title: The pore dimensions of gramicidin A.
abstract: The ion channel forming peptide gramicidin A adopts a number of distinct conformations in different environments. We have developed a new method to analyze and display the pore dimensions of ion channels. The procedure is applied to two x-ray crystal structures of gramicidin that adopt distinct antiparallel double helical dimer conformations and a nuclear magnetic resonance (NMR) structure for the beta6.3 NH2-terminal to NH2-terminal dimer. The results are discussed with reference to ion conductance properties and dependence of pore dimensions on the environment.
authors.affiliation: Department of Crystallography, Birkbeck College, University of London, England.
authors.forename: O S
authors.initials: OS
authors.lastname: Smart
authors.forename: J M
authors.initials: JM
authors.lastname: Goodfellow
authors.forename: B A
authors.initials: BA
authors.lastname: Wallace
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray / Q000379:methods; D006096:Gramicidin / Q000737:chemistry*; D007473:Ion Channels; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008433:Mathematics; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary
chemical_list: D007473:Ion Channels; D006096:Gramicidin