The interaction of glutamate decarboxylase from Escherichia coli with substrate analogues modified at C-3 and C-4.
The interaction of glutamate decarboxylase with the aspartate analogues 3-arsonoalanine and 3-phosphonoalanine, with the glutamate analogues 2-amino-4-arsonobutyric acid and 2-amino-4-phosphonobutyric acid, and with 4-(methylthio)-L-glutamic acid, both as a mixture of diastereoisomers and as the (2S,4R)-form, was studied. All these analogues were poor substrates for the enzyme and only weak inhibitors. Their decarboxylation was accompanied by transamination of the enzyme-bound pyridoxal phosphate (PLP) to pyridoxamine phosphate (PMP), thus inactivating the decarboxylase. With arsonoalanine only part of the PLP was converted into PMP.
Khristoforov
R R
RR
Engelhardt Institute of Molecular Biology, RAN, Moscow, Russia.
Sukhareva
B S
BS
Dixon
H B
HB
Sparkes
M J
MJ
Krasnov
V P
VP
Bukrina
I M
IM
D000409:Alanine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D003653:Decarboxylation; D004926:Escherichia coli / Q000201:enzymology*; D005968:Glutamate Decarboxylase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018698:Glutamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D011732:Pyridoxal Phosphate / Q000378:metabolism; D013053:Spectrophotometry / Q000379:methods; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D018698:Glutamic Acid; D011732:Pyridoxal Phosphate; D005968:Glutamate Decarboxylase; D000409:Alanine