Figure S2.

Exposure of an inside-out patch to 200 µM Cd²⁺ at −90 mV in a three-pulse protocol. Inside-out patch currents were recorded in HEK293 cells expressing T449A/V474C Shaker-IR channels. Representative traces show currents evoked by three depolarizing pulses to +50 mV. The holding potential was −120 mV before P₁ and P₃. The holding potential between pulses P₁ and P₂ was −90 mV. 200 µM Cd²⁺ was applied intracellularly (empty horizontal bar). The IF and RCF values calculated from I₁, I₂, and I₃ peak currents are in Fig. 5, B and C.