title: Isolation and characterization of salt-soluble, unsheared chromatin.
abstract: From rat liver nuclei depending on the extraction time, 10 to 20% of total chromatin has been extracted with a solution containing 0.1 M ammonium sulfate, 2 mM MnCl2, 0.1 M Tris-HCl, pH 7.9. We term this chromatin chromatin S. It has a protein: DNA ratio of 1.3, the full amount of the 5 histones in an undegraded state, and a RNA: DNA ratio of approximately 0.2. Its nonhistone protein pattern, obtained by gel electrophoresis exhibits a rich spectrum of proteins in a broad range of molecular weights. Electrophoretic analysis of the DNA fragments obtained by micrococcus nuclease digestion of chromatin S yields the same digestion pattern as that of nuclei. Thus, chromatin S fulfils an essential criterion of unsheared chromatin. In contrast to other chromatin preparations described so far, this chromatin is soluble at a salt concentration of 0.1 M ammonium sulfate. We have shown previously that it exhibits a compact conformation, low intrinsic viscosity and low radius of gyration obtained by light scattering measurements. Its mean molecular weight was determined to be nearly 10(8).
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000032:analysis; D002843:Chromatin / Q000032:analysis / Q000302:isolation & purification*; D004247:DNA / Q000032:analysis; D006657:Histones / Q000032:analysis; D008099:Liver / Q000648:ultrastructure; D008836:Micrococcal Nuclease / Q000378:metabolism; D008970:Molecular Weight; D009698:Nucleoproteins / Q000032:analysis; D011487:Protein Conformation; D012313:RNA / Q000032:analysis; D051381:Rats; D012995:Solubility
chemical_list: D002843:Chromatin; D006657:Histones; D009698:Nucleoproteins; D012313:RNA; D004247:DNA; D008836:Micrococcal Nuclease