Oxidized glutathione stimulated the amyloid formation of α-synuclein

a-Synuclein is the major filamentous constituent of Lewy bodies found in Parkinson's disease (PD). The amyloid formation of alpha-synuclein was significantly facilitated by oxidized glutathione (GSSG) as the lag period of the aggregation kinetics was shortened by 2.5-fold from its absence. Reduced glutathione (GSH), on the other hand, did not influence the lag phase although it increased the final amyloid formation. The GSSG stimulation was specific for not only a-synuclein but also its intactness. The preferred GSSG interaction of a-synuclein to GSH was also demonstrated with dissociation constants of 0.53 and 43.5 mM, respectively. It is suggested that the oxidative stress favoring the GSSG generation from GSH could result in the augmented amyloid formation of a-synuclein, which ought to be related to the pathogenesis of PD. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.