Aspartic acid
Aspartic acid or its ionized form, aspartate (symbols Asp and D) is one of the twenty amino acids with which cells make proteins. In RNA it is encoded by the GAU or GAC codons.
It has a carboxyl group (-COOH) at the end of the side chain. Its chemical formula is HO
2CCH(NH
2)CH
2CO
2H.
At physiological pH, it has a negative charge (it is acidic); It belongs to the group of amino acids with charged polar side chains. It is not an essential amino acid since it can be synthesized by the human organism. Its biosynthesis takes place by transamination of oxaloacetic acid, an intermediate metabolite of the Krebs cycle.
Discovery
Aspartic acid was discovered in 1827 by French chemists Auguste-Arthur Plisson and Étienne Ossian Henry, derived from asparagine, which had been isolated from asparagus juice in 1806, by boiling with a base.
Metabolism
Aspartate formation
Aspartate is not essential in mammals, being produced from oxaloacetate by a transamination reaction. It is also synthesized from diethyl sodium phthalimidomalonate, (C
6H
4(CO)
2NC(CO
2Et)
2).
Related metabolic pathways
Aspartate participates in the formation of glutamate through cytosolic glutamate-aspartate transaminase.
Aspartate is also a metabolite of the urea cycle and is involved in gluconeogenesis.
Inactivation
The mechanism of inactivation is reuptake. Different transport systems have been described in neuronal and glial membranes. In the neuron is EGAC1, which transports glutamate and aspartate. In the glial cell is the GLAST (aspartate-glutamate). These transport systems are sodium dependent and chlorine independent. and relationships.
Recipients
Receptors for aspartate are a very complex world. There are ionotropic and metabotropic. It stimulates NMDA receptors, although not as strongly as glutamate does.
Functions
Aspartate is one of the amino acids that act as neurotransmitters. Its function as a neurotransmitter is excitatory in the CNS.