Isolation and some properties of a deoxyribonuclease from Turbo cornutus.
1. Four DNases were found in the dried liver extract of a top shell, Turbo cornutus. The major one was purified 120-fold by phosphocellulose column chromatography, sulfoethylcellulose column chromatography and gel-filtration on Sephadex G-150. The yield was 2.7%. 2. The enzyme activity was not affected by Mg2+ (10(-3)--10(-2)M), EDTA (10(-3)--10(-2)M), or NaCl (10(-1)M). It showed a pH optimum of 4.7--4.8. Ionic strength was found to be critical for the maximal activity. The isoelectric point was 8.5--9.0. On heating at 50 degrees C C for 5 min the enzymic activity fell to half the initial value. 3. The enzyme preparation degraded native as well as heat-denatured DNA, but not RNA. It degraded heat-denatured DNA endonucleolytically to give oligonucleotides with 3'-phosphates. 4. The 3'-phosphate and 5'-hydroxy termini of oligonucleotides were investigated. At both the 3'- and 5'-terminal positions, purine nucleotides were predominant.
D003851:Deoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000201:enzymology; D008274:Magnesium / Q000494:pharmacology; D008974:Mollusca / Q000201:enzymology*; D009711:Nucleotides / Q000032:analysis; D009841:Oligonucleotides / Q000378:metabolism
D009711:Nucleotides; D009841:Oligonucleotides; D004492:Edetic Acid; D003851:Deoxyribonucleases; D008274:Magnesium