Fig. 4

The effect of 1,2-DCB was SR vesicles-dependent. The assay medium contained 20 mM Mops, pH 7.0, 80 mM KCl, 5 mM MgCl₂, 1 mM EGTA, 0.967 mM CaCl₂, different SR protein concentrations (0.01 and 0.10 mg/ml), and 1.5–15 μM A23187 (A23187 was proportionally increased with respect SR total protein). SERCA activity was assayed at 25 °C in absence of compound as control (white bars) and with 1 mM 1,2-DCB (gray bars). The reactions started by the addition of 1 mM ATP. Controls were normalized to 100 % of Ca²⁺-ATPase activity and the actual values were 2.6 ± 0.05, 2 ± 0.04, and 1.6 ± 1.3 μM P_i/min/mg. *, p = <0.001, compared to their respectively control that does not have DCB