title: Two subforms of eukaryotic topoisomerase I. Purification and structure-function relationships.
abstract: A new method for isolation of eukaryotic topoisomerase I from calf thymus and from Jurkat-1 cells using HPLC has been developed. The method allows quantitative purification of high molecular weight topo I and two low molecular weight fractions differing by their isoelectric points. It has been suggested that these fractions be characterized as two subforms of the enzyme possessing structural and functional differences. The differences in their specific activities, sensitivity to camptothecin and in their proteolytic digestion maps have been demonstrated for the two enzymes.
authors.affiliation: Engelhardt Institute of Molecular Biology, Academy of Sciences of Russia, Moscow.
authors.forename: A R
authors.initials: AR
authors.lastname: Kudinov
authors.forename: I B
authors.initials: IB
authors.lastname: Bronstein
authors.forename: A G
authors.initials: AG
authors.lastname: Gabibov
authors.forename: G V
authors.initials: GV
authors.lastname: Gololobov
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004264:DNA Topoisomerases, Type I / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D010957:Plasmids; D013329:Structure-Activity Relationship
chemical_list: D004269:DNA, Bacterial; D004264:DNA Topoisomerases, Type I