Loss of poly(ADP-ribose) synthetase activity without change in arginine-specific ADP-ribosyltransferase activity by acid-treatment; application of the treatment to simple assay for transferase in the presence of poly(ADP-ribose) synthetase

Abstract

We investigated the effects of acid treatment (pH 3.5) on the activities of arginine-specific ADP-ribosyltransferase (mono(ADPribosyl)transferase) (EC 2.4.2.31) and poly(ADP-ribose) synthetase (EC 2.4.2.30) purified from chicken liver, and we observed that the former enzyme retained completely its activity while there was no evidence for activity of the latter enzyme. Kinetic parameters, including K m values for NAD and whole histones in the reaction catalyzed by acid-treated ADP-ribosyltransferase, were the same as those in the reaction catalyzed by non-treated enzyme. The stereospecificities of the reaction forming ADP-ribosylarginine by acid-treated and non-treated ADP-ribosyltransferases were indistinguishable. We made use of this acid treatment to determine ADP-ribosyltransferase activity in chicken and chick-embryo liver extracts, with a filter assay. The enzyme activities (means± S.D. for three separate experiments) of 1-year-old chicken and 13-day-old chick embryo livers were 372.7 ± 80.20 and 110.6 ± 27.22 nmol ADP-ribose/g wet liver per h, respectively. This acid treatment is useful for f'fiter assay with labelled NAD of arginine-specific ADP-ribosyltransferase in the fraction containing poly(ADP-ribose) synthetase.