IC50: ~5 µM (skeletal muscle myosin II S1 ATPase)
BTS (2-12 μM) inhibits the Ca 2+ -stimulated ATPase activity of myosin S1 in the absence of actin, with an IC 50 of ~5 µM. BTS (2-20 μM) reversibly inhibits the gliding motility rate of heavy meromyosin (HMM). BTS (100 μM) releases myosin from actin in the presence of ADP. BTS (0-20 μM) reversibly inhibits isometric Ca 2+ -activated tension in skinned skeletal muscle fibres from rabbit and frog, with IC 50 s of ~3 µM and 1 µM, respectively.