Histone H4 acetylation and methylation variants

A cation-exchange column can separate variants with acetylated Lys- residues, since they vary in the number of + charges. However, with hydrophilic interaction superimposed on the electrostatic effects, the column can also separate variants with the same number of acetylated Lys- residues but differing in the number of methylated Lys- residues. In the figure below, the more highly acetylated forms are present in the smallest amounts and for the shortest time in the cell cycle, but their presence is required if the cell is to enter mitosis. Their identification was only possible by adding this top-down separation step prior to digestion and bottom-up peptide identification. Otherwise, they would be masked by the far more abundant, less highly acetylated variants.

Column Name : PolyCAT A™ Columns

Compound Name : Histone H4