[Change in conformation of histones F 2a and F 2b in solutions of different ionic strength]

A change was studied in the differential absorption spectra and fluorescence quantum yield of histones F2a and F2b with the ionic strength varies. It is shown that the structure of the histone F2a molecule stops changing with an increase in the concentration of NaCl up to 0.5 M. In the histone F2b molecule the conformational changes occur with the NaCl concentration less than 1.0 M. The conformation change results in formation of hydrophobic areas on the histone surface, which intensifies the histone-histone interaction. The role of the histone conformational changes for regulation of gene activity is discussed.