Fig. 4.
Determination of ion preference for pores induced by COOH-PNP (A) or amidine-PNP (B). Current-voltage (I-V) relations were obtained during voltage transitions shown in Fig. 3C with the direction of applied voltage steps shown. Insets show expanded views of the current reversal regions, in which squares and solid line indicate voltage shifts from negative to positive, while triangles and dashed line indicate voltage shifts from positive to negative. The direction of the voltage shift did not significantly affect reversal potentials (Erev) for either COOH-PNP or amidine-PNP.
