Guide to the structural characterization of protein aggregates and amyloid fibrils by CD spectroscopy.

Protein aggregation and amyloid formation are linked to numerous degenerative diseases, such as Alzheimer's or Parkinson's disease. Additionally, protein aggregation plays a crucial role in various biological processes, such as storage of molecules or cell signaling. Protein molecules can form a wide range of aggregates, from oligomers of different sizes to non-specific aggregates and highly ordered cross-β structured amyloid fibrils with diverse morphologies.