Analytical Ultracentrifuge Analysis of Nucleosomes Assembled from Recombinant, Acid-Extracted, HPLC-Purified Histones.

The accumulating discoveries of new posttranslational modifications (PTMs) and the increasing relevance of histone variants within the frame of epigenetics demand the availability of methods for a rapid and efficient nucleosome reconstitution to analyze their structural and functional implications. Here we describe a method suitable for this purpose, starting from bacterially expressed histones, solubilized by acid and purified by reversed-phase high-performance liquid chromatography. This method allows the preparation of micrograms to milligram amounts of in vitro-assembled nucleosomes. Finally, we demonstrate the efficiency of this method for the structural analysis of nucleosomes in the analytical ultracentrifuge.