Butyrolactone 3

Butyrolactone 3 is an inhibitor of histone acetyltransferase (HAT) Gcn5. Gcn5 acetylates histones H2B and H3. Butyrolactone 3 inhibits Gcn5 with an IC₅₀ value of 100 μM. It has an affinity to the Gcn5 enzyme similar to its substrate, histone H3. It inhibits pre-mRNA splicing with an IC₅₀ of 0.5 mM.