Amyloid Fibrils as Building Blocks for Natural and Artificial Functional Materials

Abstract

Proteinaceous materials based on the amyloid core structure have recently been discovered at the origin of biological functionality in a remarkably diverse set of roles, and attention is increasingly turning towards such structures as the basis of artificial self-assembling materials. These roles contrast markedly with the original picture of amyloid fibrils as inherently pathological structures. Here we outline the salient features of this class of functional materials, both in the context of the functional roles that have been revealed for amyloid fibrils in nature, as well as in relation to their potential as artificial materials. We discuss how amyloid materials exemplify the emergence of function from protein self-assembly at multiple length scales. We focus on the connections between mesoscale structure and material function, and demonstrate how the natural examples of functional amyloids illuminate the potential applications for future artificial protein based materials.

On the role of peptide hydrolysis for fibrillation kinetics and amyloid fibril morphology

“…1 However, an increasing number of examples where the amyloid-like structures are utilized in functional roles by living organisms show that protein nanobrils (PNFs) per se are not pathological. 2,3 This has opened the door of possibilities for what this class of structures can offer in nanotechnology and for the design of new biobased functional materials. 2,3 The potential for this class of material is further strengthened by the fact that proteins from abundant natural raw materials, such as whey, can form PNFs.…”

Flow-assisted assembly of nanostructured protein microfibers

“…Improved knowledge about how to control the assembly of protein molecules into higher-order structures would open the possibilities to create novel bio-based materials for a variety of applications. In this perspective, the ability of protein molecules to undergo nonnative self-assembly into protein nanofibrils (PNFs) with highly organized supramolecular structures is of significant interest (3). The formation of PNFs was initially observed in association with diseases, such as Alzheimer's and Parkinson's diseases, and type II diabetes, where human organs are impaired by fibrous protein inclusions referred to as amyloid (4).…”

Elasticity in Physically Cross-Linked Amyloid Fibril Networks

“…These structures initially identified in nature, in the context of pathological protein-prone neurodegenerative diseases, have also been discovered as key functional components in biological organisms ranging from bacteria to humans [1,4,5]. Artificial variants of these systems are now also emerging as functional materials for the design of ultralight aerogels, drug delivery platforms, cell scaffolds, artificial bones, degradable films, solar energy conversion, and water purification [6,7]. Many of these applications depend strongly on the structural and mechanical properties of the amyloid fibril networks [7,8].…”

“…Artificial variants of these systems are now also emerging as functional materials for the design of ultralight aerogels, drug delivery platforms, cell scaffolds, artificial bones, degradable films, solar energy conversion, and water purification [6,7]. Many of these applications depend strongly on the structural and mechanical properties of the amyloid fibril networks [7,8]. Yet, compared to other biological networks, such as elastin for example, the structureproperties relationship in amyloid networks, and how physical properties of the individual fibrils are reflected at larger scales, is significantly less established.…”