Supramolecular Assembly of Comb-like Macromolecules Induced by Chemical Reactions that Modulate the Macromolecular Interactions In Situ

Abstract

Supramolecular polymerization or assembly of proteins or large macromolecular units by a homogeneous nucleation mechanism can be quite slow and require specific solution conditions. In nature, protein assembly is often regulated by molecules that modulate the electrostatic interactions of the protein subunits for various association strengths. The key to this regulation is the coupling of the assembly process with a reversible or irreversible chemical reaction that occurs within the constituent subunits. However, realizing this complex process by the rational design of synthetic molecules or macromolecules remains a challenge. Herein, we use a synthetic polypeptide-grafted comb macromolecule to demonstrate how the in situ modulation of interactions between the charged macromolecules affects their resulting supramolecular structures. The kinetics of structural formation was studied and can be described by a generalized model of nucleated polymerization containing secondary pathways. Basic thermodynamic analysis indicated the delicate role of the electrostatic interactions between the charged subunits in the reaction-induced assembly process. This approach may be applicable for assembling a variety of ionic soft matters that are amenable to chemical reactions in situ.

Reactions Coupled Self‐ and Co‐Assembly: A Highly Dynamic Process and the Resultant Spatially Inhomogeneous Structure

“…In recent years, research interest rises on how reactions or energy exchange can affect the assembly process . In this aspect, dissipative/non‐equilibrium assembly has been realized by coupling with reactions such as esterification, hydrolysis and others, to mimic the self‐assembly in energy‐consumption conditions in life system, and some special reactions, such as hydrolysis and polymerization, have been applied to trigger the assembly to construct complex structures or realize some special functions . These groundbreaking pieces of work have promoted self‐assemblies to transfer from static ones to dynamic ones.…”

“…[19,20] In this aspect, dissipative/non-equilibrium assembly has been realized by coupling with reactions such as esterification, hydrolysis and others, to mimic the self-assembly in energy-consumption conditions in life system, [21][22][23][24][25][26][27][28] and somes pecialr eactions, such as hydrolysisa nd polymerization, have been appliedt ot rigger the assembly to construct complex structures or realize some special functions. [29][30][31][32][33][34][35][36] These groundbreaking pieces of work have promoted self-assemblies to transfer from static ones to dynamic ones. However,r eactions that can couple with the self-assembly are still limited because they have to match the conditions and rates of self-assembly.W hat's more, the reactions are usually used to trigger the on-off of the assembly, the dynamic change of the compositions or structures of products upon environmental conditions haven't been realized by couplingwith environment-sensing reactions.…”

Regulating the Supramolecular Polymerization of Fibrous Crystalline Structures in Aqueous Solution

“…[ 17,18 ] Establishing a similar regulation mechanism in synthetic platforms should improve our abilities in the creation of supramolecular polymers with dynamic and tunable properties, and eventually approaching the level of sophistication found in nature's self‐organized, “active” supramolecular materials. [ 19–28 ]…”

“…[17,18] Establishing a similar regulation mechanism in synthetic platforms should improve our abilities in the creation of supramolecular polymers with dynamic and tunable properties, and eventually approaching the level of sophistication found in nature's self-organized, "active" supramolecular materials. [19][20][21][22][23][24][25][26][27][28] At least three basic design requirements that must be first met to approach this goal, especially for aqueous solutions where the solubility parameters are not as easily tuned as in organic solvents. First, the subunits or their precursors should have sites that allow for specific and coordinated non-covalent interactions (e.g., hydrogen bonding), but remain in an inactive and stable form under specific environmental conditions.…”

The generation of stabilized supramolecular nanorods from star-shaped polyglutamates

“…PGA can adopt different solution conformations depending on the degree of ionization, while pH represents a critical parameter for controlled supramolecular polymerization. 28,29 We performed circular dichroism studies of F3E10 at pH 7.5 (Fig. SI1 †) and observed that PGA adopts a random coil conformation.…”