[Heterogeneity of the structure of histone (H2A-H2B) dimers]

It has been found that at pH 7.4 and 100 mM NaCl only about one third of histones (H2A-H2B) dimers are able to bind the fluorescent probe I-anilinonaphthalene-8-sulphonate. The binding constant equals 2 divided by 2.7 X 10(4) M-1. The heterogenic pattern of these dimers may be genetically important and along with other factors it can determine the structural changes of the protein core of the nucleosome and of the nucleosome proper.