Studies on the Autolysis of Aspergillus oryzae

Part VI. Properties of Nuclease O, a New Intracellular Enzyme

Abstract

Properties of nuclease O, a new intracellular enzyme which was partially purified from autolyzate of Asp. oryzae, ^l) are described in this paper. The purified enzyme preferentially depolymerized RNA and heat denatured DNA, but apparently did not attack native DNA. It was activated by 0.1mM Mg²⁺ or Mn²⁺, and inactive in the presence of EDTA. Optimum pH of the activity were 7.7 for DNA and 8.2 for RNA. By heat treatment (60°C, 10min at pH 6) the nuclease completely lost its activity for RNA and DNA. Optimum concentration of Tris buffer for enzymatic activity was 0.15_??_0.2M.