Acrolein and Copper as Competitive Effectors of α‐Synuclein

Mounting evidence supports the role of amyloidogenesis, oxidative stress, and metal dyshomeostasis in the development of neurodegenerative disorders. Parkinson's Disease is characterized by alpha-synuclein (alphaSyn) accumulation and aggregation in brain regions, also promoted by Cu(2+) . alphaSyn is modified by reactive carbonyl species, including acrolein (ACR). Notwithstanding these findings, the interplay between ACR, copper, and alphaSyn has never been investigated. Therefore, we explored more thoroughly the effects of ACR on alphaSyn using an approach based on LC-MS/MS analysis. We also evaluated the influence of Cu(2+) on the protein carbonylation and how the ACR modification impacts the Cu(2+) binding and the production of Reactive Oxygen Species (ROS). Finally, we investigated the effects of ACR and Cu(2+) ions on the alphaSyn aggregation by dynamic light scattering and fluorescence assays. Cu(2+) regioselectively inhibits the modification of His50 by ACR, the carbonylation lowers the affinity of His50 for Cu(2+) and ACR inhibits alphaSyn aggregation both in the presence and in the absence of Cu(2+) .