An artifact in the radiochemical assay of brain mitochondrial glutamate decarboxylase

Abstract

Commercial DL-[1-14C] glutamic acid contains an impurity from which 14CO2 is released during incubation with brain mitochondrial glutamate decarboxylase and the inhibitor aminooxyacetic acid. This results in an apparent stimulation of brain mitochondrial glutamate decarboxylase by aminooxyacetic acid when low levels of the enzyme are used. Both aminooxyacetic acid and chloride ion inhibited both the supernatant and mitochondrial glutamate decarboxylase activities when purified DL-[1-14C] glutamic acid was used as substrate. © 1973.