Amino-acid-encoded biocatalytic self-assembly enables the formation of transient conducting nanostructures

Abstract

Aqueous compatible supramolecular materials hold promise for applications in environmental remediation, energy harvesting and biomedicine. One remaining challenge is to actively select a target structure from a multitude of possible options, in response to chemical signals, while maintaining constant, physiological conditions. Here, we demonstrate the use of amino acids to actively decorate a self-assembling core molecule in situ, thereby controlling its amphiphilicity and consequent mode of assembly. The core molecule is the organic semiconductor naphthalene diimide, functionalized with D- and L- tyrosine methyl esters as competing reactive sites. In the presence of α-chymotrypsin and a selected encoding amino acid, kinetic competition between ester hydrolysis and amidation results in covalent or non-covalent amino acid incorporation, and variable supramolecular self-assembly pathways. Taking advantage of the semiconducting nature of the naphthalene diimide core, electronic wires could be formed and subsequently degraded, giving rise to temporally regulated electro-conductivity.

Enhanced Fluorescence for Bioassembly by Environment‐Switching Doping of Metal Ions

“…Atomic force microscopy (AFM) analysis demonstrated that the cyclodipeptides self‐assembled into diverse architectures with dimensions ranging from dozens to hundreds of nanometers, including nanospheres (cyclo‐WW), nanofibers (cyclo‐HH, cyclo‐FF, cyclo‐HY, cyclo‐WH, cyclo‐WY, cyclo‐HF, cyclo‐FY) and platelets (cyclo‐YY, cyclo‐FW) ( Table 1 ; Figure S2, Supporting Information). This implies that the supramolecular morphologies can be finely modulated by simply modifying the peptide residues . High‐magnification AFM revealed that alongside the larger supramolecular morphologies, nanoparticles of 2 to 10 nm were also present.…”

Stoichiometry-controlled secondary structure transition of amyloid-derived supramolecular dipeptide co-assemblies

“…the transition between β-sheet and helix), several strategies have been reported aiming to control the structural conversion and shift the equilibrium in either direction by changing various conditions 18 , including temperature 19,20 , pH 21 , ion strength 22 , the presence of metal ions 23,24 , X-N Acyl migration 25 , and co-assembly with additives 26,27 . The coassembly approach is particularly attractive since supramolecular non-covalent interactions, such as hydrogen bonding, π-π stacking, van der Waals interactions, and hydrophobic interactions [28][29][30][31][32][33][34][35][36][37][38][39][40][41] , are usually influenced and determined by the stoichiometric ratio of the system components, leading to completely different stacking and switched structural conformations. However, analysis of secondary structure transition of amyloid-like fibrils from β-sheet to helix triggered by the co-assembly approach remains extremely challenging.…”

Visible-light photooxidation in water by 1O2-generating supramolecular hydrogels

“…36,37 This versatile and reproducible biocatalytic assembly approach previously provided functional hydrogels by avoiding productive kinetic aggregates, and is especially relevant to self-assembly involving poorly soluble functional components. 38,39 Here, the precursors for these low molecular weight gelators (LMWGs) are composed of the chromophore diketopyrrolopyrrole (DPP) with amino acid methyl esters connected through a linker appended to the heterocyclic N ( Fig. 1).…”