Affinity chromatography of yeast nicotinamide-adenine dinucleotide-specific isocitrate dehydrogenase on immobilized nicotinamide-adenine dinucleotide. Effects of ligands.

The method of affinity chromatography has been used for studying the effects of some ligands of yeast NAD-specific isocitrate dehydrogenase on the affinity of the enzyme for NAD+ immobilized on Sepharose 4B. In absence of ligands, the enzyme is eluted from NAD+-Sepharose columns by 0.1 M phosphate buffer, pH 7.6, in a highly purified form. The elution of enzyme is accelerated by NAD+ and, more effectively, by AMP; and retarded by isocitrate and citrate. The elution patterns show a rather irregular shape, probably due to the occurrence of aggregation processes of the enzyme protein.