Continuation of studies are proposed on the mechanisms of the reactions catalyzed by and on the structure-function relationships involved in the regulation of glutamine synthetases, gamma-glutamyl cysteine synthetase, 5-oxo-L-prolinase, gamma-glutamyl transpeptidase, gamma-glutamyl cyclotransferase, glutamine-dependent carbamyl phosphate synthetase, glutamate synthase, aspartate beta-decarboxylase, and related enzymes. The enzymes will be purified and characterized by physical and chemical studies as well as by investigations of their catalytic behavior. Further insights into the relationships between the enzyme-catalyzed reactions and physiological phenomena will be sought.