Alzheimer’s is a disease of aggregation. Neurons in the human brain make a protein called amyloid beta. Such proteins on their own, called monomers of amyloid beta, perform important tasks for neurons. But in the brains of people with Alzheimer’s disease, amyloid beta monomers have abandoned their jobs and joined together. First, they form oligomers — small clumps of up to a dozen proteins — then longer strands and finally large deposits called plaques. For years, scientists believed that the plaques triggered the cognitive impairments characteristic of Alzheimer’s disease. But newer research implicates the smaller aggregates of amyloid beta as the toxic elements of this disease.
Now, a team led by researchers at the University of Washington has developed synthetic peptides that target and inhibit those small, toxic aggregates. As they report in a paper published April 19 in the Proceedings of the National Academy of Sciences, their synthetic peptides — which are designed to fold into a structure known as an alpha sheet — can block amyloid beta aggregation at the early and most toxic stage when oligomers form.