Biomaterial Database

[Substrate specificity of E. coli glutamate decarboxylase]. 1977

B S Sukhareva, and D G Malikova

Interaction of highly purified E. coli glutamate decarboxylase with a number substrate analogs was studied. Decarboxylation of the following amino acids was demonstrated: gamma-methylene glutamate, threo-beta-hydroxyglutamate, allo-gamma-hydroxyglutamate, threo-beta-methylglutamate, homocysteate, aminoadipate and cysteinesulfinate. The Km and either Ki or I50 values were determined for these compounds. The final products of the interaction of glutamate decarboxylase with these analogs have the same absorption spectra and capacity for reactivation by pyridoxal-P, as has the pyridoxamine-P form of the enzyme. Thus, decarboxylation of all the amino acids, mentioned above, was probably associated with the side reaction of transamination to coenzyme in the active center. Binding of aliphatic dicarboxylic acids or of valeric acid by glutamate decarboxylase leads to a slight shift of absorption spectra and of circular dichroism spectra from 420 to 423--425 nm. The following compounds fail to be bound and decarboxylated by the enzyme: gamma-aminobutyrate, D-glutamate, L-glutamine, 3,3-dimethylglutarate, methioninesulfone, methioninesulfoxide, norvaline, gamma-hydroxy-gamma-methylglutamate, erytro-beta-methylglutamate and erythro-beta-hydroxyglutamate.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005968	Glutamate Decarboxylase	A pyridoxal-phosphate protein that catalyzes the alpha-decarboxylation of L-glutamic acid to form gamma-aminobutyric acid and carbon dioxide. The enzyme is found in bacteria and in invertebrate and vertebrate nervous systems. It is the rate-limiting enzyme in determining GAMMA-AMINOBUTYRIC ACID levels in normal nervous tissues. The brain enzyme also acts on L-cysteate, L-cysteine sulfinate, and L-aspartate. EC 4.1.1.15.	Glutamate Carboxy-Lyase,Glutamic Acid Decarboxylase,Acid Decarboxylase, Glutamic,Carboxy-Lyase, Glutamate,Decarboxylase, Glutamate,Decarboxylase, Glutamic Acid,Glutamate Carboxy Lyase
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities