Studies on rat liver nuclear DNA damaged by chemical carcinogen (3'-Me DAB) and AP DNA endonuclease. I. Purification and some properties of AP DNA endonucleases in rat liver chromatin.
Three kinds of apurinic/apyrimidinic (AP) DNA endonuclease, APcI, APcII, APcIII, were purified from rat liver chromatin through 1M KCl extraction, DEAE-trisacryl ion exchange chromatography. Sephadex G-150 gel filtration and AP DNA cellulose affinity chromatography. Activities of the purified APcI, APcII and APcIII were 62.5, 83.3 and 52.0 EU/mg of protein, respectively. Molecular weights of APcI, APcII and APcIII, each consisting of a single polypeptide, were 30,000, 42,000 and 13,000, and isoelectric points of them were 7.2, 6.3 and 6.2, respectively. Three enzymes showed different substrate specificities; APcI acted only on AP DNA, and APcII acted on both AP DNA and UV DNA, while APcIII acted on 3'-methyl-4-monomethylaminoazobenzene (3'-Me MAB) DNA adduct as well as AP DNA and UV DNA. These results indicate that three kinds of AP DNA endonuclease present in rat liver chromatin have structural and functional diversities.
Kim
Y S
YS
Department of Biochemistry, Yonsei University College of Medicine, Korea.
Kim
J W
JW
Lee
S E
SE
Oh
S H
SH
D000818:Animals; D002273:Carcinogens; D002843:Chromatin / Q000201:enzymology*; D004249:DNA Damage / Q000502:physiology*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004591:Electrophoresis, Polyacrylamide Gel; D004706:Endodeoxyribonucleases / Q000302:isolation & purification* / Q000378:metabolism; D007525:Isoelectric Focusing; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives
D002273:Carcinogens; D002843:Chromatin; C034071:3'-methyl-4-methylaminoazobenzene; D004124:p-Dimethylaminoazobenzene; D004706:Endodeoxyribonucleases; D043223:Deoxyribonuclease IV (Phage T4-Induced); D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase