Single channel recordings of α-hemolysin reconstituted in S-layer-supported lipid bilayers

Previous studies demonstrated that lipid membranes attached to a proteinaceous crystalline surface-layer (S-layer) revealed a prolonged lifetime and showed a reduced tendency to rupture in the presence of membrane active molecules. In addition, comparative studies on folded and S-layer-supported lipid membranes (SsLM) revealed an uniform capacitance of 0.64±0.04 μF/cm2 for both composite membranes. In the present study, the feasibility to reconstitute the channel-forming protein α-hemolysin (αHL) into SsLM at single channel resolution was investigated. Single αHL channels could be recorded and the intrinsic properties like unitary conductance, current–voltage characteristics, and closure was found to be similar at both membranes. Thus, the tightly attached S-layer allowed complete reconstitution of αHL channels in SsLM.