Biochem/physiol Actions CRT0044876 targets the apurinic endonuclease (APE1) active site and inhibits its 3′-phosphodiesterase and 3′-phosphatase activities-essential steps in excision repair-with minimal effects on endonuclease IV, BamH1 restriction endonuclease, or topoisomerase I even at concentrations as high as 100 μM. At non-cytotoxic concentrations, CRT0044876 potentiates the cytotoxicity of several DNA base-targeting compounds, with accumulation of apurinic sites. |