The features of the spatial structure of the gramicidine A-cesium complex

Earlier obtained two-dimensional 1H-NMR spectroscopy data were used to analyze the spatial structure and conformational mobility of the double right increases decreases pi pi 7.2 LD helix of the complex formed by gramicidine A and Cs+ ions in an organic solvent (a chloroform-methanol mixture). Analysis of the experimental data permitted the determination of a set of conformations for each of the high-mobility residue side chains in the solution. The energy refinement of the most probable conformation of the double right increases decreases pi pi 7.2 LD helix was made and conformational rearrangements of the tryptophan residue side chain were studied in detail.