A voltage-gated ion channel model inferred from the crystal structure of alamethicin at 1.5-A resolution

Nature. 1982 Nov 25;300(5890):325-30. doi: 10.1038/300325a0.

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alamethicin*
  • Amino Acid Sequence
  • Anti-Bacterial Agents*
  • Crystallography
  • Hydrogen Bonding
  • Ion Channels*
  • Macromolecular Substances
  • Membrane Proteins*
  • Models, Molecular*
  • Models, Structural*
  • Structure-Activity Relationship

Substances

  • Anti-Bacterial Agents
  • Ion Channels
  • Macromolecular Substances
  • Membrane Proteins
  • Alamethicin