Abstract: | Poly(ADP-ribose) polymerase with a high specific activity was obtained from Ehrlich ascites tumor cells by extraction of nuclei with 175 mM potassium phosphate, followed by chromatography on DNA-agarose. Electrophoretic analysis indicated that the preparation contained two proteins, one of which was shown to catalyze the synthesis of poly(ADP-ribose). As expected from results obtained by other workers, the synthesis was inhibited by nicotinamide and thymidine, and stimulated by DNA. Addition of histones gave inhibition of the synthesis, unless DNA was present in the reaction mixture. |