Asakura, T. and Williamson, M.P. orcid.org/0000-0001-5572-1903 (2023) A review on the structure of Bombyx mori silk fibroin fiber studied using solid-state NMR: an antipolar lamella with an 8-residue repeat. International Journal of Biological Macromolecules, 245. 125537. ISSN 0141-8130
Abstract
Silk fibroin (SF) fiber from the silkworm Bombyx mori in the Silk II form has been used as an excellent textile fiber for over 5000 years. Recently it has been developed for a range of biomedical applications. Further expansion of these uses builds on the excellent mechanical strength of SF fiber, which derives from its structure. This relationship between strength and SF structure has been studied for over 50 years, but it is still not well understood. In this review, we report the use of solid-state NMR to study stable-isotope labeled SF fiber and stable-isotope labeled peptides including (Ala-Gly)15 and (Ala-Gly-Ser-Gly-Ala-Gly)5 as models of the crystalline fraction. We show that the crystalline fraction is a lamellar structure with a repetitive folding using β-turns every eighth amino acid, and that the sidechains adopt an antipolar arrangement rather than the more well-known polar structure described by Marsh, Corey and Pauling (that is, the Ala methyls in each layer point in opposite directions in alternate strands). The amino acids Ser, Tyr and Val are the next most common in B. mori SF after Gly and Ala, and occur in the crystalline and semi-crystalline regions, probably defining the edges of the crystalline region. Thus, we now have an understanding of the main features of Silk II but there is still a long way to go.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2023 The Author(s). Except as otherwise noted, this author-accepted version of a journal article published in International Journal of Biological Macromolecules is made available via the University of Sheffield Research Publications and Copyright Policy under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ |
Keywords: | Bombyx mori silk fibroin; Lamellar structure; Silk II structure; Solid-state NMR |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 13 Jul 2023 16:18 |
Last Modified: | 04 Sep 2023 12:28 |
Status: | Published |
Publisher: | Elsevier BV |
Refereed: | Yes |
Identification Number: | 10.1016/j.ijbiomac.2023.125537 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:201562 |