Fig. 6.

Metal bridges stabilize open states. (A) Representative outside-out single-channel recordings for the C-C-C construct. (Left) Thirty seconds of continuous recording in the presence of 0.3 µM ATP. (Right) Thirty seconds of continuous recording from the same patch after switching to a solution containing 0.3 µM ATP and 2 µM Cd²⁺. The dotted line is placed at −3 pA as a visual aid. (B) Expanded traces of single bursts of channel activity in ATP alone (Left) and in ATP plus Cd²⁺ (Right), demonstrating subconductance states. (C) All-points histograms from three patches for ATP alone (Left) and ATP plus Cd²⁺ (Right). In each case, the sum of three Gaussian distributions, corresponding to one closed-state level (red curves) and two open-state levels (green curves) were fit to the data. When the three patches were analyzed separately, the Gaussian distributions for the open levels had amplitudes of −1.1 ± 0.3 pA and −3.1 ± 0.1 pA for ATP alone and −3.4 ± 0.7 pA and −6.3 ± 0.4 pA in the presence of Cd²⁺.