A Deoxyribonuclease From Calf Spleen

When highly polymerized deoxyribonucleic acid is digested with pancreatic DNase and the digest further degraded with phosphodiesterase from intestinal mucose or snake venom, the mononucleotides formed are 5'-phosphates. Since a digest prepared in this manner with a purified venom diesterase contains only 5'-mononucleotides and practically no nucleosides or polynucleotides, the pancreatic DNase must form only polynucleotides with 5' monoesterified phosphate end groups. Recently the enzymatic synthesis of polydeoxyribonucleotides from eoxyribonucleoside 5'-triphosphates has been demonstrated. Thus both enzymatic synthesis and degradation of deoxyribonucleic acids have as yet involved only derivatives with 5'-monoesterified phosphate.