Glutamic Acid (Glutamate)

Glutamic acid (glutamate) is an amino acid found in proteins. In mammals, glutamic acid is a non-essential amino acid, meaning it does not need to be present in the diet. Glutamic acid (surprise!) is classified as an acidic amino acid.

In animals, vitamin K 2 carboxylates glutamate residues in certain proteins, to give -carboxyglutamate. This modification allows the protein to bind calcium, an essential event in the blood clotting cascade. Carboxylation of glutamate residues occurs in other proteins that are active in the mobilization or transport of calcium.

Glutamic acid is very important in transamination reactions in the body and as a precursor of other amino acids.

One Letter Code | Three Letter Code | Molecular Wt. (Daltons) | Genetic Code Codons
E | GLU | 129.12 | GAA, GAG

Reactions involving glutamate:

> 1. -Ketoglutarate + Glutamine + NADPH + H+ <=> 2 Glutamate + NADP+ (Catalyzed by Glutamate Synthase)

> 2. Glutamate + NH 3 + ATP <=> Glutamine + ADP + Pi (Catalyzed by Glutamine Synthetase)

> 3. Glutamine + ATP + HCO 3- <=> Glutamate + Carbamoyl Phosphate + ADP (catalyzed by Carbamoyl Phosphate Synthetase II)

> 4. Fructose-6-phosphate + Glutamine <=> Glucosamine-6-Phosphate + Glutamate (catalyzed by Glutamine:Fructose-6-Phosphate Amidotransferase)

> 5. UTP + ATP + Glutamine <=> CTP + ADP + Glutamate + Pi (catalyzed by CTP Synthetase)

> 6. Glutamate + NADP+ (or NAD+) + H 2O <=> -Ketoglutarate + NADPH (or NADH) + NH 4+(catalyzed by Glutamate Dehydrogenase)

See also: Table 5.1, Amino Acids, Genetic Code, -Carboxyglutamic Acid, Glutamine, Glutamate as a Precursor of Other Amino Acids (from Chapter 21), Transamination in Amino Acid Metabolism (from Chapter 20), Citric Acid Cycle Intermediates in Amino Acid Metabolism (from Chapter 21), Essential Amino Acids

INTERNET LINKS:

> 1. Glutamate Metabolism

> 2. Urea Cycle and Metabolism of Amino Groups