[Identification of a glutamate dehydrogenase amino acid residue modified by 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl. Study of the type of inactivation of a catalytically active enzyme oligomer in modification].

It has been shown that 2,2,6,6-tetramethyl-4-oxo-piperidine-1-oxyl selectively blocks epsilon-amino group of Lys126 residue in bovine liver glutamate dehydrogenase (L-glutamate NAD(P) oxydoreductase, EC 1.4.1.3). Modification of this residue in one of the six promoters of catalytically active hexamer is accompanied by the loss of about half of the enzymatic activity. The enzyme inactivation caused by modification has a cooperative character.