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

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.

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