Transamination


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to Transamination: deamination, Oxidative deamination

Transamination

The transfer of an amino group from one molecule to another without the intermediate formation of ammonia. Enzymatic reactions of this type play a prominent role in the formation and ultimate breakdown of amino acids by living organisms. Enzymes that catalyze such reactions are widely distributed and are termed transaminases, or amino-transferases. Perhaps the most prominent transamination reactions in higher animals are those in which glutamate is formed from α-ketoglutarate and other amino acids. See Protein metabolism

Transamination

 

a reversible transfer of an amino group (—NH2) from amino acids or amines to keto acids:

The enzymatic transamination reaction, which was discovered in 1937 by the Soviet biochemists A. E. Braunshtein and M. G. Kritsman, is an important link in the process of synthesis and deamination of many amino acids in animals, plants, and microorganisms. Most natural amino acids are synthesized in tissues by the transfer of an NH2 group from glutamic acid, the initial product of nitrogen assimilation, to various keto acids. By permitting rapid interconversion of the various amino and keto acids, the transamination reaction plays an important role in the regulation and coordination of the metabolism of amino acids and carbohydrates.

The enzymes for transamination, transaminases, are found in all living cells. There are more than 55 known transaminases, which catalyze the transamination of all the known natural amino acids and a number of biogenic amines. The coenzyme of transaminases is a derivative of vitamin B6, pyridoxal phosphate, which acts to transfer NH2 groups (for a discussion of the mechanism of transamination, see). A sharp increase in the content of some transaminases in the blood plasma of ill individuals is indicative of damage to the liver (hepatitis), the heart (myocardial infarction), or the muscles (trauma and myodystrophic diseases).

REFERENCES

Braunshtein, A. E., and M. M. Shemiakin. “Teoriia protsessov aminokislotnogo obmena, kataliziruemykh piridoksalevymi enzimami.” Biokhimiia, 1953, vol. 18, no. 4.
Meister, A. Biokhimiia aminokislot. Moscow, 1961. (Translated from English.)
The Enzymes, vol. 9. New York, 1973.

IU. M. TORCHINSKII

transamination

[tran‚sam·ə′nā·shən]
(chemistry)
The transfer of one or more amino groups from one compound to another.
The transposition of an amino group within a single compound.
References in periodicals archive ?
Second, the decrease in 2-ketoisocaproic acid concentrations in patients with PCOS suggests decreased transamination of leucine in the first step of BCAA catabolism--which is common to leucine, isoleucine, and valine--instead of the increased transamination previously suggested as a metabolic footprint of obesity and diabetes (27, 28).
Vitamin B6 in its active form is involved in the transamination of ammonia groups to other amino acids.
It is striking that the types of organic reactions in core anabolism are limited to 11 chemical transformations: hydrolysis/dehydration, carboxylation/decarboxylation, oxidation/reduction, phosphorylation/dephosphorylation, transamination, group transfer, and isomerization (Table 1).
Transamination was further investigated by Martin-Venegas who demonstrated that the preferred amino acid used for transamination was Leucine.
Furthermore, the transamination of alanine is a required step for the proper maintenance of fasting blood glucose concentrations.
For some aquatic vertebrate, like fish, alanine might be produced from glutamate and pyruvate by transamination, and ammonia is probably liberated from glutamate by oxidative deamination (Jurss and Bastrop, 1995).
The methods comprise creating a mutated enzyme that catalyzes the reductive amination or transamination of the target 2-ketoacid or ketone or the reduction of the ketone and providing the mutated enzyme in a reaction mixture comprising the target 2-ketoacid or ketone under conditions sufficient to permit the formation of the desired amino acid, amine or alcohol to thereby produce the amino acid, amine or alcohol.
In turn, the process of pyruvate transamination inhibits the build-up of toxic ammonia (N[H.
The commanding role of transamination reaction in the regulation of carbohydrate and protein metabolism was explained by Braustein (1959).
An alternate route is via a transamination reaction of 2-ketoglutarate, from the TCA cycle, with alanine being converted to pyruvate (Reaction 4, Fig.
These complexes were prepared by the transamination utilizing Ln[(N[(Si[Me.