期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：5
页码：2254-2257
DOI：10.1073/pnas.75.5.2254
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A novel enzyme that splits a bond between ADP-ribose and histone was discovered and partially purified from rat liver cytosol. The 105,000 X g supernatant of rat liver homogenate was precipitated by 45% saturated ammonium sulfate and then chromatographed on a DEAE-cellulose column. The enzyme activity was eluted in a single peak at about 0.2 M NaCl and clearly separated from poly(ADP-ribose) glycohydrolase which came out at 0.13 M NaCl. In contrast to the latter enzyme, this new enzyme catalyzed the spliting of a linkage between ADP-ribose and a protein portion in mono ADP-ribosylated histone H2B but little, if any, of the glycosidic ribosyl(1"-2') ribose bonds within poly(ADP-ribose). Analysis of the reaction product by paper chromatography and Dowex 1 column chromatography indicated that the split product contained the ADP-ribose moiety but was not exactly identical with ADP-ribose. Available evidence suggested that it was either an altered ADP-ribose molecule produced by a structural rearrangement or ADP-ribose itself linked to an unidentified compound. The enzyme had a pH optimum of about 6.0 and was inhibited by 80-90% in the presence of 5 mM ADP-ribose.
