Abundant fish protein inhibits α-synuclein amyloid formation

The most common allergen in fish, the highly-abundant protein beta-parvalbumin, forms amyloid structures as a way to avoid gastrointestinal degradation and transit to the blood. In humans, the same amyloid structures are mostly associated with neurodegenerative disorders such as Alzheimer's and Parkinson's. We here assessed a putative connection between these amyloids using recombinant Atlantic cod beta-parvalbumin and the key amyloidogenic protein in Parkinson's disease, alpha-synuclein. Using a set of in vitro biophysical methods, we discovered that beta-parvalbumin readily inhibits amyloid formation of alpha-synuclein. The underlying mechanism was found to involve alpha-synuclein binding to the surface of beta-parvalbumin amyloid fibers. In addition to being a new amyloid inhibition mechanism, the data suggest that health benefits of fish may be explained in part by cross-reaction of beta-parvalbumin with human amyloidogenic proteins.