FIGURE 1.

Representative single-channel activity recorded from a lipid bilayer membrane after incorporation of material from the mitochondrial chloroform extract. (A) Recording solutions contained 150 mM KCl, 20 mM Tris-Hepes, pH = 7.4. Expanded sections of the records (boxed) show the highly characteristic, smaller conductance fluctuations from the maximal conductance level. (B) I/V relationship of the maximal conductance state of the channel. (C) Histogram of the distribution of the detection frequency plotted against maximal conductance, based on the analysis of 78 single-channel recordings in the presence of 150 mM KCl. Mean conductance (± SD) obtained from a Gaussian fit of the histogram was 540 ± 120 pS. Note that in some experiments included into the histogram, 1 mM of CaCl₂ was present in the recording solutions. Such experiments were included in the analysis after it was established that addition of 1 mM CaCl₂ did not cause any detectable change of the conductance.