Aspartic acid (abbreviated as Asp or D; Asx or B represent either aspartic acid or asparagine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CO2H. The carboxylate anion of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, for example, the building blocks of proteins. Its codons are GAU and GAC. Aspartic acid is, together with glutamic acid, classified as an acidic amino acid with a pKa of 4.0. Aspartic acid is pervasi… (More on Aspartate)