Structural Transition During Fibrillogenesis of Amyloid β Peptide

Alzheimer’s Disease (AD) is a neurodegenerative disease marked by progressive neuronal cell death, leading to dementia. AD is the most common disease that results in dementia and largely affects the elderly, with five million people in the United States diagnosed with the disease as of 2015 and approximately 35 million people worldwide. Diseases resulting in dementia cost the US healthcare system an estimated $172 billion in 2010 and that cost is expected to increase as the population ages and as diagnostic techniques improve so that more people are treated (Holtzman, 2011). The disease was first reported by psychiatrist Alois Alzheimer at the onset of the 20th century, when one of his patients “suffered memory loss, disorientation, hallucinations and delusions and died at the age of 55,” then was found to have severe brain atrophy post-mortem (Cipriani, Dolciotti, Picchi, & Bonuccelli, 2011). There are palliative treatments available that marginally slow disease progression but there is currently no cure for the disease (Awasthi, Singh, Pandey, & Dwivedi, 2016). More research is needed to develop effective therapeutic strategies to combat the disease. Currently, AD cytotoxicity is believed to be caused by increased amyloid β (Aβ) peptide plaque deposition in the brain, as described by the amyloid cascade hypothesis (Barage & Sonawane, 2015). The current understanding is that oligomers of Aβ peptide lead to neuronal death through multiple mechanisms, most notably hyper-phosphorylation of the tau protein. Having a better understanding of the structural changes in the fibrillization process of Aβ will provide a broader insight into mechanisms of cell death and open new possibilities for pharmacological treatments, which is what this research intends to provide