title: Purification, characterization, and amino acid sequencing of DNase gamma from rat spleen.
abstract: An endonuclease named DNase gamma was purified to apparent homogeneity from rat splenocyte nuclei and its properties were characterized. We also determined the NH2-terminal and partial amino acid sequences of the proteolytic internal peptides. The molecular mass of gamma DNase was 33,000 daltons as determined by SDS-polyacrylamide gel electrophoresis. A native molecular mass of 30,000 was estimated by gel filtration. Purified DNase gamma is active in the presence of both Ca2+ and Mg2+ or Mn2+ alone and inhibited by Co2+, Ni2+, Cu2+, and especially Zn2+. Maximal activity was achieved at pH 7.2 in Mops-NaOH buffer. The sequence data on the NH2-terminal and seven internal peptides obtained by sequential digestions with Achromobacter protease I and endoproteinase Asp-N revealed that DNase gamma is a novel endonuclease that shows sequence homology with DNase I.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Science University of Tokyo, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Shiokawa
authors.forename: A
authors.initials: A
authors.lastname: Iwamatsu
authors.forename: S
authors.initials: S
authors.lastname: Tanuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003850:Deoxyribonuclease I / Q000737:chemistry / Q000145:classification; D004706:Endodeoxyribonucleases / Q000737:chemistry* / Q000145:classification / Q000187:drug effects / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017208:Rats, Wistar; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000201:enzymology*
chemical_list: D002413:Cations, Divalent; D004706:Endodeoxyribonucleases; C105124:deoxyribonuclease gamma; D003850:Deoxyribonuclease I; D008274:Magnesium; D002118:Calcium