Abstract Intimately connected to the rule of life, chirality remains a long-time fascination in biology, chemistry, physics and materials science. Chiral structures, e.g., nucleic acid and cholesteric phase developed from chiral molecules are common in nature and synthetic soft materials. While it was recently discovered that achiral but bent-core mesogens can also form chiral helices, the assembly of chiral microstructures from achiral polymers has rarely been explored. Here, we reveal chiral emergence from achiral conjugated polymers, in which hierarchical helical structures are developed through a multistep assembly pathway. Upon increasing concentration beyond a threshold volume fraction, dispersed polymer nanofibers form lyotropic liquid crystalline (LC) mesophases with complex, chiral morphologies. Combining imaging, X-ray and spectroscopy techniques with molecular simulations, we demonstrate that this structural evolution arises from torsional polymer molecules which induce multiscale helical assembly, progressing from nano- to micron scale helical structures as the solution concentration increases. This study unveils a previously unknown complex state of matter for conjugated polymers that can pave way to a field of chiral (opto)electronics. We anticipate that hierarchical chiral helical structures can profoundly impact how conjugated polymers interact with light, transport charges, and transduce signals from biomolecular interactions and even give rise to properties unimagined before.
more »
« less
Encoding hierarchical assembly pathways of proteins with DNA
The structural and functional diversity of materials in nature depends on the controlled assembly of discrete building blocks into complex architectures via specific, multistep, hierarchical assembly pathways. Achieving similar complexity in synthetic materials through hierarchical assembly is challenging due to difficulties with defining multiple recognition areas on synthetic building blocks and controlling the sequence through which those recognition sites direct assembly. Here, we show that we can exploit the chemical anisotropy of proteins and the programmability of DNA ligands to deliberately control the hierarchical assembly of protein–DNA materials. Through DNA sequence design, we introduce orthogonal DNA interactions with disparate interaction strengths (“strong” and “weak”) onto specific geometric regions of a model protein, stable protein 1 (Sp1). We show that the spatial encoding of DNA ligands leads to highly directional assembly via strong interactions and that, by design, the first stage of assembly increases the multivalency of weak DNA–DNA interactions that give rise to an emergent second stage of assembly. Furthermore, we demonstrate that judicious DNA design not only directs assembly along a given pathway but can also direct distinct structural outcomes from a single pathway. This combination of protein surface and DNA sequence design allows us to encode the structural and chemical information necessary into building blocks to program their multistep hierarchical assembly. Our findings represent a strategy for controlling the hierarchical assembly of proteins to realize a diverse set of protein–DNA materials by design.
more » « less- NSF-PAR ID:
- 10307883
- Publisher / Repository:
- Proceedings of the National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 118
- Issue:
- 40
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- Article No. e2106808118
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
more » « less
Abstract Magnetic assembly at the nanoscale level holds great potential for producing smart materials with high functional and structural diversity. Generally, the chemical, physical, and mechanical properties of the resulting materials can be engineered or dynamically tuned by controlling external magnetic fields. This Review analyzes the recent research progress on nanoscale magnetic assembly approaches toward the development of smart materials. The magnetic interactions between nanoparticles (both magnetic and nonmagnetic) and the interactions between nanoparticles and external magnetic fields are fully expatiated based on numerical simulations. In particular, the advancements of nanoscale magnetic assembly in responsive optical nanostructures, shape‐morphing systems, and advanced materials with tunable surface properties are introduced in three subsections. The key roles of magnetic interactions in nanoscale assembly toward customizable physical and chemical properties are highlighted, with focus on how to enable direct manipulation of the positional and orientational orders of the building blocks and orientational control of soft matrices through the incorporation of anisotropic magnetic structures.
-
Using Self-Assembling Peptides to Integrate Biomolecules into Functional Supramolecular BiomaterialsThroughout nature, self-assembly gives rise to functional supramolecular biomaterials that can perform complex tasks with extraordinary efficiency and specificity. Inspired by these examples, self-assembly is increasingly used to fabricate synthetic supramolecular biomaterials for diverse applications in biomedicine and biotechnology. Peptides are particularly attractive as building blocks for these materials because they are based on naturally derived amino acids that are biocompatible and biodegradable; they can be synthesized using scalable and cost-effective methods, and their sequence can be tailored to encode formation of diverse architectures. To endow synthetic supramolecular biomaterials with functional capabilities, it is now commonplace to conjugate self-assembling building blocks to molecules having a desired functional property, such as selective recognition of a cell surface receptor or soluble protein, antigenicity, or enzymatic activity. This review surveys recent advances in using self-assembling peptides as handles to incorporate biologically active molecules into supramolecular biomaterials. Particular emphasis is placed on examples of functional nanofibers, nanovesicles, and other nano-scale structures that are fabricated by linking self-assembling peptides to proteins and carbohydrates. Collectively, this review highlights the enormous potential of these approaches to create supramolecular biomaterials with sophisticated functional capabilities that can be finely tuned to meet the needs of downstream applications.more » « less
-
more » « less
Abstract Joining biology with materials science requires the ability to design, engineer and control biology/solid‐state materials interfaces at the molecular level. The specific molecular interactions that take place among biomolecules, known as molecular recognition, enable all aspects of molecular processes in living systems prerequisite to the biological functions. Having the ability to establish specific biological interactions between the solid materials and biological constituents is essential for precise design of biologically viable soft interfaces that are molecularly tailored at solid surfaces. Solid‐binding peptides offer excellent opportunities in surface biofunctionalization over the traditionally utilized chemical approaches which generally make use of covalent bonds for surface molecular attachments with limited flexibility. Solid‐binding peptides are selected using directed evolution techniques using genotype to phenotype relationships and therefore referred also as genetically engineered peptides for inorganics (GEPI) and exclusively bind to solid materials using molecular recognition. Here, the peptide has weak interactions at multiple contact points that are established between the biomolecule and the solid lattice, and then folds into a conformation coherent with the underlying solid lattice through self‐organization on the surface. Solid‐binding peptides provide an unprecedented biological advantage as modular building blocks to couple biological and synthetic entities at the bio–solid interfaces. Taking full advantage of biology's versatility, they can easily be engineered to form chimeric molecules with inherent multifunctionality displaying biofunctional molecular entities, such as enzymes, co‐factors, antimicrobial peptides, antibodies, nucleic acids and molecular probes that target biomarkers. This minireview provides an insight into the key principles of solid‐binding peptides for advancing surfaces biofunctionalization by a selected set of examples on chimeric functions built upon linking, displaying and assembling functional molecular moieties at solid surfaces ranging from enzymatic biocatalysis to antimicrobial coatings. Modular multifunctional peptide design offers to tune molecular processes with coupled biological functions for a wide variety of applications in biotechnology, nanotechnology and medicine.
-
more » « less
Abstract Well‐defined tunable nanostructures formed through the hierarchical self‐assembly of peptide building blocks have drawn significant attention due to their potential applications in biomedical science. Artificial protein polymers derived from elastin‐like polypeptides (ELPs), which are based on the repeating sequence of tropoelastin (the water‐soluble precursor to elastin), provide a promising platform for creating nanostructures due to their biocompatibility, ease of synthesis, and customizable architecture. By designing the sequence and composition of ELPs at the gene level, their physicochemical properties can be controlled to a degree that is unmatched by synthetic polymers. A variety of ELP‐based nanostructures are designed, inspired by the self‐assembly of elastin and other proteins in biological systems. The choice of building blocks determines not only the physical properties of the nanostructures, but also their self‐assembly into architectures ranging from spherical micelles to elongated nanofibers. This review focuses on the molecular determinants of ELP and ELP‐hybrid self‐assembly and formation of spherical, rod‐like, worm‐like, fibrillar, and vesicle architectures. A brief discussion of the potential biomedical applications of these supramolecular assemblies is also included.
