title: The H50Q mutation induces a 10-fold decrease in the solubility of α-synuclein.
abstract: The conversion of α-synuclein from its intrinsically disordered monomeric state into the fibrillar cross-β aggregates characteristically present in Lewy bodies is largely unknown. The investigation of α-synuclein variants causative of familial forms of Parkinson disease can provide unique insights into the conditions that promote or inhibit aggregate formation. It has been shown recently that a newly identified pathogenic mutation of α-synuclein, H50Q, aggregates faster than the wild-type. We investigate here its aggregation propensity by using a sequence-based prediction algorithm, NMR chemical shift analysis of secondary structure populations in the monomeric state, and determination of thermodynamic stability of the fibrils. Our data show that the H50Q mutation induces only a small increment in polyproline II structure around the site of the mutation and a slight increase in the overall aggregation propensity. We also find, however, that the H50Q mutation strongly stabilizes α-synuclein fibrils by 5.0 ± 1.0 kJ mol(-1), thus increasing the supersaturation of monomeric α-synuclein within the cell, and strongly favors its aggregation process. We further show that wild-type α-synuclein can decelerate the aggregation kinetics of the H50Q variant in a dose-dependent manner when coaggregating with it. These last findings suggest that the precise balance of α-synuclein synthesized from the wild-type and mutant alleles may influence the natural history and heterogeneous clinical phenotype of Parkinson disease.
authors.affiliation: From the Wolfson Drug Discovery Unit, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, and.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Porcari
authors.affiliation: the Department of Clinical Neuroscience, Institute of Neurology, University College London, London NW3 2PF, United Kingdom.
authors.forename: Christos
authors.initials: C
authors.lastname: Proukakis
authors.affiliation: the Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Waudby
authors.affiliation: the Centre for Genomic Regulation and University Pompeu Fabra, 08003 Barcelona, Spain.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bolognesi
authors.affiliation: From the Wolfson Drug Discovery Unit, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, and the Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, 27100 Pavia, Italy.
authors.forename: P Patrizia
authors.initials: PP
authors.lastname: Mangione
authors.affiliation: the Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Jack F S
authors.initials: JF
authors.lastname: Paton
authors.affiliation: the Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mullin
authors.affiliation: the Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Cabrita
authors.affiliation: the Department of Physics, University of Genoa, 16146 Genoa, Italy.
authors.forename: Amanda
authors.initials: A
authors.lastname: Penco
authors.affiliation: the Department of Physics, University of Genoa, 16146 Genoa, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Relini
authors.affiliation: From the Wolfson Drug Discovery Unit, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, and the Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, 27100 Pavia, Italy.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Verona
authors.affiliation: the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom, and.
authors.forename: Michele
authors.initials: M
authors.lastname: Vendruscolo
authors.affiliation: the Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, 27100 Pavia, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Stoppini
authors.affiliation: the Centre for Genomic Regulation and University Pompeu Fabra, 08003 Barcelona, Spain.
authors.forename: Gian Gaetano
authors.initials: GG
authors.lastname: Tartaglia
authors.affiliation: the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom, and.
authors.forename: Carlo
authors.initials: C
authors.lastname: Camilloni
authors.affiliation: the Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom, j.christodoulou@ucl.ac.uk.
authors.forename: John
authors.initials: J
authors.lastname: Christodoulou
authors.affiliation: the Department of Clinical Neuroscience, Institute of Neurology, University College London, London NW3 2PF, United Kingdom.
authors.forename: Anthony H V
authors.initials: AH
authors.lastname: Schapira
authors.affiliation: From the Wolfson Drug Discovery Unit, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, and the Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, 27100 Pavia, Italy, v.bellotti@ucl.ac.uk.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Bellotti
mesh_terms: D000682:Amyloid / Q000737:chemistry; D001665:Binding Sites; D006801:Humans; D016631:Lewy Bodies / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D009154:Mutation; D010300:Parkinson Disease / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D010641:Phenotype; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D012995:Solubility; D013816:Thermodynamics; D051844:alpha-Synuclein / Q000737:chemistry / Q000235:genetics*
chemical_list: D000682:Amyloid; D010455:Peptides; D020033:Protein Isoforms; D011994:Recombinant Proteins; D051844:alpha-Synuclein; C011083:polyproline
keywords: Aggregation Propensity; Amyloid; Fibril; Fibrils Thermodynamic Stability; Parkinson Disease; Polyproline II Structure; Protein Aggregation; alpha-Synuclein (a-synuclein)