The Evolution of Amyloid-β Toxicity in Alzheimer’s Disease

The action of any protein, whether it is life-supporting or toxic, is tied to its structure. Amyloid-β molecules, linked to Alzheimer’s disease, appear to become toxic within our bodies when they make contact with each other and form small aggregates. Oddly, they may become less toxic again as the aggregates grow larger in size and form ordered fibrillar deposits. This begs the question: what’s different about these small aggregates? Determining this difference is a challenge, however, because standard tools fail to decipher much about these transient aggregation states. We have utilized the speed and sensitivity of optical spectroscopy and harnessed the resolution of NMR to address this question. Our results provide us some clues which differentiate between the smaller and larger forms of the aggregates, and provide a basis for understanding why the smaller aggregates may be more toxic.