Transamination

Transamination

There are two chemical reactions known as transamination (or aminotransfer). The first is the reaction between an amino acid and an alpha-keto acid. The amino group is transferred from the former to the latter; this results in the amino acid being converted to the corresponding α-keto acid, while the reactant α-keto acid is converted to the corresponding amino acid (if the amino group is removed from an amino acid, an α-keto acid is left behind).

Transamination in biochemistry is accomplished by enzymes called transaminases or aminotransferases. The human body synthesizes the 10 non-essential amino acids and transamination is the process by which most of these syntheses occur. The chirality of an amino acid is determined during transamination.This reaction uses the coenzyme PLP, and is considered to be a kinetically perfect reaction. The product of transamination reactions depend on the availability of alpha-keto acids. The products usually are either alanine, aspartate or glutamate, since their corresponding alpha-keto acids are produced through metabolism of fuels.

The second type of transamination reaction, which can be described as an alkylamino-de-amination is a nucleophilic substitution of one amine or amide anion on an amine or ammonium salt. [Smith, M. B. and March, J. "Advanced Organic Chemistry: Reactions, Mechanisms, and Structure", 5th ed. Wiley, 2001, p. 503. ISBN 0471585890] For example, the attack of a primary amine by a primary amide anion can be used to prepare secondary amines:

:RNH2 + R'NH → RR'NH + NH2

Symmetric secondary amines can be prepared using Raney nickel (2RNH2 → R2NH + NH3). And finally, quaternary ammonium salts can be dealkylated using ethanolamine:

:R4N+ + NH2CH2CH2OH → R3N + RN+H2CH2CH2OH

ee also

* Transaminase

References

External links

* [http://www.rpi.edu/dept/bcbp/molbiochem/BiochSci/sbello/new_page_2.htm Overview of amino acid synthesis]
* [http://www2.ufp.pt/~pedros/bq/urea.htm The chemical logic behind aminoacid degradation and the urea cycle]


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  • transamination — ● transamination nom féminin Transfert d un groupement aminé d un acide aminé sur un acide cétonique pour former un nouvel acide aminé et un nouvel acide cétonique …   Encyclopédie Universelle

  • transamination — [transam΄ə nā′shən, tranzam΄ə nā′shən] n. [ TRANS + AMIN(E) + ATION] the transfer of an amino group from one molecule to another, usually by the action of a transaminase …   English World dictionary

  • Transamination — Exemple de réaction de transamination La réaction de transamination est catalysée par une enzyme transaminase, cette réaction réversible consiste en l échange d une fonction amine primaire entre un acide α aminé et un α cétoacide. Par… …   Wikipédia en Français

  • transamination — peramininimas statusas T sritis chemija apibrėžtis Fermentų katalizuojamas aminogrupės perkėlimas iš aminorūgšties į oksorūgštį. atitikmenys: angl. transamination rus. пераминирование; трансаминирование …   Chemijos terminų aiškinamasis žodynas

  • transamination — noun Etymology: International Scientific Vocabulary trans + amine + ation Date: 1939 a reversible oxidation reduction reaction in which an amino group is transferred typically from an alpha amino acid to the carbonyl carbon atom of an alpha keto… …   New Collegiate Dictionary

  • transamination — (trans am i na shun) The removal of amino acid s amino group by transferring it to an a keto acid acceptor …   Dictionary of microbiology

  • transamination — /trans am euh nay sheuhn, tranz /, n. Biochem., Chem. the transfer of an amino group from one compound to another. [1940 45; TRANS + AMIN(O) + ATION] * * * …   Universalium

  • transamination — noun the transfer of an amino group from an amino acid to another molecule See Also: transaminase …   Wiktionary

  • transamination — The reaction between an amino acid and an α keto acid through which the amino group is transferred from the former to the latter; in certain cases the reaction may be between an amino acid and an aldehyde ( e.g., glutamate with glutamate… …   Medical dictionary

  • transamination — n. transfer of an amino group from one compound to another (Chemistry) …   English contemporary dictionary

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