The ?-thioglycoligase derived from a GH89 ?-N-acetylglucosaminidase synthesizes ?-N-acetylglucosamine-based glycosides of biomedical interest".

We report here on the preparation of a novel a-thioglycoligase that can be used for the fast and efficient synthesis of a-N-acetylglucosamine- based glycosides. Using the a-N-acetyl-glucosamini- dase from Clostridium perfr ingens of family GH89 (according to the Carbohydrate Active Enzymes classification) as starting point, we prepare d mutants in the acid/base residue glutamic acid 483 that were found to have different synthetic efficiencies (maxi-mal yields > 80% after 24 h) in the presence of an activated donor and suitable acceptors. The synthetic potential of the Glu483 alanine mutant as an a-thio-glycoligase - only the third biocatalyst with this ste-reospecificity reported to date, and the first selectivefor the N-acetylglucosamine moiety - was demon- strated by producing for the first time N-acetyl-a-d-glucosaminyl azide and N-acetylglucosamine a-thio-glycosides in high yields. To showcase the application of such compounds, we show that they offer the wild-type CpGH89 protection from thermal unfold-ing, demonstrating their potential as pharmacological chaperones for the treatment of mucopolysacchari-dosis IIIB (Sanfilippo syndrome)