A-Ketosuccinamic acid

A number of reports have described the transamination of asparagine by crude extracts or by more purified preparations (cf. Lea and Miflin, this volume. Chapter 16 and Mazelis, this volume. Chapter 15 Wightman and Forest, 1978 Lloyd and Joy, 1978). The transamination of asparagine to a-ketosuccinamic acid has been found to take place using either glyoxylate or pyruvate as the amino acceptor, and to a lesser extent with oxaloacetate (Streeter, 1977). 

A second type of deamidation reaction for glutamine and asparagine exists. Early work by Greenstein and co-workers demonstrated the existence of an a-keto acid-activated glutaminase and aspart nase in liver 43). It was own later by Meister and associates ( 44, 4 ) that these enzymes catalyze a transamination reaction between the amino acid amides and a-keto acids followed by the hydrolysis of the a-ketoglutaramic or a-ketosuccinamic acids with the release of ammoiua. These reactions will be considered in Section IV, 2. 

Extracts of a number of tissues catalyze the hydrolysis of the a-keto acid-(o-amides (a-ketoglutaramic and a-ketosuccinamic acids). The enzyme has been partially purified from rat liver 256, 270, 271). 

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