and lyotropic liquid crystals, and some non-ionic surfactants which have been shown to be useful for membrane-protein solubilization and crystallization.

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“…The conformations available to the exocyclic hydroxymethyl group of different sugars have been investigated [6][7][8][9] and commonly two out of three staggered or nearly so conformations are highly preferred whereas the last one is only populated to a small extent, based on preferences due to the gauche effect 10,11 and the 1,3-diaxial steric/repulsive interactions. 12 Previous studies of (1→6)-linked carbohydrates with gluco-configuration (hydroxyl group at C4 equatorial for D-Glcp in the 4 C 1 conformation) in aqueous solution using NMR spectroscopy combined with computational methods have found that φ prefers the conformation predicted by the exo-anomeric effect, while ψ mainly adopts an extended anti-conformation around 180° with either a broad distribution or limited excursions to conformations having values of ψ around either +90°…”

Section: Introductionmentioning

confidence: 99%

Conformation and Dynamics at a Flexible Glycosidic Linkage Revealed by NMR Spectroscopy and Molecular Dynamics Simulations: Analysis of β-l-Fucp-(1→6)-α-d-Glcp-OMe in Water Solution

2013

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The intrinsic flexibility of carbohydrates facilitates different three-dimensional structures in response to altered environments. At glycosidic (1→6)-linkages three torsion angles are variable and herein the conformation and dynamics of β-L-Fucp-(1→6)-α-D-Glcp-OMe are investigated using a combination of NMR spectroscopy and molecular dynamics (MD) simulations. The disaccharide shows evidence of conformational averaging for the ψ and ω torsion angles, best explained by a four-state conformational distribution. Notably, there is a significant population of conformations having ψ = 85° (clinal) in addition to those having ψ = 180° (antiperiplanar). Moderate differences in13 C R 1 relaxation rates are found to be best explained by axially symmetric tumbling in combination with minor differences in librational motion for the two residues, whereas the isomerization motions are occurring too slowly to be contributing significantly to the observed relaxation rates. The MD simulation was found to give a reasonably good agreement with experiment, especially with respect to diffusive properties among which the rotational anisotropy,, is found to be 2.35. The force field employed showed too narrow ω torsion angles in the gauche-trans and gauche-gauche states as well as overestimating the population of the gauchetrans conformer. This information can subsequently be used in directing parameter developments and emphasizes the need for refinement of force fields for (1→6)-linked carbohydrates.

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The Structure of Molecules Containing Cyclohexane or Pyranose Rings.

Cited by 160 publications

References 0 publications

Three‐dimensional structure of the oligosaccharide terminus of globotriaosylceramide and isoglobotriaosylceramide in solution

Three‐dimensional structure of the oligosaccharide terminus of globotriaosylceramide and isoglobotriaosylceramide in solution

Crystallographic studies of carbohydrates

Conformation and Dynamics at a Flexible Glycosidic Linkage Revealed by NMR Spectroscopy and Molecular Dynamics Simulations: Analysis of β-l-Fucp-(1→6)-α-d-Glcp-OMe in Water Solution

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