Asparagine transaminase

This enzyme [EC 2.6.1.21], also known as D-aspartate aminotransferase, D-amino acid aminotransferase, and D-amino acid transaminase, catalyzes the reversible pyridoxal-phosphate-dependent reaction of D-alanine with a-ketoglutarate to yield pyruvate and D-glutamate. The enzyme will also utilize as substrates the D-stereoisomers of leucine, aspartate, glutamate, aminobutyrate, norva-hne, and asparagine. See o-Amino Acid Aminotransferase... 

Fig. 2. The incorporation of ammonia derived by a number of pathways, into asparagine in higher plants, a. Nitrate reductase b, nitrite reductase c, nitrogenase .d, glutamine synthetase e, asparagine synthetase f, arginase g, urease h, ornithine transaminase i, glutamate dehydrogenase j, proline dehydrogenase k, transaminases.

Transamination with Glutamine and Asparagine. Meister and collaborators have described two types of transaminase in which the amino donor is glutamine or asparagine. Transamination from glutamine to any of more than 30 a-keto acids leads to the formation of a-ketoglutaramic acid, which is hydrolyzed by a specific amidase (HI). The reaction... 

S) Amino Acid Amide Transaminases. Mention was made previously (see Amidases) of the observations by Greenstein and co-workers that the addition of pyruvic and other a-keto acids to liver extracts accelerated the formation of ammonia from glutamine and asparagine. This reaction has been shown by Meister and co-workers to involve a transamination reaction different in several respects from those previously discussed. The reaction for glutamine may be formulated as follows ... 

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