How Modulator Binding at the Amyloidβ-γ-Secretase Interface Enhances Substrate Binding and Attenuates Membrane
Shu-Yu Chen1, Matthias Koch2, Lucía Chávez-Gutiérrez2
1Center for Functional Protein Assemblies, Garching 85748, Germany.
Journal of Medicinal Chemistry
|December 7, 2023
Summary
γ-secretase modulators (GSM) offer an alternative to inhibitors for Alzheimer's disease by reducing toxic amyloid-beta (Aβ) peptides. This study reveals how GSMs like E2012 interact with the enzyme, substrate, and membrane to achieve this effect.
Area of Science:
- Biochemistry
- Neuroscience
- Structural Biology
Background:
- γ-secretase inhibition for Alzheimer's disease (AD) causes side effects.
- γ-secretase modulators (GSMs) offer a safer alternative by altering peptide production without inhibiting enzyme activity.
Purpose of the Study:
- To elucidate the mechanism of action for γ-secretase modulators (GSMs) at a molecular level.
- To understand the structural basis of E2012 GSM interaction with γ-secretase, substrate (Aβ43), and membrane lipids.
Main Methods:
- Generated a structural model of γ-secretase complexed with Aβ43 peptide and E2012 GSM.
- Analyzed molecular interactions at the enzyme-substrate-membrane interface.
- Performed experimental validation of predicted effects of γ-secretase mutations on GSM modulation.
Main Results:
- E2012 binding attenuates membrane distortion by shielding substrate-membrane interactions.
- GSM modulation is predicted to be charge-dependent, explaining conserved structural features in imidazole-based GSMs.
- Experimental data confirmed predictions regarding γ-secretase mutations and E2012 modulation.
Conclusions:
- The study provides a structural mechanism for how GSMs modulate γ-secretase activity.
- Understanding these interactions facilitates the design of novel and effective GSMs for Alzheimer's disease treatment.
- This research paves the way for developing safer therapeutics targeting amyloid-beta production.
