The structure of the voltage-sensitive sodium channel: Inferences derived from computer-aided analysis of the Electrophorus electricus channel primary structure

• Published in: FEBS letters 1985-12, Vol.193 (2), p.125-134
• Main Authors: Greenblatt, R.E., Blatt, Y., Montai, M.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amphipathic helix; Animals; Biological and medical sciences; Cell physiology; Chemical Phenomena; Chemistry; Chemistry, Physical; Computer modelling; Computers; electric organs; Electrochemistry; Electrophorus; Electrophorus electricus; Fundamental and applied biological sciences. Psychology; Ion Channels; Membrane and intracellular transports; Membrane protein; Membrane Proteins; Models, Molecular; Molecular and cellular biology; Protein Conformation; secondary structure; Secondary structure prediction; sodium; Sodium channel
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(85)80136-8

A variety of computer-aided analyses was applied to the recently derived amino acid sequence of the Electrophorus electricus sodium channel protein in order to extract structural information such as hydrophobicity, periodicity, and secondary structure predictors. We propose a schematic model for the arrangement and folding of the polypeptide chain within the bilayer. The model consists of 4 homologous regions, each containing 8 membrane-spanning (probably α-helical) structures. Several of these structures are amphipathic with a repeat of 3.5 residues, 4 of which (one from each homologous region) are postulated to form a negatively charged channel lining. Gating currents are proposed to arise from voltage-dependent separation of multiple ion pairs buried within the hydrophobic, intramembranous protein interior.