Isolation and Properties of a Ribonuclease from Aspergillus saitoi
1967 Volume 62 Issue 5 Pages 509-518
Details
1967 Volume 62 Issue 5 Pages 509-518
1. A ribonuclease, (RNase M)[EC 2.7.7.17 ribonucleate nucleotido-2'-transferase (cyclizing)] was isolated from “Molsin” (Aspergillus saitoi). RNase M was purified about 125 fold by means of column chromatography using IRC-50, phospho-cellulose, DEAE-cellulose and Sephadex G-75.
2. RNase M is very similar in molecular weight to RNase T2 from Asp. ogzae.
3. RNase M has a base specificity similar to that of RNase T2 and releases adenylic acid more rapidly than the other nucleotides. However, RNase M is different from RNase T2 in the more precise base specificity.
4. RNase M is different from RNase T2 in the pH optimum as examined with RNA and U-cyclic-p as substrates.
5. The enzyme is inhibited markedly by Cu++, Zn++, Hg++ and Cd++ and less stable against heat treatment than RNase A or T1.
