Studies of the Specificity of Deoxyribonuclease I

When the oligonucleotides obtained by the digestion of desoxyribonucleic acid by splenic desoxyribonuclease are subjected to digestion by pancreatic desoxyribonuclease, neither nucleosides nor mononucleotides are among the products, but mononucleoside 3', 5' -diphosphates are present. This suggests that monoesterified phosphate in position 3' labilizes the preceding internucleotide linkage while monoesterified phosphate or free hydroxyl in position 5' makes the following linkage resistant. The predominant products are dinucleotides and their derivatives, suggesting that they represent the ultimate product of the reaction. Increased hydrolysis can be achieved both by removal of products and increased enzyme concentration. (auth)