Fig. 4

Linear regression analyses between t _1/2, pCa₅₀ and ΔpCa₅₀. a Relationship between pCa₅₀ and ΔpCa₅₀ (R = 0.98, P < 0.0005). b Relationship between t _1/2 and pCa₅₀ (R = 0.95, P < 0.05). c Relationship between t _1/2 and ΔpCa₅₀ (R = 0.97, P < 0.01). In (a–c), plots were constructed using the data in Figs. 2 and 3. pCa₅₀ obtained at SL 2.0 μm. Dashed lines in (a–c) data obtained with PLV in our previous study [8] under the same experimental condition with SL varied between 1.9 and 2.3 μm. The values of pCa₅₀ and t _1/2 were obtained at the slack SL (1.9 μm) for PLV