Figure 4.

The Bcl-2 (Δh5, 6) mutant fails to form channels. Membrane currents from lipid bilayers containing His₆-Bcl-2 (ΔTM) (A) and the deletion mutant lacking helices 5 and 6 (B). The final protein concentrations were 50 μg/ml. Currents recorded at 100 mV in symmetric 0.5 M KCl, 1 mM CaCl₂, 5 mM Hepes, pH 7.4. Note the occurrence of stray, erratic fluctuations in membrane current produced by the deletion mutant contrasted with the square events produced by the wild-type Bcl-2. Data representative of seven experiments.