Suicide-substrate inactivation of β-galactosidase by diazomethyl β-d-galactopyranosyl ketone☆

Add time:08/23/2019    Source:sciencedirect.com

Diazomethyl β-d-galactopyranosyl ketone (1) has been proven to be a mechanism-based, irreversible (suicide-substrate) inactivator of Aspergillus oryzae β-d-galactosidase, but not an inactivator of E. coli lacZ β-d-galactosidase. Compound 1 is stable in buffers of normal physiological pH. It is decomposed by H+, but not by nucleophiles. Inactivation of A. oryzae β-d-galactosidase was proven to be mechanism-based and irreversible via experiments which showed that the enzyme could be protected from inactivation by a competitive inhibitor, neither diazomethyl β-d-glucopyranosyl ketone (2) nor diazomethyl α-d-galactopyranosyl ketone inactivated the enzyme and therefore inactivation is stereospecific, excess inhibitor could be separated from inactive enzyme without regain of activity and therefore it is bound irreversibly, and a second pulse of enzyme is inactivated at the same rate as enzyme inactivated to 95% activity by the first pulse. Diazomethyl β-d-glucopyranosyl ketone (2) inhibited sweet almond β-d-glucosidase.

We also recommend Trading Suppliers and Manufacturers of 1-(diazomethyl)-4-nitrobenzene (cas 19479-80-2). Pls Click Website Link as below: cas 19479-80-2 suppliers

Prev:Theoretical studies on the low-lying electronic states of the diazomethyl (HCNN) radical and its ions
Next:Inactivation of cathepsin B1 by diazomethyl ketones)