1. Biochemistry and Chemical Biology
  2. Structural Biology and Molecular Biophysics
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Measuring protein stability in the GroEL chaperonin cage reveals massive destabilization

  1. Ilia Korobko
  2. Hisham Mazal
  3. Gilad Haran
  4. Amnon Horovitz  Is a corresponding author
  1. Weizmann Institute of Science, Israel
Research Article
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Cite this article as: eLife 2020;9:e56511 doi: 10.7554/eLife.56511

Abstract

The thermodynamics of protein folding in bulk solution have been thoroughly investigated for decades. By contrast, measurements of protein substrate stability inside the GroEL/ES chaperonin cage have not been reported. Such measurements require stable encapsulation, i.e. no escape of the substrate into bulk solution during experiments, and a way to perturb protein stability without affecting the chaperonin system itself. Here, by establishing such conditions, we show that protein stability in the chaperonin cage is reduced dramatically by more than 5 kcal mol-1 compared to that in bulk solution. Given that steric confinement alone is stabilizing, our results indicate that hydrophobic and/or electrostatic effects in the cavity are strongly destabilizing. Our findings are consistent with the iterative annealing mechanism of action proposed for the chaperonin GroEL.

Article and author information

Author details

  1. Ilia Korobko

    Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
  2. Hisham Mazal

    Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2071-9552
  3. Gilad Haran

    Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1837-9779
  4. Amnon Horovitz

    Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
    For correspondence
    Amnon.Horovitz@weizmann.ac.il
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7952-6790

Funding

United States-Israel Binational Science Foundation (2015170)

  • Amnon Horovitz

Minerva Foundation

  • Amnon Horovitz

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Lewis E Kay, University of Toronto, Canada

Publication history

  1. Received: February 29, 2020
  2. Accepted: July 25, 2020
  3. Accepted Manuscript published: July 27, 2020 (version 1)

Copyright

© 2020, Korobko et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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