Redirecting Amyloid Fibril Growth

Synthetic macromolecules can redirect the aggregation of amyloid-β (Aβ), the peptide associated with brain plaques in Alzheimer’s disease, from microscale fibrils to spherical nanostructures, chemists report (J. Am. Chem. Soc. 2014, DOI: 10.1021/ja501102f). The findings could help illuminate how amyloid fibrils grow, as well as suggest new therapeutic strategies for the disease, the researchers say. Jeffrey S. Moore and colleagues at the University of Illinois, Urbana-Champaign, wanted to disrupt amyloid assembly by interfering with weak interactions between Aβ monomers. Their inhibitors consisted of a copolymer backbone decorated with 21 copies of a peptide that binds to a region of Aβ that interacts with other monomers. When the team added the polymer-peptide conjugate to an equal amount of Aβ peptide, the conjugate completely suppressed fibril formation. The chemists were surprised to find that instead Aβ formed nearly spherical structures about 30 nm in diameter. The researchers are currently investigating the composition of these nanostructures. Understanding their structures and how they form may suggest new ways to prevent or disrupt amyloid aggregation, Moore says.