title: Purification of Caenorhabditis elegans DNA topoisomerase I.
abstract: DNA topoisomerase I was partially purified from Caenorhabditis elegans worms. The enzyme is a 95 kDa polypeptide and its proteolytically degraded form of 70 kDa was also observed. The enzyme removed not only negative but also positive DNA supercoils. The optimum salt concentration for the DNA relaxation activity was 100 mM KCl, and divalent cations were not required but stimulated the activity. The DNA relaxation activity was weakly sensitive to 125 microM camptothecin but was completely inhibited by 125 microM berenil.
authors.affiliation: Department of Biochemistry, College of Science, Yonsei University, Seoul, South Korea.
authors.forename: S M
authors.initials: SM
authors.lastname: Park
authors.forename: H S
authors.initials: HS
authors.lastname: Koo
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology*; D002166:Camptothecin / Q000494:pharmacology; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification* / Q000378:metabolism; D004133:Diminazene / Q000031:analogs & derivatives / Q000494:pharmacology; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D059004:Topoisomerase I Inhibitors; D014344:Trypanocidal Agents / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; D059004:Topoisomerase I Inhibitors; D014344:Trypanocidal Agents; D004264:DNA Topoisomerases, Type I; C003915:diminazene aceturate; D002166:Camptothecin; D004133:Diminazene