Expression and catalytic properties of rat liver NADP-isocitrate dehydrogenase under normal conditions, after administration of tumor necrosis factor-α and thioctic acid action

Abstract

Development of apoptosis is accompanied by a decrease in transcripts of NADP-isocitrate dehydrogenase (NADP-ICDH, EC 1.1.1.42), and also by alterations of catalytic properties from the rat liver enzyme in comparison with control. Administration of thioctic acid increased the level of expression towards normal values. Molecular weight of homogenous preparations of NADP-ICDH purified from livers of control and experimental rats was the same 112 ± 5.8 kDa, however, Km values and pH-optimum changed during induction of apoptosis. Regulation of NADP-ICDH activity by some intermediates of the tricarboxylic acid cycle also differed in these groups.