As a promising biomaterial with numerous potential applications, various types of synthetic spider silk fibers have been produced and studied in an effort to produce man-made fibers with mechanical and physical properties comparable to those of native spider silk. In this study, two recombinant proteins based on Nephila clavipes Major ampullate Spidroin 1 (MaSp1) consensus repeat sequence were expressed and spun into fibers. Mechanical test results showed that fiber spun from the higher molecular weight protein had better overall mechan- ical properties (70 KD versus 46 KD), whereas postspin stretch treatment in water helped increase fiber tensile strength significantly. Carbon-13 solid-state NMR studies of those fibers further revealed that the postspin stretch in water promoted protein molecule rearrangement and the formation of β-sheets in the polyalanine region of the silk. The rearrangement correlated with improved fiber mechanical properties and indicated that postspin stretch is key to helping the spider silk proteins in the fiber form correct secondary structures, leading to better quality fibers.
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机译:作为具有许多潜在应用前景的有前途的生物材料,已经生产并研究了各种类型的合成蜘蛛丝纤维,以生产具有与天然蜘蛛丝相当的机械和物理性能的人造纤维。在这项研究中,表达了两种基于Nephila clavipes Major ampullate Spidroin 1(MaSp1)共有重复序列的重组蛋白,并将其纺制成纤维。力学测试结果表明,由较高分子量的蛋白质纺制而成的纤维具有更好的总体机械性能(70 KD与46 KD),而在水中进行销后拉伸处理有助于显着提高纤维的拉伸强度。这些纤维的碳13固态NMR研究进一步表明,水中的后旋拉伸促进了蛋白质分子的重排,并在丝绸的聚丙氨酸区域内形成了β-折叠。重排与改善的纤维机械性能相关,并表明后旋拉伸是帮助纤维中的蜘蛛丝蛋白形成正确的二级结构,从而导致纤维质量更好的关键。
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