Association of the chromatin domains with the nuclear skeleton in ehrlich ascites carcinoma cells. Analysis by means of nucleoprotein-celite chromatography

Distribution of the nucleoproteins, of different tightness has been studied in isolated nuclei and in the nuclear matrix by means of the NPC chromatography. A salt-urea resistant (DNAII) and sensitive (DNAI) DNA-matrix bonds and a fraction of residual chromatin have been detected in the matrix preparations obtained from DNAsel treated nuclei. All bonds are resistant to the action of mercaptoethanol, EDTA and low ionic strength. DNAII is sensitive to nuclease SI, the DNA melting is necessary for its destruction. Restrictases cause the DNAII degradation with unequal effectivity: the four base cutters are more effective as compared to the six base cutters. Among the latter EcoRl, PstI and PvuII degrade the bond to a greater degree than Hindlll, SalGl, BamHI. The totality of the DNAI and DNAII features indicate that these bonds do not correspond to differing types of the DNA-matrix boundings revealed by other methods.