title: Structural studies of synthetic peptides dissected from the voltage-gated sodium channel.
abstract: Peptides representing transmembrane regions of the alpha-subunit of the voltage-gated sodium channel were synthesised and their structures analysed, using 1H NMR and CD, in trifluoroethanol and in dodecylphosphocholine micelles. Sequence analysis suggests that the channel has six regions, S1 to S6, predicted to span the membrane in four homologous domains, designated, I, II, III and IV. Presented here are studies of representatives examples of possible single spanning segments (IS2, IS4, IVS4) and a double spanning segment, IS34, composed of segments IS3 and IS4. In addition, we investigated ISlink56, the putative linker region between segments IS5 and IS6. All of the peptides were found to have predominantly alpha-helical structures in both solvent systems. There was some evidence for bending of the longer helices but there was no discernible evidence for well-defined tertiary structure.
authors.affiliation: Oxford Centre for Molecular Science, University of Oxford, UK.
authors.forename: D G
authors.initials: DG
authors.lastname: Doak
authors.forename: D
authors.initials: D
authors.lastname: Mulvey
authors.forename: K
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: J
authors.initials: J
authors.lastname: Villalain
authors.forename: I D
authors.initials: ID
authors.lastname: Campbell
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003198:Computer Simulation; D015640:Ion Channel Gating; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D010767:Phosphorylcholine / Q000031:analogs & derivatives; D017433:Protein Structure, Secondary; D015222:Sodium Channels / Q000737:chemistry*
chemical_list: D008823:Micelles; D010446:Peptide Fragments; D015222:Sodium Channels; D010767:Phosphorylcholine; C028810:dodecylphosphocholine