Identification of lysine residue involved in inactivation of brain glutanmmate dehydrogenase isoproteins by o-phthalaldehyde

摘要

Incubation of two types of glutamate dehydrogenase(GDH)isoproteins from bovine brain with o-phthalaldehyde resulted in a time-dependent loss of enzyme activity. The inactivation was partially prevented by preincubation of the GDH isoproteins with 2-oxoglutarate or NADH. Spectrophotometric studies indicated that the inactivatin of GDH isoproteins with o-phthalaldehyde resulted in isoindole derivatives characterized by typical fluorescence emission spectra with a stoichiometry of one isoindole derivative per molecule of enzyme subunit.