Inactivation of Glycosidases - Exo and Paracatalytic Activation

Family, enzyme Source (nucleophile water unless indicated) Ref 

GH 2 P-mannosidase, acid-base mutant Cellulomonas fimi E429A 1.12, 1.17 (N3-) 211 

Unsurprisingly, the nitrogen analogue of conduritol epoxide inactivated GH 13 yeast ot-glucosidase and a GH 1 p-glucosidase from Agrobacterium faecalis the inactivation appeared faster than with conduritol B epoxide itself. 

Particularly with overtly reactive labelling reagents such as halocarbonyl compounds, it is desirable to have confirmation that the labelling is active site directed. Only one molecule of the reagent should be incorporated per active site inactivated (these days this readily established by mass spectrometry with soft ionisation techniques such as electrospray) and the kinetics of inactivation in the presence of excess inactivator should be first order (if A is activity, then At = oexp(—kobsO- particular, quantitative protection by a reversible 

Family Substrate stereochemistry Acidjbase Trajectory Nucleophile ES conformation Glycosyl-enzyme, conformation rs 

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