Cargando…

Peptide backbone modifications of amyloid β (1–40) impact fibrillation behavior and neuronal toxicity

Fibril formation of amyloid β (Aβ) peptides is one of the key molecular events connected to Alzheimer’s disease. The pathway of formation and mechanism of action of Aβ aggregates in biological systems is still object of very active research. To this end, systematic modifications of the Phe(19)–Leu(3...

Descripción completa

Detalles Bibliográficos
Autores principales: Schwarze, Benedikt, Korn, Alexander, Höfling, Corinna, Zeitschel, Ulrike, Krueger, Martin, Roßner, Steffen, Huster, Daniel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8660793/
https://www.ncbi.nlm.nih.gov/pubmed/34887476
http://dx.doi.org/10.1038/s41598-021-03091-4
Descripción
Sumario:Fibril formation of amyloid β (Aβ) peptides is one of the key molecular events connected to Alzheimer’s disease. The pathway of formation and mechanism of action of Aβ aggregates in biological systems is still object of very active research. To this end, systematic modifications of the Phe(19)–Leu(34) hydrophobic contact, which has been reported in almost all structural studies of Aβ(40) fibrils, helps understanding Aβ folding pathways and the underlying free energy landscape of the amyloid formation process. In our approach, a series of Aβ(40) peptide variants with two types of backbone modifications, namely incorporation of (i) a methylene or an ethylene spacer group and (ii) a N-methylation at the amide functional group, of the amino acids at positions 19 or 34 was applied. These mutations are expected to challenge the inter-β-strand side chain contacts as well as intermolecular backbone β-sheet hydrogen bridges. Using a multitude of biophysical methods, it is shown that these backbone modifications lead, in most of the cases, to alterations in the fibril formation kinetics, a higher local structural heterogeneity, and a somewhat modified fibril morphology without generally impairing the fibril formation capacity of the peptides. The toxicological profile found for the variants depend on the type and extent of the modification.