Aspartic acid

Aspartic acid (symbol Asp or D; is an α-amino acid that is used in the biosynthesis of proteins. Like all other amino acids, it contains an amino group and a carboxylic acid. Aspartic acid has an acidic side chain (CH2COOH) which reacts with other amino acids, enzymes and proteins in the body. 
It is a non-essential amino acid in humans, meaning the body can make it as needed. It is encoded by the codons GAU and GAC.
-Aspartate is one of two -amino acids commonly found in mammals.[3]