Biopolymers and cell. 1993. Volume 9. № 5. 44 - 51

SOLOVYAN V. T., ANDREYEV I. O., KUNAKH V. A.

The Fractionation of Eukaryotic DNA by Pulsed Field Gel Electrophoresis. Evidence for Nuclear DNA Organization as Constituent Component of Topoisomerase II/DNA Complex

Summary

    We investigated the pattern variation of discrete DNA fragments resulted from fractionation of nuclear DNA preparations by field inversion gel electrophoresis in response to different influences. The discrete cleavage of nuclear DNA has been shown to be SDS-dependent in Mg²⁺-containing medium and SDS-independent in Ca²⁺-containing one. Topoisomerase II specific poisons teniposide (VM-26) and amsacrine (m-AMSA) have been shown to increase the SDS-dependent nuclear DNA cleavage while NaCl promotes to rejoining of cleaved DNA. The data presented allow to considere the nuclear DNA organization as constituent component of topoisomerase II/DNA complex the main property of which is its ability to mediate the cleavage/rejoining equilibrium-reactions. The involvement of nuclear DNA in functioning topoII/DNA complex offers the possibility to investigate the role of topoll enzyme in structural organization and functioning of eukaryotic genome.