Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Mg-phosphoribosyldiphosphate | no glutamine-binding site in the absence of Mg-phosphoribosyldiphosphate | Escherichia coli | |
phosphoribosyl-5-phosphate | 3-4fold activation of glutaminase activity in the presence of phosphate or diphosphate | Escherichia coli |
General Stability | Organism |
---|---|
stable during all stages of purification provided thiols and oxygen are avoided | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-amino-4-oxo-5-chloropentanoate | approx. 80% inactivation of NH3-dependent activity after 30 min | Escherichia coli | |
6-diazo-5-oxo-L-norleucine | approx. 98% inactivation of amidotransferase activity after 30 min | Escherichia coli | |
ADP | - |
Escherichia coli | |
AMP | approx. 10 mM, complete inhibition, sigmoidal inhibition curve, competitive vs. 5-phospho-alpha-D-ribose 1-diphosphate, GMP and AMP together have a synergistic effect on inhibition | Escherichia coli | |
GDP | - |
Escherichia coli | |
GMP | approx. 2.5 mM, complete inhibition, highly sigmoidal inhibition curve, competitive vs. 5-phospho-alpha-D-ribose 1-diphosphate, GMP and AMP together have an synergistic effect on inhibition | Escherichia coli | |
GTP | 5 mM, 79% inhibition | Escherichia coli | |
IMP | 5 mM, 86% inhibition | Escherichia coli | |
iodoacetamide | approx. 60% inactivation of amidotransferase activity after 30 min, very weak inactivation of NH3-dependent activity | Escherichia coli | |
p-mercuribenzoate | 0.001 mM, complete inhibition | Escherichia coli | |
XMP | 51% inhibition; 5 mM | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.067 | - |
5-phospho-alpha-D-ribose 1-diphosphate | - |
Escherichia coli | |
1.7 | - |
L-glutamine | - |
Escherichia coli | |
8.8 | - |
NH3 | - |
Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | - |
Escherichia coli | |
additional information | non-heme iron is not present in significant amounts | Escherichia coli | |
additional information | not activated by iron or sulfide | Escherichia coli |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
57000 | - |
3-4 * 57000, SDS-PAGE | Escherichia coli |
194000 | - |
sedimentation equilibrium centrifugation | Escherichia coli |
224000 | - |
gel filtration | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O | Escherichia coli | first reaction in de-novo pathway of purine biosynthesis | L-glutamate + 5-phospho-beta-D-ribosylamine + diphosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
strains K-12 or B-96, purine requiring strain | - |
Oxidation Stability | Organism |
---|---|
anaerobic conditions stabilize | Escherichia coli |
low concentrations of thiols e.g. dithiothreitol or 2-mercaptoethanol accelerate aerobic inactivation | Escherichia coli |
oxygen inactivates during purification | Escherichia coli |
Purification (Comment) | Organism |
---|---|
ammonium sulfate, heat treatment, DEAE-Sepharose, Blue Dextran-Sepharose, hydroxylapatite | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
17.2 | - |
- |
Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O | - |
Escherichia coli | 5-phospho-beta-D-ribosylamine + L-glutamate + diphosphate | - |
? | |
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O | first reaction in de-novo pathway of purine biosynthesis | Escherichia coli | L-glutamate + 5-phospho-beta-D-ribosylamine + diphosphate | - |
? | |
L-glutamine + H2O | enzyme exhibits glutaminase activity in the absence of other substrates or effectors | Escherichia coli | L-glutamate + NH3 | - |
? | |
NH3 + 5-phospho-alpha-D-ribose 1-diphosphate + H2O | 2.8fold higher aminotransferase activity compared to amidotransferase activity | Escherichia coli | 5-phospho-beta-D-ribosylamine + diphosphate | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | 3-4 * 57000, SDS-PAGE | Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
additional information | - |
AMP and GMP enhance thermal stability | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.6 | 7.7 | broad, amidotransferase activity, phosphate buffer | Escherichia coli |
7.8 | 8.6 | broad, amidotransferase activity, Tris/HCl buffer | Escherichia coli |
8.5 | - |
aminotransferase activity, Tris buffer | Escherichia coli |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.36 | - |
AMP | - |
Escherichia coli |