Structure of the nonhelical filament of the Alzheimer's disease tau core.
Proc Natl Acad Sci U S A
; 120(44): e2310067120, 2023 Oct 31.
Article
em En
| MEDLINE
| ID: mdl-37878719
ABSTRACT
The microtubule-associated protein tau aggregates into neurofibrillary tangles in Alzheimer's disease (AD). The main type of aggregates, the paired helical filaments (PHF), incorporate about 20% of the full-length protein into the rigid core. Recently, cryo-electron microscopy data showed that a protease-resistant fragment of tau (residues 297-391) self-assembles in vitro in the presence of divalent cations to form twisted filaments whose molecular structure resembles that of AD PHF tau [S. Lövestam et al., Elife 11, e76494 (2022)]. To investigate whether this tau construct is uniquely predisposed to this morphology and structure, we fibrillized tau (297-391) under the reported conditions and determined its structure using solid-state NMR spectroscopy. Unexpectedly, the protein assembled predominantly into nontwisting ribbons whose rigid core spans residues 305-357. This rigid core forms a ß-arch that turns at residues 322CGS324. Two protofilaments stack together via a long interface that stretches from G323 to I354. Together, these two protofilaments form a four-layered ß-sheet core whose sidechains are stabilized by numerous polar and hydrophobic interactions. This structure gives insight into the fibril morphologies and molecular conformations that can be adopted by this protease-resistant core of AD tau under different pH and ionic conditions.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas tau
Limite:
Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2023
Tipo de documento:
Article