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.

中文翻译：

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乌贼Suckerin仿生肽形成具有鲁棒机械性能的淀粉样蛋白晶体

我们提出了从鱿鱼吸盘齿（SRT）的suckin蛋白衍生的肽序列（A1H1）形成的纤维的自组装。SRT是仅蛋白质的生物聚合物，具有非常规的一组物理化学和机械性能，包括高弹性模量和热塑性。我们从suckerins中鉴定了一个保守的肽结构单元，该结构单元具有组装成具有与天然SRT相似的机械性能的材料的能力。A1H1具有两亲特性，并自下而上自组装为毫米级纤维，这是通过添加极性非质子溶剂引发的。甲1H1纤维在高达239°C的温度下具有耐热性，并具有约7.7 GPa的弹性模量，这可以通过宽角度X射线散射（WAXS）鉴定出的富含β-片层的晶体结构块的紧密堆积来解释，层间和链间距离分别为5.37和4.38Å。分子动力学模拟证实了肽在纤维内富含Ala的末端的紧密堆积，我们提出了成熟肽纤维的纤维组装的层次模型。