Structural characterization of copper(II) binding to alpha-synuclein: Insights into the bioinorganic chemistry of Parkinson's disease.
The aggregation of alpha-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen/oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS-Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson's disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders.
Rasia
Rodolfo M
RM
Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Bertoncini
Carlos W
CW
Marsh
Derek
D
Hoyer
Wolfgang
W
Cherny
Dmitry
D
Zweckstetter
Markus
M
Griesinger
Christian
C
Jovin
Thomas M
TM
Fernández
Claudio O
CO
D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular; D010300:Parkinson Disease / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D013053:Spectrophotometry; D051843:Synucleins; D051844:alpha-Synuclein
D009419:Nerve Tissue Proteins; D009587:Nitrogen Isotopes; D010446:Peptide Fragments; C497604:SNCA protein, human; D051843:Synucleins; D051844:alpha-Synuclein; D003300:Copper