Histone deacetylase (HDAC) enzymes are epigenetic regulators that affect diverse protein function by removing acyl groups from lysine side chains throughout the proteome. The most recently discovered human isozyme, HDAC11, differs from other HDACs in substrate preference and tissue expression profile. Elucidation of the biological function of this enzyme has been scarce and only a few chemical probes to help advance this insight have been developed thus far.
In this presentation, I will share our recent discovery of macrocyclic inhibitors that exhibit selectivity for HDAC11 and penetrate the cytoplasmic membrane in cultured cells as determined by the chloroalkane penetration assay (CAPA). Further, we provide evidence of selective targeting of HDAC11 in cultured cells through various biomarkers of HDAC11 inhibition. Our work establishes the combination of de novo macrocycle synthesis with incorporation of N-alkylated hydroxamic acid moieties as a viable strategy for targeting HDAC11. Further, this work demonstrates the potential of applying macrocyclic peptide-based library synthesis to directly furnish high-affinity, cell-permeating ligands. The discovered inhibitors comprise tool compounds for the investigation of the biological function of HDAC11.