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Allosteric peptides bind a caspase zymogen and mediate caspase tetramerization

Nature Chemical Biology volume 8, pages 655660 (2012) | Download Citation

  • A Corrigendum to this article was published on 17 June 2013

This article has been updated

Abstract

The caspases are a family of cytosolic proteases with essential roles in inflammation and apoptosis. Drug discovery efforts have focused on developing molecules directed against the active sites of caspases, but this approach has proved challenging and has not yielded any approved therapeutics. Here we describe a new strategy for generating inhibitors of caspase-6, a potential therapeutic target in neurodegenerative disorders, by screening against its zymogen form. Using phage display to discover molecules that bind the zymogen, we report the identification of a peptide that specifically impairs the function of caspase-6 in vitro and in neuronal cells. Remarkably, the peptide binds at a tetramerization interface that is uniquely present in zymogen caspase-6, rather than binding into the active site, and acts via a new allosteric mechanism that promotes caspase tetramerization. Our data illustrate that screening against the zymogen holds promise as an approach for targeting caspases in drug discovery.

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Change history

  • 21 May 2013

    In the version of this article initially published, Irina Krylova was inadvertently acknowledged rather than included in the author list. The author list, author contributions and acknowledgements have been edited to reflect this change. The text and Supplementary Methods have also been updated to more accurately describe phage clone and peptide optimization. The errors have been corrected in the HTML and PDF versions of the article.

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Acknowledgements

We thank L. Sun for contributions in the very early phase of this project, A. Eztevez and K. Bowman for protein expression, J. Wu for help with protein purification and W. Fairbrother for insightful discussions.

Author information

Author notes

    • Micah Steffek
    • , Lijuan Zhou
    •  & Christine D Pozniak

    These authors contributed equally to this work.

Affiliations

  1. Department of Early Discovery Biochemistry, Genentech, South San Francisco, California, USA.

    • Karen Stanger
    • , Lijuan Zhou
    • , Clifford Quan
    • , Jeff Tom
    • , Irina Krylova
    • , Yingnan Zhang
    •  & Rami N Hannoush
  2. Department of Structural Biology, Genentech, South San Francisco, California, USA.

    • Micah Steffek
    • , Yvonne Franke
    • , Christine Tam
    •  & Jeremy Murray
  3. Department of Neuroscience, Genentech, South San Francisco, California, USA.

    • Christine D Pozniak
    •  & Joseph W Lewcock
  4. Department of Protein Chemistry, Genentech, South San Francisco, California, USA.

    • J Michael Elliott

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Contributions

K.S., M.S., L.Z., C.D.P., J.W.L., Y.Z., J.M. and R.N.H. designed experiments. K.S., M.S., L.Z., C.D.P., I.K., J.M.E., Y.Z. and R.N.H. performed experiments. C.Q. and J.T. conducted peptide synthesis, and Y.F. and C.T. performed DNA cloning. J.M. solved the cocrystal structure of zymogen caspase-6–pep419 complex. K.S., J.W.L. and J.M. provided input on the manuscript. R.N.H. conceived of and directed the study and wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Rami N Hannoush.

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    Supplementary Methods and Supplementary Results

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DOI

https://doi.org/10.1038/nchembio.967

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