Activity of Glutamine Synthetase toward threo-γ-Methyl-L-glutamic Acid and the Isomers of γ-Hydroxyglumatic Acid

Biochemistry ◽  
1966 ◽  
Vol 5 (7) ◽  
pp. 2423-2432 ◽  
Author(s):  
Herbert M. Kagan ◽  
Alton Meister
Keyword(s):  
Glutamine Synthetase ◽  
Glutamic Acid

Differential effects of exogenous L-glutamine, L-glutamic acid, sodium glutamate, and casamino acids on glutamine synthetase and nitrate reductase in isolated pea roots cultured with or without sucrose

1981 ◽  
Vol 59 (7) ◽  
pp. 1121-1127 ◽  
Author(s):  
J. Sahulka ◽  
L. Lisá
Keyword(s):  
Nitrate Reductase ◽  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Sodium Salt ◽  
Sodium Glutamate ◽  
Negative Effect ◽  
Isolated Roots ◽  
Pea Roots ◽  
Casamino Acids ◽  
Glutamic Acid Sodium

Exogenous L-glutamine, the sodium salt of L-glutamic acid, and casamino acids do not decrease glutamine synthetase (GS) level in isolated pea (Pisum sativum L. cv. Jupiter and cv. Proteus) roots cultured with 20 g∙L−1 sucrose while L-glutamic acid does decrease it. The effect of L-glutamic acid is stronger in solutions lacking nitrate. By contrast, only the exogenous sodium salt of L-glutamic acid does not enhance the decrease in GS level caused by sugar starvation in isolated roots cultured without any sugar while, the other compounds tested do enhance this decrease. These facts confirm our earlier conclusion that sugar availability and the concentration of H+ ions are more important for GS level regulation in pea roots than nitrogen substrate availability and the presence of the end products. Nitrate reductase (NR) level is depressed by exogenous L-glutamine, the sodium salt of L-glutamic acid, casamino acids, and a low (0.2 mM) concentration of L-glutamic acid whereas it is increased by higher (0.8 and 1.0 mM) concentrations of L-glutamic acid, by α-ketoglutaric acid (0.4 to 0.6 mM), and by nitric acid (0.2 to 0.4 mM) added to saturating concentration (10 mM) of nitrate present in the form of potassium and calcium salts. The negative effect of L-glutamine, sodium glutamate, and casamino acids can be reversed by L-glutamic acid. This suggests that more mechanisms may be involved in NR regulation by these compounds and that the mechanism controlled by increased concentration of H+ ions is of great importance.

Inhibition of rat liver glutamine synthetase by phosphonic analogues of glutamic acid

1981 ◽  
Vol 37 (5) ◽  
pp. 461-462 ◽  
Author(s):  
B. Lejczak ◽  
H. Starzemska ◽  
P. Mastalerz
Keyword(s):  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Rat Liver

scholarly journals Some Properties of Glutamine Synthetase From the Nitrifying Bacterium Nitrosomonas Euro Paea

1981 ◽  
Vol 34 (6) ◽  
pp. 527 ◽  
Author(s):  
Basant Bhandari ◽  
DJD Nicholas
Keyword(s):  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Glutamate Dehydrogenase ◽  
Glutamate Synthase ◽  
Nitrosomonas Europaea ◽  
Main Route

Nitrosomonas europaea oxidizes ammonia to nitrite, thereby deriving energy for growth. Glutamate dehydrogenase (NADP+) (EC 1.4.1.4) is the main route for the incorporation of ammonia into glutamic acid, because glutamate synthase (NADPH) (EC 1.4.1.13) was not detected in cell-free extracts of N. europaea.

THE ACTIVATION OF GLUTAMIC ACID AND GLUTAMINE IN MAMMALIAN TISSUES

1963 ◽  
Vol 41 (5) ◽  
pp. 1135-1145 ◽  
Author(s):  
M. A. Alford ◽  
M. Brotman ◽  
M. A. Chudy ◽  
M. J. Fraser
Keyword(s):  
Amino Acid ◽  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Specific Enzyme ◽  
Ehrlich Ascites ◽  
Mammalian Tissues ◽  
Made In

Measurements of α-glutamyl-RNA synthetase and glutaminyl-RNA synthetase activities have been made in fractions derived from 105,000 × g supernatants of homogenates of rat liver and of mouse Ehrlich ascites carcinoma cells. Evidence is presented which indicates that each amino acid is activated by a specific enzyme. Both enzymes catalyze amino acid dependent ATP-32PP exchange. The α-glutamyl-RNA synthetase purified 42-fold from rat liver 105,000 × g supernatant is free of glutamine synthetase.

THE ACTIVATION OF GLUTAMIC ACID AND GLUTAMINE IN MAMMALIAN TISSUES

1963 ◽  
Vol 41 (1) ◽  
pp. 1135-1145 ◽  
Author(s):  
M. A. Alford ◽  
M. Brotman ◽  
M. A. Chudy ◽  
M. J. Fraser
Keyword(s):  
Amino Acid ◽  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Specific Enzyme ◽  
Ehrlich Ascites ◽  
Mammalian Tissues ◽  
Made In

Measurements of α-glutamyl-RNA synthetase and glutaminyl-RNA synthetase activities have been made in fractions derived from 105,000 × g supernatants of homogenates of rat liver and of mouse Ehrlich ascites carcinoma cells. Evidence is presented which indicates that each amino acid is activated by a specific enzyme. Both enzymes catalyze amino acid dependent ATP-32PP exchange. The α-glutamyl-RNA synthetase purified 42-fold from rat liver 105,000 × g supernatant is free of glutamine synthetase.

scholarly journals Metabolic engineering of Escherichia coli for efficient production of L-alanyl-L-glutamine

2020 ◽  
Author(s):  
Jiangming Zhu ◽  
Wei Yang ◽  
Bohua Wang ◽  
Qun Liu ◽  
Xiaotong Zhong ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Glutamic Acid ◽  
Water Solubility ◽  
Glutamine Metabolism ◽  
Cell Factory ◽  
Efficient Production ◽  
Microbial Cell Factory ◽  
Good Thermal Stability ◽  
Glutamine Synthesis ◽  
Engineered Strain

Abstract Background: L-alanyl-L-glutamine (AQ) is a functional dipeptide with high water solubility, good thermal stability and high bioavailability. It is widely used in clinical treatment, post-operative rehabilitation, sports health care and other fields. AQ is mainly produced via chemical synthesis which is complicated, time-consuming, labor-intensive, and have a low yield accompanied with the generation of by-products. It is therefore highly desirable to develop an efficient biotechnological process for the industrial production of AQ.Results: A metabolically engineered E. coli strain for AQ production was developed by over-expressing L-amino acid α-ligase (BacD) from Bacillus subtilis, and inactivating the peptidases PepA, PepB, PepD, and PepN, as well as the dipeptide transport system Dpp. In order to use the more readily available substrate glutamic acid, a module for glutamine synthesis from glutamic acid was constructed by introducing glutamine synthetase (GlnA). Additionally, we knocked out glsA-glsB to block the first step in glutamine metabolism, and glnE-glnB involved in the ATP-dependent addition of AMP/UMP to a subunit of glutamine synthetase, which resulted in increased glutamine supply. Then the glutamine synthesis module was combined with the AQ synthesis module to develop the engineered strain that uses glutamic acid and alanine for AQ production. The expression of BacD and GlnA was further balanced to improve AQ production. Using the final engineered strain p15/AQ10 as a whole-cell biocatalyst, 71.7 mM AQ was produced with a productivity of 3.98 mM/h and conversion rate of 71.7 %.Conclusion: A metabolically engineered strain for AQ production was successfully developed via inactivation of peptidases, screening of BacD, introduction of glutamine synthesis module, and balancing the glutamine and AQ synthesis modules to improve the yield of AQ. This work provides a microbial cell factory for efficient production of AQ with industrial potential.

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