臨床検査において、アンモニアおよびATPの測定に利用されます。
| 由来 | microorganism |
|---|---|
| 系統名 | L-Glutamate : ammonia ligase (ADP-forming) |
| EC 番号 | 6.3.1.2 |
| 反応式 | ATP + L-Glutamate + NH3→→→ ADP + Orthophosphate + L-Glutamine |
Glutamine Synthetase (GST) グルタミンシンセターゼ (GST)
- 臨床診断用酵素
仕様
| 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) |
アプリケーション
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.