Reactions of decarboxylated and side transamination during interaction of glutamate decarboxylase from Escherichia coli with substrate analogs, modified through C3 and C4 atoms
Khristoforov, R.R.; Sukhareva, B.S.; Dixon, H.B.; Sparkes, M.J.; Krasnov, V.P.; Bukrina, I.M.; Grishakov, A.N.
Biokhimiia 61(3): 464-471
1996
ISSN/ISBN: 0320-9725 PMID: 8724605 Document Number: 469032
The interaction of glutamate decarboxylase with the aspartate and glutamate analogues modified at C3 and C4 was studied. 3-Arsonoalanine, 3-phosphonoalanine, 2-amino-4-arsonobutyric acid, 2-amino-4-phosphonobutyric acid, a mixture of diastereoisomers of 4-(methylthio) glutamic acid and erythro-4-(methylthio) glutamic acid were shown to be poor substrates for the enzyme. Their decarboxylation was accompanied by transamination of the coenzyme (PLP) to pyridoxamine phosphate (PMP) which reversibly inactivated the enzyme. With arsonoalanine only part of PLP was converted into PMP and another part irreversibly formed a complex. 4-(Methylsulfonyl)-L-glutamic and 4-[(phenyl)(hydroxy)phosphoryl]-L-glutamic acids did not react with the glutamate decarboxylase.