NMR study of hydroxy and amide protons in hyaluronan polymers

Abstract

Hyaluronan (HA) is an important and well characterized glycosaminoglycan with high viscosity and water-retaining capacity. Nonetheless, it is not fully understood whether conformational properties of the easily characterized HA oligomers can be transferred to HA polymers. To investigate possible differences in hydration, hydrogen bonding and flexibility between HA polymers and oligomers, hydroxy and amide protons of HA polymers were studied by solution-state and high-resolution magic angle spinning (HR-MAS) NMR spectroscopy. Measurements of chemical shifts, temperature coefficients and NOEs in HA polymers revealed that the NMR data are very similar compared to the interior of a HA octasaccharide, supporting transient hydrogen bond interactions across the beta(1 -> 3) and beta(1 -> 4) glycosidic linkages. However, differences in NOEs suggested a cis-like orientation between NH and H2 in the HA polymer. The lack of concentration dependence of the hydroxy proton chemical shifts suggests that there are no direct inter-chain interactions involving hydroxy protons at the concentrations investigated. (C) 2016 Elsevier Ltd. All rights reserved.

Keywords

Hyaluronan; NMR spectroscopy; Hydroxy proton; Hydrogen bonding; Hydration

Published in

Carbohydrate Polymers
2017, Volume: 157, pages: 920-928 Publisher: ELSEVIER SCI LTD

SLU Authors

• Nestor, Gustav

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

• Sandström, Corine

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Organic Chemistry


Publication identifier

DOI: https://doi.org/10.1016/j.carbpol.2016.10.005

Permanent link to this page (URI)

https://res.slu.se/id/publ/86922