title: Kinetics of inactivation of glutamate decarboxylase by cysteine-specific reagents.
abstract: Mercuric chloride, p-chloromercuribenzoate and 5,5'-dithiobis(2-nitrobenzoic acid) irreversibly inhibited the activity of Escherichia coli glutamate decarboxylase. Their second order rate constants for inactivation are 0.463 microM(-1) min(-1), 0.034 microM(-1) min(-1), 0.018 microM(-1) min(-1), respectively. The characteristics of the inhibition by the three thiol-group reagents supports the idea that cysteinyl residues at the binding sites for the cofactor and/or the substrate are important for enzyme activity in E. coli.
authors.affiliation: Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Evansville, IN 47712, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: McCormick
authors.forename: G
authors.initials: G
authors.lastname: Tunnicliff
mesh_terms: D001665:Binding Sites; D003545:Cysteine / Q000737:chemistry; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology; D005968:Glutamate Decarboxylase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D007700:Kinetics; D008627:Mercuric Chloride / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D020245:p-Chloromercuribenzoic Acid / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D013439:Sulfhydryl Reagents; D008627:Mercuric Chloride; D020245:p-Chloromercuribenzoic Acid; D004228:Dithionitrobenzoic Acid; D005968:Glutamate Decarboxylase; D003545:Cysteine