Squid suckerin biomimetic peptides form amyloid-like crystals with robust mechanical properties

• Main Authors: Hiew, Shu Hui, Sánchez-Ferrer, Antoni, Amini, Shahrouz, Zhou, Feng, Adamcik, Jozef, Guerette, Paul, Su, Haibin, Mezzenga, Raffaele, Miserez, Ali
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: Bioinformatics; Peptides
• Online Access: https://hdl.handle.net/10356/86572; http://hdl.handle.net/10220/45172
• Institution: Nanyang Technological University

We present the self-assembly of fibers formed from a peptide sequence (A1H1) derived from suckerin proteins of squid sucker ring teeth (SRT). SRT are protein-only biopolymers with an unconventional set of physicochemical and mechanical properties including high elastic modulus coupled with thermoplastic behavior. We have identified a conserved peptide building block from suckerins that possess the ability to assemble into materials with similar mechanical properties as the native SRT. A1H1 displays amphiphilic characteristics and self-assembles from the bottom-up into mm-scale fibers initiated by the addition of a polar aprotic solvent. A1H1 fibers are thermally resistant up to 239 °C, coupled with an elastic modulus of ∼7.7 GPa, which can be explained by the tight packing of β-sheet-enriched crystalline building blocks as identified by wide-angle X-ray scattering (WAXS), with intersheet and interstrand distances of 5.37 and 4.38 Å, respectively. A compact packing of the peptides at their Ala-rich terminals within the fibers was confirmed from molecular dynamics simulations, and we propose a hierarchical model of fiber assembly of the mature peptide fiber.