title: The involvement of dityrosine crosslinking in α-synuclein assembly and deposition in Lewy Bodies in Parkinson's disease.
abstract: Parkinson's disease (PD) is characterized by intracellular, insoluble Lewy bodies composed of highly stable α-synuclein (α-syn) amyloid fibrils. α-synuclein is an intrinsically disordered protein that has the capacity to assemble to form β-sheet rich fibrils. Oxidiative stress and metal rich environments have been implicated in triggering assembly. Here, we have explored the composition of Lewy bodies in post-mortem tissue using electron microscopy and immunogold labeling and revealed dityrosine crosslinks in Lewy bodies in brain tissue from PD patients. In vitro, we show that dityrosine cross-links in α-syn are formed by covalent ortho-ortho coupling of two tyrosine residues under conditions of oxidative stress by fluorescence and confirmed using mass-spectrometry. A covalently cross-linked dimer isolated by SDS-PAGE and mass analysis showed that dityrosine dimer was formed via the coupling of Y39-Y39 to give a homo dimer peptide that may play a key role in formation of oligomeric and seeds for fibril formation. Atomic force microscopy analysis reveals that the covalent dityrosine contributes to the stabilization of α-syn assemblies. Thus, the presence of oxidative stress induced dityrosine could play an important role in assembly and toxicity of α-syn in PD.
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.|College of Sciences, Chemistry Department, Al-Mustansiriyah University, Baghdad, Iraq.
authors.forename: Youssra K
authors.initials: YK
authors.lastname: Al-Hilaly
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Biasetti
authors.affiliation: School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
authors.forename: Ben J F
authors.initials: BJ
authors.lastname: Blakeman
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.
authors.forename: Saskia J
authors.initials: SJ
authors.lastname: Pollack
authors.affiliation: Laboratory of Molecular Biology, MRC Centre, Hills Rd, Cambridge, CB2 OQH, UK.
authors.forename: Shahin
authors.initials: S
authors.lastname: Zibaee
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.
authors.forename: Alaa
authors.initials: A
authors.lastname: Abdul-Sada
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.
authors.forename: Julian R
authors.initials: JR
authors.lastname: Thorpe
authors.affiliation: School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
authors.forename: Wei-Feng
authors.initials: WF
authors.lastname: Xue
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.
authors.forename: Louise C
authors.initials: LC
authors.lastname: Serpell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001921:Brain / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D016631:Lewy Bodies / Q000378:metabolism*; D008297:Male; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D053719:Tandem Mass Spectrometry; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D051844:alpha-Synuclein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D051844:alpha-Synuclein; D014443:Tyrosine; D003300:Copper; C007543:dityrosine