An investigation of a maximum entropy method for the processing of 1H and 13C nmr spectra from glycosaminoglycan oligo- and poly-saccharides

13C-NMR spectroscopy of keratan sulphates. Assignments for four poly(N-acetyllactosamine)-repeat-sequence tetrasaccharides derived from bovine articular cartilage keratan sulphate by keratanase II digestion

Skeletal keratan sulphate has been fragmented using the enzyme keratanase II, and the complete 13C chemical shift data are reported for the four tetrasaccharides which derived from the repeat region. They have the structures: Gal beta(1-4)GlcNAc(6S)beta(1-3)Gal beta(1-4)GlcNAc(6S)-ol, Gal(6S)beta(1-4)GlcNAc(6S)beta(1-3)Gal(1-4)GlcNAc(6S)-ol, Gal beta(1-4)GlcNAc(6S)beta(1-3)Gal(6S)beta(1-4)GlcNAc(6S)-ol, and Gal(6S)beta(1-4)GlcNAc(6S)(1-3)Gal(6S)beta(1-4)GlcNAc(6S)-ol, where GlcNAc(6S)-ol represents N-acetyl-glucosaminitol-6-O-sulphate. The value of these data for microstructural analysis of undegraded keratan sulphate samples using 13C-NMR spectroscopy is discussed with respect to galactose sulphation levels and the block sulphation structure.

Spectroscopic characterisation of disaccharides derived from keratan sulfates

Skeletal keratan sulfates have been degraded by three independent techniques and the resultant, borohydride-reduced, disaccharides have been characterised by NMR spectroscopy. The 1H and 13C (where available) chemical shifts are reported for the following substances, where GalNAc-ol represents N-acetyl-galactosaminitol, GlcNAc-ol represents N-acetyl-glucosaminitol, GlcNAc(6S)-ol represents N-acetyl-glucosaminitol 6-O-sulfate and 2,5AnMan(6S)-ol represents 2,5-anhydro-D-mannitol 6-O-sulfate. (a) GlcNAc(6S)beta(1-3)Gal-ol, isolated after keratanase (from Pseudomonas sp.) digestion. (b) Gal beta(1-4)GlcNAc(6S)-ol and Gal(6S)beta(1-4) GlcNAc(6S)-ol, the 1H chemical shifts have been reported previously [Brown, G. M., Huckerby, T. N., Morris, H. G., Abram, B. L. & Nieduszynski, I. A. (1994) Biochemistry 33, 4836-4846; Brown, G. M., Huckerby, T. N. & Nieduszynski, I. A. (1994) Eur. J. Biochem. 224, 281-308], GlcNAc(6S)beta(1-6)GalNAc-ol, [formula: see text], [formula: see text], all isolated after keratanase II digestion. (c) Gal beta(1-4)2,5AnMan(6S)-ol and Gal(6S)beta(1-4)2,5AnMan(6S)-ol, isolated after hydrazinolysis and nitrous acid digestion. In addition, the model compounds Gal beta(1-4)GlcNAc-ol and Gal beta(1-6)GlcNAc-ol have also been examined by 1H and 13C NMR spectroscopy. The value of these data for microstructural analysis of keratan sulfate samples is discussed.