Affinity chromatography of nuclear enzymes.

There are a number of nuclear enzymes that bind nicotinamide, thymidine or nucleotides. We use this fact to prepare affinity columns for the purification of nuclear enzymes. In particular the nuclei of eukaryotic cells have an enzyme that catalyses the synthesis of the homopolymer poly(ADP-ribose) from NAD. Isolation and partial purification has been achieved (Yamada et al., 1971 ; Ueda et al., 1975; Yoshihara, 1972). Nicotinamide and thymidine are potent inhibitors of the enzyme activity. We have therefore prepared nicotinamide and thymidine analogues that are suitable for attachment to Sepharose and have tested both analogues in affinity chromatography. Dextran Blue coupled to Sepharose has been used for the isolation and purification of NAD-linked dehydrogenases (Ryan & Vestling, 1974; Thompson et al., 1975). The Dextran Blue chromophore has a structure similar to NAD (Thompson et a!., 1975). We have investigated the use of Dextran Blue coupled to Sepharose for affinity chromatography of poly(ADP-ribose) polymerase.