Deamination of £-amino

Strecker Degradation (Oxidative Deamination), Mild oxidizing agents such as aqueous sodium hypochlorite or aqueous A-bromosuccinimide, cause decarboxylation and concurrent deamination of amino acids to give aldehydes. 

Figure 11.3 is a flow model representing in extremely simple form the main relevant features of nitrogen metabolism. It is not difficult to propose a sufficient explanation why Bprot is isotopically heavier than the diet. We might expect that the net effect of transamination and deamination of amino acids is to remove isotopically lighter N (Macko et al. 1987). That is to say, we may expect that the equilibrium constant for the reaction ... 

The citric acid cycle is not only a pathway for oxidation of two-carbon units—it is also a major pathway for interconversion of metabolites arising from transamination and deamination of amino acids. It also provides the substtates for amino acid synthesis by transamination, as well as for gluconeogenesis and fatty acid synthesis. Because it fimctions in both oxidative and synthetic processes, it is amphibolic (Figure 16—4). 

Glycogenolysis and glycogen synthesis P-oxidation of fatty acids transamination and deamination of amino acids Cori cycle and glucose-alanine cycle, which recycles substrates between muscle and liver. 

The chemistry of the 2,5-anhydrides of aldoses subsequently entered a prolonged lull, and Peat s review21 of 1946 in this Series does not report on any work later than 1925. The experimental basis of the deamination of amino sugars with nitrous acid was, nevertheless, established. The progress afterwards made in the conformational analysis of sugars made it possible for Shafizadeh22 to draw a parallel with the nitrous acid deamination of the aminocyclohexanols, and to rationalize the whole of these results. 

B. Glutamate dehydrogenase the oxidative deamination of amino acids... 

Figure 24-10 Biosynthesis of citrulline, arginine, and urea. The green arrows indicate reactions directly involved in deamination of amino acids and the synthesis of urea. N from amino acids and C from C02 are traced in green.

Figure 24-11 Integration of the urea cycle with mitochondrial metabolism. Green lines trace the flow of nitrogen into urea upon deamination of amino acids or upon removal of nitrogen from the side chain of glutamine.

Thus far we have considered the deamination of amino acids and the fate of the resulting ammonium ion. The carbon skeleton remaining after deamination can be used in... 

Deamination of amino acids and nucleic acid bases. 

Amino acids are chemically reactive at their a-amino groups and their side chains. The carboxyl groups are relatively unreactive unless activated. A very useful reaction is the oxidative deamination of amino acids with ninhydrin. The reaction produces a blue pigment, which can be used for the detection of amino acids both qualitatively and quantitatively. The series of reactions producing the blue complex is given in Equation (4.2). 

The enzymes discussed in this paragraph are D- and L-amino acid oxidases, the presence of which has been detected in numerous organisms and tissues. They were only recently identified in bacteria and the corresponding enzymes were isolated (for a review see [54]). These enzymes are flavin adenine dinucleotide (FAD)-containing flavoproteins that catalyze the oxidative deamination of amino acids (Scheme 13.21). 

By (often photoinduced) oxidative deamination of amino acids (E (L) = -0.05 V) coordinated to Fe(III), these are converted to 2-oxocarboxylates or glyoxy-late and eventually oxalate (E (L) = -0.17 V)... 

The most revealing study of the deamination of amino alcohols was carried out by Shoppee on the four epimeric i7-amino-i7a-hydroxy-i7a-methyl-D-homoandrostanes [307. The product from each of these compounds was predictable in terms of a trans coplanar 4-centre transition state, and the outcome of each reaction was entirely analogous to the result expected from hydrolysis of a halohydrin fixed in the same... 

The important reaction commonly employed in the breakdown of an amino acid is always the removal of its a-amino group. The product ammonia is excreted after conversion to urea or other products and the carbon skeleton is degraded to C02 releasing energy. The important reaction involved in the deamination of amino acids is... 

Although amino sugars in the soil were not detected unambiguously until a decade ago, they are now the best investigated of the carbohydrates of the soil. Various independent methods have been used for the determination of amino sugars in soil hydrolyzates. The alkaline deamination of amino sugars followed by the determination of the ammonia liberated, ... 

Precipitation of CaC03 is also promoted by ammonia which may be produced by organisms under both aerobic and anaerobic conditions. The most common reaction is oxidative deamination of amino acids which liberates ammonia according to eqn (10) ... 

Tchoubar, B. Extension of alicylic rings of 1-(aminomethyl)cycioaikanois by nitrous deamination, iii. Theoreticai consideration of the reaction mechanism of nitrous deamination of amino alcohols. Bull. soc. chim. France 1949, 169-172. 

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