Diamino acid

In chemistry, a diamino acid, also called a diamino carboxylic acid, is a molecule containing at least one carboxyl and two amine functional groups. Diamino acids belong to the class of amino acids.

Biochemical function

Asparagine, glutamine and lysine are proteinaceous diamino acids (i.e. they are components of proteins), and are accordingly coded by codons of the genetic material. In the pH range found inside living cells, both their amino groups are protonated, and they can be classified therefore as cationic amino acids.

Ornithine and 2,6-diaminopimelic acid are non-proteinaceous diamino acids.

In biochemistry, diamino acids are of particular interest. Diamino acids are used for the synthesis of specific peptide nucleic acids, such as daPNA. Artificial peptide nucleic acids are capable of forming duplex structures with individual DNA- and RNA-strands and are, therefore, not only called DNA-analog, but also they are considered as candidates for the first genetic material on Earth. The corresponding diamino acids such as 2,3-diaminopropanoic acid were detected in the Murchison meteorite and in a simulated comet.

Further reading

• Uwe Meierhenrich (2008). Amino acids and the asymmetry of life. Springer-Verlag, ISBN 978-3-540-76885-2.