Abstract
Advances in computer simulation techniques have made it possible to model complex macromolecular assemblies. It is now reasonable to believe that these methods will become useful tools for understanding the properties and behavior of transmembrane ion channels, the physiological functional units facilitating ion transport across cell membranes. This article is a progress report on modeling the behavior of the simplest such system—gramicidin A and its analogues. Theory can account for many of the qualitative features of alkali cation-channel interaction. Quantitative predictions still leave much to be desired, suggesting a need for more accurate treatment of the long-range interactions between ions and water and ions and membranes.