Protein Chemistry of Amyloid Fibrils and Chaperones: Implications for Amyloid Formation and Disease

Understanding the mechanisms by which amyloid fibrils are formed, both in vivo and in vitro, is vital for developing methods to treat and prevent debilitating deposition diseases such as Alzheimer's disease, Parkinsona's disease, type II diabetes and systemic amyloidoses. In recent years, computer modelling and biophysical studies have broadened our understanding of the biochemical mechanisms underpinning protein aggregation. As a result, it is now believed that the ability to form fibrils is an intrinsic property of polypeptide chains and not isolated to disease-related proteins or peptides. Molecular chaperones are a diverse group of functionally related proteins well known for their ability to suppress amyloid formation, and are likely to be important determinants in deciding the fate of protein aggregation prone proteins in vivo. Evidence is presented that suggests that there is striking commonality in the anti-amyloidogenic activity of molecular chaperones regardless of their structural and spatial differences. In this review, we focus on what in vitro biophysical studies tell us about amyloid formation and molecular chaperones, and how investigating the role of chaperones in fibril formation can enhance our understanding of protein misfolding diseases.