title: Quantitative thermophoretic study of disease-related protein aggregates.
abstract: Amyloid fibrils are a hallmark of a range of neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. A detailed understanding of the physico-chemical properties of the different aggregated forms of proteins, and of their interactions with other compounds of diagnostic or therapeutic interest, is crucial for devising effective strategies against such diseases. Protein aggregates are situated at the boundary between soluble and insoluble structures, and are challenging to study because classical biophysical techniques, such as scattering, spectroscopic and calorimetric methods, are not well adapted for their study. Here we present a detailed characterization of the thermophoretic behavior of different forms of the protein α-synuclein, whose aggregation is associated with Parkinson's disease. Thermophoresis is the directed net diffusional flux of molecules and colloidal particles in a temperature gradient. Because of their low volume requirements and rapidity, analytical methods based on this effect have considerable potential for high throughput screening for drug discovery. In this paper we rationalize and describe in quantitative terms the thermophoretic behavior of monomeric, oligomeric and fibrillar forms of α-synuclein. Furthermore, we demonstrate that microscale thermophoresis (MST) is a valuable method for screening for ligands and binding partners of even such highly challenging samples as supramolecular protein aggregates.
authors.affiliation: Systems Biophysics, Physics Department, Nanosystems Initiative Munich and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 München, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Wolff
authors.affiliation: Faculty of Physics and Center for Nanoscience (CeNS), Ludwig Maximilians University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Mittag
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Therese W
authors.initials: TW
authors.lastname: Herling
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Erwin De
authors.initials: ED
authors.lastname: Genst
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Dobson
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Tuomas P J
authors.initials: TP
authors.lastname: Knowles
authors.affiliation: Systems Biophysics, Physics Department, Nanosystems Initiative Munich and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 München, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Braun
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Buell
mesh_terms: D002151:Calorimetry; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D066329:Protein Aggregates; D011485:Protein Binding; D055672:Static Electricity; D013696:Temperature; D051844:alpha-Synuclein / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D066329:Protein Aggregates; D051844:alpha-Synuclein; D002392:Catechin; C045651:epigallocatechin gallate