Degradation of Alzheimer's Amyloid-ß by a Catalytically Inactive Insulin-Degrading Enzyme.
J Mol Biol
; 433(13): 166993, 2021 06 25.
Article
em En
| MEDLINE
| ID: mdl-33865867
It is known that insulin-degrading-enzyme (IDE) plays a crucial role in the clearance of Alzheimer's amyloid-ß (Aß). The cysteine-free IDE mutant (cf-E111Q-IDE) is catalytically inactive against insulin, but its effect on Aß degradation is unknown that would help in the allosteric modulation of the enzyme activity. Herein, the degradation of Aß(1-40) by cf-E111Q-IDE via a non-chaperone mechanism is demonstrated by NMR and LC-MS, and the aggregation of fragmented peptides is characterized using fluorescence and electron microscopy. cf-E111Q-IDE presented a reduced effect on the aggregation kinetics of Aß(1-40) when compared with the wild-type IDE. Whereas LC-MS and diffusion ordered NMR spectroscopy revealed the generation of Aß fragments by both wild-type and cf-E111Q-IDE. The aggregation propensities and the difference in the morphological phenotype of the full-length Aß(1-40) and its fragments are explained using multi-microseconds molecular dynamics simulations. Notably, our results reveal that zinc binding to Aß(1-40) inactivates cf-E111Q-IDE's catalytic function, whereas zinc removal restores its function as evidenced from high-speed AFM, electron microscopy, chromatography, and NMR results. These findings emphasize the catalytic role of cf-E111Q-IDE on Aß degradation and urge the development of zinc chelators as an alternative therapeutic strategy that switches on/off IDE's function.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Mutantes
/
Doença de Alzheimer
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Insulisina
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article