GrTX-SIA inhibits multiple Na V channel subtypes. (A–C) Representative current traces (A), normalized conductance (G/Gmax)–voltage and channel availability (I/Imax) relationships (B), and recovery from inactivation (% rec) are shown before (black) and after (red) a 4-min incubation period with 100 nM GrTX-SIA (C). Data were normalized by comparing the saturated toxin effect to the corresponding control recordings obtained before toxin addition to the same oocyte. The holding potential was −90 mV with 5 s between depolarizing pulses, except for NaV1.8, which was measured with 10 s between pulses (protocol shown in Fig. S1). Traces shown were recorded at −15 mV for NaV1.1, NaV1.3, NaV1.4, and NaV1.7, −20 mV for NaV1.2 and NaV1.6, −30 mV for NaV1.5, and +10 mV for NaV1.8. X-axis represents 10 ms for all traces, Y-axis value is indicated. Fit values are reported in Table S1. Circles represent mean ± SEM of n = 6 oocytes for NaV1.1, NaV1.5, NaV1.6, NaV1.7, and NaV1.8, n = 5 oocytes for NaV1.2 and NaV1.4, and n = 4 oocytes for NaV1.3.