Degradation of Nucleic Acids by Lysosomal Extracts of Rat Liver and Ehrlich Ascites Tumor Cells

The ability of rat liver lysosomes and Ehrlich ascites tumor lysosomes to degrade nucleic acids has been studied. Extracts of rat liver tritosomes and of tumor cell mitochondrial plus lysosomal fractions were incubated with various types of DNA and RNA from sources ranging from bacteria to mammals. The extracts were able to hydrolyze all the nucleic acids completely to free nucleosides and inorganic phosphate. The influence of the nature and concentration of substrate, of pH, and of temperature are reported for calf thymus DNA and yeast-soluble RNA. In comparison with the lysosomal enzyme systems responsible for the hydrolysis of other cellular constituents, it appears that the nuclease systems have similar stability and may be even more active.