Voltage-dependent Shaker and Kv1.2 conductance and fluorescence deflections. Typical current traces (A and D) and fluorescence signals (B and E) are shown for Shaker C245V A359C and Kv1.2 C181 A291C for 100-ms pulses between −120 and 60 mV from −80 mV. The dashed line in E marks the approximate division of the two observed components of A291C fluorescence for depolarizations positive to 0 mV. (C and F) Normalized conductance-voltage (G-V; closed symbols) and total fluorescence-voltage (F-V; open symbols) relationships were calculated from data obtained at the end of each 100-ms pulse (mean ± SEM; n = 7–8), and data were well fit with Boltzmann equations. The V_1/2 values for Shaker C245V A359C were −12.9 ± 1.6 mV and −39.5 ± 1.5 mV for G-V and F-V, and slope factors (k) were 17.8 ± 1.1 mV and 22.3 ± 1.4 mV, respectively. The Kv1.2 A291C G-V had a V_1/2 and slope factor of −11.2 ± 1.6 mV and 22.4 ± 0.9 mV, respectively, whereas the F-V relationship had a V_1/2 and k of −62.9 ± 1.2 mV and 23.2 ± 1.0 mV.