Open AccessThe 13 C‐NMR Spectra of Hyaluronate and Chondroitin Sulphates
Author(s) -
BOCIEK Stephen M.,
DARKE Arthur H.,
WELTI David,
REES David A.
Publication year - 1980
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1980.tb04814.x
Subject(s) - chondroitin , chemistry , spectral line , chondroitin sulphate , chemical shift , alkali metal , nmr spectra database , carbon 13 nmr , proton nmr , chondroitin sulfate , nuclear magnetic resonance , crystallography , stereochemistry , organic chemistry , biochemistry , glycosaminoglycan , physics , astronomy
Complete assignments are given for the 13 C NMR spectra of hyaluronate and chondroitin in deuterium oxide solution at 50.32 MHz. The assignments published earlier for chondroitin 6‐sulphate and chondroitin 4‐sulphate were largely confirmed but were found to need some revision in detail. Our conclusions for hyaluronate and the chondroitin sulphates were confirmed by off‐resonance experiments based on the proton NMR assignments. The spectra for hyaluronate show line narrowing and chemical shift changes from neutral to alkaline solution which are consistent with, and clearer than, the effects reported earlier for the proton spectra. As before no such changes occur for the chondroitin sulphates. The suggested interpretation is in terms of a conformation change for hyaluronate which originates mainly in altered interaction energies across the 1 → 3 linkage with the results that motional freedom is enhanced above that of the parent hyaluronate and even above the chondroitin sulphates. This, and the evidence from a temperature effect, suggests that an additional potential energy minimum is made favourable in alkali so that the overall amplitudes of the bond oscillations are increased.