1. Immunology and Inflammation
  2. Structural Biology and Molecular Biophysics
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The allosteric modulation of Complement C5 by knob domain peptides

  1. Alex Macpherson  Is a corresponding author
  2. Maisem Laabei
  3. Zainab Ahdash
  4. Melissa A Graewert
  5. James R Birtley
  6. Monika-Sarah ED Schulze
  7. Susan Crennell
  8. Sarah A Robinson
  9. Ben Holmes
  10. Vladas Oleinikovas
  11. Per H Nilsson
  12. James Snowden
  13. Victoria Ellis
  14. Tom Eirik Mollnes
  15. Charlotte M Deane
  16. Dmitri Svergun
  17. Alastair DG Lawson
  18. Jean MH van den Elsen  Is a corresponding author
  1. University of Bath, United Kingdom
  2. UCB-Celltech, United Kingdom
  3. EMBL Hamburg, Germany
  4. University of Oxford, United Kingdom
  5. Oslo University hospital, Sweden
  6. University of Oslo, Norway
  7. EMBL/DESY, Germany
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Cite this article as: eLife 2021;10:e63586 doi: 10.7554/eLife.63586

Abstract

Bovines have evolved a subset of antibodies with ultra-long CDRH3 regions that harbour cysteine-rich knob domains. To produce high affinity peptides, we previously isolated autonomous 3-6 kDa knob domains from bovine antibodies. Here, we show that binding of four knob domain peptides elicits a range of effects on the clinically validated drug target complement C5. Allosteric mechanisms predominated, with one peptide selectively inhibiting C5 cleavage by the alternative pathway C5 convertase, revealing a targetable mechanistic difference between the classical and alternative pathway C5 convertases. Taking a hybrid biophysical approach, we present C5-knob domain co-crystal structures and, by solution methods, observed allosteric effects propagating >50 Å from the binding sites. This study expands the therapeutic scope of C5, presents new inhibitors and introduces knob domains as new, low molecular weight antibody fragments, with therapeutic potential.

Data availability

Structural datasets presented in this study have been made publicly available in the Protein Data Bank (PDB) and Small Angle Scattering Biological Data Bank (SASBDB)

The following data sets were generated

Article and author information

Author details

  1. Alex Macpherson

    Biology & Biochemistry, University of Bath, Bath, United Kingdom
    For correspondence
    Alex.MacPherson@ucb.com
    Competing interests
    Alex Macpherson, employee of UCB and may hold shares and/or stock options.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4508-5322
  2. Maisem Laabei

    Biology and Biochemistry, University of Bath, Bath, United Kingdom
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8425-3704
  3. Zainab Ahdash

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Zainab Ahdash, employee of UCB and may hold shares and/or stock options.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4495-8689
  4. Melissa A Graewert

    Biological Small Angle Scattering, EMBL Hamburg, Hamburg, Germany
    Competing interests
    No competing interests declared.
  5. James R Birtley

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    James R Birtley, employee of UCB and may hold shares and/or stock options.
  6. Monika-Sarah ED Schulze

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Monika-Sarah ED Schulze, employee of UCB and may hold shares and/or stock options.
  7. Susan Crennell

    Biology & Biochemistry, University of Bath, Bath, United Kingdom
    Competing interests
    No competing interests declared.
  8. Sarah A Robinson

    Statistics, University of Oxford, Oxford, United Kingdom
    Competing interests
    No competing interests declared.
  9. Ben Holmes

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Ben Holmes, employee of UCB and may hold shares and/or stock options.
  10. Vladas Oleinikovas

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Vladas Oleinikovas, employee of UCB and may hold shares and/or stock options.
  11. Per H Nilsson

    Immunology, Oslo University hospital, Oslo, Sweden
    Competing interests
    No competing interests declared.
  12. James Snowden

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    James Snowden, employee of UCB and may hold shares and/or stock options.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4855-7329
  13. Victoria Ellis

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Victoria Ellis, employee of UCB and may hold shares and/or stock options.
  14. Tom Eirik Mollnes

    Department of Immunology, University of Oslo, Oslo, Norway
    Competing interests
    Tom Eirik Mollnes, T.E.M is a Board member of Ra Pharmaceuticals, Inc.
  15. Charlotte M Deane

    Department of Statistics, University of Oxford, Oxford, United Kingdom
    Competing interests
    Charlotte M Deane, Reviewing editor, eLife.
  16. Dmitri Svergun

    Biological Small Angle Scattering, EMBL/DESY, Hamburg, Germany
    Competing interests
    No competing interests declared.
  17. Alastair DG Lawson

    Immunology, UCB-Celltech, Slough, United Kingdom
    Competing interests
    Alastair DG Lawson, employee of UCB and may hold shares and/or stock options.
  18. Jean MH van den Elsen

    Biology & Biochemistry, University of Bath, Bath, United Kingdom
    For correspondence
    bssjmhve@bath.ac.uk
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0367-1956

Funding

No specific external funding was received for this work.

Reviewing Editor

  1. John Kuriyan, University of California, Berkeley, United States

Publication history

  1. Received: September 29, 2020
  2. Accepted: February 11, 2021
  3. Accepted Manuscript published: February 11, 2021 (version 1)
  4. Version of Record published: March 18, 2021 (version 2)

Copyright

© 2021, Macpherson 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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