title: Variations in DNA topoisomerase I activity after gamma irradiation of mature neurons.
abstract: The activity of DNA topoisomerase I in nuclear extracts from rat cerebral cortex neurons increases about two-fold after gamma irradiation (700 rads) of rats or incubated cerebral cortex slices. Analysis of the salt dependence of the DNA topoisomerase I association with chromatin shows a change of the activity only for tight-bound pool of the enzyme. The change appears to reflect a modification of the enzyme which results from its repair function.
authors.affiliation: Institute of Biological Physics, Academy of Sciences, Poustchino, Moscow Region, U.S.S.R.
authors.forename: V A
authors.initials: VA
authors.lastname: Ivanov
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology / Q000528:radiation effects; D002540:Cerebral Cortex / Q000201:enzymology / Q000528:radiation effects*; D004264:DNA Topoisomerases, Type I / Q000378:metabolism / Q000528:radiation effects*; D004278:DNA, Superhelical / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D005720:Gamma Rays; D066298:In Vitro Techniques; D007700:Kinetics; D009474:Neurons / Q000201:enzymology / Q000528:radiation effects*; D009675:Novobiocin / Q000494:pharmacology; D051381:Rats
chemical_list: D004278:DNA, Superhelical; D009675:Novobiocin; D004264:DNA Topoisomerases, Type I