A short peptide hydrogel with high stiffness induced by 310-helices to beta-sheet transition in water

• Main Authors: Hiew, Shu Hui, Mohanram, Harini, Ling, Lulu, Guo, Jingjing, Sánchez-Ferrer, Antoni, Shi, Xiangyan, Pervushin, Konstantin, Mu, Yuguang, Mezzenga, Raffaele, Miserez, Ali
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Materials Science and Engineering; Engineering::Materials; β‐sheet Transition; Molecular Dynamics (MD) Simulations
• Online Access: https://hdl.handle.net/10356/138702; https://doi.org/10.21979/N9/7OITQJ
• Institution: Nanyang Technological University

Biological gels generally require polymeric chains that produce long-lived phys- ical entanglements. Low molecular weight colloids offer an alternative to macro- molecular gels, but often require ad-hoc synthetic procedures. Here, a short biomimetic peptide composed of eight amino acid residues derived from squid sucker ring teeth proteins is demonstrated to form hydrogel in water without any cross-linking agent or chemical modification and exhibits a stiffness on par with the stiffest peptide hydrogels. Combining solution and solid-state NMR, circular dichroism, infrared spectroscopy, and X-ray scattering, the peptide is shown to form a supramolecular, semiflexible gel assembled from unusual right-handed 310-helices stabilized in solution by π–π stacking. During gelation, the 310-helices undergo conformational transition into antiparallel β-sheets with formation of new interpeptide hydrophobic interactions, and molecular dynamic simulations corroborate stabilization by cross β-sheet oligomeriza- tion. The current study broadens the range of secondary structures available to create supramolecular hydrogels, and introduces 310-helices as transient building blocks for gelation via a 310-to-β-sheet conformational transition.