Wolny, M, Batchelor, M, Bartlett, GJ et al. (7 more authors) (2017) Characterization of long and stable de novo single alpha-helix domains provides novel insight into their stability. Scientific Reports, 7. 44341. ISSN 2045-2322
Abstract
Naturally-occurring single α-helices (SAHs), are rich in Arg (R), Glu (E) and Lys (K) residues, and stabilized by multiple salt bridges. Understanding how salt bridges promote their stability is challenging as SAHs are long and their sequences highly variable. Thus, we designed and tested simple de novo 98-residue polypeptides containing 7-residue repeats (AEEEXXX, where X is K or R) expected to promote salt-bridge formation between Glu and Lys/Arg. Lys-rich sequences (EK3 (AEEEKKK) and EK2R1 (AEEEKRK)) both form SAHs, of which EK2R1 is more helical and thermo-stable suggesting Arg increases stability. Substituting Lys with Arg (or vice versa) in the naturally-occurring myosin-6 SAH similarly increased (or decreased) its stability. However, Arg-rich de novo sequences (ER3 (AEEERRR) and EK1R2 (AEEEKRR)) aggregated. Combining a PDB analysis with molecular modelling provides a rational explanation, demonstrating that Glu and Arg form salt bridges more commonly, utilize a wider range of rotamer conformations, and are more dynamic than Glu–Lys. This promiscuous nature of Arg helps explain the increased propensity of de novo Arg-rich SAHs to aggregate. Importantly, the specific K:R ratio is likely to be important in determining helical stability in de-novo and naturally-occurring polypeptides, giving new insight into how single α-helices are stabilized.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
Keywords: | Biochemical assays; Intrinsically disordered proteins; Molecular modelling |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > Cell Biology (Leeds) The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > Molecular Contractility (Leeds) |
Funding Information: | Funder Grant number BBSRC BB/I007423/1 BBSRC BB/M009114/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Feb 2017 11:03 |
Last Modified: | 23 Jun 2023 22:24 |
Published Version: | https://doi.org/10.1038/srep44341 |
Status: | Published |
Publisher: | Nature Publishing Group |
Identification Number: | 10.1038/srep44341 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:112576 |