Probing the transferase activity of glycosidases by means of in situ NMR spectroscopy

This paper describes the conditions in which in situ NMR spectroscopy is a suitable technique to use when following the course of enzymatic transglyco sylation reactions. Using this methodology, the reactions must be carried o ut in D2O. Our experiments indicate that the rate of the transglycosylation reaction is reduced in this solvent while the rate of the hydrolysis of th e disaccharides produced is enhanced depending on the nature of the anomeri c substituent. However, this undesirable effect is generally weak because t he rates of the transglycosylation reactions are always faster than the rat es of the hydrolysis whatever the solvent. The great advantage of NMR spect roscopy lies in its potential to detect, in a single experiment, all the co mponents of the reaction without any disturbance of the reaction medium. (C ) 1999 Elsevier Science Ltd. All rights reserved.