(a) Time course of the cytosolic Ca²⁺ level with the addition of 15 μM CPA at 30 sec (arrow). The traces were generated from the mean and standard error of the mean. (n = 4). (b) Time course of the cytosolic Ca²⁺ level with the addition of 7.6 μM TG at 30 sec (arrow) and 15 μM CPA at 240 sec (arrow, n = 5) (c) Time course of the cytosolic Ca²⁺ level with the addition of 10 μM A23187 at 30 sec (arrow, n = 3) (d) Time courses of the cytosolic Ca²⁺ level with the addition of DMSO as a solvent control at 30 sec (arrow, n = 3). The cytosolic Ca²⁺ level is represented by R/R₀ value, where R is the YFP/CFP ratio and R₀ is the mean YFP/CFP ratio before addition of the drug as baseline (time between 0–30 s). Model structures of TG (yellow) with human SERCA (HsSERCA) (e) or P. falciparum SERCA (PfSERCA) (f) Illustrate a structural difference in the TG-binding pocket. Colored regions of each SERCA are located within 4.0 Å distance from TG and were used for binding energy calculations. (g,h) Schematics represent surface structure from ribbon diagrams corresponding to (e,f), respectively.