Some optical properties of bacterial glutamate decarboxylase

Glutamate decarboxylase. Substrate specificity and inhibition by carboxylic acids

“…Besides L-glutamate only -methyl-DL-glutamic acid gave appreciable activity in the present study. -Methyl-DL-glutamic acid has been shown previously to be slowly decarboxylated by the enzyme, and it also inactivates the enzyme by transaminating the pyridoxal phosphate (Sukhareva and Torchinsky, 1966;Huntley and Metzler, 1968). It has been suggested that glutamate decarboxylase undergoes a conformational change upon interaction with glutamic acid (Sastchenko et at.…”

“…The enzyme has been reported to have a pH optimum between pH 4 and 4.5 (Shukuya and Schwert, 1960a,b;O'Leary et al, 1970). Bacterial glutamate decarboxylase is most active toward L-glutamic acid, but has been reported to also decarboxylate ymethyleneglutamic and t/ireo-d-hydroxyglutamic acids (Homola and Dekker, 1967), glutamate -methyl ester (Lupo and Halpern, 1970), and -methyl glutamic acid (Sukhareva and Torchinsky, 1966; Huntley and Metzler, 1968).…”

Escherichia coli has two homologous glutamate decarboxylase genes that map to distinct loci

“…Gale (14) proposed a general role for the inducible bacterial amino acid decarboxylases, including GAD, in the maintenance of physiological pH under acidic conditions. E. coli GAD has been extensively characterized with respect to its biophysical and biochemical properties (1,14,30,31,(39)(40)(41)(42)(43)(44)(45)(46), and a partial protein sequence has been available for some time (42,43). Based on genetic linkage studies in E. coli, the structural gene for GAD (gadS) and a potential regulatory gene (gadR) have been mapped between mtl at approximately 80.7 minutes and gltS at approximately 82.4 minutes (3,23,26,27), but these early results have not been followed up.…”

Coenzyme analog inhibitors of apoglutamate decarboxylase

“…Their suggestion of a Schiff-base linkage between coenzyme and protein was confirmed by the borohydride reduction studies of Anderson and Chang (1965). Absorption spectra (Shukuya and Schwert, 1960b) and circular dichroism (Huntley and Metzler, 1967a; Sukhareva and Torchinsky, 1966) have been reported. Although the enzyme is most active toward glutamic acid, 7-methylene glutamic acid and i/zreo-d-hydroxyglutamic acid are also decarboxylated (Homola and Dekker, 1967).…”