Copolymers peptide block

Fig. 6.6.4. Reversible self-assembly of PEO-b-peptide block copolymers based on protein-folding motifs.

In biological membranes, integral proteins are amphipatic molecules their hydro-phobic moiety is embedded in the lipid bilayer and their hydrophilic moiety protrudes from the surface of the membrane279. So, it was interesting to prepare polymeric models of such amphipatic proteins. For that purpose, two new classes of block copolymers have been synthetized in Orleans, namely copolymers with a polyvinyl block and a polypeptide block and copolymers with a saccharide and a peptide block. We shall give some information concerning the preparation of these copolymers and then describe their structure. 

D) Synthesis and Structure of Copolymers with Saccharide and Peptide Blocks... 

In these copolymers, the saccharide block is a carbohydrate fraction (0Q or Op) of a glycoprotein (ovomucoid) and the peptide block is a poly(benzyl-L-glutamate) block or a poly(cinnamyl-L-glutamate) block. 

Copolymers with a hydrophilic saccharide block and a hydrophobic peptide block exhibit mesophases in dimethyl sulfoxide for DMSO concentrations ranging from zero to a limiting value which depends upon the nature of the carbohydrate block and the composition of the copolymer284 the range of stability of the mesophases increases with the saccharide content of the copolymer285. ... 

The lamellar structure of saccharide-peptide block copolymers presents many analogies with the structure of copolymers with a hydrophobic polyvinyl block and a hydrophobic polypeptide block and exhibits a similar behaviour as a function of the solvent concentration. When the solvent concentration increases the total thickness of a sheet and the thickness of the carbohydrate layer both increase while the thickness of the polypeptide layer remains nearly constant284. ... 

Alternative total solid phase-based strategies for the preparation of polymer-peptide block copolymers were based on the polymerization of the synthetic polymer block from the supported peptide segment using either nitroxide-mediated radical polymerization (NMP) or ATRP (Fig. 15) [64,65]. 

Keywords Block copolymer Peptide Secondary structure Self-assembly Vesicle Hierarchical structure... 

This review discusses the sohd-state structure, organization and properties of peptide-synthetic hybrid block copolymers. Hybrid block copolymers composed of a synthetic block and a peptide segment are an interesting class of materials, both from a structural and a functional point of view [14-16]. Peptide sequences can adopt ordered conformations such as a-hehces or /J-strands. In the former case, this leads to block copolymers with rod-coil character. Peptide sequences with a /1-strand conformation can un-... 

The microphase-separated structures formed by the PB-based y-benzyl-L-glutamate containing triblock copolymers appeared to be sensitive to the conformation of the peptide blocks [28]. When instead of y-benzyl-L-glutamate N-carboxyanhydride an equimolar mixture of y-benzyl-L-glutamate AT-car-boxyanhydride and y-benzyl-D-glutamate AT-carboxyanhydride was used for... 

Peptide-poly(ethylene glycol) (PEG) block copolymers are ofparticiflar interest, both from a structural and a functional point of view. Poly(ethylene glycol) is also often referred to as poly(ethylene oxide) (PEG). Throughout this article, however, this polyether will be referred to as PEG. In contrast to the hybrid block copolymers discussed in the previous paragraphs, which were based on amorphous synthetic polymers, PEG is a semi-crystalline polymer. In addition to microphase separation and the tendency of the peptide blocks towards aggregation, crystallization of PEG introduces an additional factor that can influence the structure formation of these hybrid block copolymers, furthermore, PEG is an FDA approved biocompatible polymer, which makes peptide-PEG hybrid block copolymers potentially interesting materials for biomedical applications. 

Ma et al. have investigated the solid-state structure and properties of three poly(ethylene glycol)-b-poly(L-alanine) (PEG-PLA) diblock copolymers that were prepared from a PEG macroinitiator with a number-average molecular weight of 2000 [62]. The diblock copolymers contained 39.8, 49.6 and 65.5 mol% PLA. PTIR spectra of the diblock copolymers were indicative for an a-helical secondary structure of the peptide block. DSC traces of the polymers, in particular for the sample containing 49.6 mol % PLA, showed features of both of the respective homopolymers, which led the authors to propose a microphase-separated bulk structure. 

Fig. 1 a-d Chemical structures of linear peptide block copolymers a 1,2-Polybutadiene-block-poly(L-glutamate) (PB-h-PLGlu). b Polybutadiene-Wock-poly(L-lysine) (PB-h-PLLys). c Poly (L-glutamate)-Wock-poly(L-lysine) (PLGlu-h-PLLys). d Poly(methyl methacrylate)-Wock-peptide-Wock-poly(methyl methacrylate) (PMMA-h-peptide-h-PMMA)... 

Yusufoglu, Y. Hu, Y. Kanapathipillai, M. Kramer, M. Kalay, Y. E. Thiyagarajan, P. Akinc, M. Schmidt-Rohr, K. Mallapragada, S., Bioinspired synthesis of self-assembled calcium phosphate nanocomposites using block copolymer-peptide conjugates. Journal of Materials Research 2008, 23, (12), 3196-3212. 

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