Ubiquitin binds the amyloid β peptide and interferes with its clearance pathways


Bellia, F., Lanza, V., García-Viñuales, S. et al.

Chemical Science 2019, vol:10(9), 2732 doi: 10.1039/c8sc03394c


Several lines of evidence point to a compromised proteostasis associated with a reduction of the Ubiquitin Proteasome System (UPS) activity in patients affected by Alzheimer's Disease (AD) and suggest that the amyloid β peptide (Aβ) is an important player in the game. Inspired also by many reports, underlining the presence of ubiquitin (Ub) in the amyloid plaques of AD brains, here we set out to test whether Ub may bind the Aβ peptide and have any effect on its clearance pathways. By using an integrated array of MALDI-TOF/UPLC-HRMS, fluorescence, NMR, SPR, Microscale Thermophoresis (MST) and molecular dynamics studies, we consistently demonstrated that Aβ40 binds Ub with a 1 : 1 stoichiometry and Kd in the high micromolar range. In particular, we show that the N-terminal domain of the Aβ peptide (through residues D1, E3 and R5) interacts with the C-terminal tail of Ub (involving residues K63 and E64), inducing the central region of Aβ (14HQKLVFFAEDVGSNK28) to adopt a mixed α-helix/β-turn structure. ELISA assays, carried out in neuroblastoma cell lysates, suggest that Aβ competitively binds Ub also in the presence of the entire pool of cytosolic Ub binding proteins. Ub-bound Aβ has a lower tendency to aggregate into amyloid-like fibrils and is more slowly degraded by the Insulin Degrading Enzyme (IDE). Finally, we observe that the water soluble fragment Aβ1–16 significantly inhibits Ub chain growth reactions. These results evidence how the non-covalent interaction between Aβ peptides and Ub may have relevant effects on the regulation of the upstream events of the UPS and pave the way to future in vivo studies addressing the role played by Aβ peptide in the malfunction of proteome maintenance occurring in AD.

View Publication

Topics: Neurodegenerative diseases, Monolith – MicroScale Thermophoresis, MST,  Publications



Previous Article
Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D
Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D

Up next
The Parkinson’s-associated protein DJ-1 regulates the 20S proteasome
The Parkinson’s-associated protein DJ-1 regulates the 20S proteasome

Characterize the molecular mechanisms of neurodegenerative diseases

Learn how

Sign up to receive
the latest NanoTemper news, product updates, event announcements and more

First Name
Last Name
Company Name
Agree to Subscribe & Privacy Policy*
*I have fully read, understood and agree to the Privacy Policy. I accept the storing and processing of my personal data by NanoTemper as described in the Privacy Policy.

By completing this form, you provide us consent to contact you with educational content, news and information about our products, services and events. You may unsubscribe at any time.
Thank you!
Error - something went wrong!