Pyroglutamate-modified Amyloid Beta Peptide (AβpE3)

Pyroglutamate-modified amyloid beta peptide (AβpE3 or pE-Aβ) is a post-translationally modified form of the amyloid beta (Aβ) peptide, characterized by the presence of a pyroglutamate residue at its N-terminus. This modification occurs after the removal of the first two amino acids from full-length Aβ, exposing glutamate at position 3, which is then cyclized to pyroglutamate by glutaminyl cyclase. The most studied variant is pE-Aβ(3–42), but other forms such as pE-Aβ(3–40) and pE-Aβ(11–40/42) also exist. Pyroglutamate-modified Aβ peptides are highly relevant in Alzheimer’s disease (AD). They are found abundantly in AD brains, comprising 15–45% of total amyloid beta deposits. These peptides exhibit increased aggregation propensity and stability compared to unmodified Aβ. They form β-sheet structures more readily and resist degradation, contributing to their accumulation in plaques. Pyroglutamate modification enhances hydrophobicity and removes electrical charges from key residues, further promoting aggregation and toxicity. These species co-oligomerize with other forms like Aβ42 and are associated with higher neurotoxicity than full-length peptides. Their presence correlates with severe neuron loss in animal models overexpressing them. Pyroglutamated amyloid beta species are considered crucial targets for next-generation Alzheimer’s therapeutics due to their abundance in plaques, high toxicity, resistance to degradation, diagnostic potential as plasma biomarkers distinguishing AD patients from controls, and role as active participants driving disease progression rather than mere byproducts or inert deposits.

Other names

Pyro abetaAbetaPE3APP fragment

Unknown, but potential therapeutic strategies include inhibition of glutaminyl cyclase, promotion of degradation, and prevention of aggregation.