Probing supramolecular protein assembly using covalently attached fluorescent molecular rotors

Changes in microscopic viscosity and macromolecular crowding accompany the transition of proteins from their monomeric forms into highly organised fibrillar states. Previously, we have demonstrated that viscosity sensitive fluorophores termed ‘molecular rotors’, when freely mixed with monomers of in...

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Detalles Bibliográficos
Autores: Kubánková, Markéta, López Duarte, Ismael, Bull, James A., Vadukul, Devkee M., Serpell, Louise C., Victor, Marie de Saint, Stride, Eleanor, Kuimova, Marina K.
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/114924
Acceso en línea:https://hdl.handle.net/20.500.14352/114924
Access Level:acceso abierto
Palabra clave:615.31
615:54
Amyloid aggregation
Live cells
Microviscosity
Fluorescence lifetime imaging microscopy (FLIM)
Sensors for Ab(1-42) aggregates
Química farmaceútica
23 Química
Descripción
Sumario:Changes in microscopic viscosity and macromolecular crowding accompany the transition of proteins from their monomeric forms into highly organised fibrillar states. Previously, we have demonstrated that viscosity sensitive fluorophores termed ‘molecular rotors’, when freely mixed with monomers of interest, are able to report on changes in microrheology accompanying amyloid formation, and measured an increase in rigidity of approximately three orders of magnitude during aggregation of lysozyme and insulin. Here we extend this strategy by covalently attaching molecular rotors to several proteins capable of assembly into fibrils, namely lysozyme, fibrinogen and amyloid-b peptide (Ab(1e42)). We demonstrate that upon covalent attachment the molecular rotors can successfully probe supramolecular assembly in vitro. Importantly, our new strategy has wider applications in cellulo and in vivo, since covalently attached molecular rotors can be successfully delivered in situ and will colocalise with the aggregating protein, for example inside live cells. This important advantage allowed us to follow the microscopic viscosity changes accompanying blood clotting and during Ab(1e42) aggregation in live SHSY5Y cells. Our results demonstrate that covalently attached molecular rotors are a widely applicable tool to study supramolecular protein assembly and can reveal microrheological features of aggregating protein systems both in vitro and in cellulo not observable through classical fluorescent probes operating in light switch mode.