On the interaction of histones with polyanions.

Histones precipitate from a solution of 0.14 mol/l NaCl with increasing concentrations of the polyanions polypentosesulphate; dextran sulphate; inorganic polyphosphate; heparin; or copolymer ethylene-maleic acid forming complexes from which histones cannot be extracted by 0.25 mol/l HCl. Affinities of the histone classes for polypentosesulphate appeared in the order from greatest to least: H4 approximately H3 greater than H2A greater than H2B greater than H1. At increased concentrations of most polyanions studied, the complexes of histones with polyanions remained partially soluble. Complexes of histones with all polyanions used were completely soluble in 2% SDS electrophoresis buffer, in 0.14 mol/l NaCl buffered at pH 12, and in 2 mol/l NaCl buffered at pH 7.2. Solubilisation of the complex polypentosesulphate-histone in 2 mol/l NaCl proved to be due to its dissociation.