EML 425

EML 425 is a potent and selective inhibitor of CREB binding protein (CBP) /p300 (IC50s: 2.9 and 1.1 μM, respectively) . EML 425 is shown to be a reversible inhibitor, noncompetitive versus both acetyl-CoA and a histone H3 peptide, and able to bind both the free enzyme and the enzyme-substrate complex, even with unequal affinity constants. EML 425, noncompetitive versus both acetyl-CoA and a histone H3 peptide, shows good cell permeability. EML 425 inhibits both p300 and CBP (IC50 values of 2.9 and 1.1 μM, respectively) while being practically inactive against the enzymes general control non-derepressible-5 (GCN5) and p300/CBP-associated factor (PCAF) . EML 425 causes a marked and time-dependent reduction in the acetylation of lysine H4K5 and H3K9 in U937 cells. The binding site for EML 425 is an alternative pocket lying near the substrate lysine binding groove and close to the acetylation site.