Surface effects on functional amyloid formation
(2024) In Nanoscale 16(34). p.16172-16182- Abstract
Functional amyloids formed by the protein FapC in Pseudomonas bacteria are key structural components of Pseudomonas biofilms, which mediate chronic infections and also contribute to antimicrobial resistance. Here, we combine kinetic experiments with mechanistic modelling to probe the role of surfaces in FapC functional amyloid formation. We find that nucleation of new fibrils is predominantly heterogeneous in vitro, being catalysed by reaction vessel walls but not by the air/water interface. Removal of such interfaces by using microdroplets greatly slows heterogeneous nucleation and reveals a hitherto undetected fibril surface-catalysed “secondary nucleation” reaction step. We tune the degree of catalysis by varying the interface... (More)
Functional amyloids formed by the protein FapC in Pseudomonas bacteria are key structural components of Pseudomonas biofilms, which mediate chronic infections and also contribute to antimicrobial resistance. Here, we combine kinetic experiments with mechanistic modelling to probe the role of surfaces in FapC functional amyloid formation. We find that nucleation of new fibrils is predominantly heterogeneous in vitro, being catalysed by reaction vessel walls but not by the air/water interface. Removal of such interfaces by using microdroplets greatly slows heterogeneous nucleation and reveals a hitherto undetected fibril surface-catalysed “secondary nucleation” reaction step. We tune the degree of catalysis by varying the interface chemistry of the reaction vessel and by adding nanoparticles with tailored surface properties that catalyse fibril nucleation. In so doing, we discover that the rate of nucleation is controlled predominantly by the strength with which FapC binds to the catalytic sites on the interface, and by its surface area. Surprisingly, neither primary nucleation rate nor catalytic site binding strength appear closely correlated to the charge and hydrophilicity of the interface. This indicates the importance of considering experimental design in terms of surface chemistry of the reaction container while also highlighting the notion that fibril nucleation during protein aggregation is a heterogeneous process.
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- author
- Dear, Alexander J. LU ; Meisl, Georg ; Taylor, Christopher G. ; Palmiero, Umberto Capasso ; Stubbe, Susanne Nordby ; Liu, Qian ; Arosio, Paolo ; Linse, Sara LU ; Knowles, Tuomas P.J. and Andreasen, Maria
- organization
- publishing date
- 2024-08
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nanoscale
- volume
- 16
- issue
- 34
- pages
- 11 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- pmid:39135495
- scopus:85201273814
- ISSN
- 2040-3364
- DOI
- 10.1039/d4nr01496k
- language
- English
- LU publication?
- yes
- id
- 4c8090f6-350b-44fc-b67a-5ffac557b1c1
- date added to LUP
- 2024-11-01 10:28:51
- date last changed
- 2025-07-12 09:08:02
@article{4c8090f6-350b-44fc-b67a-5ffac557b1c1,
abstract = {{<p>Functional amyloids formed by the protein FapC in Pseudomonas bacteria are key structural components of Pseudomonas biofilms, which mediate chronic infections and also contribute to antimicrobial resistance. Here, we combine kinetic experiments with mechanistic modelling to probe the role of surfaces in FapC functional amyloid formation. We find that nucleation of new fibrils is predominantly heterogeneous in vitro, being catalysed by reaction vessel walls but not by the air/water interface. Removal of such interfaces by using microdroplets greatly slows heterogeneous nucleation and reveals a hitherto undetected fibril surface-catalysed “secondary nucleation” reaction step. We tune the degree of catalysis by varying the interface chemistry of the reaction vessel and by adding nanoparticles with tailored surface properties that catalyse fibril nucleation. In so doing, we discover that the rate of nucleation is controlled predominantly by the strength with which FapC binds to the catalytic sites on the interface, and by its surface area. Surprisingly, neither primary nucleation rate nor catalytic site binding strength appear closely correlated to the charge and hydrophilicity of the interface. This indicates the importance of considering experimental design in terms of surface chemistry of the reaction container while also highlighting the notion that fibril nucleation during protein aggregation is a heterogeneous process.</p>}},
author = {{Dear, Alexander J. and Meisl, Georg and Taylor, Christopher G. and Palmiero, Umberto Capasso and Stubbe, Susanne Nordby and Liu, Qian and Arosio, Paolo and Linse, Sara and Knowles, Tuomas P.J. and Andreasen, Maria}},
issn = {{2040-3364}},
language = {{eng}},
number = {{34}},
pages = {{16172--16182}},
publisher = {{Royal Society of Chemistry}},
series = {{Nanoscale}},
title = {{Surface effects on functional amyloid formation}},
url = {{http://dx.doi.org/10.1039/d4nr01496k}},
doi = {{10.1039/d4nr01496k}},
volume = {{16}},
year = {{2024}},
}