Analyses of relative protein content and distribution of histones in euchromatic and heterochromatic fractions.

Euchromatic and heterochromatic fractions obtained by autodigestion of mouse TLT (taper liver tumour) hepatoma chromatin (Paul, I. J & Duerksen, J. D. (1976) Arch. Biochem. Biophys. 174, 491-505) were analyzed for relative protein content and histone content. With one exception, all fractions had the same DNA to protein ratio. Similarly, the total histone to DNA ratio was also constant in all fractions. In addition, the relative contents of the major histones, H1, (H2A + H2B + H3), and H4, were also constant in all fractions.