Toxicity
Although it has been thought that the mature protein aggregates themselves are toxic, recent evidence suggests that it is in fact that immature protein aggregates are most toxic . The hydrophobic patches of these aggregates can interact with other components of the cell and damage them. One hypothesis about how protein aggregates damage cells is through disruption of cell membranes. It is known that protein aggregates in vitro can destabilize artificial phospholipid bilayers, leading to permabilization of the membrane.
Read more about this topic: Protein Aggregation