Open-state substructure of single chloride channels from Torpedo electroplax.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences

PubMedID: 6130538

Miller C. Open-state substructure of single chloride channels from Torpedo electroplax. Philos Trans R Soc Lond, B, Biol Sci. 1982;299(1097):401-11.
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.