title: [Structural heterogeneity of chromatin preparations at the level of DNA topology].
abstract: The structural heterogeneity of calf thymus chromatin preparations was studied at the level of DNA topology by analysing the influence of ethidium bromide on the chromatin viscosity in deproteinizing medium. In 0.7 M NaCl the chromatin was separated into the fractions with linear DNA (3--36% in various preparations) and with supercoiled circular DNA (scc DNA), which differ from each other in their adhesive properties. Reduction of disulfide bonds in residual chromatin protein with 5% mercaptoethanol linearized scc DNA, present in chromatin preparations as nuclear matrix subunits containing some loops of scc DNA on the protein globule.
authors: V D
authors: VD
authors: Paponov
authors: G A
authors: GA
authors: Sigora
authors: S P
authors: SP
authors: Rad'ko
mesh_terms: D000818:Animals; D002417:Cattle; D002843:Chromatin; D004247:DNA; D004278:DNA, Superhelical; D009690:Nucleic Acid Conformation; D013950:Thymus Gland
chemical_list: D002843:Chromatin; D004278:DNA, Superhelical; D004247:DNA
vernacular_title: Strukturnaia geterogennost' preparatov khromatina na urovne topologii DNK.