The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

Stanley J. Opella - One of the best experts on this subject based on the ideXlab platform.

Michael Zasloff - One of the best experts on this subject based on the ideXlab platform.

Burkhard Bechinger - One of the best experts on this subject based on the ideXlab platform.

  • Structure and dynamics of the Antibiotic Peptide PGLa in membranes by solution and solid-state nuclear magnetic resonance spectroscopy.
    Biophysical Journal, 1998
    Co-Authors: Burkhard Bechinger, Michael Zasloff, Stanley J. Opella
    Abstract:

    PGLa, a 21-residue member of the magainin family of Antibiotic Peptides, is shown to be helical between residues 6 and 21 when associated with detergent micelles by multidimensional solution nuclear magnetic resonance (NMR) spectroscopy. Solid-state NMR experiments on specifically 15N-labeled Peptides in oriented phospholipid bilayer samples show that the helix axis is parallel to the plane of the bilayers. 15N solid-state NMR powder pattern line shapes obtained on unoriented samples demonstrate that the amino-terminal residues are highly mobile and that the fluctuations of backbone sites decrease from Ala6 toward the carboxy terminus. The powder pattern observed for 15N-labeled Ala20 is essentially that expected for a rigid site. These findings are similar to those for the 23-residue magainin2 Peptide in membrane environments.

  • structure and orientation of the Antibiotic Peptide magainin in membranes by solid state nuclear magnetic resonance spectroscopy
    Protein Science, 1993
    Co-Authors: Burkhard Bechinger, Michael Zasloff, Stanley J. Opella
    Abstract:

    Magainin 2 is a 23-residue Peptide that forms an amphipathic alpha-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 alpha-helix, immobilized by its interactions with the phospholipids, and oriented parallel to the membrane surface.

Jennifer Gesell - One of the best experts on this subject based on the ideXlab platform.

Kazuyoshi Ueda - One of the best experts on this subject based on the ideXlab platform.

  • structure and orientation of Antibiotic Peptide alamethicin in phospholipid bilayers as revealed by chemical shift oscillation analysis of solid state nuclear magnetic resonance and molecular dynamics simulation
    Biochimica et Biophysica Acta, 2015
    Co-Authors: Takashi Nagao, Daisuke Mishima, Namsrai Javkhlantugs, Jun Wang, Daisuke Ishioka, Kiyonobu Yokota, Kazushi Norisada, Izuru Kawamura, Kazuyoshi Ueda
    Abstract:

    Abstract The structure, topology and orientation of membrane-bound Antibiotic alamethicin were studied using solid state nuclear magnetic resonance (NMR) spectroscopy. 13 C chemical shift interaction was observed in [1- 13 C]-labeled alamethicin. The isotropic chemical shift values indicated that alamethicin forms a helical structure in the entire region. The chemical shift anisotropy of the carbonyl carbon of isotopically labeled alamethicin was also analyzed with the assumption that alamethicin molecules rotate rapidly about the bilayer normal of the phospholipid bilayers. It is considered that the adjacent Peptide planes form an angle of 100° or 120° when it forms α-helix or 3 10 -helix, respectively. These properties lead to an oscillation of the chemical shift anisotropy with respect to the phase angle of the Peptide plane. Anisotropic data were acquired for the 4 and 7 sites of the N- and C-termini, respectively. The results indicated that the helical axes for the N- and C-termini were tilted 17° and 32° to the bilayer normal, respectively. The chemical shift oscillation curves indicate that the N- and C-termini form the α-helix and 3 10 -helix, respectively. The C-terminal 3 10 -helix of alamethicin in the bilayer was experimentally observed and the unique bending structure of alamethicin was further confirmed by measuring the internuclear distances of [1- 13 C] and [ 15 N] doubly-labeled alamethicin. Molecular dynamics simulation of alamethicin embedded into dimyristoyl phophatidylcholine (DMPC) bilayers indicates that the helical axes for α-helical N- and 3 10 -helical C-termini are tilted 12° and 32° to the bilayer normal, respectively, which is in good agreement with the solid state NMR results.