Affinity chromatography of mitochondrial nicotinamide nucleotide transhydrogenase.

The binding of mitochondrial nicotinamide nucleotide transhydrogenase to NAD+ and NADP+ immobilized to agarose through different parts of the nicotinamide nucleotide molecule was investigated. NADP+ bound at the C8 atom in the adenine moiety proved to be the most efficient ligand whereas that bound at the C3 atom of the ribose moiety was relatively inefficient. NAD+ ligands were generally inactive independently of the site of attachment. Previous results suggest, however, that binding to immobilized NAD+ may be influenced by the detergent in which transhydrogenase is dispersed. Binding to neither ligand was affected by the presence of the second substrate.