[Effect of the supranucleosomal chromatin organization on histone-DNA interrelations]

It has been demonstrated by the method of competitive displacement of own chromatin histone by excess total histone that chromatin dispersity influence the strength of histone-DNA interactions in a medium of physiological ionic strength. Histone NI was removed from chromatin after the quantity of total histone added to chromatin was equivalent to that existing in chromatin. The proportion of histones H2A and H2B removed from chromatin was increased after mechanical of ultrasonic degradation of chromatin at 5-20-fold excess of total extra-histone. In some histone preparations, the removal of histones H2A and H2B was not detectable at even 200-fold excess of total histone. This may be explained by strengthening histone-DNA interactions in superhelical loops of chromatin.