Deamination


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Related to Deamination: transamination, Oxidative deamination

deamination

[dē‚am·ə′nā·shən]
(organic chemistry)
Removal of an amino group from a molecule.

Deamination

 

the elimination of an amino group (NH2) from organic compounds. Deamination is accompanied by the substitution of some other group, such as H, OH, OR, or Hal, for the amino group or by the formation of a double bond. In particular, deamination is brought about by the action of nitrous acid on primary amines. In this reaction, acyclic amines yield alcohols (I) and olefins (II), for example:

The deamination of alicyclic amines is accompanied by ring expansion or contraction. In the presence of strong inorganic acids, aromatic amines and nitrous acid yield diazonium salts. Such reactions as hydrolysis, hydrogenolysis, decomposition of quaternary ammonium salts, and pyrolytic reactions also result in deamination.

Deamination plays an important part in the life processes of animals, plants, and microorganisms. Oxidative deamination, with the formation of ammonia and α-keto acids, is characteristic of d-amino acids. Amines also undergo oxidative deamination. Except for glutamate dehydrogenase, which deaminates L-glutamic acid, oxidases of natural amino acids are not very active in animal tissues. Therefore, most L-amino acids undergo indirect deamination by means of prior transamination, with the formation of glutamic acid, which then undergoes oxidative deamination or other transformations. Other types of deamination are reductive, hydrolytic (deamination of amino derivatives of purines, pyrimidines, and sugars), and intramolecular (histidine deamination), which occur mainly in microorganisms.

REFERENCE

Zbarskii, B. I., I. I. Ivanov, and S. R. Mardashev. Biologicheskaia khimiia, 4th ed. Leningrad, 1965.
References in periodicals archive ?
Hence, the deamination of glutamine is an important route in the food industry with the aim of enhancing the umami taste.
By using this analytical method, phenolic compounds were unable to inhibit the oxidative deamination of radiolabelled [[sup.
Metabolism of histamine is mostly dependent on one-carbon metabolism via histamine N-methyltransferase (H-NMT) and deamination via diamine oxidase (DAO).
MAO is a mitochondrial enzyme that catalyses the oxidative deamination of the neurotransmitters serotonin (5-HT), dopamine and noradrenalin, which are involved in the regulation of aggressive behaviour.
These higher alcohols are mostly produced from the deamination of nitrogen from amino acids, for example, arginine, which has a free [alpha]-amino group.
5-MeO-DMT is primarily inactivated through MAO-A-mediated deamination pathway.
But new bicarbonate is also produced through two mechanisms: (1) From glutamine (2/1) by deamination in the proximal tubule, resulting in alpha-ketoglutarate which is metabolised with C[O.
Off-target deamination by AID results in nucleotide substitutions and genomic rearrangements in B lymphocyte tumours.
Also the existence of autistic abnormalities of several genes was found involved in carrying out processes in the redox reactions, such as functional polymorphism in the monoamine oxidase A (MAOA) promoter region (MAOA catalyze the oxidative deamination of monoamines, serotonin) (35).
6 These crosslinks are formed by oxidative deamination of lysine oxidases which are copper dependent.
E-ADA is considered to be a key enzyme in the purine metabolism, catalyzing the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively, and closely regulating extracellular adenosine and inosine concentrations (9,10).
On the other hand, the increase of the enzyme in the serum may be attributed to the process of either deamination or transamination caused by the plant leaf dust.