Biopolym. Cell. 1985; 1(4):203-207.
Cell Biology
Topoisomerase II. Its role in conformation changes in superhelical nuclear DNA of lymphocytes after γ-irradiation
1Vashchenko V. I., 1Shchedrina L. V., 1Komar V. E.
  1. Central Research Institute for Roentgenology and Radiology, Ministry of Public Health
    Leningrad, USSR


Inhibitors of DNA topoisomerase system (novobiocin, nalidixic acid) are studied for their effect on the repair of superhelical DNA structure damaged by ionizing radiation (8 Gy) in rat lymphocytes. The data obtained show that the topoisomerase II participates in the appearance of the second relaxation of superhelical domains in nuclear DNA after irradiation. The scheme is suggested concerning the participation of this enzyme in the structure of nucleoids in their interaction with chemical and physical agents. BND-cellulose chromatography reveals the presence of repair synthesis in human lymphocytes after their γ-irradiation (20 Gy) in vitro.


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