Biomaterial Database

gamma-Glutamyltranspeptidase from Escherichia coli K-12: purification and properties. 1986

H Suzuki, and H Kumagai, and T Tochikura

gamma-Glutamyltranspeptidase (GGT) (EC 2.3.2.2) was purified from the periplasmic fraction of Escherichia coli K-12 to electrophoretic homogeneity. The final purification step, chromatofocusing, gave two protein peaks showing GGT activity (fractions A and B). The major heavy fraction (fraction A) consisted of two different subunits, with molecular weights of 39,200 and 22,000. The minor light fraction (fraction B) consisted of those with molecular weights of 38,600 and 22,000. Fraction A catalyzes the hydrolysis and transpeptidation of all gamma-glutamyl compounds tested, but it prefers basic amino acids and aromatic amino acids as acceptors. The apparent Km values for glutathione and gamma-glutamyl-p-nitroanilide as gamma-glutamyl donors in the transpeptidation reaction were both 35 microM, and those for glycylglycine and L-arginine as acceptors were 0.59 and 0.21 M, respectively. The enzyme was inhibited by some amino acids and by protease inhibitors and affinity-labeling reagents for GGT. The temperature stability of the purified GGT supports our hypothesis that E. coli GGT is synthesized only at lower temperature rather than that the synthesized GGT is degraded or inactivated at higher temperature.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
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
D005723	gamma-Glutamyltransferase	An enzyme, sometimes called GGT, with a key role in the synthesis and degradation of GLUTATHIONE; (GSH, a tripeptide that protects cells from many toxins). It catalyzes the transfer of the gamma-glutamyl moiety to an acceptor amino acid.	GGTP,Glutamyl Transpeptidase,gammaglutamyltransferase,gamma-Glutamyl Transpeptidase,Transpeptidase, Glutamyl,Transpeptidase, gamma-Glutamyl,gamma Glutamyl Transpeptidase,gamma Glutamyltransferase
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
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
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures