Molecular homogeneity of the histone content of HeLa chromatin subunits

Abstract

Interaction of affinity chromatographically purified antihistone H3 and antihistone H4 with isolated [human cervical cancer] HeLa core particles, followed by separation of unreacted and reacted particles by sedimentation, demonstrates that every core particle contains these histones. Taken with previous data indicating the presence of H2B in every nucleosome, these data lead to the conclusion that each core particle contains 2 each of the 4 smaller histones. In contrast to the lack of interference in binding of more than 1 molecule of antibody to a single species of histone to the core particle, steric hindrance exists when attempts are made to bind both anti-H3 and anti-H4 to core particles.