FIG. 4.

Black lipid bilayer analysis. Single-channel conductance measurements were done after addition of first the BrkA N-terminal protein (DO218) and then the BrkA C-terminal protein (RF1065). Protein was added to a 1 M KCl solution bathing a membrane of 1.5% oxidized cholesterol in n-decane. There was an applied voltage of 50 mV. Protein from DO218 was purified in a way similar to that used for the protein from RF1065. The N-terminal protein was diluted in 0.1% Triton X-100–10 mM Tris (pH 8.0) before addition.