Self-folding of supramolecular polymers into bioinspired topology
Deepak D. Prabhu, Keisuke Aratsu, Yuichi Kitamoto, Hayato Ouchi, Tomonori Ohba, Martin J. Hollamby, Nobutaka Shimizu, Hideaki Takagi, Rie Haruki, Shin-ichi Adachi, Shiki Yagai
Folding one-dimensional polymer chains into well-defined topologies represents an important organization process for proteins, but replicating this process for supramolecular polymers remains a challenging task. We report supramolecular polymers that can fold into protein-like topologies. Our approach is based on curvature-forming supramolecular rosettes, which affords kinetic control over the extent of helical folding in the resulting supramolecular fibers by changing the cooling rate for polymerization. When using a slow cooling rate, we obtained misfolded fibers containing a minor amount of helical domains that folded on a time scale of days into unique topologies reminiscent of the protein tertiary structures. Thermodynamic analysis of fibers with varying degrees of folding revealed that the folding is accompanied by a large enthalpic gain. The self-folding proceeds via ordering of misfolded domains in the main chain using helical domains as templates, as fully misfolded fibers prepared by a fast cooling rate do not self-fold.
Polymers, Thermal stability, Chemical stability, Thermodynamics