Deuterated disaccharides for the investigation of protein-carbohydrate interactions - Application of bio-affinity- and STD-NMR

NMR spectroscopic analysis of carbohydrates often suffers from severe overl ap of resonance signals, especially in H-1 NMR spectra. Therefore, we synth esized four 2,3,4-trideuterio-alpha-L-fucose containing disaccharides, alph a-L-Fuc-(1-->6)-beta-D-GlcNAc-OMe 1, alpha-L-Fuc-(1-->4)-beta-D-GlcNAc-OMe 2, alpha-L-Fuc-(1-->3)-beta-D-GlcNAc-OMe 3, and alpha-L-Fuc-(1-->2)-beta-D- Gal-OMe 4. Compounds 1 to 4 are well suited to be subjected to NMR conforma tional analysis because their H-1 NMR spectra show almost no overlap of sig nals. The deuterated disaccharides 1 to 4 will therefore be used as NMR pro bes for the exploration of fucose-binding proteins. With a mixture of the c orresponding nondeuterated disaccharides it is demonstrated that recently d eveloped parallel NMR screening protocols, Bio-Affinity NMR and STD-NMR, de liver fast and robust tools to assay the compounds synthesized for protein- binding affinity.