Copper(I)-?-Synuclein Interaction: Structural Description of Two Independent and Competing Metal Binding Sites.
Related Articles Copper(I)-?-Synuclein Interaction: Structural Description of Two Independent and Competing Metal Binding Sites.
Inorg Chem. 2013 Jan 23;
Authors: Camponeschi F, Valensin D, Tessari I, Bubacco L, Dell'acqua S, Casella L, Monzani E, Gaggelli E, Valensin G
Abstract
The aggregation of ?-synuclein (?S) is a critical step in the etiology of Parkinson's disease. Metal ions such as copper and iron have been shown to bind ?S, enhancing its fibrillation rate in vitro. ?S is also susceptible to copper-catalyzed oxidation that involves the reduction of Cu(II) to Cu(I) and the conversion of O(2) into reactive oxygen species. The mechanism of the reaction is highly selective and site-specific and involves interactions of the protein with both oxidation states of the copper ion. The reaction can induce oxidative modification of the protein, which generally leads to extensive protein oligomerization and precipitation. Cu(II) binding to ?S has been extensively characterized, indicating the N terminus and His-50 as binding donor residues. In this study, we have investigated ?S-Cu(I) interaction by means of NMR and circular dichroism analysis on the full-length protein (?S(1-140)) and on two, designed ad hoc, model peptides: ?S(1-15) and ?S(113-130). In order to identify and characterize the metal binding environment in full-length ?S, in addition to Cu(I), we have also used Ag(I) as a probe for Cu(I) binding. Two distinct Cu(I)/Ag(I) binding domains with comparable affinities have been identified. The structural rearrangements induced by the metal ions and the metal coordination spheres of both sites have been extensively characterized.
PMID: 23343468 [PubMed - as supplied by publisher]
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