Plant polyphenols inhibit functional amyloid and biofilm formation in Pseudomonas strains by directing monomers to off-pathway oligomers

Zahra Najarzadeh, Hossein Mohammad-Beigi, Jannik Nedergaard Pedersen, Gunna Christiansen, Thorbjørn Vincent Sønderby, Seyed Abbas Shojaosadati*, Dina Morshedi, Kristian Strømgaard, Georg Meisl, Duncan Sutherland, Jan Skov Pedersen, Daniel E. Otzen

*Corresponding author for this work
    8 Citations (Scopus)
    2 Downloads (Pure)

    Abstract

    Self-assembly of proteins to β-sheet rich amyloid fibrils is commonly observed in various neurodegenerative diseases. However, amyloid also occurs in the extracellular matrix of bacterial biofilm, which protects bacteria from environmental stress and antibiotics. Many Pseudomonas strains produce functional amyloid where the main component is the highly fibrillation-prone protein FapC. FapC fibrillation may be inhibited by small molecules such as plant polyphenols, which are already known to inhibit formation of pathogenic amyloid, but the mechanism and biological impact of inhibition is unclear. Here, we elucidate how polyphenols modify the self-assembly of functional amyloid, with particular focus on epigallocatechin gallate (EGCG), penta-O-galloyl-β-d-glucose (PGG), baicalein, oleuropein, and procyanidin B2. We find EGCG and PGG to be the best inhibitors. These compounds inhibit amyloid formation by redirecting the aggregation of FapC monomers into oligomeric species, which according to small-angle X-ray scattering (SAXS) measurements organize into core-shell complexes of short axis diameters 25–26 nm consisting of ~7 monomers. Using peptide arrays, we identify EGCG-binding sites in FapC’s linker regions, C and N-terminal parts, and high amyloidogenic sequences located in the R2 and R3 repeats. We correlate our biophysical observations to biological impact by demonstrating that the extent of amyloid inhibition by the different inhibitors correlated with their ability to reduce biofilm, highlighting the potential of anti-amyloid polyphenols as therapeutic agents against biofilm infections.

    Original languageEnglish
    Article number659
    JournalBiomolecules
    Volume9
    Issue number11
    Number of pages21
    ISSN2218-273X
    DOIs
    Publication statusPublished - 2019

    Keywords

    • Aggregation inhibitor
    • Bacterial amyloid
    • Extracellular matrix
    • FapC protein
    • Peptide array

    Fingerprint

    Dive into the research topics of 'Plant polyphenols inhibit functional amyloid and biofilm formation in Pseudomonas strains by directing monomers to off-pathway oligomers'. Together they form a unique fingerprint.

    Cite this