Studies on Poly(Adenosine Diphosphate Ribose) IX. DIRECTION OF HYDROLYSIS OF POLY(ADENOSINE DIPHOSPHATE RIBOSE) BY RAT LIVER PHOSPHODIESTERASE

摘要: Abstract The direction of exonucleolytic degradation poly(ADP-ribose) by rat liver phosphodiesterase was investigated. 1. When 14C-labeled hydrolyzed with phosphodiesterase, the concentration 5'-AMP in hydrolysate increased early stage hydrolysis and then after 25% remained constant. 2. Poly(ADP-ribose) preparations labeled 32P two ways were prepared: (I) at ribose phosphate derived from NMN moiety NAD (II) AMP portion NAD. These polymers 14 to 22% phosphodiesterase. Partially poly(ADP-ribose), named trimmed polymer, purified passage through a Sephadex G-50 column. Trimmed incubated Escherichia coli alkaline phosphomonoesterase radioactive inorganic released determined. Three 6% radioactivity polymer recovered as phosphate, whereas only 0.7% phosphate. 3. doubly 14C adenine prepared. After incubation removal phosphomonoesterase, it completely venom 2'-(Ribosyl)-5'-AMP but 2'-(5''-phosphoribosyl)-adenosine not detected. From these results is concluded that degraded terminus other an exonucleotic fashion.