title: A hydrophobic stretch of 12 amino acid residues in the middle of alpha-synuclein is essential for filament assembly.
abstract: Neuronal and oligodendrocytic aggregates of fibrillar alpha-synuclein define several diseases of the nervous system. It is likely that these inclusions impair vital metabolic processes and compromise viability of affected cells. Here, we report that a 12-amino acid stretch ((71)VTGVTAVAQKTV(82)) in the middle of the hydrophobic domain of human alpha-synuclein is necessary and sufficient for its fibrillization based on the following observations: 1) human beta-synuclein is highly homologous to alpha-synuclein but lacks these 12 residues, and it does not assemble into filaments in vitro; 2) the rate of alpha-synuclein polymerization in vitro decreases after the introduction of a single charged amino acid within these 12 residues, and a deletion within this region abrogates assembly; 3) this stretch of 12 amino acids appears to form the core of alpha-synuclein filaments, because it is resistant to proteolytic digestion in alpha-synuclein filaments; and 4) synthetic peptides corresponding to this 12-amino acid stretch self-polymerize to form filaments, and these peptides promote fibrillization of full-length human alpha-synuclein in vitro. Thus, we have identified key sequence elements necessary for the assembly of human alpha-synuclein into filaments, and these elements may be exploited as targets for the design of drugs that inhibit alpha-synuclein fibrillization and might arrest disease progression.
authors.affiliation: Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, 19104, USA.
authors.forename: B I
authors.initials: BI
authors.lastname: Giasson
authors.forename: I V
authors.initials: IV
authors.lastname: Murray
authors.forename: J Q
authors.initials: JQ
authors.lastname: Trojanowski
authors.forename: V M
authors.initials: VM
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D009422:Nervous System Diseases / Q000188:drug therapy; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism / Q000648:ultrastructure; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein
chemical_list: D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C497604:SNCA protein, human; C497607:SNCB protein, human; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein