Deoxyribonuclease mechanism

Acid deoxyribonuclease (DNase) is an enzyme which splits the phosphodiester bonds of native DNA by both a diplotomic and a haplotomic mechanism (see Section 111,0) leaving the terminal phosphate in a 3 position. The enzyme is very widely distributed in animal cells and appears to be localized in the lysosomes. The best known acid DNase is that from hog spleen this explains why most of the data presented here refer to this enzyme. It should be stressed, however, that the properties of acid DNases obtained from the tissues of other vertebrates appear to be extremely similar to those of the hog spleen enzyme ... 

B25. Brody, S., and Balis, M. E., Mechanism of growth. I. Interrelation between deoxyribonuclease and deoxyribonucleic acid synthesis in nonmalignant growth. Cancer Res. 19, 538-543 (1959). 

Reaction of Deoxyribonuclease. DNAase -acts on polymers of various lengths and forms a mixture of oligonucleotides with very little mononucleotide. Dinucleotides containing purines, pyrimidines, and both have been isolated from digests. The substrate specificity is obviously not so restricted as that of pancreatic RNAase, but has yet to be defined completely. The mechanism of action is also obscure. The linkage of phosphate to the 3 position is split by pancreatic DNAase the monoesters found in the products are all 5 -phosphates. From analogy with ribonucleic acid metabolism, it may be anticipated that DNAase with different specificities will be found, and that some will be found to split the 5 ester bonds. 

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