INSIGHT INTO THE STRUCTURE-FUNCTION RELATION OF CHLORIDE CHANNELS

Chloride channels are highly selective transport proteins ubiquitously expressed in eukaryotic cells. Biophysical methods allow discriminati on between several different types of chloride channels with respect t o their gating properties, single-channel conductances and main regula tory mechanisms. The common feature is, however, their high selectivit y for chloride ions. Beside the cystic fibrosis transmembrane conducta nce regulator and ligand-gated channels, five different protein famili es involved in chloride transport have so far been described in terms of their molecular structure. All of them show distinct structural cha racteristics and, according to mutation experiments, are believed to b e genuine channels.