Coiled-coil polypeptide self-assembly

Cai C, Zhu W, Chen T, Lin J, Tian X (2009) Synthesis and self-assembly behavior of amphiphilic polypeptide-based brush-coil block copolymers. J Polym Sci A Polym Chem 47 5967-5978... 

Owing to the well-defined stereochemistry, the diversities in choosing hydropbobic/hydrophilic amino acids, and specific secondary structures, polypeptides have been intensively investigated as a biomaterial.Contrary to the random hydrophobically driven self-assembly of the most synthetic polymer, the secondary structures of the polypeptides such as a-helix, /3-sheet, and random coil significantly affect the gelation behavior. 

Self-assembly of polypeptides via other naturally occurring or de novo designed self-assembling domains such as coiled coUs... 

Polypeptide Materials Based on other Naturally Occurring or De Novo Designed Self-Assembling Domains such as Coiled Coils... 

Besides the naturally occurring proteins, coiled-coil protein, amphiphilic block-copolypeptide, and two-component protein are also used for constructing self-assemblies with interest to biomaterial and biomedical engineering fields [3]. Figure 6.7 depicts the self-assemblies built from these proteins or polypeptides. 

Figure 6.7 Protein-based self-assembled nanomaterials and fabrication strategies (a) structure of coiled-coil polypeptide, (b) association of the end helices into coiled-coils results in hydrogel formation, (c) amphiphilic block copolymers assemble into extended tapered end fibers, forming hydrogels, and (d) association of two-component proteins to form a hydrogel. Modified firom Ref. [3] with permission.

Figure 24 Poly(butadiene-/)/ock- L-gliitamate)) copolymers self-assemble into peptosomes. These are vesicular aggregates stabilized by the polypeptide segments. The size of the peptosomes does not depend on the pH that is, the solvating peptide can perform a helix-to-coil transition as illustrated (transition from right to left). Reprinted with permission from Kukula, H. Schlaad, H. Antonietti, M. Forster, S. J. Am. Chem. Soc. 2002, 124,1658. Copyright 2002, American Chemical Society. ...

The combination of bio-inspired structure elements and classical polymer chemistry provides promising opportunities to design polymeric materials with unique solution and solid state properties. Examples are rod-coil type polymers comprising hehcal polypeptide and flexible vinyl polymer blocks. Block copolymers of this architecture are of interest from both functional and structural points of view. Compared to simple coil-coil block copoljmers the self-assembling of the rod-coil block copolymers is not only controlled by the microphase separation, but also by the tendency to form anisotropic supramole-cular assemblies. These competitive processes can lead to morphologies which are different from those commonly observed for block copolymers.f ... 

Fig. 48 Assembly of a lamellar-forming polypeptide-coil diblock copolymer depicting the main techniques employed in our studies. Small-angle X-ray scattering (SAXS) is employed for the domain spacing, d. C NMR and wide-angle X-ray scattering (WAXS) are employed to identify the type of the peptide secondary structure (a-helical in the schematic). WAXS is further employed to specify the lateral self-assembly of a-helices within the polypeptide domain (a hexagonal lattice is indicated). Dielectric spectroscopy (DS) and site-specific NMR techniques are employed for the dynamics. Furthermore, the most intense DS process provides the persistence length. Ip, of a-helical segments [181]...

Rubatat, L., Kong, X., Jenekhe, S.A. et al. (2008) Self-assembly of polypeptide/it-conjugated polymer/polypeptide triblock copolymers in rod-rod-iod and coil-iod-coil conformations. Macromolecules, 41,1846-1852. 

This chapter will focus on linear polymer structures composed of synthetic polypeptide or polypeptide-polymer systems formed in bulk. Our aim is to present an overview of bulk self-assembled structures from polypeptide-based conjugates, specifically diblock and triblock architectures. Recent advances in theoretical developments and the first phase diagrams of such kind of polypeptide rod-coil systems will be also presented. 

Figure 20.7 (Pseudo) experimental phase diagrams obtained for (a) polypeptide-based and (b) conductive-based block copolymers. (Reprinted with permission from N. Sary, L. Rubatat, C. Brochon et aL, Self-assembly of poly(diethylhexyloxy-/ -phenylenevinylene)- -poly(4-vinylpyridine) rod-coil block copolymer systems, Macromolecules, 40, 19, 6990-6997, 2007. 2007 American Chemical Society.)...

Kuo S-W, Lee H-F, Huang C-F, Huang C-J, Chang F-C (2008) Synthesis and self-assembly of helical polypeptide-random coil amphiphilic diblock copolymer. J Polym Sci A Polym Chem 46 3108-3119... 

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