Minimum structural requirement for an inhalational anesthetic binding site on a protein target

Biochim Biophys Acta. 1996 May 21;1290(1):63-8. doi: 10.1016/0304-4165(95)00187-5.


The present study makes use of direct photoaffinity labeling and fluorescence and circular dichroism spectroscopy to examine the interaction of the inhalational anesthetic halothane with the uncharged alpha-helical form of poly(L-lysine) over a range of chain lengths. Halothane bound specifically to long chain homopolymers (190 to 1060 residues), reaching a stable stoichiometry of 1 halothane to 160 lysine residues in polymers longer than 300 residues. Halothane bound only non-specifically to an alpha-helical 30 residue polymer and to all of the polymers in their charged, random coil form. The data suggest that halothane binding is a function of supersecondary structure whereby intramolecular helix-helix clusters form in the longer polymers, resulting in the creation of confined hydrophobic domains. Circular dichroism spectroscopy cannot demonstrate changes in poly(L-lysine) secondary structure at any chain length with up to 12 mM halothane, suggesting that extensive hydrogen bond disruption by the anesthetic does not occur.

Publication types

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

MeSH terms

  • Affinity Labels
  • Anesthetics, Inhalation / chemistry
  • Anesthetics, Inhalation / metabolism*
  • Anilino Naphthalenesulfonates
  • Binding Sites
  • Circular Dichroism
  • Fluorescent Dyes
  • Protein Binding
  • Protein Structure, Secondary
  • Spectrometry, Fluorescence


  • Affinity Labels
  • Anesthetics, Inhalation
  • Anilino Naphthalenesulfonates
  • Fluorescent Dyes
  • 1-anilino-8-naphthalenesulfonate