Diffusion ordered spectroscopy as a complement to size exclusion chromatography in oligosaccharide analysis

P. Groves
2004 Glycobiology  
A series of N-acetyl-chitooligosaccharides (GlcNAc) 1±6 have been studied by a nuclear magnetic resonance (NMR) method, diffusion ordered spectroscopy (DOSY). DOSY has also been applied to two additional synthetic related oligosaccharides [GlcNH 2 -(GlcNAc) 4 and GlcNH 2 -(GlcNAc) 2 -GlcNAcSO 3 Na]. A plot of the log of the determined diffusion coefficients (logD) of (GlcNAc) n versus the log of molecular weight was linear (6 points, R 2 0.995). The molecular weights of the two synthetic chitin
more » ... wo synthetic chitin derivatives could be estimated to within 10% error. The processed NMR data of all the chitooligosaccharides was also plotted in a polyacrylamide gel±like format to aid visual interpretation. Moreover, the logD value of the NMR signal resonances of a chitinbinding protein (hevein) changed as a function of a given titrated ligand, (GlcNAc) 6 . Evidence for a 2:1 hevein:(GlcNAc) 6 complex is detected by DOSY at high hevein:(GlcNAc) 6 ratios. This data is consistent with published analytical ultracentrifugation and isothermal titration calorimetry data. A 1:1 complex is preferred at higher ligand concentrations. DOSY can complement size exclusion chromatography in carbohydrate research with the advantage that oligosaccharides are more readily detected by NMR.
doi:10.1093/glycob/cwh037 pmid:14693914 fatcat:lrjeo4pmwzapjbjfvbes3abjga