Cyanoalanine
Cyanoalanine is an amino acid with the formula NCCH2CHCO2H. Like most amino acids, it exists as a tautomer NCCH2CHCO2−. It is a rare example of a nitrile-containing amino acid. It is a white, water-soluble solid. It can be found in common vetch.
Cyanoalanine arises in nature by the action of cyanide on cysteine catalyzed by L-3-cyanoalanine synthase:
It is converted to aspartic acid and asparagine enzymatically.
When cyanoalanine is introduced into proteins, it's CN vibration serves as a reporter of the local environment.