What does deaminase mean?
A deaminase is an enzyme that removes an amino group from a molecule — most commonly from amino acids, purines, or pyrimidines — releasing ammonia as a by-product. This reaction is central to metabolism: deaminases help break down dietary proteins for energy, recycle DNA and RNA building blocks, and regulate signaling molecules such as cytokines. The term is always used within biochemistry, medicine, or molecular biology and is typically qualified by the substrate involved, giving compounds like adenosine deaminase, cytidine deaminase, and guanine deaminase. Clinically, deaminases matter because their absence or excess signals disease: inherited deficiency of adenosine deaminase produces severe combined immunodeficiency, while elevated deaminase activity can indicate liver damage. Related forms include the verb 'deaminate' and the noun 'deamination', describing the process these enzymes perform. Though obscure to lay readers, the word is indispensable to anyone discussing how cells dismantle nitrogen-containing molecules.
nounAn enzyme that removes an amino group from a molecule, typically converting it into the corresponding keto acid and releasing ammonia. Deaminases play essential roles in amino acid metabolism and nucleotide turnover.
- (biochemistry) An enzyme that catalyzes the removal of an amino group from a compound, releasing ammonia.
"Adenosine deaminase deficiency causes severe combined immunodeficiency."
"Adenosine deaminase deficiency leads to severe combined immunodeficiency."
"Serum deaminase levels can serve as markers of certain liver disorders."
Regular plural; used when referring to multiple distinct enzymes of this class.
"Several cytosolic deaminases contribute to nucleotide catabolism."
The same adenosine deaminase gene that keeps your immune system alive was the first human gene ever used in approved gene therapy.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of deaminase
The word combines the prefix 'de-', from Latin meaning removal or reversal, with 'amino', derived from 'amine' (coined from 'ammonia'), plus '-ase', the suffix introduced by French chemist Émile Duclaux in the late nineteenth century to name enzymes generally. It therefore arose in the early twentieth-century biochemical literature as enzymes were systematically classified by the reactions they performed. Cognates sharing the root include 'amine' and 'ammonia' itself.
Related word forms
How deaminase is actually used
A technical term confined to biochemistry, medicine, and molecular biology; it is rarely encountered outside scientific literature and clinical contexts. It is almost always paired with the name of its substrate (e.g., adenosine, cytidine, guanine).
Easily confused with deaminase
A deaminase is an enzymatic protein, whereas a deaminating agent is any chemical substance that removes amino groups, often without biological catalysis.
A transaminase transfers amino groups between molecules rather than removing them outright.