{{Infobox
| infobox-header = Beta-amyloid Peptide
| infobox-subheader = Aβ - Amyloid-beta Peptide
| label1 = Gene
| data1 = APP
| label2 = UniProt ID
| data2 = P05067 (APP770 isoform)
| label3 = Alternative Names
| data3 = Aβ, Amyloid-beta, Aβ1-40, Aβ1-42
| label4 = Precursor
| data4 = Amyloid Precursor Protein (APP)
| label5 = Molecular Weight
| data5 = 4.3 kDa (Aβ1-42)
| label6 = Aggregation State
| data6 = Forms soluble oligomers, protofibrils, and amyloid plaques
| label7 = Pathological Form
| data7 = Amyloid plaques (neuritic, diffuse, CAA)
}}
Beta Amyloid Peptide is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Beta-amyloid (Aβ) is a 38-43 amino acid peptide derived from the Amyloid Precursor Protein (APP) through sequential proteolytic cleavage by β-secretase and γ-secretase. Aβ is the main component of amyloid plaques in Alzheimer's disease and is central to the amyloid cascade hypothesis.
Amyloidogenic pathway (Aβ-generating):
Non-amyloidogenic pathway (alternative):
| Species | Length | Abundance | Aggregation |
|---|---|---|---|
| Aβ1-38 | 38 aa | Most abundant | Less aggregation-prone |
| Aβ1-40 | 40 aa | 80-90% of total | Forms diffuse plaques |
| Aβ1-42 | 42 aa | 5-10% | Highly aggregation-prone |
| Aβ1-43 | 43 aa | Minor | Most aggregation-prone |
Monomers → Oligomers → Protofibrils → Fibrils → Plaques
Soluble oligomers are considered the most toxic species:
Evidence supporting:
Evidence challenging:
| Approach | Example | Status |
|---|---|---|
| Active vaccination | AN1792 (failed), ACI-35 | Phase 1/2 |
| Monoclonal antibodies | Aducanumab, Lecanemab, Donanemab | Approved/Phase 3 |
| Antibody fragments | Nanobodies | Preclinical |
| Target | Strategy | Status |
|---|---|---|
| BACE1 inhibitors | Reduce Aβ production | Failed (safety) |
| γ-secretase modulators | Shift to shorter Aβ | Phase trials |
| α-secretase activators | Promote non-amyloidogenic | Preclinical |
The study of Beta Amyloid Peptide has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.