iifr i-yvi



Ty r j¡ le-G I u - Ala- Leu - Ly s- Al a- GI lil C- y-^k^^iif" M ? 17,45, m - Jfi n 1 Jri f) = 1,2,3

the self-organization of the block copolymers. The self-assembly of PEO-b-peptide block copolymers inspired by coiled-coil protein-folding motifs can be described as an equilibrium between unimeric block copolymer molecules with partially ordered peptide blocks and intermolecular coiled-coil dimers and tetramers (Figure 6.6.4). The folding and unfolding of the peptide blocks is sensitive to temperature and concentration; this affords prospects for the development of polypeptide hybrid materials whose structure and properties can be precisely controlled by external stimuli. The PEO-b-peptide block copolymers are not amphiphilic and their self-organization is exclusively driven by the propensity of the peptide segments to fold into higher-order structures. As a result, only discrete, in this instance mainly dimeric and tetrameric, aggregates are found, in contrast with the large and polydisperse structures which are formed on self-assembly of conventional amphiphilic block copolymers. Although the work performed so far is merely a proof of concept, the experiments clearly demonstrate the feasibility of using concepts from protein folding to develop novel block copolymer-type materials whose self-organization is mediated by the formation of well-defined hierarchically organized supramolecular structures.

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