Controllable membrane damage by tunable peptide aggregation with albumin

Abstract

Aggregation of otherwise soluble proteins into amyloid structures is a hallmark of many disorders, such as Alzheimers and Parkinsons diseases. There is increasing evidence and acceptance that instead of ordered amyloid assemblies, the misfolded oligomer aggregations are the main toxic structures. However, there is no system to study the mechanism and kinetics of aggregation, distinguish between ordered structures and misfolded oligomers, and correlate the structures to their toxicity. The exact role of oligomer aggregation in the pathological process remains to be elucidated. Here, we use an engineered co-assembling oppositely charged amyloid-like peptide pair ([II]) to relate its aggregation to toxicity. The toxicity mechanism of [II] is through cell membrane damage and stress, as shown with YAP and eIF2 biomarkers, as in the amyloid protein-initiated diseases. Albumin is used to control the aggregation of [II], and so its toxicity. This study represents a molecular engineering strategy to study the aggregation process of amyloid-like structures in diseases. Understanding the nature of protein aggregation through engineered peptides paves the way for future designs and drug development applications.