Figure 3.

KCl dependence of Ca²⁺-ATPase activity of myosin fragments. Ca²⁺-ATPase activity was measured in 0.01 mg/ml myosin fragment, 5 mM CaCl₂, 3 mM EDTA, 50 mM Tris·HCl (pH 7.5), and various concentrations of KCl at 25°C. The reaction was started by adding ATP, and the liberated inorganic phosphate was measured as described (20).