Amyloid-beta peptide N-terminal EFRH epitope (Aβ EFRH) (Aβ EFRH)

The Amyloid-beta (Aβ) peptide N-terminal EFRH epitope is a specific sequence of four amino acids (Glu-Phe-Arg-His) located at positions 3 through 6 of the Aβ peptide [Frenkel et al., 1998, PNAS]. This epitope is widely recognized as the immunodominant region of the Aβ molecule, making it a primary target for the development of monoclonal antibodies in Alzheimer's disease research [Frenkel et al., 1998; Miles et al., 2013, Sci Rep]. The Aβ peptide is produced through the sequential cleavage of the Amyloid Precursor Protein (APP) and is the main component of the amyloid plaques found in the brains of Alzheimer's patients [Linse et al., 2020, Nat Commun]. Therapeutic strategies targeting the EFRH epitope, such as the drug Aducanumab, aim to clear these pathological aggregates by facilitating microglial-mediated phagocytosis or by neutralizing soluble toxic oligomers [Sevigny et al., 2016, Nature]. Binding to this N-terminal region is thought to disrupt the stability of Aβ fibrils and prevent further polymerization into larger, more toxic structures [Miles et al., 2013]. While effective at reducing plaque burden, drugs targeting this epitope are frequently associated with Amyloid-Related Imaging Abnormalities (ARIA), which present as brain edema (ARIA-E) or microhemorrhages (ARIA-H) [Sperling et al., 2011, Alzheimers Dement]. This epitope is also relevant in Cerebral Amyloid Angiopathy, where Aβ deposits in the walls of cerebral blood vessels [Sperling et al., 2011]. Overall, the EFRH epitope remains a cornerstone of passive immunotherapy efforts to modify the course of neurodegenerative diseases characterized by amyloidosis [Sevigny et al., 2016].

Other names

Aβ(3-6) epitopeGlu-Phe-Arg-His sequence [Frenkel et al., 1998]Immunodominant Aβ epitopeN-terminal Aβ epitope

Passive immunotherapy; monoclonal antibodies bind the EFRH epitope to promote microglial-mediated plaque clearance, neutralize toxic Aβ oligomers, and inhibit the aggregation of Aβ monomers into fibrils [Frenkel et al., 1998; Sevigny et al., 2016; Miles et al., 2013].