Bioorganic Models for Protein Ion Channels.

Abstract

We have prepared seven variants of the peptide, H2N- (LeuSerSerLeuLeuSerLeu)3.CONH2 in which a residue in the central heptad has been replaced by Trp. Extensive fluorescence measurement indicate that the peptide binds to phospholipid (PL) vesicles (PL/peptide ratio 100:1, no transmembrane voltage) with its helical axis parallel to the surface of the membrane. Trp residues that replace Leu are efficiently quenched by phospholipids bearing a nitroxide at various positions along their fatty acid chains, while Trp residues that replace Ser are efficiently quenched by aqueous-phase quenchers. These findings indicate that the voltage-dependence of channel opening in planar bilayers involves a voltage-induced change in peptide orientation from a surface to a transbilayer configuration.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1991
Accession Number
ADA262767

Entities

People

  • William DeGrado

Tags

DTIC Thesaurus Topics

  • Amino Acids
  • Biotechnology
  • Carrier Proteins
  • Chemical Synthesis
  • Chemistry
  • Computer Graphics
  • Fatty Acids
  • Graphics
  • Membrane Lipids
  • Membranes
  • Orientation (Direction)
  • Proteins
  • Template Patterns
  • Universities

Readers

  • Materials Science and Engineering.
  • Molecular and Cellular Biochemistry