Single channel recordings of BpsOmp38 porin in artificial lipid membranes.

Typical ion current traces of single BpsOmp38 variant channels in a fully open state at a transmembrane potential of +100 mM, (B) Current-voltage relationship of BpsOmp38WT in comparison with its two mutants. The current through a single open BpsOmp38 channel was monitored in 1 M KCl, following discrete changes in the voltage across the phospholipid membrane, from −100 to +125 mV. The slopes of a linear fit yielded the single channel conductances of individual BpsOmp38 channels. Data points for BpsOmp38WT, BpsOmpY119A and BpsOmpY119F are plotted as circles, squares and triangles, respectively. Differences in the three data sets were evaluated using one-way ANOVA. Statistically significant difference (P<0.05) is shown with an asterisk (*).