Glutamic Acid

Glutamic acid/Glutamate (denoted as Glu or E) is one of the 20 naturally occuring amino acids, and one of the two acidic, negatively charged amino acids, along with Aspartic acid/Aspartate (Asp, or D). The negative charge of E occurs due to the presence of a carboxylic acid group (COOH) in the R chain (as well as with D), which is ionized to it's negative form at physiological pH.
   Due to this nagative charge, E is hydrophilic; a characteristic shared by the 10 charged and unchared polar amino acids D, E, R,K, H, N, Q, S, T and Y.

E is encoded genetically by two codons; GAA and GAG.

E has a role in the body as a neurotransmitter, acting on glutamate receptors including the NMDA receptor and playing a role in synaptic plasticity [1], thought to be important in memory and learning.

References

[1] Jin SX et al, PLoS One, Jul 2010  vol. 5 (7), 11732