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Research article - Peer-reviewed, 2022

Engineered Spider Silk Proteins for Biomimetic Spinning of Fibers with Toughness Equal to Dragline Silks

Arndt, Tina; Greco, Gabriele; Schmuck, Benjamin; Bunz, Jessica; Shilkova, Olga; Francis, Juanita; Pugno, Nicola M.; Jaudzems, Kristaps; Barth, Andreas; Johansson, Jan; Rising, Anna

Abstract

Spider silk is the toughest fiber found in nature, and bulk production of artificial spider silk that matches its mechanical properties remains elusive. Development of miniature spider silk proteins (mini-spidroins) has made large-scale fiber production economically feasible, but the fibers' mechanical properties are inferior to native silk. The spider silk fiber's tensile strength is conferred by poly-alanine stretches that are zipped together by tight side chain packing in beta-sheet crystals. Spidroins are secreted so they must be void of long stretches of hydrophobic residues, since such segments get inserted into the endoplasmic reticulum membrane. At the same time, hydrophobic residues have high beta-strand propensity and can mediate tight inter-beta-sheet interactions, features that are attractive for generation of strong artificial silks. Protein production in prokaryotes can circumvent biological laws that spiders, being eukaryotic organisms, must obey, and the authors thus design mini-spidroins that are predicted to more avidly form stronger beta-sheets than the wildtype protein. Biomimetic spinning of the engineered mini-spidroins indeed results in fibers with increased tensile strength and two fiber types display toughness equal to native dragline silks. Bioreactor expression and purification result in a protein yield of approximate to 9 g L-1 which is in line with requirements for economically feasible bulk scale production.

Keywords

biomimetic materials; biomimetic spider silk fibers; fibers; protein engineering; recombinant protein production

Published in

Advanced Functional Materials
2022, volume: 32, number: 23, article number: 2200986
Publisher: WILEY-V C H VERLAG GMBH

Authors' information

Arndt, Tina
Karolinska Institutet
University of Trento
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Karolinska Institute
Bunz, Jessica
Karolinska Institutet
Shilkova, Olga
Karolinska Institutet
Francis, Juanita
Karolinska Institutet
Pugno, Nicola M.
Queen Mary University London
Pugno, Nicola M.
University of Trento
Jaudzems, Kristaps
Latvian Institute of Organic Synthesis
Barth, Andreas
Stockholm University
Johansson, Jan
Karolinska Institutet
Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Karolinska Institute

UKÄ Subject classification

Bio Materials
Biochemistry and Molecular Biology

Publication Identifiers

DOI: https://doi.org/10.1002/adfm.202200986

URI (permanent link to this page)

https://res.slu.se/id/publ/116646