<amino acid>

<biochemistry> A nonessential amino acid that plays a critical part of the enzyme in the liver that transfers nitrogen-containing amino groups, either in building new proteins and amino acids or in breaking down proteins and amino acids for energy and detoxifying the nitrogen in the form of urea.

Depleted levels of aspartic acid may occur temporarily within certain tissues under stress, but, because the body is able to make its own aspartic acid to replace any depletion, deficiency states do not occur.

Aspartic acid is abundant in plants, especially in sprouting seeds. In protein, it exists mainly in the form of its amide, asparagine.

The popular sweetener Aspartame is a combination of aspartic acid and phenylalanine. Aspartic acid is considered nontoxic.

(15 Nov 1997)