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Published on: February 22, 2019
Structure and Dynamics of Macrophage Infectivity Potentiator Proteins from Pathogenic Bacteria and Protozoans Bound
Victor Hugo Pérez Carrillo1, Jacob J Whittaker2, Christoph Wiedemann1
1Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany.
Abstract:
Macrophage infectivity potentiator (MIP) proteins, found in pro- and eukaryotic pathogens, influence microbial virulence, host cell infection, pathogen replication, and dissemination. MIPs share an FKBP (FK506 binding protein)-like prolyl-cis/trans-isomerase domain, making them attractive targets for inhibitor development. We determined high-resolution crystal structures of Burkholderia pseudomallei and Trypanosoma cruzi MIPs in complex with fluorinated pipecolic acid inhibitors. The inhibitor binding profiles in solution were compared across B. pseudomallei, T. cruzi, and Legionella pneumophila MIPs using 1H, 15N, and 19F NMR spectroscopy. Demonstrating the versatility of fluorinated ligands for characterizing inhibitor complexes, 19F NMR spectroscopy identified differences in ligand binding dynamics across MIPs. EPR spectroscopy and SAXS further revealed inhibitor-induced global structural changes in homodimeric L. pneumophila MIP. This study demonstrates the importance of integrating diverse methods to probe protein dynamics and provides a foundation for optimizing MIP-targeted inhibitors in this structurally conserved yet dynamically variable protein family.
Insights
Macrophage infectivity potentiator (MIP) proteins are crucial for pathogen virulence. This study used diverse biophysical methods to characterize novel inhibitors, revealing insights into MIP dynamics for drug development.
Area of Science:
- Biochemistry
- Structural Biology
- Microbiology
Background:
- Macrophage infectivity potentiator (MIP) proteins are virulence factors in various pathogens.
- MIPs possess a conserved FKBP-like domain, making them targets for inhibitor design.
Purpose of the Study:
- To determine high-resolution structures of MIP-inhibitor complexes.
- To compare inhibitor binding dynamics across different MIPs using biophysical techniques.
- To investigate inhibitor-induced structural changes in MIPs.
Main Methods:
- X-ray crystallography for structural determination.
- Nuclear Magnetic Resonance (NMR) spectroscopy (¹H, ¹⁵N, ¹⁹F) for solution-state analysis.
- Electron Paramagnetic Resonance (EPR) spectroscopy and Small-Angle X-ray Scattering (SAXS) for probing structural dynamics.
Main Results:
- High-resolution crystal structures of Burkholderia pseudomallei and Trypanosoma cruzi MIPs with fluorinated pipecolic acid inhibitors were obtained.
- ¹⁹F NMR revealed distinct ligand binding dynamics across B. pseudomallei, T. cruzi, and Legionella pneumophila MIPs.
- EPR and SAXS demonstrated inhibitor-induced global structural alterations in L. pneumophila MIP.
Conclusions:
- Fluorinated ligands are versatile tools for characterizing inhibitor interactions with MIPs.
- Integrating diverse biophysical methods is essential for understanding protein dynamics.
- This research provides a basis for optimizing inhibitors targeting the conserved MIP protein family.
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