Glutamine Synthetase (GST) 谷氨酰胺合成酶

  • 临床检测用酶

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

规格

Appearancelight yellow lyophilizate
Activity≧7 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)

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.

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