Uchida K, Suzuki H, Maruta H, Abe H, Aoki K, Miwa M, Tanuma S
Department of Biochemistry, University of Tsukuba, Japan.
J Biol Chem. 1993 Feb 15;268(5):3194-200.
Poly(ADP-ribose) glycohydrolase, extensively purified to homogeneity from nuclei of human placenta, is composed of a single polypeptide with a molecular mass of 71,000 daltons on sodium dodecyl sulfate-polyacrylamide gel. Judging from its physico-chemical and catalytic properties, the enzyme is similar to the nuclear glycohydrolase (glycohydrolase I), but not to the cytoplasmic glycohydrolase (glycohydrolase II) that has been purified from guinea pig liver (Tanuma, S., Kawashima, K., and Endo, H. (1986) J. Biol. Chem. 261, 965-969; Maruta, H., Inageda, K., Aoki, T., Nishina, H., and Tanuma, S. (1991) Biochemistry 30, 5907-5912). The rates of hydrolysis of (ADP-ribose)n bound to various proteins by the purified nuclear glycohydrolase were higher than those of the corresponding free polymers. Kinetic analyses revealed that the enzyme had more activity toward poly(ADP-ribose) bound to histone H1 or to poly(ADP-ribose) polymerase than toward oligo(ADP-ribose) bound to cytoplasmic proteins from mitochondria or mRNA ribonucleoprotein although the Km and Vmax values were dependent on the chain length (n). In contrast, cytoplasmic glycohydrolase purified from human erythrocytes was more active toward oligo(ADP-ribose) (n = 2.6 or 4.2) bound to the cytoplasmic proteins than to poly(ADP-ribose) (n = 14.6) bound to histone H1, and their kinetic parameters of glycohydrolase II were rather dependent on the acceptor molecules for (ADP-ribose)n. These results suggest that poly(ADP-ribose) glycohydrolase I may play an important role in regulation of poly(ADP-ribosyl)ation levels on chromosomal proteins in nuclei.
从人胎盘细胞核中广泛纯化至同质的聚（ADP - 核糖）糖水解酶，在十二烷基硫酸钠 - 聚丙烯酰胺凝胶上由一条分子量为71,000道尔顿的单一多肽组成。从其物理化学和催化特性判断，该酶类似于核糖水解酶（糖水解酶I），但不同于从豚鼠肝脏中纯化的细胞质糖水解酶（糖水解酶II）（Tanuma，S.，Kawashima，K.，和Endo，H.（1986）J. Biol. Chem. 261，965 - 969；Maruta，H.，Inageda，K.，Aoki，T.，Nishina，H.，和Tanuma，S.（1991）Biochemistry 30，5907 - 5912）。纯化的核糖水解酶对与各种蛋白质结合的（ADP - 核糖）n的水解速率高于相应的游离聚合物。动力学分析表明，该酶对与组蛋白H1或聚（ADP - 核糖）聚合酶结合的聚（ADP - 核糖）的活性比对与线粒体或mRNA核糖核蛋白的细胞质蛋白结合的寡聚（ADP - 核糖）的活性更高，尽管Km和Vmax值取决于链长（n）。相反，从人红细胞中纯化的细胞质糖水解酶对与细胞质蛋白结合的寡聚（ADP - 核糖）（n = 2.6或4.2）的活性比对与组蛋白H1结合的聚（ADP - 核糖）（n = 14.6）的活性更高，并且它们的糖水解酶II的动力学参数相当依赖于（ADP - 核糖）n的受体分子。这些结果表明，聚（ADP - 核糖）糖水解酶I可能在调节细胞核中染色体蛋白上的聚（ADP - 核糖基）化水平方面发挥重要作用。
