Glutamine Synthetase (GST) グルタミンシンセターゼ

  • 臨床診断用酵素

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

仕様

Appearancelight yellow lyophilizate
Activity≧15.0 U/mg lyophilizate
Contaminantscatalase <0.5%
Stabilizersucrose
Storagebelow -20℃

特性

Molecular weightca. 900 kDa (gel filtration)
Structure57 kDa (SDS-PAGE)
Isoelectric point6.5
Michaelis constant1.5×10-2M (L-glutamate)
1.3×10-4M (ammonia)
8.7×10-4M (ATP)
pH Optimum7.0
pH Stability6.5–9.5
Optimum temperature60℃
Thermal stabilitybelow 40℃
Stability (liquid form)stable at 20℃ for at least two weeks
Stability (powder form)stable at 37℃ for at least one month
Inhibitorsmethionine sulfoximine, carbamyl phosphate
ActivatorsMg2+,Mn2+
SpecificityL-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.

TOP