More than one way to spin a crystallite: multiple trajectories through liquid crystallinity to solid silk

Walker, Andrew A., Holland, Chris and Sutherland, Tara D. (2015) More than one way to spin a crystallite: multiple trajectories through liquid crystallinity to solid silk. Proceedings of the Royal Society B: Biological Sciences, 282 1809: 1-9. doi:10.1098/rspb.2015.0259


Author Walker, Andrew A.
Holland, Chris
Sutherland, Tara D.
Title More than one way to spin a crystallite: multiple trajectories through liquid crystallinity to solid silk
Journal name Proceedings of the Royal Society B: Biological Sciences   Check publisher's open access policy
ISSN 1471-2954
0962-8452
Publication date 2015-06-03
Year available 2015
Sub-type Critical review of research, literature review, critical commentary
DOI 10.1098/rspb.2015.0259
Open Access Status Not yet assessed
Volume 282
Issue 1809
Start page 1
End page 9
Total pages 9
Place of publication London, United Kingdom
Publisher The Royal Society Publishing
Language eng
Formatted abstract
Arthropods face several key challenges in processing concentrated feedstocks of proteins (silk dope) into solid, semi-crystalline silk fibres. Strikingly, independently evolved lineages of silk-producing organisms have converged on the use of liquid crystal intermediates (mesophases) to reduce the viscosity of silk dope and assist the formation of supramolecular structure. However, the exact nature of the liquid-crystal-forming-units (mesogens) in silk dope, and the relationship between liquid crystallinity, protein structure and silk processing is yet to be fully elucidated. In this review, we focus on emerging differences in this area between the canonical silks containing extended-β-sheets made by silkworms and spiders, and ‘non-canonical’ silks made by other insect taxa in which the final crystallites are coiled-coils, collagen helices or cross-β-sheets. We compared the amino acid sequences and processing of natural, regenerated and recombinant silk proteins, finding that canonical and non-canonical silk proteins show marked differences in length, architecture, amino acid content and protein folding. Canonical silk proteins are long, flexible in solution and amphipathic; these features allow them both to form large, micelle-like mesogens in solution, and to transition to a crystallite-containing form due to mechanical deformation near the liquid–solid transition. By contrast, non-canonical silk proteins are short and have rod or lath-like structures that are well suited to act both as mesogens and as crystallites without a major intervening phase transition. Given many non-canonical silk proteins can be produced at high yield in E. coli, and that mesophase formation is a versatile way to direct numerous kinds of supramolecular structure, further elucidation of the natural processing of non-canonical silk proteins may to lead to new developments in the production of advanced protein materials.
Keyword Coiled coil
Collagen
Cross-b-sheet
Liquid crystal
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Critical review of research, literature review, critical commentary
Collections: Non HERDC
Institute for Molecular Bioscience - Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 15 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 07 Jul 2015, 11:34:58 EST by System User on behalf of Scholarly Communication and Digitisation Service