Application of the Bacterial C-DAG System for Analysis of the Ability of Amyloids to Seed Protein Aggregation In Vitro

The search for new amyloid proteins and investigation of their properties, is an actual task, which addressed by using a number of model systems. One of the most popular is the C-DAG approach, based on the analysis of aggregation of the studied proteins on the surface of Escherichia coli cells. According to the original protocol, it can be used to demonstrate one of the characteristic properties of amyloids: the ability to bind the amyloid-specific dye Congo red, exhibiting apple-green birefringence. The C-DAG technique provides also for analysis of the aggregate morphology and their resistance to detergents. In the present work, using Sup35NM as an example, we tested whether the aggregates on the surface of bacterial cells can act as inducers of aggregation of the relevant protein.