Amyloid-beta fibrillar aggregate (Aβ fibril)

Amyloid-beta fibrillar aggregates are highly ordered, insoluble protein deposits formed by self-assembly of amyloid-beta peptides (typically Aβ40 and Aβ42) into elongated fibrils. These fibrils feature a characteristic cross-beta sheet structure wherein β-strands run perpendicular to the fibril axis, stabilized by hydrogen bonds parallel to the axis. The formation of such fibrils is a nucleation-dependent process, often initiated by critical aggregation nuclei and propagating by recruitment of monomeric Aβ, affecting cellular functions and leading to neuronal toxicity. Aβ fibrils are polymorphic in nature (exhibiting distinct molecular conformations and packing arrangements), and their accumulation in brain tissue is a pathological hallmark of Alzheimer’s disease. The fibril surface can catalyze secondary nucleation, producing toxic Aβ oligomers implicated in neurodegeneration. Therapies targeting these aggregates aim to inhibit their formation, promote clearance, and monitor their presence for disease diagnosis and progression.

Other names

Amyloid-beta fibrilAβ fibrilAmyloid-beta aggregateAβ aggregateAmyloid-beta plaque (when in tissue context)Fibrillar Aβ

Antibodies: bind fibrillar or aggregated Aβ to promote immune clearance, block growth, or disrupt aggregate structure. Small molecules: stabilize or destabilize fibril structure; inhibit aggregation kinetics. Imaging agents: bind the cross-beta motif for visualization of amyloid deposits