Alzheimer’s disease (AD) is a neurodegenerative disorder that cause irreversible loss of neurons. Despite it is the most common form of dementia, the mechanism by which AD develops is still unclear. One of the hypothesis is based on the aggregation and the accumulation of amyloid β (Aβ) peptide around neuronal cells. Aβ peptide is present in two different form: Aβ40 and Aβ42. The first one is the most abundant in amyloid plaques and can assumes only a U-shaped structure, the second one is the most toxic and can assumes both U- and S- shaped structure. Recent studies demonstrate that the S-shaped form is more stable and compact.