deaminates

Deaminates are the products of deamination, the removal of an amino group (–NH2) from an organic molecule. In biochemistry, deamination typically yields a carbonyl-containing product and releases ammonia or ammonium. Deaminates can arise through enzymatic action by deaminases or via chemical reactions such as hydrolysis or nitrosation.

In metabolism, oxidative deamination of amino acids produces α-keto acids and free ammonia. Examples include alanine deamination to pyruvate, glutamate deamination to α-ketoglutarate, and aspartate deamination to oxaloacetate. The resulting α-keto acids can enter central metabolic pathways, while the released ammonia is ultimately processed by the urea cycle in many organisms.

In nucleic acids, deamination alters bases and can affect genetic information. Cytosine deaminates to uracil, adenine to hypoxanthine, and guanine to xanthine; 5-methylcytosine deaminates to thymine. Such changes are mutagenic in DNA if unrepaired. Cells employ base-excision repair pathways (for example, uracil-DNA glycosylase) to recognize and remove deamination-induced lesions and to restore correct base pairing.

Enzymes known as deaminases catalyze physiologic deaminations, including cytidine deaminase (in RNA and DNA editing) and adenosine deaminase (A-to-I editing in RNA). Other oxidative deamination processes involve enzymes such as glutamate dehydrogenase. Chemical deamination can also occur under nitrosating conditions or hydrolysis, and is used in some organic synthesis and analytical contexts.