Fig. 5: Tse5-CT forms stable pores with ohmic behaviour and preference for cations, and some pores with noisy currents and strong voltage dependence.

a Representative Tse5-CT-induced stable current traces were obtained in a 250/50 mM (upper panel) or 50/250 mM (middle panel) KCl gradient using a polar lipid extract from E. coli to form the membrane. The lower panel shows a representative trace in 250/50 mM KCl gradient when a neutral DOPE membrane was used. The applied voltages are shown at the bottom in light grey. b I/V curves corresponding to the traces shown in (a). Linear regressions (solid lines) allow calculation of the conductance (1.76 nS (black), 0.99 nS (red) and 0.95 nS (blue)) and reversal potential (RP, indicated by circles and arrows). A negative (positive) RP corresponds to a cation (anion) selectivity. c Permeability ratios, P_K⁺/P_Cl⁻, calculated from corresponding reversal potentials using the GHK equation⁷⁸. Solid circles correspond to the individual data points. Data are means of 7 (black), 8 (red), and 4 (blue) independent experiments. d Representative Tse5-CT-induced noisy current trace was obtained in a 250/50 mM KCl gradient using the E. coli polar lipid extract to form the membrane. The applied voltage is shown at the bottom in light grey. Current records in (a) and (d) were digitally filtered with 500 Hz using a low-pass 8-pole Bessel filter for better visualisation.