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.

Self-Assembled Nanostructures Regulate H2S Release from Constitutionally Isomeric Peptides

“…This kind of molecular packing behavior has been widely found in peptide systems composed of uniform (AB) n amino acid periodicity (where A and B are polar and nonpolar residues, respectively). 11,29−32 Importantly, these images for peptide K S EK S E indicate that non-natural amino acids, such as the derivatized K residues used here, can also promote twisted ribbon formation. The pitch of the twisted ribbons measured from the cryo-TEM micrographs was 103 ± 8 nm.…”

Significant Enhancement of Proton Transport in Bioinspired Peptide Fibrils by Single Acidic or Basic Amino Acid Mutation

“…These effects were attributed to sequence dependent changes of the fibrils' morphology, as well as to direct contribution of various peptide side chains. Accordingly, noncanonical aromatic amino acids have been used to enhance electron conductivity of peptide fibrils . We have further demonstrated the possibility of inducing proton and mixed proton–electron transport in such fibrils .…”

Structural and Spectroscopic Properties of Assemblies of Self-Replicating Peptide Macrocycles

“… 30 Because of the many identical molecules in a self-assembled nanostructure, these systems typically represent a well-averaged ensemble and should thus form an ideal case for the frequency mapping algorithms originally developed for proteins. In addition, the structural heterogeneity of supramolecular systems (and sometimes polymorphism 16 , 31 , 32 ) is intrinsically sampled when multiple snapshots from the MD are considered in higher level calculations.…”