The Conformation of Acetylcholine in its Receptor-Bound State

It is unlikely that structures determined by NMR spectroscopy will be of as high resolution as those determined by x-ray crystallography. However, two-dimensional proton NMR nuclear Overhauser enhancements (2D- NOE) provide otherwise unavailable distance information for molecules that are difficult to crystallize. One such example is acetylcholine in its receptor- bound state, for which we have used 2D-NOE measurements to determine its bound state conformation.