Figure 5.

Mean blockade standard deviation depends on the estimated peptide charge, which suggests structural changes can give rise to a reduction in current noise. The mean standard deviation of A1 (blue circles) and NT (purple squares) scales with the electrolyte pH in a manner expected from the corresponding pK values of each peptide. Decreasing the pH leads to a structural change in the A1 peptide which leads to a corresponding reduction in the noise within current blockades. No such behavior is seen or expected for the NT. The solid lines are least-squares linear fits to the data. All data was taken under a 70 mV applied transmembrane potential in 3 M KCl with a gold cluster present in the pore.