Application of High-Resolution Single-Channel Recording to Functional Studies of Cystic Fibrosis Mutants

The patch-clamp technique is a powerful and versatile method to investigate the cystic fibrosis transmembrane conductance regulator (CFTR) Cl^– channel, its malfunction in disease and modulation by small molecules. Here, we discuss how the molecular behaviour of CFTR is investigated using high-resolution single-channel recording and kinetic analyses of channel gating. We review methods used to quantify how cystic fibrosis (CF) mutants perturb the biophysical properties and regulation of CFTR. By explaining the relationship between macroscopic and single-channel currents, we demonstrate how single-channel data provide molecular explanations for changes in CFTR-mediated transepithelial ion transport elicited by CF mutants.