Glutamine enzymatic synthesis

Walker, J.B., 1995, Enzymatic synthesis of aminocyclitol moieties of aminoglycoside antibiotics from inositol by Streptomyces spp. Detection of glutamine-aminocyclitol aminotransferase and diaminocyclitol aminotransferase activities in a spectinomycin producer. J. Bacteriol. 177 818-822. 

The activity of glutamine synthetase is also controlled by reversible covalent modification —the attachment of an AMP unit by a phosphodiester bond to the hydroxyl group of a specific tyrosine residue in each subunit (Figure 24.26). This adenylylated enzyme is less active and more susceptible to cumulative feedback inhibition than is the deadenylylated form. The covalently attached AMP unit is removed from the adenylylated enzyme by phosphorolysis. The attachment of an AMP unit is the final step in an enzymatic cascade that is initiated several steps back by reactants and immediate products in glutamine synthesis. 

Sodium benzoate Sodium benzoate has already been successfully used to treat congenital enzymatic defects of the urea synthesis (M. L. Batshaw et at, 1981). In HE, the administration of sodium benzoate or sodium phenylacetate (each 10 g/day) achieved clinical success equivalent to lactulose therapy in ca. 80% of cases. (122, 144, 159) These substances (which are cheap and practically free of side effects) lead to an increased excretion of nitrogen through the conjugation of glycine and glutamine, whereby ammonium is bound as hippuric acid and excreted renally (bypassing the urea cycle). 

An enzymatic method for the synthesis of theanine involving bacterial y-glutam-yltranspeptidase (GOT) was developed the conversion from glutamine was 60%. ... 

The amino group from glutamine is enzymatically transferred by PhzE, the phenazine synthesis-specific... 

Both AMP and GMP inhibited purine synthesis at the level of formation of phosphoribosylamine irrespective of whether glutamine or ammonia was the N-donor. Detailed analysis of the AMP studies however was difficult because of the rapid enzymatic deamination of AMP with this enzyme preparation in the absence of GTP. 

ATP is involved in the synthesis of hippuric acid and its analogs. The role of ATP is to form the aromatic acyl-Co A which then condenses with glycine to form the quasi-peptide. In the synthesis of glutamine from glutamic acid and ammonia Co A is not required, but ATP is. And in the synthesis of glutathione, the one case so far elucidated of an enzymatic... 

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