Histone deacetylase enzymes (HDACs and sirtuins) have received considerable attention due to their potential as targets for therapeutic intervention in a variety of disease states, including several types of cancer. Methods for accurate biochemical profiling of putative drug candidates are therefore desirable. Furthermore, recent reports in the literature have shown that acyl groups other than acetyl may also play important roles in cellular signaling, which considerably broadens the scope of this class of ε-N-acyllysine posttranslational modifications.1
Here, the evaluation of a series of diverse fluorogenic substrates against the panel of human zinc-dependent HDACs 1–11 as well as the NAD-dependent sirtuins (SIRT1–7), will be discussed. Kinetic parameters describing a selection of the enzyme–substrate interactions in further detail were performed, and a selection of inhibitors were evaluated. Our investigations show noteworthy trends in certain ligands’ mechanism-of-inhibition across different enzyme isoforms, which is of importance for correct selectivity profiling.
Additionally, efficient new fluorogenic substrates for SIRT52 and SIRT6 screening will be presented, and finally, we have shown that HDAC3 harbors lysine decrotonylase activity in addition to deacetylase activity,3 albeit at a considerably lower rate than its deacetylase acitivity.
Generally, our synthetic chemical peptide tool approach holds promise for discovery and investigation of yet undiscovered enzyme function related to this class of posttranslational modification.