Structure and orientation of the antibiotic peptide magainin in membranes by solid-state nuclear magnetic resonance spectroscopy

Authors

  • Burkhard Bechinger,

    1. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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  • Michael Zasloff,

    1. Departments of Pediatrics and Genetics, Division of Human Genetics and Molecular Biology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
    Current affiliation:
    1. Magainin Pharmaceuticals Inc., 5110 Campus Drive, Plymouth Meeting, Pennsylvania 19462
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  • Stanley J. Opella

    Corresponding author
    1. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
    • Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Abstract

Magainin 2 is a 23-residue peptide that forms an amphipathic α-helix in membrane environments. It functions as an antibiotic and is known to disrupt the electrochemical gradients across the cell membranes of many bacteria, fungi, and some tumor cells, although it does not lyse red blood cells. One- and two-dimensional solid-state 15N NMR spectra of specifically 15N-labeled magainin 2 in oriented bilayer samples show that the secondary structure of essentially the entire peptide is α-helix, immobilized by its interactions with the phospholipids, and oriented parallel to the membrane surface.

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