Figure 2.

Both d- and l-Aβ_1–42 isomers form channel-like pores in painted bilayer membranes and are inhibited by addition of Zn²⁺. (A) Representative current vs time trace of d-Aβ_1–42 isomer activity. (B) Representative current vs time trace of l-Aβ_1–42 isomer activity. (C) Inhibition of d-Aβ_1–42 activity by addition of Zn²⁺. (D) Inhibition of l-Aβ_1–42 activity by Zn²⁺ addition. Time of Zn²⁺ addition (2 mM) is marked by tilted arrows on panels C and D. In panels C and D, the increased noise between the two vertical arrows shows when stirring begins and ends. The C letters on top of vertical lines show monitoring of bilayer capacitance during these recordings. Changes in the applied voltage are indicated by the voltage–time plot under the current traces. Final Aβ_1–42 peptide concentrations were 9 (A), 8.5 (B), 5 (C), and 5 μM (D). Lipids and electrolyte solution are the same as in Figure 1; either Aβ_1–42 peptide was added to the cis (hot wire) side. All traces were subjected to low-pass Gaussian filtering set at 50 Hz.