Chemical Studies of Histone Acetylation

The activity of a calf thymus histone deacetylase was tested on histone F2A1 and derivative peptides prepared by cyanogen bromide cleavage, chymotryptic digestion, and solid phase peptide synthesis. Enzyme assays were based on the release of radioactively labeled acetate from the substrates. The large fragment (residues 1 to 84) derived by CNBr treatment and the NH2-terminal sequence (residues 1 to 37) prepared by chymotryptic digestion were both active as substrates for the deacetylase. The enzyme failed to remove acetyl groups from a smaller synthetic peptide (residues 15 to 21) encompassing the major site of acetylation at Lys16.