Carbodiimide‐Fueled Assembly of π‐Conjugated Peptides Regulated by Electrostatic Interactions**

Abstract

Peptides naturally have stimuli-adaptive structural conformations that are advantageous for endowing synthetic materials with dynamic functionalities. Here, we investigate a carbodiimide-based approach, combined with electrostatic modulation, to instruct π-conjugated peptides to self-assemble and be responsive to thermal disassembly cues upon consumption of the assembly trigger. Quaterthiophenefunctionalized peptides are utilized as a model system herein to study the formation of kinetically trapped structures at non-equilibrium states. Peptides were designed to have aspartic acid at the termini to allow intramolecular anhydride formation upon adding carbodiimide, which consequentially reduces the electrostatic repulsion and facilitates assembly. We show that the carbodiimide-fueled assembly and subsequent thermally assisted disassembly can be modulated by the net charge of the peptidic monomers, suggesting an assembly mechanism that can be encoded by sequence design. This carbodiimide-based approach for the assembly of designer π-conjugated systems offers a unique opportunity to develop bioelectronic supramolecular materials with controllable formation of transient structures.

Thermochromic Behavior of Polydiacetylene Nanomaterials Driven by Charged Peptide Amphiphiles

“…These three peptide-polymer samples all form one-dimensional (1-D) nanostructures but with significant differences in the aspect ratio, similar to sequence-dependent morphological variations previously reported in other self-assembling peptide systems. 34 − 36 D 3 GV-PDA exhibited the shortest mean length for nanostructures (with the broadest distribution), while the equimolar coassemblies are more polydisperse in nanostructure lengths, with a mean length average that is skewed closer to the mean length of D 3 GV-PDA assemblies ( Figure 1 e). Considering the electrostatic interactions that coexist with H-bonding and hydrophobic interactions for the peptide-polymers under investigation, our charged single-component peptide-PDA samples represent the control system with repulsive electrostatic interactions, while the two-component/coassembled peptide-PDA can be considered to have both repulsive (within blocks of the same peptides) and attractive (at the interface of K 3 GV and D 3 GV units) electrostatic interactions.…”

Lattice-guided assembly of optoelectronically active π-conjugated peptides on 1D van der Waals single crystals

“…2A and fig. S1) (51)(52)(53). The ideality of the model DDD-4T πconjugated peptide relies on both the attractive semiconducting and optoelectronic properties of high aspect ratio 1D nanostructures formed by peptide-functionalized 4T units, as well as the pH-triggered hydrogen bonding interactions arising from the incorporation of three aspartic acids that reliably facilitate supramolecular 1D growth (45,47,50,54,55).…”

“…Synthesis of the π-conjugated peptide of DDD-4T was conducted according to the reported methods ( 51 , 52 ). Peptides were synthesized using a Liberty Blue peptide synthesizer using Fmoc-protected amino acids, starting from Wang resin preloaded with the first amino acid [Wang-Asp(OtBu) = 0.6 mmol g −1 , Advanced ChemTech].…”

Chemically fueled dynamic switching between assembly-encoded emissions

“…In this context, the carbodiimide-fueled transformation of a dicarboxylic acid to its anhydride form has emerged as a powerful tool to control the molecular packing as well as self-assembly behavior of peptide-based small molecules. 45,67–69…”