Studies on the mechanism of removal of histones from chromatin by deoxycholate

Abstract We have studied the effects of several cholanic acids and some of their conjugated derivatives on the selective dissociation of slightly lysine-rich histones II from chromatin. The results suggest that the driving force for the interaction between the cholanic acid anion and histones is the lowering of the activity coefficient of the cholanic acid anion which occurs when it is partially removed from solution by interaction with hydrophobic regions of the positively charged histones. The complete separation of chromatin and 14 C-labeled sodium deoxycholate by sucrose sedimentation indicated that the binding of sodium deoxycholate to chromatin is readily and completely reversible.