proteinaggregaten

Proteinaggregaten are assemblies formed when misfolded proteins associate into larger structures. They can occur as small soluble oligomers, insoluble amorphous aggregates, or highly ordered amyloid fibrils. Aggregation can arise during normal biology or under stress conditions such as heat, oxidative stress, or pH changes, and can involve a single protein species or multiple co-aggregating proteins.

In healthy cells, proteostasis networks—including molecular chaperones, the ubiquitin-proteasome system, and autophagy—help fold proteins correctly or remove misfolded species. When these systems are overwhelmed or defective, misfolded proteins can accumulate and form aggregates. Some aggregates, such as bacterial inclusion bodies or seed aggregates used in research, can be functional or used as a protein production strategy; many others are toxic.

Pathological protein aggregates are characteristic of several neurodegenerative diseases, notably amyloid plaques in Alzheimer's disease (amyloid-β and tau tangles) and Lewy bodies in Parkinson's disease (α-synuclein). Aggregates may disrupt membranes, impair proteostasis, and trigger inflammation. Not all aggregates are equally toxic; smaller, soluble oligomers are often more harmful than large insoluble deposits.

In biotechnology and medicine, protein aggregation is a major concern for therapeutic protein production because aggregates can provoke immune responses. Approaches to control aggregation include stabilizing native folding, optimizing formulation, engineering more soluble variants, and employing purification and refolding strategies. Research also targets aggregation with small molecules, chaperones, and immunotherapies intended to halt formation or promote clearance of aggregates.