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Customized Flagelliform Spidroins Form Spider Silk-like Fibers at pH 8.0 with Outstanding Tensile Strength - PubMed

  • ️Sat Jan 01 2022

Customized Flagelliform Spidroins Form Spider Silk-like Fibers at pH 8.0 with Outstanding Tensile Strength

Xue Li et al. ACS Biomater Sci Eng. 2022.

Abstract

Spider flagelliform silk shows the best extensibility among various types of silk, but its biomimetic preparation has not been much studied. Herein, five customized flagelliform spidroins (FlSps: S and NTDFl-Sn-CTDFl, n = 1-4), in which the repetitive region (S) and N-/C- terminal domains (NTDFl and CTDFl) are from the same spidroin and spider species, were produced recombinantly. The recombinant spidroins with terminal domains were able to form silk-like fibers with diameters of ∼5 μm by manual pulling at pH 8.0, where the secondary structure transformation occurred. The silk-like fibers from NTDFl-S4-CTDFl showed the highest tensile strength (∼250 MPa), while those ones with 1-3 S broke at a similar stress (∼180 MPa), suggesting that increasing the amounts of the repetitive region can improve the tensile strength, but a certain threshold might need to be reached. This study shows successful preparation of flagelliform silk-like fibers with good mechanical properties, providing general insights into efficient biomimetic preparations of spider silks.

Keywords: customized FlSp; flagelliform; manual pulling; mechanical properties; silk formation at pH 8.0.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1

Orb-web spider silks and spinning strategy in this study. (A) Seven types of silk from orb-web spider, corresponding spidroins, and biological applications. (B) Scanning electron microscopy (SEM) images of native spider flagelliform silk generated in this study. The scale bars are 10 μm (left) and 2 μm (right), respectively. (C) Facile manual pulling strategy utilized for spider flagelliform silk-like fiber preparation from a recombinant protein droplet at pH 8.0.

Figure 2
Figure 2

Architecture of different customized FlSps and SDS-PAGE analysis of recombinant preparations. (A) Amino acid sequences of the Flag repetitive region S, NTDFl, and CTDFl used in this study. (B) Architecture of customized FlSps (S, NS1C, NS2C, NS3C, and NS4C). NTDFl and CTDFl indicate N- and C- terminal domains from A. ventricosus flagelliform spidroin, respectively. S stands for the repetitive region trimmed from A. ventricosus flagelliform spidroin. (C) SDS-PAGE analysis of the purified customized FlSps—S (right), NS1C, NS2C, NS3C, and NS4C (left). Lane M is the protein marker.

Figure 3
Figure 3

CD spectra of customized FlSps under different pHs. CD spectra of customized FlSps in 20 mM phosphate at different pHs (7.5, 6.5, and 5.5) were recorded at room temperature. (A) NS1C. (B) NS1C. (C) NS3C. (D) NS4C. (E) S. The Y axis is given by mdeg.

Figure 4
Figure 4

SEM observation of different silk-like fibers from customized FlSps. Spider silk-like fibers were prepared via the manual-pulling method and observed under SEM. (A) NS1C. (B) NS1C. (C) NS3C. (D) NS4C. The scale bars are 10 μm (upper panel) and 2 μm (lower panel), respectively.

Figure 5
Figure 5

Mechanical property of silk-like fibers from the customized FlSps. (A) Stress–strain curves of silk-like fibers from NS1C, NS2C, NS3C, and NS4C. (B) Tensile strength comparison, where ns is for no significant difference and ** for p < 0.01. (C) Mechanical properties of silk-like fibers. The mean values were calculated from independent tests of each silk type, and data were shown as mean ± standard deviation.

Figure 6
Figure 6

Secondary structure evaluation of silk-like fibers from customized FlSps by ATR-FTIR.

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References

    1. Rising A.; Johansson J. Toward spinning artificial spider silk. Nat. Chem. Biol. 2015, 11, 309–315. 10.1038/nchembio.1789. - DOI - PubMed
    1. Lewis R. V. Spider silk: ancient ideas for new biomaterials. Chem. Rev. 2006, 106, 3762–3774. 10.1021/cr010194g. - DOI - PubMed
    1. Hayashi C. Y.; Lewis R. V. Spider flagelliform silk: lessons in protein design, gene structure, and molecular evolution. BioEssays 2001, 23, 750–756. 10.1002/bies.1105. - DOI - PubMed
    1. Yarger J. L.; Cherry B. R.; van der Vaart A. Uncovering the structure-function relationship in spider silk. Nat. Rev. Mater. 2018, 3, 18008.10.1038/natrevmats.2018.8. - DOI
    1. Aigner T. B.; DeSimone E.; Scheibel T. Biomedical Applications of Recombinant Silk-Based Materials. Adv. Mater. 2018, 30, 1704636.10.1002/adma.201704636. - DOI - PubMed

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