title: Hydrogen bonding involving the ornithine side chain of gramicidin S.
abstract: The side-chain and backbone hydrogen bonding pattern is identical in the computed minimum-energy conformation of gramicidin S and in the recently determined X-ray crystallographic structure of the hydrated urea complex of this peptide. The identity of hydrogen bonding (except where it is affected by intermolecular interactions in the crystal) and the close agreement of the overall backbone conformation attest to the validity of the conformational energy computations used to determine the unique low-energy conformation of this cyclic peptide.
mesh_terms: D006096:Gramicidin; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009952:Ornithine; D011487:Protein Conformation; D014508:Urea; D014961:X-Ray Diffraction
chemical_list: D006096:Gramicidin; D014508:Urea; D009952:Ornithine