Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10738696 | Free Radical Biology and Medicine | 2011 | 10 Pages |
Abstract
Oxidative stress has been implicated in the etiology of neurodegenerative disorders with α-synuclein pathology. Lipid peroxidation products such as 4-oxo-2-nonenal (ONE) and 4-hydroxy-2-nonenal (HNE) can covalently modify and structurally alter proteins. Herein, we have characterized ONE- or HNE-induced α-synuclein oligomers. Our results demonstrate that both oligomers are rich in β-sheet structure and have a molecular weight of about 2000 kDa. Atomic force microscopy analysis revealed that ONE-induced α-synuclein oligomers were relatively amorphous, with a diameter of 40-80 nm and a height of 4-8 nm. In contrast, the HNE-induced α-synuclein oligomers had a protofibril-like morphology with a width of 100-200 nm and a height of 2-4 nm. Furthermore, neither oligomer type polymerized into amyloid-like fibrils despite prolonged incubation. Although more SDS and urea stable, because of a higher degree of cross-linking, ONE-induced α-synuclein oligomers were less compact and more sensitive to proteinase K treatment. Finally, both ONE- and HNE-induced α-synuclein oligomers were cytotoxic when added exogenously to a neuroblastoma cell line, but HNE-induced α-synuclein oligomers were taken up by the cells to a significantly higher degree. Despite nearly identical chemical structures, ONE and HNE induce the formation of off-pathway α-synuclein oligomers with distinct biochemical, morphological, and functional properties.
Keywords
AFMDLBHNEMSA4-oxo-2-nonenal4-hydroxy-2-nonenalMTTα-synucleinMultiple-system atrophyOligomersLewy bodiesThTParkinson diseaseEnzyme-linked immunosorbent assayELISAOxidative stressDementia with Lewy bodiesThioflavin TFree radicalscircular dichroismatomic force microscopyLipid peroxidationProteinase KONE
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Authors
Thomas Näsström, Therese Fagerqvist, Mikael Barbu, Mikael Karlsson, Fredrik Nikolajeff, Alex Kasrayan, Monica Ekberg, Lars Lannfelt, Martin Ingelsson, Joakim Bergström,