Background:EP300 (E1A binding protein p300) played a significant role in serial diseases such as
cancer, neurodegenerative disease. Therefore, it became a significant target.Methods:Targeting EP300 discovery of a novel drug to alleviate these diseases. In this paper, 17 candidate
compounds were obtained using a structure-based virtual screening approach, 4449-0460, with an IC50 of 5.89
± 2.08 uM, which was identified by the EP300 bioactivity test. 4449-0460 consisted of three rings. The middle
benzene ring connected the 5-ethylideneimidazolidine-2,4-dione group and the 3-F-Phenylmethoxy group.Results:Furthermore, the interaction mechanism between 4449-0460 and EP300 was explored by combining
molecular dynamics (MD) simulations and binding free energy calculation methods.Conclusion:The binding free energy of EP300 with 4449-0460 was -10.93 kcal/mol, and mainly came from
the nonpolar energy term (ΔGnonpolar). Pro1074, Phe1075, Val1079, Leu1084, and Val1138 were the key residues
in EP300/4449-0460 binding with more -1 kcal/mol energy contribution. 4449-0460 was a promising inhibitor
targeting EP300, which had implications for the development of drugs for EP300-related diseases.