Studies on the Conformation of Heparin by 1H and 13C NMR Spectroscopy

Gatti, Giuseppe; Casu, Benito; Hamer, Gordon K.; Perlin, A. S.

doi:10.1021/ma60071a044

Cited by 129 publications

(65 citation statements)

References 7 publications

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“…lc) of the unmodified inactive oligosaccharides. The spectrum of the latter is roughly similar to that of typical heparins (Gatti et al, 1979) Minor signals are present in both active and inactive oligosaccharides, especially in the inactive species, which also contained non-carbohydrate contaminants (shaded areas in Fig. 1).…”

Section: Extraction Oligosaccharidesmentioning

confidence: 67%

“…Since C-3 of As of the 'regular' heparin sequence is at 70.6 p.p.m. (Gatti et al, 1979; value corrected for the different internal reference), C-3 of A* has to be expected somewhere around 78.5 p.p.m. This is unfortunately a region where severe overlap by other signals prevents unambiguous observation of a relevant signal.…”

Section: Discussionmentioning

confidence: 99%

“…Further, Lindahl et al (1980) demonstrated that the As residue of the above tetrasaccharide fragment bears a 3-0-sulphate group. Heparin has been studied by n.m.r. All the 13C signals of the regular regions as well as some signals originated by residues in the irregular regions of heparin were recently assigned (Gatti et al, 1979). This provides a basis for comparison with the spectra of high-affinity oligosaccharides, thus allowing further insight into the structure of the compounds.…”

Section: (Received 23 February 1981/accepted 27 April 1981)mentioning

confidence: 99%

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The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin III-binding sequence Chemical and13C nuclear-magnetic-resonance studies

Casu¹,

Oreste²,

Torri³

et al. 1981

Biochemical Journal

336

122

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The chemical composition and the 13C n.m.r. spectra of heparin oligosaccharides (essentially octasaccharides), having high affinity for antithrombin III and high anti-(Factor Xa) activity, prepared by three independent approaches (extraction, partial deaminative cleavage with HNO2 and partial depolymerization with bacterial heparinase), leading to different terminal residues, have been studied and compared with those of the corresponding inactive species. Combined with chemical data, the spectra of the active oligosaccharides and of their fragmentation products afforded information on composition and sequence. The three types of active oligosaccharides were shown to have the common hexasaccharide core

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Section: Extraction Oligosaccharidesmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

Section: (Received 23 February 1981/accepted 27 April 1981)mentioning

confidence: 99%

See 1 more Smart Citation

The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin III-binding sequence Chemical and13C nuclear-magnetic-resonance studies

Casu¹,

Oreste²,

Torri³

et al. 1981

Biochemical Journal

336

122

View full text Add to dashboard Cite

show abstract

“…[21][22][23] Most common to porcine mucosal heparins (75%) are disaccharide repeats of 2-Osulfated-iduronic acid and 6-O-sulfated, N-sulfated-glucosamine. 23 The influence of heparin on protein aggregation is complicated. Calamai et al reported that polyanions, including heparin, promote the aggregation of amyloidogenic proteins.…”

Section: Introductionmentioning

confidence: 99%

Suppression of Insulin Aggregation by Heparin

et al. 2008

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The aggregation of insulin near its isoelectric point and at low ionic strength was suppressed in the presence of heparin. To understand this effect, we used turbidimetry and stopped-flow to study the pH-and ionic strength (I)-dependence of the aggregation of heparin-free insulin. The results supported the role of interprotein electrostatic interactions, contrary to the commonly held view that such forces are minimized at pH ) pI. Electrostatic modeling of insulin (DelPhi) revealed that attractive interactions arise from the marked charge anisotropy of insulin near pI. We show how screening of the interprotein attractions by added salt lead to maximum aggregation near I ) 0.01 M, corresponding to a Debye length nearly equal to the diameter of the insulin dimer, consistent with a dipole-like protein charge distribution. This analysis is also consistent with suppression of aggregation by heparin, a strong polyanion that by binding to the positive domain of one protein, inhibits its interaction with the negative domain of another.

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“…5 b, c). This steric occlusion is likely to underlie the preponderance of the gg rotamer by GlcNAc O-6-SO3 in heparan sulphate and heparin [Gatti et al, 1979;Ragazzi et al, 1990]. In contrast, sulphation of GlcNAc at O-3 would be expected to considerably perturb the conformation of the ␤ 1 ] 4 linkage, by the loss of the inter-residue hydrogen bond ( fig.…”

mentioning

confidence: 99%

Investigating the Molecular Basis for the Virulence of Escherichia coli K5 by Nuclear Magnetic Resonance Analysis of the Capsule Polysaccharide

Blundell

Roberts²,

Sheehan³

et al. 2009

Microb Physiol

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The capsular polysaccharide of Escherichia coli K5 has been hypothesised to promote virulence through its molecular mimicry of host heparan sulphate. To test this hypothesis, we have produced pure oligosaccharides from K5 capsular polysaccharide and investigated their conformational properties with ultra-high-field nuclear magnetic resonance (NMR) (900 MHz). Ultra-high-field affords a significant resolution enhancement over previous studies and allowed a full-atomic assignment of the K5 hexasaccharide for the first time. All carbohydrate rings adopt a ⁴C₁ conformation, the amide sidechains have a trans orientation and the hydroxymethyl group is freely exposed to bulk solvent. Initial models of the glycosidic linkage conformation based upon simple interpretation of NOE cross-peaks suggests that the β1→4 linkage adopts a 3D geometry of φ ≈ 60°, ψ ≈ 0° and the α1→4 linkage prefers φ ≈ –30°, ψ ≈ –30° (φ and ψ being defined by dihedral angles involving linkage protons). In this conformation the overall molecular geometries of K5 polysaccharide, heparan sulphate and even fully-sulphated heparin are remarkably similar. These results substantiate the hypothesis that the K5 capsular polysaccharide confers virulence to E. coli K5 by being a 3D molecular mimetic of host heparan sulphate, helping it to evade detection by the mammalian immune system.

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Studies on the Conformation of Heparin by ¹H and ¹³C NMR Spectroscopy

Cited by 129 publications

References 7 publications

The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin III-binding sequence Chemical and13C nuclear-magnetic-resonance studies

The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin III-binding sequence Chemical and13C nuclear-magnetic-resonance studies

Suppression of Insulin Aggregation by Heparin

Investigating the Molecular Basis for the Virulence of <i>Escherichia coli</i> K5 by Nuclear Magnetic Resonance Analysis of the Capsule Polysaccharide

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