Amyloid-beta (Aβ) aggregated species, N-terminal neoepitope (pGlu3-Aβ)

Aggregated beta-amyloid species, N-terminal neoepitope refers to a pathological target in Alzheimer's disease consisting of amyloid-beta (Aβ) peptides that have assembled into oligomers, protofibrils, or insoluble plaques and display a unique N-terminal signature. This signature often involves post-translational modifications, such as the formation of N-terminal pyroglutamate at position 3 (pGlu3-Aβ), or the exposure of specific N-terminal sequences (e.g., residues 3-7) that are hidden or less accessible in the monomeric state (NIH, 2024). These neoepitopes are highly desirable therapeutic targets because they are predominantly found in neurotoxic aggregates and mature plaques rather than the ubiquitous soluble monomers, allowing for more selective clearance of disease-related pathology (AlzForum, 2021). Drugs targeting these epitopes, such as the monoclonal antibody donanemab, bind to the aggregates and recruit microglial cells to clear the amyloid burden through phagocytosis (FDA, 2024). Clinical trials have demonstrated that targeting these specific aggregated species can significantly reduce plaque levels in the brain and slow the progression of cognitive and functional decline in patients with early Alzheimer's disease (The Innovation, 2023). However, the use of these therapies is associated with significant safety challenges, most notably amyloid-related imaging abnormalities (ARIA), which require careful monitoring via MRI (NIH, 2024).

Other names

N-terminal pyroglutamate amyloid-betapGlu3-AβAβpE3N3pG amyloid-betaPyroglutamate-modified amyloid-betaAggregated Aβ N-terminal epitope

Passive immunotherapy using monoclonal antibodies that selectively bind to N-terminal epitopes or modifications (such as pyroglutamate) present in aggregated amyloid-beta, facilitating microglial-mediated clearance of plaques and neutralizing toxic oligomers.