Abstract
An acid DNase* was purified about 700-fold from the pupae of Bombyx mori by ammonium sulfate fractionation, gel filtration, and chromatography with CM-cellulose. The optimal pH and temperature of the enzyme were found at about 5 and 50°C, respectively. Requirement of magnesium ion for the enzyme activity was not absolute. The enzyme liberates acid-soluble nucleotides from heat-denatured DNA slightly faster than from native DNA. The action of the DNase was endonucleolytic. Mono- and oligonucleotides of various sizes bearing 3'-phosphate were detected among the digestion products. These properties substantially resemble those of mammalian DNases of type II.
