Solution studies of the interactions between the histone core proteins and DNA using fluorescence spectroscopy.
The equilibrium interactions between histone H2A-H2B and H3/H4 subunits with 200 base pair chicken erythrocyte DNA have been studied by monitoring the fluorescence polarization of a long-lived fluorescence probe covalently bound to the histone subunits. These studies have brought to light the formation of highly asymmetric complexes exhibiting very high histone/DNA stoichiometries as well as very high apparent affinities. The stoichiometries observed for these non-nucleosome complexes depended both upon the concentration of the histones and the concentration of the DNA 200mer. The observed stoichiometries varied approximately between 4 and 16 histone octamers/DNA 200mer and the affinities were in the nanomolar range. These results are discussed in terms of their in vitro as well as their possible in vivo significance.
Royer
C A
CA
University of Wisconsin, School of Pharmacy, Madison 53706.
Ropp
T
T
Scarlata
S F
SF
D000818:Animals; D002645:Chickens; D004247:DNA / Q000737:chemistry* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000737:chemistry; D005454:Fluorescence Polarization; D006657:Histones / Q000737:chemistry* / Q000302:isolation & purification; D066298:In Vitro Techniques; D012965:Sodium Chloride; D012995:Solubility; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D006657:Histones; D012965:Sodium Chloride; D004247:DNA