The straightforward syntheses of polyisocyanides containing the alanine–cysteine motif in their side chains have been achieved. Detailed characterization of the polymers revealed a well-defined and highly stable helical conformation of the polyimine backbone responsible for the formation of rodlike structures of over one hundred nanometers. The 41 helix is further stabilized by β-sheet-like interactions between the peptide arms. As a result, the cysteine sulfur atoms are regularly aligned along the polymer axis, which provides a unique platform for the scaffolding of various entities by using versatile click-chemistry postmodification approaches. For instance, pyrene derivatives were introduced through thio-specific reactions involving either maleimide, iodoacetamide, or thioester groups, leading to arrays of stacked chromophores with excimer-like emission. A water-soluble cysteine-rich polyisocyanide was successfully biotinylated and coupled to streptavidin.
- chromophoric scaffolding
- helical structures
- Click chemistry
le Gac, S., Le Gac, S., Schwartz, E., Schwartz, E., Koepf, M., Cornelissen, J. J. L. M., ... Nolte, R. J. M. (2010). Cysteine-containing polyisocyanides as versatile nanoplatforms for chromophoric and bioscaffolding. Chemistry: a European journal, 16(21), 6176-6186. https://doi.org/10.1002/chem.200903502