Figure 2. Comparison of cation selectivity between the nonselective NsvBa and Na⁺-selective NaChBac channels.

(A and C) Representative current traces from NsvBa channel (A) or from the NaChBac channel (C) showing the first 0.25 s of 0.5 s activations from −180 mV holding potential: Top, 150 mM Na⁺ was substituted with an equal concentration of the indicated monovalent ions; Bottom, 110 mM Na⁺ was substituted for equal concentrations of the indicated divalent cations. (B and D) Resulting current-voltage relationships measured for the conditions tested in (A) and (C). NsvBa: n = 5–9, NaChBac: n = 6–9; Error = ±SEM.

DOI: http://dx.doi.org/10.7554/eLife.04387.005

Figure 2—figure supplement 1. Na⁺ and K⁺ are highly conductive through the nonselective NsvBa channel.

(A) Example single channel opening events recorded from Na⁺ and K⁺ conditions in the inside-out patch configuration. (B) Average current amplitudes plotted over the indicated potentials (n = 4, Error = ±SEM). The conductance for the K⁺ (36 pS) and Na⁺ (30 pS) conditions was derived from the slope of a linear fit of the current amplitudes.

DOI: http://dx.doi.org/10.7554/eLife.04387.006