Allostery‐Mimicking Self‐assembly of Helical Poly(phenylacetylene) Block Copolymers and the Chirality Transfer

Abstract

Allostery can regulate protein self‐assembly which further affects biological activities, and achieving precise control over the chiral suprastructures during self‐assembly remains challenging. Herein, to mimic the allosterical nature of proteins, the poly(phenylacetylene) block copolymers PPA‐b‐PsmNap with the dynamic helical backbone were synthesized to investigate their conformational‐transition‐induced self‐assembly. As the helical conformation of the block PsmNap spontaneously transforms from cis‐transiod to cis‐cisoid, the decreasing solubility of PsmNap blocks in THF induced self‐assembly of PPA‐b‐PsmNap. The self‐assembly structures of copolymers can sequentially evolve from vesicles to nanobelts to helical strands during the process of conformation transformation. The screw sense of final helical strands was strictly correlated to the helicity of the block PsmNap. This is helpful to understand the mechanism of allostery‐modulated self‐assembly.

Self-Assembly of Poly(Janus particle)s into Unimolecular and Oligomeric Spherical Micelles

“…As shown in Figure 4, Tables S3 and S4, and Figure S11, unimolecular spherical micelles were obtained in DPD simulations after minimizing the total free energy. Additionally, simulation results also showed that the diameters of unimolecular spherical micelles formed by solution self-assembly of poly(APOSS-BPOSS) 12 , poly(APOSS-BPOSS) 17 , poly(APOSS-BPOSS) 22 , and poly-(APOSS-BPOSS) 35 were 3.25, 3.58, 4.44, and 5.02 nm, respectively. Considering the inevitable errors of the coarse-grained (CG) model and experimental errors, the micellar sizes obtained by simulations were consistent with the experimental results measured by DLS (3.4, 3.6, 3.7, and 4.5 nm for n = 12, 17, 22, and 35, respectively).…”

“…The successful deprotection of the tert-butyl group was verified by 1 H NMR data. For example, in the 1 H NMR spectrum of poly(APOSS-BPOSS) 12 (Figure 1a, black curve), signals of protons in the tert-butyl group at δ 1.47 ppm (peak c) completely disappeared, while signals of protons in carboxyl groups at δ 4.57 ppm (peak e) appeared (the residue signals around 1.50 ppm were denoted to inevitable water). Then, we explored the self-assembly behaviors of poly-(APOSS-BPOSS) n in solution.…”

“…Air-dried samples from prepared solution were examined by bright-field transmission electron microscopy (TEM; sample preparation was described in the Supporting Information (SI)), and typical spherical morphologies were observed for all poly(APOSS-BPOSS) n samples with an initial concentration of 2 mg/mL (Figure S7). The diameters of these spherical micelles formed by poly(APOSS-BPOSS) 12 , poly(APOSS-BPOSS) 17 , poly-(APOSS-BPOSS) 22 , and poly(APOSS-BPOSS) 35 were measured by TEM as 3.2 ± 0.5, 3.3 ± 0.5, 3.5 ± 0.5, and 4.2 ± 0.6 nm, respectively. To further confirm the morphologies and diameters of these spherical micelles, we performed DLS characterization of all solutions.…”

“…The synthesis of well-defined nanoscale JPs with molecular precision, high uniformity, and shape and volume persistence is usually challenging. Traditionally, JPs can be constructed by inorganic nanoparticles, colloidal particles, or an amphiphilic flexible polymer chain with special topological structures; however, their large variations in sizes, shapes, or flexible conformation result in limited controllability of their self-assembly to three-dimensional long-range ordered structures. − In this respect, researchers have recently designed and synthesized a set of molecular JPs based on volume and shape-persistent molecular nanoparticles (MNPs), such as fullerene (C60), polyoxometalate (POM), and polyhedral oligomeric silsesquioxanes (POSS) , through efficient chemical transformations like “click” reactions. − The resulting molecular JPs can self-assemble into several unconventional structures in solution and bulk, − attributing to the symmetry breaking in both molecular geometries and chemical interactions. − Besides that, diverse functional groups are able to be efficiently incorporated into MNPs, affording these MNP-based molecular JPs with specific functions. In this regard, constructing molecular JPs using MNPs is not only of scientific importance, but also provides a versatile platform to generate functional materials with nanosized features.…”

Chiral transfer‐dictated self‐assembly of chiral block copolymers

“…In addition, the erasing/inversion of morphological chirality by manipulating the stimuli-responsive conformational chirality of BCPs* not only proved the strong relationships between conformational and morphological chirality, but it also represented a novel methodology on morphological control. [128]…”