A Voltage-Gated Ion Channel Model Inferred from the Crystal Structure of Alamethicin at 1.5-A Resolution.
Fox Jr, R.O., Richards, F.M.(1982) Nature 300: 325
- PubMed: 6292726 
- DOI: https://doi.org/10.1038/300325a0
- Primary Citation of Related Structures:  
1AMT - PubMed Abstract: 
The crystal structure of alamethicin in nonaqueous solvent has been determined, and refined at 1.5-A resolution. The molecular conformation of the three crystallographically independent molecules is largely alpha-helical with a bend in the helix axis at an internal proline residue. The helix structure is highly amphipathic as most of the solvent-accessible polar atoms lie on a narrow strip of surface parallel to the helix axis. Molecular models for the voltage-gated ion channel, with n-fold symmetry and based on the molecular conformations observed in the crystal, are characterized by strong surface complementarity, a hydrophilic interior and a hydrophobic exterior. The channel structures are stabilized by a hydrated annulus of hydrogen-bonded glutamine residues which produce the greatest restriction in the channel diameter.