Historically, asparagine was the first amino acid to be isolated from its natural source. In 1806, scientists excreted this amino acid during the purification of asparagus juice. Actual proof of this amino, however, did not become valid until the early 1930’s. Despite this known history, little information remains about this minute amino acid.
Asparagine is a common nonessential amino acid that is found, primarily, in animal proteins. It is a beta-amide derivative of the amino acid, aspartic acid. Because of this, aspartic acid will synthesize asparagine in the body if dietary needs are not sufficient. Asparagine closely resembles aspartic acid in its chemical structuring, but differs slightly from the unique coupling of ammonia on its acidic side-chain. This allows for the metabolism of toxic ammonia present in the body. The properties of this side-chain, however, prove insignificant when included within a protein by two peptide bonds.
Because asparagine is readily synthesized by the body and does not have to be obtained by diet, appropriate food sources for human consumption remains limited. The best food sources for fulfilling the dietary needs of asparagine (per serving) include; dairy products, beef, poultry, eggs, and protein supplements. Mammalian protein provides the greatest source of this amino acid. Asparagine is degraded by the preparation process of foods including cooking (heat), storage, or applying an acid based substance.
Information concerning asparagine usage in the body remains quite limited. It does, however, provide for specific processes in the body that are critical in overall physical and mental health.
The central nervous system relies on this amino acid for maintenance, proper functioning, and overall chemical balance in the brain. Asparagine assists us in maintaining our equilibrium and prevents us from extreme mood swings; either being to overly anxious/nervous, or being too calm.
Physically, asparagine is responsible for amino acid transformation and its associated processes, all of which take place in the liver. It is able to do this because metabolism is achieved when asparagine is converted back into aspartic acid, releasing energy for these important processes.  Asparagine is also a precursor for the synthesis of RNA, DNA, and ATP (energy). Other asparagine process include; antibody functioning, conversion of aspartate for cellular function, collagen assembly of enzymatic activity, and cell-to-cell recognition.
There have been no established dosages for the intake of this nonessential amino acid, however, the U.S. National Academy of Sciences recommends that healthy people achieve .36 grams of highly bioavailable protein for each pound of bodyweight - equaling 0.8 grams of protein, per kilogram of bodyweight.
Deficiencies of asparagine have not been reported in medical literature. It is theorized that a deficiency of the nonessential amino acid could contribute to immune system suppression, which may lead to autoimmune disorders, infections, and allergic reactions.
To date, asparagine toxicity is not known to occur.
1. Balch, Phyllis A., James F. “Amino Acids.” Prescription for Nutritional Healing. Ed. Amy C. Tecklenberg. New York, NY: Penguin Putnam Inc., 3rd Ed. 2000. 42-53.
2. Zest for life information page. “RDA of amino acids.” (1999-2003) http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml (14 Sept. 2004).