Open-state substructure of single chloride channels from Torpedo electroplax.
Chloride channels from Torpedo californica electroplax were inserted into planar phospholipid membranes, and single-channel currents were studied at high time-resolution. The open channel fluctuates rapidly between three substates, with conductances of 18.5, 9.4 and 0 pS in 150 mM Cl-. Under various ionic conditions the three substates are always equally spaced in conductance; at various voltages leading to different probabilities of observing the three substates, the substate frequencies are always binomially distributed. The conclusion emerges that the conducting of unit of Cl- channel is composed of two identical Cl- diffusion pathways, each with a voltage-dependent gate.
D000818:Animals; D002712:Chlorides / Q000502:physiology*; D004553:Electric Conductivity; D004557:Electric Organ / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D014101:Torpedo
D002712:Chlorides; D007473:Ion Channels