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Aβ40 Aggregation under Changeable Conditions
Jofre Seira Curto1, Maria Rosario Fernandez1, Josep Cladera2
1Unitat de Bioquímica, Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain.
International Journal of Molecular Sciences
|May 13, 2023
Summary
Altered brain pH and amyloid-β-peptide (Aβ) aggregation are linked to Alzheimer's disease. This study reveals how pH influences Aβ40 aggregation, showing neutral conditions promote stable fibril formation.
Area of Science:
- Biochemistry
- Neuroscience
- Cell Biology
Background:
- Homeostasis is vital for cellular function; disruptions, particularly altered pH, are linked to neurological disorders.
- Acidic conditions in the brain, specifically in endosomes and lysosomes, are associated with amyloid-β-peptide (Aβ) aggregation and Alzheimer's disease pathogenesis.
- The isoelectric point of Aβ favors aggregation under acidic conditions due to reduced charge repulsion.
Purpose of the Study:
- To investigate the impact of varying pH levels on the aggregation kinetics and conformational dynamics of amyloid-β-peptide 40 (Aβ40).
- To explore how different aggregated conformations of Aβ40 interact and influence the overall aggregation process under diverse pH conditions.
- To understand the relationship between brain pH variations, Aβ aggregation, and the development of Alzheimer's disease.
Main Methods:
- Analysis of Aβ40 aggregation under a range of pH conditions, mimicking physiological and pathological brain pH.
- Characterization of different macromolecular conformations formed during the aggregation process.
- Assessment of the influence of neutral pH and physiological salt concentrations on aggregation rates and fibril stability.
Main Results:
- Observed that different macromolecular conformations can interact, modulating the Aβ40 aggregation pathway.
- Demonstrated that neutral pH and physiological salt concentrations lead to slow aggregation kinetics.
- Identified the formation of ordered, stable Aβ40 fibrils with low cytotoxic effects under neutral conditions.
Conclusions:
- pH is a critical factor influencing the aggregation of amyloid-β-peptide, with implications for Alzheimer's disease.
- Interactions between different aggregated conformations contribute to the complexity of Aβ aggregation in various environments.
- Neutral pH and physiological conditions favor the formation of less toxic, stable amyloid fibrils, offering insights into potential therapeutic strategies.
