On the Binding of Congo Red to Amyloid Fibrils

Amyloids are characterized by their capacity to bind Congo red (CR), one of the most used amyloid‐specific dyes. The structural features of CR binding were unknown for years, mainly because of the lack of amyloid structures solved at high resolution. In the last few years, solid‐state NMR spectrosco...

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Detalles Bibliográficos
Autores: Espargaró Colomé, Alba, Llabrés Prat, Salomé, Saupe, Sven J., Curutchet Barat, Carles E., Luque Garriga, F. Xavier, Sabaté Lagunas, Raimon
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/167301
Acceso en línea:https://hdl.handle.net/2445/167301
Access Level:acceso abierto
Palabra clave:Amiloïdosi
Polímers
Proteïnes
Prions
Colorants
Amyloidosis
Polymers
Proteins
Coloring matter
Descripción
Sumario:Amyloids are characterized by their capacity to bind Congo red (CR), one of the most used amyloid‐specific dyes. The structural features of CR binding were unknown for years, mainly because of the lack of amyloid structures solved at high resolution. In the last few years, solid‐state NMR spectroscopy enabled the determination of the structural features of amyloids, such as the HET‐s prion forming domain (HET‐s PFD), which also has recently been used to determine the amyloid-CR interface at atomic resolution. Herein, we combine spectroscopic data with molecular docking, molecular dynamics, and excitonic quantum/molecular mechanics calculations to examine and rationalize CR binding to amyloids. In contrast to a previous assumption on the binding mode, our results suggest that CR binding to the HET‐s PFD involves a cooperative process entailing the formation of a complex with 1:1 stoichiometry. This provides a molecular basis to explain the bathochromic shift in the maximal absorbance wavelength when CR is bound to amyloids.