Active-site-directed inactivation of human liver alpha-L-fucosidase by conduritol C trans-epoxide.
Conduritol C trans-epoxide was found to inactivate human liver alpha-L-fucosidase (alpha-L-fucoside fucohydrolase, EC 3.2.1.51), exhibiting an apparent dissociation constant of 43 mM. The cis-isomer of the inactivator had no apparent effect on the enzyme's activity. The pH profile for the inactivation yielded two apparent pK values of approx. 3.7 and 6.1 alpha-L-Fucose (a competitive inhibitor) was effective in protecting the enzyme from inactivation. These results are consistent with a requirement for two amino acid side chains at the active site involved in the reaction of the enzyme with conduritol C trans-epoxide.
D001665:Binding Sites; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007294:Inositol / Q000031:analogs & derivatives* / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D013237:Stereoisomerism; D005644:alpha-L-Fucosidase / Q000037:antagonists & inhibitors*
D007294:Inositol; D005644:alpha-L-Fucosidase; C011423:conduritol epoxide