Two-Dimensional Probability Density Analysis of Single Channel Currents fromReconstituted Acetylcholine Receptors and Sodium Channels

摘要

Two-dimensional probability density analysis of single channel current recordingswas applied to two purified channel proteins reconstituted in planar lipid bilayers: Torpedo acetylcholine receptors and voltage-sensitive sodium channels from rat brain. The information contained in the dynamic history of the gating process, i.e., the time sequence of opening and closing events was extracted from two-dimensional distributions of transitions between identifiable states. This approach allows one to identify kinetic models consistent with the observables. Gating of acetylcholine receptors expresses memory of the transition history: the receptor has two channel open (0) states; the residence time in each of them strongly depends on both the preceding open time and the intervening closed interval.