Forced protein unfolding leads to highly elastic and tough protein hydrogels.

TitleForced protein unfolding leads to highly elastic and tough protein hydrogels.
Publication TypeJournal Article
Year of Publication2013
AuthorsFang, J., Mehlich A., Koga N., Huang J., Koga R., Gao X., Hu C., Jin C., Rief M., Kast J., Baker D., & Li H.
JournalNature communications
Date Published2013 Dec 19
KeywordsCollaborative Publication

Protein-based hydrogels usually do not exhibit high stretchability or toughness, significantly limiting the scope of their potential biomedical applications. Here we report the engineering of a chemically cross-linked, highly elastic and tough protein hydrogel using a mechanically extremely labile, de novo-designed protein that assumes the classical ferredoxin-like fold structure. Due to the low mechanical stability of the ferredoxin-like fold structure, swelling of hydrogels causes a significant fraction of the folded domains to unfold. Subsequent collapse and aggregation of unfolded ferredoxin-like domains leads to intertwining of physically and chemically cross-linked networks, entailing hydrogels with unusual physical and mechanical properties: a negative swelling ratio, high stretchability and toughness. These hydrogels can withstand an average strain of 450% before breaking and show massive energy dissipation. Upon relaxation, refolding of the ferredoxin-like domains enables the hydrogel to recover its massive hysteresis. This novel biomaterial may expand the scope of hydrogel applications in tissue engineering.


Alternate JournalNat Commun