Stavrianopoulos J G, Chargaff E
Proc Natl Acad Sci U S A. 1973 Jul;70(7):1959-63. doi: 10.1073/pnas.70.7.1959.
Ribonuclease H of calf thymus has been purified better than 3000-fold to yield an almost homogeneous preparation. The enzyme, which comprises about 0.03% of the total protein in the initial extract, is a slightly acidic protein (pI = 4.95) of molecular weight of about 64,000, possibly composed of subunits. The enzyme requires a metal ion for activation; the conditions for activation by Mg, Co, and Mn are described. It is inhibited by S-adenosylmethionine. The substrates cleaved were poly(dT).poly(rA) and the DNA-RNA hybrid made from phage f1 DNA; ribosomal RNA was not attacked.
小牛胸腺核糖核酸酶已被纯化至超过3000倍,得到了几乎均一的制剂。该酶在初始提取物中约占总蛋白的0.03%,是一种略带酸性的蛋白质(pI = 4.95),分子量约为64,000,可能由亚基组成。该酶需要金属离子来激活;描述了由镁、钴和锰激活的条件。它被S-腺苷甲硫氨酸抑制。被切割的底物是聚(dT)·聚(rA)以及由噬菌体f1 DNA制成的DNA-RNA杂交体;核糖体RNA未受到攻击。