The Strong Influence of Structure Polymorphism on the Conductivity of Peptide Fibrils

Abstract

Peptide fibril nanostructures have been advocated as components of future biotechnology and nanotechnology devices. However, the ability to exploit the fibril functionality for applications, such as catalysis or electron transfer, depends on the formation of well‐defined architectures. Fibrils made of peptides substituted with aromatic groups are described presenting efficient electron delocalization. Peptide self‐assembly under various conditions produced polymorphic fibril products presenting distinctly different conductivities. This process is driven by a collective set of hydrogen bonding, electrostatic, and π‐stacking interactions, and as a result it can be directed towards formation of a distinct polymorph by using the medium to enhance specific interactions rather than the others. This method facilitates the detailed characterization of different polymorphs, and allows specific conditions to be established that lead to the polymorph with the highest conductivity.

Supramolecular assemblies of a 1,8-naphthalimide conjugate and its aggregation-induced emission property

“…The details of gelation of NMI-GW-OMe is given in Table 1. Recently, several emerging properties 26,[36][37][38][39][40][41][42][43] of planar fluorophores have been observed in mixed solvents. One of them is supramolecular gelation [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] .…”

Macroscale Biomolecular Electronics and Ionics

“…Short peptides with the sequence of the core recognition motif (or similar sequences) can both inhibit the fibrillization process, as well as forming similar amyloid‐like structures by themselves . In recent years, Ashkenasy and co‐workers have used these short peptides as well as other fibril‐forming short peptides to increase the conduction across amyloid‐like fibrils . The main advantage of using short peptide sequences is the relative ease of chemical modifications in terms of amino acids and sequence changes.…”

“…Another group of fibril‐forming peptides that belong to the short peptide family but bear no resemblance to amyloid proteins/peptides in terms of the amino acid sequence are termed amyloid‐like structures. Several amyloid‐like structures which can self‐assemble from diverse peptide building blocks have been studied for their electrical conductance properties ( Figure ) . Ashkenasy and co‐workers have shown that both electrostatic and aromatic interactions can induce the fibrillization of (FKFE) 2 peptides to thin (3–5 nm) fibrils in water.…”

“…Several amyloid‐like structures which can self‐assemble from diverse peptide building blocks have been studied for their electrical conductance properties ( Figure ) . Ashkenasy and co‐workers have shown that both electrostatic and aromatic interactions can induce the fibrillization of (FKFE) 2 peptides to thin (3–5 nm) fibrils in water. They further showed that the fibrils are not conductive, but can gain conductivity by replacing one of the phenylalanines with a naphthalene diimide (Figure a) modified amino acid, and especially when the fibril is formed in water, i.e., when the amine and carboxylic groups are charged positively and negatively, respectively.…”

“…Peptide models for the formation of amyloid‐like structures. a) (FKFE) 2 sequence with a naphthalene diimide modification . b) Fmoc‐LLL .…”