Methods for Processing and Analyzing Single-Channel Data

Analysis of data from single-channel studies can provide us with insights into the detailed physicochemical features of channel proteins, such as ion permeation rate, ion selectivity, and gating. However, single-channel analysis, particularly gating analysis, is sometimes time-consuming, unconvincing, and unproductive. Notwithstanding, if it is combined with structure information and site-directed mutagenesis of channel proteins, it can prove to be a powerful tool that moves us toward the ultimate understanding of structure–function of channel proteins. This chapter is composed of roughly two parts. The first part describes the technical aspect how to set up the hardware for correct acquisition of the tiny, long-lasting single-channel currents against background noises and drifts. The second part deals with the statistical estimation of the current amplitude and dwell times of the open and closed states and how to fit the estimated data to an appropriate reaction model. Each section is described in a step-by-step fashion so even beginners can understand and experience the course of single-channel study, from data acquisition to model fitting.