Isothermal calorimetry (ITC) assays with G-actin and ATP.
In G-actin polymerization experiments, Bistramide A decreased polymerization at concentrations 50-400 nM. In F-actin depolymerization assays, Bistramide A increased depolymerization at concentrations 120-450 nM. These results were confirmed in later experiments using TIRF microscopy (see PNAS paper).
PDB ID for probe-target interaction (3D structure):