title: Functional amyloids keep quorum-sensing molecules in check.
abstract: The mechanism by which extracellular metabolites, including redox mediators and quorum-sensing signaling molecules, traffic through the extracellular matrix of biofilms is poorly explored. We hypothesize that functional amyloids, abundant in natural biofilms and possessing hydrophobic domains, retain these metabolites. Using surface plasmon resonance, we demonstrate that the quorum-sensing (QS) molecules, 2-heptyl-3-hydroxy-4(1H)-quinolone and N-(3-oxododecanoyl)-l-homoserine lactone, and the redox mediator pyocyanin bind with transient affinity to functional amyloids from Pseudomonas (Fap). Their high hydrophobicity predisposes them to signal-amyloid interactions, but specific interactions also play a role. Transient interactions allow for rapid association and dissociation kinetics, which make the QS molecules bioavailable and at the same time secure within the extracellular matrix as a consequence of serial bindings. Retention of the QS molecules was confirmed using Pseudomonas aeruginosa PAO1-based 2-heptyl-3-hydroxy-4(1H)-quinolone and N-(3-oxododecanoyl)-l-homoserine lactone reporter assays, showing that Fap fibrils pretreated with the QS molecules activate the reporters even after sequential washes. Pyocyanin retention was validated by electrochemical analysis of pyocyanin-pretreated Fap fibrils subjected to the same washing process. Results suggest that QS molecule-amyloid interactions are probably important in the turbulent environments commonly encountered in natural habitats.
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and twseviour@ntu.edu.sg.
authors.forename: Thomas
authors.initials: T
authors.lastname: Seviour
authors.affiliation: the Center for Microbial Communities, Aalborg University, 9220 Aalborg East, Denmark.
authors.forename: Susan Hove
authors.initials: SH
authors.lastname: Hansen
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and.
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.affiliation: the School of Biological Sciences (SBS), Nanyang Technological University, Singapore 637551, Singapore.
authors.forename: Yin Hoe
authors.initials: YH
authors.lastname: Yau
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and the School of Materials Science and Engineering (MSE), Nanyang Technological University, Singapore 639798.
authors.forename: Victor Bochuan
authors.initials: VB
authors.lastname: Wang
authors.affiliation: the Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Center for Insoluble Protein Structures (inSPIN), and.
authors.forename: Marcel R
authors.initials: MR
authors.lastname: Stenvang
authors.affiliation: the Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Gunna
authors.initials: G
authors.lastname: Christiansen
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and.
authors.forename: Enrico
authors.initials: E
authors.lastname: Marsili
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and the Department of International Health, Immunology and Microbiology, University of Copenhagen, 1165 Copenhagen, Denmark, and.
authors.forename: Michael
authors.initials: M
authors.lastname: Givskov
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and.
authors.forename: Yicai
authors.initials: Y
authors.lastname: Chen
authors.affiliation: the Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Center for Insoluble Protein Structures (inSPIN), and.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Otzen
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and the Center for Microbial Communities, Aalborg University, 9220 Aalborg East, Denmark.
authors.forename: Per Halkjær
authors.initials: PH
authors.lastname: Nielsen
authors.affiliation: the School of Biological Sciences (SBS), Nanyang Technological University, Singapore 637551, Singapore.
authors.forename: Susana
authors.initials: S
authors.lastname: Geifman-Shochat
authors.affiliation: From the Singapore Centre on Environmental Life Sciences Engineering (SCELSE) and the Centre for Marine Bio-innovation and School of Biotechnology and Biomolecular Science, University of New South Wales, Mosman, New South Wales 2088, Australia.
authors.forename: Staffan
authors.initials: S
authors.lastname: Kjelleberg
authors.affiliation: the Center for Microbial Communities, Aalborg University, 9220 Aalborg East, Denmark.
authors.forename: Morten S
authors.initials: MS
authors.lastname: Dueholm
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000737:chemistry; D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism; D018441:Biofilms; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D017510:Protein Folding; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000235:genetics; D053038:Quorum Sensing / Q000235:genetics*
chemical_list: D000682:Amyloid; C088386:homoserine lactone; D015107:4-Butyrolactone
keywords: Amyloid; Biofilm; Functional Amyloid; Pseudomonas; Pseudomonas aeruginosa (P. aeruginosa); Quorum Sensing