Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
a (5-L-glutamyl)-peptide + an amino acid | Bacillus subtilis | - |
a peptide + a 5-L-glutamyl amino acid | - |
? | |
a (5-L-glutamyl)-peptide + an amino acid | Bacillus subtilis 168 | - |
a peptide + a 5-L-glutamyl amino acid | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bacillus subtilis | P54422 | - |
- |
Bacillus subtilis 168 | P54422 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(gamma-L-glutamyl)-4-nitroanilide + glycylglycine | chromogenic gamma-glutamyl-4-nitroanilide (GPNA) reacts as the donor substrate affording the gamma-glutamyl-enzyme intermediate through reaction with the catalytically active threonine residue at the N-terminus of the small subunit of the enzyme. In this step 4-nitroaniline (PNA) is liberated, which can be spectrophotometrically detected at 410 nm. The gamma-glutamyl-enzyme intermediate is then resolved by nucleophilic attack of the free amino group of glycylglycine, present in solution in excess amount. The transpeptidation product gamma-glutamylglycylglycine is formed and the enzyme is restored in its free state, able to start a new catalytic cycle. The reaction of the gamma-glutamyl enzyme intermediate with a nucleophile is the rate-determining step of the process, thus the rate of liberation of PNA is usually considered a measure of the rate of the transpeptidase activity | Bacillus subtilis | 4-nitroaniline + gamma-glutamylglycylglycine | - |
? | |
(gamma-L-glutamyl)-4-nitroanilide + glycylglycine | chromogenic gamma-glutamyl-4-nitroanilide (GPNA) reacts as the donor substrate affording the gamma-glutamyl-enzyme intermediate through reaction with the catalytically active threonine residue at the N-terminus of the small subunit of the enzyme. In this step 4-nitroaniline (PNA) is liberated, which can be spectrophotometrically detected at 410 nm. The gamma-glutamyl-enzyme intermediate is then resolved by nucleophilic attack of the free amino group of glycylglycine, present in solution in excess amount. The transpeptidation product gamma-glutamylglycylglycine is formed and the enzyme is restored in its free state, able to start a new catalytic cycle. The reaction of the gamma-glutamyl enzyme intermediate with a nucleophile is the rate-determining step of the process, thus the rate of liberation of PNA is usually considered a measure of the rate of the transpeptidase activity | Bacillus subtilis 168 | 4-nitroaniline + gamma-glutamylglycylglycine | - |
? | |
a (5-L-glutamyl)-peptide + an amino acid | - |
Bacillus subtilis | a peptide + a 5-L-glutamyl amino acid | - |
? | |
a (5-L-glutamyl)-peptide + an amino acid | - |
Bacillus subtilis 168 | a peptide + a 5-L-glutamyl amino acid | - |
? |
Synonyms | Comment | Organism |
---|---|---|
gamma-glutamyltransferase | - |
Bacillus subtilis |
GGT | - |
Bacillus subtilis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.2 | - |
assay at | Bacillus subtilis |
General Information | Comment | Organism |
---|---|---|
physiological function | gamma-glutamyltransferases (GGTs) are widespread, conserved enzymes that catalyze the transfer of the gamma-glutamyl moiety from a donor substrate to water (hydrolysis, EC 3.4.19.13) or to an acceptor amino acid (transpeptidation)through the formation of a gamma-glutamyl enzyme intermediate | Bacillus subtilis |