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G1270 Sigma-Aldrich

L-Glutamine Synthetase from Escherichia coli

lyophilized powder, 400-2,000 units/mg protein

Synonym: L-Glutamate:ammonia ligase (ADP-forming)



Related Categories 6.3.x.x C-N Bonds, 6.x.x.x Ligases, Biochemicals and Reagents, Cell Biology, Enzyme Class Index,
form   lyophilized powder
purified by   affinity chromatography
contains   dithioerythritol as preservative
composition   Protein, ~5% Lowry
solubility   H2O: soluble 0.95-1.05 mg/mL, clear to hazy
foreign activity   ATPase <0.2%
storage temp.   −20°C
Gene Information   Escherichia coli K12 ... glnA(948370)


Biochem/physiol Actions

Degradative enzyme for glutamic acid

L-glutamine synthetase catalyzes the condensation of L-glutamate and ammonia to L-glutamine. It is a degradative enzyme for glutamic acid.

Nitrogen starvation dictates the expression of the glutamine synthetase (GS) gene in E. coli. GS plays a key role in ammonia assimilation in bacteria. Adenylylation of GS is catalyzed by adenylyltransferase. Adenylylation of GS modulates its catalytic functionality resulting in glutamine limitation in E coli.

Unit Definition

One unit will convert 1.0 μmole of L-glutamate to L-glutamine in 15 min at pH 7.1 at 37 °C.

Physical form

Contains potassium phosphate, sodium citrate and magnesium acetate buffer salts


L-Glutamine Synthetase from Escherichia coli has been used in the synthesis of methylglutamine from methylammonium in E coli and in the glutamine synthetase protection activity of human thioredoxin peroxidase enzyme, AOE372.

L-Glutamine synthetase may be used for the purification of proteases from Escherichia coli.

General description

L-Glutamine Synthetase from bacteria shows dodecameric structure comprising of 12 active sites. Each active site termed bifunnel, has an ATP and glutamate binding sites. The dodecamer is stabilized by two hexameric rings.

Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 
Protocols & Articles

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Enzymes & Proteins

Application Index | Enzyme Index | Substrate Index | Inhibitor Index | Cofactor Index | Lectin Index
Keywords: Cell signaling, Diagnostic, Drug discovery, Metabolomics, Molecular biology

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