[Reorganization of the protein composition of the nuclear matrix of hepatoma cells after inhibition of DNA synthesis with novobiocin].

The nuclear matrix of Zajdela hepatoma cells, in which DNA synthesis was blocked by novobiocin, contained 2.5-3.0 times more DNA and protein not dissociating in 2 M NaCl than the nuclear matrix of control cells. Chromatography of nuclear matrix preparations on Sepharose 2B-CL resulted in isolation of tightly bound DNA-protein complexes which did not dissociate in 8 M urea or 0.1% SDS. Subsequent elution of DNA-protein complexes on a hydroxylapatite column with a buffer containing 4 M guanidine hydrochloride and 5 M urea caused partial dissociation of the complexes. Electrophoretic analysis revealed essential changes in the composition of proteins DNA-protein complexes of hepatoma cells nuclear matrix during inhibition of DNA synthesis.