The enzyme is useful for the determination of ammonia and ATP in clinical analysis.
| 由来 | microorganism |
|---|---|
| 系统名称 | L-Glutamate : ammonia ligase (ADP-forming) |
| EC编号 | 6.3.1.2 |
| 反应式 | ATP + L-Glutamate + NH3→→→ ADP + Orthophosphate + L-Glutamine |
Glutamine Synthetase (GST) 谷氨酰胺合成酶
- 临床检测用酶
规格
| Appearance | white to light yellow lyophilizate | |
|---|---|---|
| Activity | ≧15.0 U/mg | |
| Contaminants | Catalase ≦0.5 U/U％ | |
| Stabilizer | sucrose | |
| Storage condition | below-20℃ |
特性
| Molecular weight | ca. 900 kDa (gel filtration) |
|---|---|
| Structure | 57 kDa (SDS-PAGE) |
| Isoelectric point | 6.5 |
| Michaelis constant | 1.5×10-2M (L-glutamate) |
| 1.3×10-4M (ammonia) | |
| 8.7×10-4M (ATP) | |
| pH Optimum | ca. 7.0 |
| pH Stability | 6.5–9.5 |
| Optimum temperature | 60℃ |
| Thermal stability | below 40℃ |
| Inhibitors | methionine sulfoximine, carbamyl phosphate |
| Activators | Mg2+，Mn2+ |
| Specificity | L-glutamate (100), D-glutamate (0.8) |
| NH₃(100), NH₂OH (12) | |
| ATP (100), GTP (2.5) |
适用类型
The enzyme is useful for the determination of ammonia and ATP in clinical analysis.
参考文献
Ebner, E. et al., “Methods in Enzymology,” Vol. 17A, Academic Press, New York, 1970, pp. 910–922.