Molecular Classification
Peptide/protein aggregate
Other Names
Amyloid beta aggregates, Aβ aggregates
Disease Roles
Alzheimer's diseaseNeurodegenerative disease

Aggregates of β-Amyloid Peptide Overview

Aggregates of β-amyloid peptide (Aβ) are assemblies formed by the self-association of amyloid beta peptides, which are 36–43 amino acid residues in length. These aggregates are a hallmark of Alzheimer's disease and other neurodegenerative disorders, where they accumulate as extracellular plaques in the brain. The most common forms involved in aggregation are Aβ40, Aβ42, and to a lesser extent Aβ43. Aggregated forms—especially soluble oligomers—are considered highly neurotoxic and central to Alzheimer's disease pathogenesis due to their ability to disrupt cellular function and induce neuronal death. Mature fibrillar aggregates constitute the core component of amyloid plaques observed histopathologically. A variety of cell surface receptors recognize aggregated Aβ, including scavenger receptors (SCARA1, MARCO, SCARB1), RAGE (receptor for advanced glycation end products), G-protein coupled receptors (FPR2), Chemokine-like receptor (CMKLR1), Toll-like receptors (TLR2/TLR4 with co-receptor CD14). These mediate microglial activation/inflammation or promote phagocytosis/clearance. Some such as CD33 may accelerate accumulation by inhibiting clearance mechanisms.

Mechanism of Action

Unknown

Biological Functions

Aggregation
Neurotoxicity
Receptor binding
Microglial activation
Inflammation

Disease Associations

Alzheimer's disease
Neurodegenerative disease

Safety Considerations

  • Targeting aggregated forms may be difficult due to structural heterogeneity.
  • Immunotherapies targeting Aβ aggregates have shown limited efficacy and potential side effects like ARIA (Amyloid-Related Imaging Abnormalities).

Associated Biomarkers

Biomarker
Aβ40
Aβ42
Aβ43