Amyloid-β (1-40) peptide Aβ (1-40) is a 40-residue protein fragment of the C-terminal portion of the β-amyloid protein implicated in Alzheimer’s disease. Aβ (1-40) is more abundant, less neurotoxic, and does not form oligomers as easily as amyloid-β (1-42) peptide (Aβ (1-42).

• More abundant
• Less neurotoxic
• Does not form oligomers as easily as amyloid-β (1-42) peptide (Aβ (1-42)

In rat cortical cultures, Aβ (1-40) (3 µM) prevented neuronal cell death by inhibiting fibril formation when administered concurrently with Aβ (1-42) (5, 10, and 20 µM). In the same study, Aβ (1-40) prevented neuronal damage when injected into rat entorhinal cortex with Aβ (1-42) (both at 400 µM).