Spiders Use Structural Conversion of Globular Amyloidogenic Domains to Make Strong Silk Fibers

Abstract

Spider silk-an environmentally friendly protein-based material-is widely recognized for its extraordinary mechanical properties. Biomimetic spider silk-like fibers made from recombinant spider silk proteins (spidroins) currently falls short compared to natural silks in terms of mechanical performance. In this study, it is discovered that spiders use structural conversion of molecular enhancers-conserved globular 127-residue spacer domains-to make strong silk fibers. This domain lacks poly-Ala motifs but interestingly contains motifs that are similar to human amyloidogenic motifs, and that it self-assembles into amyloid-like fibrils through a non-nucleation-dependent pathway, likely to avoid the formation of cytotoxic intermediates. Incorporating this spacer domain into a recombinant chimeric spidroin facilitates self-assembly into silk-like fibers, increases fiber molecular homogeneity, and markedly enhances fiber mechanical strength. These findings highlight that spiders employ diverse strategies to produce silk with exceptional mechanical properties. The spacer domain offers a way to enhance the properties of recombinant spider silk-like fibers and other functional materials.Spiders use structural conversion of the conserved globular 127-residue spacer domains to make strong silk fibers. This domain, interestingly containing motifs that are similar to human amyloidogenic motifs, self-assembles into amyloid-like fibrils through a non-nucleation-dependent pathway. Integrating this spacer into a chimeric spidroin enhances silk-like fiber assembly, improves molecular homogeneity and significantly strengthens the fibers. image

Keywords

amyloid-like fibril; mechanical property; recombinant spider silk; spacer; spidroin

Published in

Advanced Functional Materials
2024, volume: 34, number: 23, article number: 2315409
Publisher: WILEY-V C H VERLAG GMBH

SLU Authors

• Rising, Anna

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Bio Materials
Biochemistry and Molecular Biology

Publication identifier

• DOI: https://doi.org/10.1002/adfm.202315409

Permanent link to this page (URI)

https://res.slu.se/id/publ/128720