Allosteric regulation of metal-binding sites inside an optically-active helical foldamer and its tubular assemblies.

A helical foldamer possessing conformationally switchable metal-binding linkers underwent supramolecular polymerization to form a helical nanofiber. A reversible helix-to-helix transition of the helical nanofiber took place upon cooperative binding and release of Ag(i) ions via a metal-coordination-driven W-to-U-shape conformational change of the linkers in a positive allosteric manner.