Y-Glutamyl hydrazide

Recently it has been established that pyridazines can be formed by enzymic catalysis. For example, pyridazinones are formed from y-glutamyl hydra-zones of a-keto acids in the presence of liver glutamine transaminase, or from y-glutamyl hydrazide in the presence of L-amino acid oxidase. ... 

Perez de la Mora M, Fuxe K, Hokfelt T, and Ljungdahl A (1977) Evidence for an impulse-dependent GABA accumulation in the substantia nigra after treatment with y-glutamyl-hydrazide Neurosci Lett 5, 75-82... 

In several studies of the L-glutamine D-fructose 6-phosphate amidotransferase reaction it has been shown that specific glutamine antagonists may be used to inhibit the reaction. Ghosh et al. (1960) showed that 6-diazo-5-oxo-L-norleucine (DON) was a potent inhibitor of the enzyme, whereas azaserine was less effective. The glutamine analogs, methionine sulfoxide and y-glutamyl hydrazide, on the other hand, were not inhibitory (Clarke and Pasternak, 1962). 

Conversion of the free y-glutamyl carboxy groups to 7-hydrazides makes peptide bonds in model compounds (and probably in proteins) next to these modified glutamic acid residues susceptible to splitting by trypsin (Ebata and Akabori, 1960 Ebata, 1961). 

The reaction was applied to model dipeptides exemplified by the y-phenyl-hydrazide of N-carbobenzoxy-a-L-glutamyl-L-methionine methyl ester (4) and found to afford the carboxylic acid (S) in good yield without disturbance of the carbo-benzoxy and ester protective groups. The results suggest use of the phenylhydrazide group for protection of carboxyl groups in peptide chemistry. 

Levenberg, B. Isolation and structure of agaritine, a y-glutamyl-substituted aryl-hydrazide derivative from Agaricaceae. J. Biol. Chem. 239, 2267 (1964). 

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