Lactoferricins impair the cytosolic membrane of Escherichia coli within a few seconds and accumulate inside the cell

  1. Enrico Federico Semeraro  Is a corresponding author
  2. Lisa Marx
  3. Johannes Mandl
  4. Ilse Letofsky-Papst
  5. Claudia Mayrhofer
  6. Moritz PK Frewein
  7. Haden L. Scott
  8. Sylvain Prévost
  9. Helmut Bergler
  10. Karl Lohner
  11. Georg Pabst  Is a corresponding author
  1. University of Graz, Austria
  2. Graz University of Technology, Austria
  3. Institut Laue-Langevin, France
  4. University of Tennessee at Knoxville, United States

Abstract

We report the real-time response of E. coli to lactoferricin-derived antimicrobial peptides (AMPs) on length-scales bridging microscopic cell-sizes to nanoscopic lipid packing using millisecond time-resolved synchrotron small-angle X-ray scattering. Coupling a multi-scale scattering data analysis to biophysical assays for peptide partitioning revealed that the AMPs rapidly permeabilize the cytosolic membrane within less than three seconds-much faster than previously considered. Final intracellular AMP concentrations of ~ 80 to 100 mM suggest an efficient obstruction of physiologically important processes as primary cause for bacterial killing. On the other hand, damage of the cell envelope and leakage occurred also at sublethal peptide concentrations, thus emerging as a collateral effect of AMP activity that does not kill the bacteria. This implies that the impairment of the membrane barrier is a necessary but not sufficient condition for microbial killing by lactoferricins. The most efficient AMP studied exceeds others in both speed of permeabilizing membranes and lowest intracellular peptide concentration needed to inhibit bacterial growth.

Data availability

The current manuscript is a biophysical study, reporting data analysis of scattering data and peptide partitioning assays in vitro. All relevant data are included and plotted in the manuscript.In addition SANS raw data are accessible (DOI in Methods and Materials section).The modelling code for data analysis consists of a standard chi-squared minimization algorithm. The implemented analytical functions are described in the Methods and Materials section of the manuscript.

Article and author information

Author details

  1. Enrico Federico Semeraro

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    For correspondence
    enrico.semeraro@uni-graz.at
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6096-1108
  2. Lisa Marx

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
  3. Johannes Mandl

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
  4. Ilse Letofsky-Papst

    Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
  5. Claudia Mayrhofer

    Center for Electron Microscopy, Graz University of Technology, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
  6. Moritz PK Frewein

    Institut Laue-Langevin, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0329-5305
  7. Haden L. Scott

    Center for Environmental Biotechnology, University of Tennessee at Knoxville, Knoxville, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Sylvain Prévost

    Institut Laue-Langevin, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6008-1987
  9. Helmut Bergler

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7724-309X
  10. Karl Lohner

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    Competing interests
    The authors declare that no competing interests exist.
  11. Georg Pabst

    Institute of Molecular Biosciences, University of Graz, Graz, Austria
    For correspondence
    georg.pabst@uni-graz.at
    Competing interests
    The authors declare that no competing interests exist.

Funding

Austrian Science Fund (P 30921)

  • Karl Lohner

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Patricia Bassereau, Institut Curie, France

Publication history

  1. Received: August 6, 2021
  2. Accepted: June 6, 2022
  3. Accepted Manuscript published: June 7, 2022 (version 1)

Copyright

© 2022, Semeraro et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Enrico Federico Semeraro
  2. Lisa Marx
  3. Johannes Mandl
  4. Ilse Letofsky-Papst
  5. Claudia Mayrhofer
  6. Moritz PK Frewein
  7. Haden L. Scott
  8. Sylvain Prévost
  9. Helmut Bergler
  10. Karl Lohner
  11. Georg Pabst
(2022)
Lactoferricins impair the cytosolic membrane of Escherichia coli within a few seconds and accumulate inside the cell
eLife 11:e72850.
https://doi.org/10.7554/eLife.72850

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