Toward an understanding of structure and function of ion channels

The second half of the 1980s is certain to be considered a turning point in the study of ion channels. Within the last few years, monumental advances in the application of molecular biology, single-channel recording, and direct molecular characterization have been brought to bear on the problem of relating the molecular structure of the ion channel proteins to their function in the cell membrane. Structure-function relationships can now be studied at a level of detail that was unimagined a decade ago. Recently, advances made with the techniques of molecular biology appear to have dominated the literature in this field; however, innovative strategies of structural characterization and electrical measurements of functioning channels in native and artificial membranes continue to break new ground. This paper is a selective review of current progress in understanding structure-function relationships in ion channels. The relative usefulness of determining amino acid sequences of channel proteins together with the resulting deductions about 3-dimensional structure and function will be evaluated with respect to the potential importance of studying the channel molecules more directly by biochemical, immunological, and electrophysiological methods. A full understanding of the details of channel structure and its relationship to function may be realized in the near future as a result of the interdisciplinary application of biophysical, biochemical, and molecular biological techniques.