Electrophoretic heterogeneity of maize histones.

Histones from maize embryos and seedlings have been isolated using a fast extraction procedure. Three different electrophoretic systems have been applied for the study of the heterogeneity of maize core histones. Electrophoresis in acetic acid/urea polyacrylamide gels, containing high concentrations of urea, resulted in optimum fractionation of the core histones and especially of histone H4. Sodium dodecyl sulfate-containing polyacrylamide gels were not useful for the fractionation of maize histone classes H2a and H2b, nor for the various subfractions of H3 and H4. Gels containing Triton X-100, used for the dimension in two-dimensional electrophoresis proved to be efficient for the separation of all histone classes, as well as their structural variants and chemical modifications. Maize core histones have been oxidized in an attempt to define which of the Triton X-100 resolved subfractions represent oxidation forms.