Unraveling the Role of Functional Amyloids and Amyloid Peptides in Disease Detection.

Amyloid refers to a specific quaternary structure characterized by fibrillar arrangements of proteins or peptides forming cross β-sheet architectures. Initially associated with diseases like Alzheimer's, amyloid was seen predominantly as pathological. However, recent research has revealed that amyloid also plays functional roles across various biological systems, from bacteria to mammals. The cross β-sheet structure of amyloid enables the transformation of soluble proteins into insoluble fibrils, providing high stability and a robust prion-like copying mechanism. However, recent research has revealed that amyloid also plays functional roles in various biological systems, such as biofilm formation in bacteria, aiding melanin biosynthesis in humans, and supporting the formation of fungal hyphae. Understanding the dual nature of amyloid-a pathological and functional entity-offers insights into disease mechanisms and therapeutic strategies. Recognizing the distinction between pathological and functional amyloids is crucial for advancing diagnostics and treatments. This review highlights the importance of functional amyloids (FAs), particularly in disease detection, underscoring their significant biological roles and potential applications.