title: [Effect of novobiocin on degradation and repair of the superhelical structure of nuclear DNA from rat thymocyte fractions].
abstract: A study was made of the action of novobiocin on degradation and repair events in supercoiled nuclear DNA from three thymocyte fractions obtained by ficoll-paque gradient sedimentation. When added before gamma-irradiation novobiocin (1.9 mg/ml) exerted a radioprotective effect during the "second wave" of supercoiled DNA degradation. It is suggested that this effect may be due to the inhibition of DNA topoisomerase II.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004260:DNA Repair / Q000187:drug effects* / Q000528:radiation effects; D004278:DNA, Superhelical / Q000032:analysis / Q000528:radiation effects*; D007700:Kinetics; D009675:Novobiocin / Q000494:pharmacology*; D051381:Rats; D013950:Thymus Gland / Q000032:analysis / Q000187:drug effects* / Q000528:radiation effects; D014783:Viscosity
chemical_list: D004278:DNA, Superhelical; D009675:Novobiocin
vernacular_title: Deĭstvie novobiotsina na protsess degradatsii i vosstanovleniia superspiral'noĭ struktury iadernoĭ DNK fraktsiĭ timotsitov krysy.