deaminate

Deaminate is a verb used in chemistry and biochemistry to describe the removal of an amino group (−NH2) from an organic molecule. The process, called deamination when described as a noun, yields a product in which the amino group is replaced by a carbonyl or hydrogen, depending on the reaction pathway. In biological systems, deamination is a key step in nitrogen metabolism. It commonly occurs on amino acids, producing an α-keto acid and ammonia. Oxidative deamination, performed by deaminase enzymes such as glutamate dehydrogenase, converts amino acids to their corresponding α-keto acids while releasing ammonia. Hydrolytic deamination involves the replacement of an amino group with a carbonyl group via hydrolysis, and is observed in some cytosine and adenine deaminations in nucleic acids or in some synthetic reactions.

In metabolism, deamination enables the body to dispose of excess nitrogen and to funnel carbon skeletons into central metabolism. Ammonia released is typically converted to urea in the liver for excretion. In genetics and molecular biology, deamination of nucleobases, such as cytosine to uracil, can cause mutations if not corrected by DNA repair systems.

The term deaminate is used to describe the action of specific enzymes called deaminases, and as a general chemical verb for removing amino groups from molecules. Etymology combines de- (remove) with amino, reflecting the functional change produced.