Gaudreau A, Ménard L, de Murcia G, Poirier G G
Biochem Cell Biol. 1986 Feb;64(2):146-53. doi: 10.1139/o86-023.
Hydrolysis of protein-bound 32P-labelled poly(ADP-ribose) by poly(ADP-ribose) glycohydrolase shows that there is differential accessibility of poly(ADP-ribosyl)ated proteins in chromatin to poly(ADP-ribose) glycohydrolase. The rapid hydrolysis of hyper(ADP-ribosyl)ated forms of histone H1 indicates the absence of an H1 dimer complex of histone molecules. When the pattern of hydrolysis of poly(ADP-ribosyl)ated histones was analyzed it was found that poly(ADP-ribose) attached to histone H2B is more resistant than the polymer attached to histone H1 or H2A or protein A24. Polymer hydrolysis of the acceptors, which had been labelled at high substrate concentrations (greater than or equal to 10 microM), indicate that the only high molecular weight acceptor protein is poly(ADP-ribose) polymerase and that little processing of the enzyme occurs. Finally, electron microscopic evidence shows that hyper(ADP-ribosyl)ated poly(ADP-ribose) polymerase, which is dissociated from its DNA-enzyme complex, binds again to DNA after poly(ADP-ribose) glycohydrolase action.
聚（ADP - 核糖）糖水解酶对与蛋白质结合的32P标记的聚（ADP - 核糖）的水解表明，染色质中聚（ADP - 核糖基）化蛋白质对聚（ADP - 核糖）糖水解酶的可及性存在差异。组蛋白H1的高（ADP - 核糖基）化形式的快速水解表明不存在组蛋白分子的H1二聚体复合物。当分析聚（ADP - 核糖基）化组蛋白的水解模式时，发现与组蛋白H2B相连的聚（ADP - 核糖）比与组蛋白H1或H2A或蛋白A24相连的聚合物更具抗性。在高底物浓度（大于或等于10 microM）下标记的受体的聚合物水解表明，唯一的高分子量受体蛋白是聚（ADP - 核糖）聚合酶，并且该酶几乎没有加工过程。最后，电子显微镜证据表明，从其DNA - 酶复合物中解离的高（ADP - 核糖基）化聚（ADP - 核糖）聚合酶在聚（ADP - 核糖）糖水解酶作用后再次与DNA结合。
