Butyrolactone 3 (MB-3) is a specific, cell-permeable small-molecule inhibitor of histone acetyltransferase GCN5 with IC50 of 100 uM. Butyrolactone 3 (MB-3) shows high affinity to the Gcn5 enzyme comparable to that of its natural substrate, histone H3. Butyrolactone 3 (MB-3) decreased E2A-PBX1 acetylation and E2A-PBX1 protein levels in leukemic cells. Butyrolactone 3 (MB-3) also is a chemical inhibitor of the histone acetyltransferase in Arabidopsis.
