EX 527

EX 527 is a potent and selective inhibitor of the SIRT1 class III histone deacetylase enzyme, thought to block the release of deacetylated peptide and O-acetyl-ADP-ribose from the enzyme following the deacetylation process. EX 527 has been used a powerful tool for studying the relationship between SIRT1 and cell regulation. The deacetylation of cortactin, a protein responsible for rearrangements of the actin cytoskeleton, is associated with cell motility and possibly tumorigenesis, and blocking of this deacetylation by EX 527 correlated to a decrease in cell motility. Blocking of SIRT1 by EX 527 also demonstrated that deacetylation of the important tumor suppressor protein p53 is mediated by SIRT1 as well. EX 527 inhibits other sirtuin family deacetylases only at much higher concentrations (IC₅₀ = 19.6 and 48.7 μM for SIRT2 and SIRT3, respectively).