Construction of chemoreactive heterogeneous nanofibers through strategic coassembly of different proteins

In nature, hierarchically ordered supramolecular assemblies built from protein building blocks become key elements in the composition of both functional nanostructures such as collagens in extracellular matrix, biofilm matrix, and pathological nanostructures including amyloid deposits. Hence, the construction of multiprotein nanoarchitecture is an important research target for innovations in the designing of bioactive nanomaterials. Although β-strand-template-mediated coassembly/cross-seeding of diverse proteins have been reported, the structural and catalytic characteristics of the resultant heterogeneous nanofibers remain largely unknown. Here, we demonstrate the genesis of stable and chemoreactive multiprotein nanofibers via kinetically favored coassembly of diverse proteins with low sequence similarity (insulin, serum albumin, cytochrome c, lysozyme, β-lactoglobulin). The multiprotein-nanofibers contained β-sheet-rich amyloid-like conformers, and we find that gain of charge-complementarity and H-bond-promoting sticky-groups are crucial for fabricating heterogeneous nanofibers. Unlike self-assembly, a lower activation energy barrier was observed for coassembly process, and coaggregation rates increased with increasing degree of heterogeneity in protein mixture. The heterogeneous nanofibers exhibit surface-catalyzing property by hastening dopamine oxidation and triggering amyloid-cross-seeding of diverse proteins, and we also observed their cellular internalization and cytotoxic effect. Our results provide experimental and conceptual foundations for the construction of protein-based hybrid nanomaterials relevant to both biological and material science research.