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Updated: May 30, 2026

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages
08:34

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages

Published on: February 22, 2017

Collagen IV-derived peptide binds hydrophobic cavity of Legionella pneumophila Mip and interferes with bacterial

Can Ünal1, Kai F Schwedhelm, Alexandra Thiele

  • 1Institut für Mikrobiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany.

Cellular Microbiology
|July 29, 2011
PubMed

Insights

The Legionella macrophage infectivity potentiator (Mip) protein binds collagen IV, aiding bacterial spread. A collagen-derived peptide (P290) blocks this interaction, inhibiting Legionella pneumophila lung cell transmigration.

Area of Science:

  • Microbiology
  • Structural Biology
  • Biochemistry

Background:

  • Legionella virulence factor Mip (macrophage infectivity potentiator) facilitates bacterial dissemination in lung tissue.
  • Mip is an FK506-binding protein (FKBP) that specifically binds collagen IV.

Purpose of the Study:

  • To investigate the interaction between Mip and collagen IV.
  • To identify Mip-binding sequences in collagen IV and evaluate their potential as inhibitors of Legionella transmigration.
  • To develop optimized peptide variants targeting Mip for potential therapeutic applications.

Main Methods:

  • Identification of a Mip-binding sequence in human collagen IV α1 (NC1 domain).
  • Co-precipitation and competitive inhibition assays to confirm Mip-P290 interaction.
  • Inhibition of Legionella pneumophila transmigration across lung epithelial cells.
  • NMR, docking studies, molecular dynamics (MD) simulations to model Mip-P290 interaction.
  • Structural analysis of Mip(77-213)-P290 complex and comparison with human FKBP12.

Main Results:

  • A collagen IV-derived peptide (P290) was identified that binds Mip and inhibits Mip-collagen IV interaction.
  • P290 significantly reduced Legionella pneumophila transmigration across lung epithelial cells.
  • NMR and docking studies elucidated the Mip-P290 binding mode, identifying key amino acids (D142, Y185) in Mip's hydrophobic cavity.
  • Optimized P290 variants with enhanced binding specificity for Mip were proposed.

Conclusions:

  • The Mip-collagen IV interaction is a key target for inhibiting Legionella dissemination.
  • The P290 peptide is a potent inhibitor of Legionella transmigration.
  • Structural insights enable the design of novel Mip-targeting inhibitors for therapeutic development.

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