Substrate Specificity of Histone Deacetylase from Calf Thymus

Abstract

Previous studies demonstrated the presence of histone deacetylase, an enzyme which released ¹⁴C-acetate from ¹⁴C-acetate-labeled histones, in an extract of calf thymus. This paper is concerned with the substrate specificity of the enzyme. In agreement with the observations by Vidali et al. (J. Biol. Chem., 243, 6361 (1968)), ¹⁴C-acetyl.groups in the substrate histones prepared by incubating the calf thymus nuclei with ¹⁴C-acetate were mainly attached to the ɛ-amino groups of lysyl residues in arginine-rich histones (f2al and f3). Histone deacetylase attacked ¹⁴C-acetyllysyl residues in both f2al and f3 histones. In contrast, ɛ-N-¹⁴C-acetyl-histones prepared by the non-enzymatic acetylation with ¹⁴C-acetyl-CoA was deacetylated by this enzyme to a lesser extent. These results suggest that histones deacetylase has a high degree of specificity to distinguish specific acetyl-lysyl residues in histones.