title: Water structure in the Gramicidin A transmembrane channel.
abstract: The interaction energy and the structure of water molecules either inside the Gramicidin A transmembrane channel or at its two extremities is examined with the use of iso-energy maps and Monte Carlo simulations. The shape of the channel as experienced by water is analyzed in detail. Variations in the hydration structure due to the presence of a sodium ion placed at several positions along the channel are simulated, analyzed and discussed. Preliminary data on Li+ and K+ interacting with Gramicidin A and the system of water molecules are reported. The Gramicidin A atomic coordinates have been taken from Urry's recent papers (Urry, D.W. (1971) Proc. Natl. Acad. Sci. U.S.A. 68, 672-676 and Urry, D.W., Trapane, T.L. and Prasad, K.U. (1982) Int. J. Quant. Chem. Quant. Biol. Symp. 9, 31-40).
mesh_terms: D006096:Gramicidin; D007473:Ion Channels / Q000502:physiology*; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D013816:Thermodynamics; D014867:Water
chemical_list: D007473:Ion Channels; D014867:Water; D006096:Gramicidin