GLUTAMATE OXIDASE-CATALYZED OXIDATION OF BETA-N-OXALYL-L-ALPHA,BETA-N-DIAMINOPROPIONIC ACID (BETA-ODAP), A NEUROTOXIN IN THE SEEDS OF LATHYRUS-SATIVUS

Seven enzymes were tested in a screening of catalytic activity towards the neurotoxic L-amino acid, beta-ODAP. L-glutamate oxidase, G1OD, wa s found to be the only one that showed activity and its kinetic proper ties were examined by measuring the rate of formation of hydrogen pero xide which was monitored spectrophotometrically at 512 nm, using Trind er's chromogenic reagent. The Michaelis constant, K-M, for the toxin i s 0.24 mM at pH 7, comparable with the reported value for glutamate (0 .21 mM). The activity of the enzyme was, however, considerably lower ( 0.78%) than that of the main substrate. Ammonia formation in the react ion was confirmed by the consumption of nicotinamide adenine dinucleot ide (NADH) during reduction of alpha-ketoglutarate in presence of L-gl utamate dehydrogenase (G1DH) and catalase.