Solution conformation of the biantennary N-linked oligosaccharide of human serotransferrin using 1H NMR nuclear Overhauser effect measurements

AbstractThe conformation in solution of the biantennary complex type oligosaccharide unit derived from human serotransferrin has been investigated using 1H—1H Nuclear Overhauser Effect (NOE) measurements at 300 MHz. From quantitation of the NOE, the α(1–3) antenna is shown to exist in a preferred solution conformation with respect to the mannosyl-chitobiose core. The flexibility of the α(1–6) arm, together with the absence of NOE data between this arm and the core, indicates that, in contrast to the α(1–3) arm the α(1–6) arm has no preferred conformation with respect to the core

Inositol phosphoglycan P-type in infants of preeclamptic mothers

Background. Inositol phosphoglycan P-type (P-IPG) has consistently found to be elevated during active preeclampsia, although the biosynthetic source has to be identified yet. This multicenter prospective cross-sectional case-control study evaluated the fetus/newborn as the source of P-IPG. Methods. A urine specimen was collected longitudinally for three consecutive days after delivery from 90 newborns and their mothers, and ordered according to clinical diagnosis of preeclampsia, gestational hypertension, or healthy pregnancy. Results. The urinary excretion of P-IPG on day 0 was higher in the mothers in all groups (p<0.05) with higher levels in preeclamptic women (p<0.01) in the mothers compared to their newborns in the preeclamptic group (p<0.01). The difference persisted at least two days post partum. Conclusion. Findings of this study confirm the specificity of the increase in urinary excretion of P-IPG in preeclamptic mothers at day of birth compared to healthy pregnancy and GH, but does not extend to their newborns. © 2012 Informa UK, Ltd

Structure and dynamics in oligomannose-type oligosaccharides

Using a combination of 1H NMR nuclear Overhauser effect measurements, molecular orbital calculations, and molecular dynamics simulations, we have determined the tertiary structure and dynamic properties of the oligomannose oligosaccharide Man alpha 6(Man alpha 3)Man alpha 6(Man alpha 3)Man beta 4GlcNAc beta 4GLcNAc. While the calculated potential surfaces for the majority of the glycosidic linkages could be described by a single deep potential well, similar calculations for the Man alpha 1-6Man alpha and Man alpha 1-6Man beta linkages described a diffuse, shallow well, suggesting that a larger degree of flexibility exists about the latter. These conclusions are supported by the results of molecular dynamics simulations, which suggest that the NMR data should be interpreted in terms of a degree of flexibility about the Man alpha 1-6Man beta and Man alpha 1-6Man alpha linkages. In contrast, a similar series of investigations suggests that the conformation of the Man alpha 1-6Man beta linkage in Man alpha 2Man6(Man alpha 2Man alpha 3)Man alpha 6 (Man alpha 2Man alpha 2Man alpha 3)Man beta 4GlcNAc beta 4GlcNAc is more restricted, resulting in an overall structure that is "restrained"