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Please use this identifier to cite or link to this item : http://hdl.handle.net/2078.1/35432
AD (Alzheimer's disease) is linked to A beta (amyloid beta-peptide) misfolding. Studies demonstrate that the level Of Soluble A beta oligomeric forms correlates better with the progression of the disease than the level of fibrillar forms. Conformation-dependent antibodies have been developed to detect either A beta oligomers or fibrils, suggesting that structural differences between these forms of At exist. Using conditions which yield well-defined A beta (1-42) oligomers or fibrils, We studied the secondary structure of these species by ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy. Whereas fibrillar A beta was organized in a parallel beta-sheet conformation, oligomeric A beta displayed distinct spectral features, which were attributed to an antiparallel beta-sheet structure. We also noted striking similarities between A beta oligomers spectra and those of bacterial outer membrane porins. We discuss our results in terms of a possible organization of the antiparallel beta-sheets in A beta oligomers, which may be related to reported effects of these highly toxic species in the amyloid pathogenesis associated with AD.
|Publication Date :||2009|
|Document type :||Article de périodique (Journal article) - (Article de recherche)|
|Source :||"Biochemical Journal" - Vol. 421, p. 415-423 (2009)|
|Publisher :||Portland Press Ltd (London)|
|Publication status :||Publié|
|Subject :||Alzheimer's disease ; amyloid beta-peptide ; antiparallel beta-sheet ; infrared spectroscopy ; oligomeric A beta ; OmpF|
|PDF_01||1042 - Dufrene-Cerf- 2009||-1 bytes||Request copy|