Molecular Plumbing to Bend Self-Assembling Peptide Nanotubes.
Ontology highlight
ABSTRACT:
SUBMITTER: Novelli F
PROVIDER: S-EPMC8456905 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The lipid bilayer membranes are Nature's dynamic structural motifs that individualize cells and keep ions, proteins, biopolymers and metabolites confined in the appropriate location. The compartmentalization and isolation of these molecules from the external media facilitate the sophisticated functions and connections between the different biological processes accomplished by living organisms. However, cells require assistance from minimal energy shortcuts for the transport of molecules across membranes so that they can interact with the exterior and regulate their internal environments. Ion channels and pores stand out from all other possible transport mechanisms due to their high selectivity and efficiency in discriminating and transporting ions or molecules across membrane barriers. Nevertheless, the complexity of these smart "membrane holes" has driven researchers to develop simpler artificial structures with comparable performance to the natural systems. As a broad range of supramolecular interactions have emerged as efficient tools for the rational design and preparation of stable 3D superstructures, these results have stimulated the creativity of chemists to design synthetic mimics of natural active macromolecules and even to develop artificial structures with functions and properties. In this Account, we highlight results from our laboratories on the construction of artificial ion channel models that exploit the self-assembly of conformationally flat cyclic peptides (CPs) into supramolecular nanotubes. Because of the straightforward synthesis of the cyclic peptide monomers and the complete control over the internal diameter and external surface properties of the resulting hollow tubular suprastructure, CPs are the optimal candidates for the fabrication of ion channels. The ion channel activity and selective transport of small molecules by these structures are examples of the great potential that cyclic peptide nanotubes show for the construction of functional artificial transmembrane transporters. Our experience to date suggests that the next steps for achieving conceptual devices with better performance and selectivity will derive from the topological control over cyclic peptide assembly and the functionalization of the lumen.
| S-EPMC3867521 | biostudies-literature
Project description:Hepatitis C virus (HCV) infects chronically 3% of the world population and the current therapy against this pathogen is only partially effective. With the aim of developing novel antiviral strategies against HCV, we screened a D,L-?-peptide library using an unbiased methodology based on a cell culture infection system for HCV. We found a family of highly active amphiphilic eight-residue cyclic D,L-?-peptides that specifically blocked entry of all tested HCV genotypes into target cells at a postbinding step without affecting infection by other enveloped RNA viruses. Structure-activity relationship studies indicate that antiviral activity was dependent on cyclic D,L-?-peptide self-assembly processes and that, although they possess a net neutral charge, they display a characteristic charge distribution. Our results indicate that supramolecular amphiphilic peptide structures constitute a class of highly selective HCV entry inhibitors.
| S-EPMC3225806 | biostudies-literature
Project description:Here we show that 4-aminocyclohexanecarboxylic acid is a rigid stretcher building block for the preparation of cyclic peptides that self-assemble to form peptide nanotubes with large diameter and hydrophobic pores. The hydrophobic properties of the resulting nanotubes provided by the two methylene groups per δ-residue allow the encapsulation of C60 moieties forming a new type of bionanopeapod structure.
| S-EPMC6240800 | biostudies-literature
Project description:Rational molecular design of self- assembling peptide-based materials that spontaneously form self-supporting hydrogels shows potential in many healthcare applications. Binary peptides based on complementary charged sequences are developed, and the use of biophysical analysis and cell-based studies highlights that the charged interactions can influence the properties of peptide materials and ultimately affect biomaterial applications.
| S-EPMC3607250 | biostudies-literature
Project description:A series of self-assembling multidomain peptides have been designed, synthesized, and tested for their ability to individually suspend single-walled carbon nanotubes (SWCNTs) in water while preserving strong near-IR nanotube luminescence. Photometric and spectral measurements on individual SWCNTs revealed that emission in the common biocompatible coating agents Pluronic F127, ss-DNA, and BSA is approximately an order of magnitude weaker than in the bioincompatible ionic surfactant SDBS. By contrast, one of the engineered peptides gave SWCNT emission approximately 40% as intense as in SDBS. A strong inverse correlation was also found between the spectral line widths of coated SWCNTs and the efficiency of their emission. Peptides with rationally designed self-assembly properties appear to be promising coatings that may enable SWCNT optical sensing applications in biological environments.
| S-EPMC2639792 | biostudies-literature
Project description:The designer self-assembling peptide RADA16-I forms nanofiber matrices which have shown great promise for regenerative medicine and three-dimensional cell culture. The RADA16-I amino acid sequence has a ?-strand-promoting alternating hydrophobic/charged motif, but arrangement of ?-strands into the nanofiber structure has not been previously determined. Here we present a structural model of RADA16-I nanofibers, based on solid-state NMR measurements on samples with different schemes for (13)C isotopic labeling. NMR peak positions and line widths indicate an ordered structure composed of ?-strands. The NMR data show that the nanofibers are composed of two stacked ?-sheets stabilized by a hydrophobic core formed by alanine side chains, consistent with previous proposals. However, the previously proposed antiparallel ?-sheet structure is ruled out by measured (13)C-(13)C dipolar couplings. Instead, neighboring ?-strands within ?-sheets are parallel, with a registry shift that allows cross-strand staggering of oppositely charged arginine and aspartate side chains. The resulting structural model is compared to nanofiber dimensions observed via images taken by transmission electron microscopy and atomic force microscopy. Multiple NMR peaks for each alanine side chain were observed and could be attributed to multiple configurations of side chain packing within a single scheme for intermolecular packing.
| S-EPMC3946435 | biostudies-literature
Project description:The plasmonic properties of silver nanoparticle (AgNP) arrays are directly controlled by AgNP size, shape, and spatial arrangement. Reported here is a strategy to prepare chiral AgNP arrays templated by two constitutionally isomeric aromatic peptide amphiphiles (APAs), KSC'EKS and C'EKSKS (KS = S-aroylthiooxime-modified lysine, C' = citrulline, and E = glutamic acid). In phosphate buffer, both APAs initially self-assembled into nanoribbons with a similar geometry. However, in the presence of silver ions and poly(sodium 4-styrenesulfonate) (PSSS), one of the nanoribbons (KSC'EKS) turned into nanohelices with a regular twisting pitch, while the other (C'EKSKS) remained as nanoribbons. Both were used as templates for synthesis of arrays of ∼8 nm AgNPs to understand how small changes in molecular structure affect the plasmonic properties of these chiral AgNP/APA hybrids. Both hybrids showed improved colloidal stability compared to pure AgNPs, and both showed enhanced sensitivity as surface-enhanced Raman spectroscopy (SERS) substrates for model analytes, with nanohelices showing better SERS performance compared to their nanoribbon counterparts and pure AgNPs.
| S-EPMC7657666 | biostudies-literature
Project description:In recent years, fabricating flexible one-dimensional nanofibers with a high aspect ratio and controlling their two-dimensional patterns on a certain surface have attracted more and more attention. Although molecular self-assembly as a useful strategy has been widely used to obtain nanofibers from soft materials such as peptides and polymers, extremely long nanofibers with high flexibility were rarely reported, and it's even more challenging to organize these organic nanofibers into ordered patterns in a controllable manner. In this study, we designed a flat-wedge-shaped bolaamphiphilic peptide which could self-assemble into ultra-flexible long nanofibers. These nanofibers were deposited on a mica surface by long-term incubation and exhibited various self-patterning behaviours as controlled by intended treatment. By changing the incubation time on the mica surface, vapour pH in the incubation device, and the peptide concentration, various patterns including nanofiber coils, parallel or single straight long nanofibers, and a network of hexagonally aligned short nanofibers could be obtained. These results indicated that not only the nanostructure formed by self-assembling peptides, but also the higher-order patterning behaviour of the nanostructures could be rationally controlled, providing a promising strategy for fabricating complicated nanoscale architectures with various potential applications.
| S-EPMC9419878 | biostudies-literature
Project description:The first computationally designed self-assembling oligomer consisting of exclusively ?-amino acids (?AAs) is presented. The packing of a ?-3(14) helix into coiled-coils of varying stoichiometries as a function of amino acid sequence is examined. ?-Peptides with hVal repeating every third residue in the sequence appeared to have a strong propensity to pack into hexameric bundles. The designed sequence was synthesized and characterized with CD spectroscopy, NMR, and analytical ultracentrifugation, suggesting that the peptide adopts a well-folded hexameric structure.
| S-EPMC3807245 | biostudies-literature
Project description:An ability to mimic the boundaries of biological compartments would improve our understanding of self-assembly and provide routes to new materials for the delivery of drugs and biologicals and the development of protocells. We show that short designed peptides can be combined to form unilamellar spheres approximately 100 nanometers in diameter. The design comprises two, noncovalent, heterodimeric and homotrimeric coiled-coil bundles. These are joined back to back to render two complementary hubs, which when mixed form hexagonal networks that close to form cages. This design strategy offers control over chemistry, self-assembly, reversibility, and size of such particles.
| S-EPMC6485442 | biostudies-literature