Physicochemical properties of salt-soluble, unsheared chromatin. Molecular weight studies.
A chromatin fraction, which can reproducibly be extracted from rat liver nuclei at moderate salt concentration (0.1 M (NH4)2SO4, 0.1 M Tris-HCl, 2 mM MnCl2, pH 7.9), was analyzed with regard to changes of its molecular weight in the range of (NH4)2SO4 concentrations between 0.1 M and 0.4 M. With the transition from 0.1 M to 0.2 M (NH4)2SO4 histone H1 is released and the molecular weight obtained from both sedimentation-viscosity and light scattering is reduced by approximately one-half. A spatial expansion of the resulting half-molecules is observed with further increasing salt concentration. On the basis of these results a double-fibrillar structure of this chromatin fraction is proposed.
D000818:Animals; D002467:Cell Nucleus / Q000032:analysis; D002843:Chromatin / Q000032:analysis*; D004247:DNA / Q000032:analysis*; D006657:Histones / Q000032:analysis*; D008027:Light; D008099:Liver / Q000032:analysis; D008970:Molecular Weight; D051381:Rats; D012542:Scattering, Radiation; D012995:Solubility; D014783:Viscosity
D002843:Chromatin; D006657:Histones; D004247:DNA