Influence of membrane environments and copper ions on the structural features of amyloidogenic proteins correlated to neurodegeneration

Amyloidogenic proteins are associated with severe neurodegenerative disorders afflicting millions of people worldwide. The main hallmarks of these diseases are the presence of amyloid plaques in the brain, primarily formed by fibrils of misfolded cellular proteins. The process leading to protein aggregation, is far from completely understood. However, it is well accepted that many factors are able to influence the morphology and kinetics of amyloids formation. In the last years, a plethora of studies have suggested that the aggregation process is greatly influenced by the interactions of these proteins with copper and membranes. Amyloidogenic proteins undergo large conformational changes in the presence of membranes and show the presence of stable α helix structures in the presence of high concentrations of unilamellar vesicles or detergent micelles. The regions involved in the helicoidal rearrangements are those which are critical for protein aggregation. In addition, the α helix structuring of amyloidogenic proteins may strongly affect copper binding, in terms of donor atoms and complex stability since metal binding domains are often located near regions experiencing transitions from random-coil to α helix conformations.