Amyloid-beta (Aβ) neoepitope (Aβ neoepitope)

Amyloid-beta (Aβ) neoepitopes are unique molecular structures formed through the post-translational modification or proteolytic cleavage of the amyloid-beta peptide, which is central to Alzheimer's disease pathogenesis (Saido et al., 1995, Neuron). One of the most significant neoepitopes is the N-terminal pyroglutamate-modified Aβ (pGlu-Aβ), which forms when the third amino acid (glutamate) is truncated and cyclized (Gunn et al., 2010, Journal of Neurochemistry). These neoepitopes are highly hydrophobic, prone to rapid aggregation, and are found almost exclusively within deposited amyloid plaques rather than in soluble circulating Aβ (Mintun et al., 2021, NEJM). Because they are specific to pathological aggregates, they serve as ideal targets for immunotherapy, allowing drugs to selectively clear plaques while sparing physiological forms of the peptide. Targeting these neoepitopes, as seen with monoclonal antibodies like Donanemab, aims to reduce the amyloid burden in the brain and slow cognitive decline in patients with early-stage Alzheimer's disease (Sims et al., 2023, JAMA). The presence of these neoepitopes is associated with increased neurotoxicity and the acceleration of tau pathology. Therapeutic intervention targeting these sites often triggers microglial-mediated clearance of existing deposits. Clinical monitoring for safety typically involves neuroimaging to detect potential vascular side effects, such as amyloid-related imaging abnormalities (Sperling et al., 2011, Alzheimer's & Dementia).

Other names

pGlu-AβPyroglutamate-modified amyloid-betaAβpE3N3pE-AβTruncated amyloid-betaN-terminal truncated amyloid-beta

Selective binding to aggregated amyloid-beta species followed by microglial-mediated phagocytosis and plaque clearance (Mintun et al., 2021, NEJM).