Chimeric channels of mSlo1 and dSlo1 retain features of their native WT channels. (A, top) Current traces of Chim2 and mSlo1 at [Ca2+]i of 2, 10, and 100 μM. Test potentials were −80 to +200 mV, holding and repolarization potentials were −50 mV. (Bottom) Steady-state G-V relations of Chim2 and mSlo1. Smooth curves are fits of the Boltzmann equation with parameters for Chim2, in 2 μM [Ca2+]i: V1/2 = 240.1 mV, z = 0.95, in 10 μM [Ca2+]i: V1/2 = 76.1 mV, z = 1.5, in 100 μM [Ca2+]i: V1/2 = 43.5 mV, z = 1.5; for mSlo1, in 2 μM [Ca2+]i: V1/2 = 84.8 mV, z = 1.5, in 10 μM [Ca2+]i: V1/2 = 31.4 mV, z = 1.5, in 100 μM [Ca2+]i: V1/2 = 14.4 mV, z = 1.4. (B, top) Current traces of Chim6 and mSlo1 at [Ca2+]i of 0, 10, and 500 μM. Test potentials were −80 to +200 mV, holding and repolarization potentials were −50 mV. (Bottom) Steady-state G-V relations of Chim6 and mSlo1. Smooth curves are fits of the Boltzmann equation with parameters for Chim6, in 0 [Ca2+]i: V1/2 = 206.7 mV, z = 1.3, in 10 μM [Ca2+]i: V1/2 = 101.1 mV, z = 1.2, in 500 μM [Ca2+]i: V1/2 = 52.5 mV, z = 1.2; for mSlo1, in 0 [Ca2+]i: V1/2 = 189.7 mV, z = 1.1, in 10 μM [Ca2+]i: V1/2 = 33.8 mV, z = 1.7, in 500 μM [Ca2+]i: V1/2 = −13.2 mV, z = 1.8.