Pyroglutamate-3 amyloid-beta (pGlu3-Aβ) (pGlu3-Aβ)

Pyroglutamate-3 amyloid-beta (pGlu3-Aβ) is a highly pathogenic, post-translationally modified form of the amyloid-beta peptide found predominantly within the core of neuritic plaques in Alzheimer's disease [PMID: 22084068]. This modification occurs when the N-terminal glutamate at position 3 is truncated and cyclized by the enzyme glutaminyl cyclase, resulting in a peptide that is more hydrophobic, protease-resistant, and prone to rapid aggregation compared to full-length Aβ [PMID: 28435104]. Because pGlu3-Aβ is specific to pathological plaques and largely absent from soluble Aβ monomers or healthy brain tissue, it serves as a highly selective target for immunotherapy [PMID: 34161707]. Drugs like donanemab are designed to bind specifically to this epitope, facilitating the removal of existing plaque burdens through microglial-mediated phagocytosis [PMID: 37459331]. Clinical trials have demonstrated that targeting this epitope can lead to significant plaque clearance and a slowing of cognitive decline in early-stage Alzheimer's patients [PMID: 37459331]. However, like other anti-amyloid therapies, it is associated with safety risks such as amyloid-related imaging abnormalities (ARIA), which require careful monitoring via MRI [PMID: 34161707]. The presence of pGlu3-Aβ is considered a key driver of amyloid cascade progression due to its ability to seed the aggregation of other Aβ species [PMID: 22084068]. Therapeutic strategies targeting this epitope aim to minimize off-target effects on physiological Aβ while maximizing the clearance of established, neurotoxic deposits.

Other names

N3pE amyloid-betaAβpE3Pyroglutamated amyloid-betapE3-AβAmyloid-beta peptide (3-42), pyroglutamylN3pE-Aβ

Monoclonal antibody-mediated plaque clearance via microglial phagocytosis following binding to the N-terminal pyroglutamate-3 epitope [PMID: 37459331].