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Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q

Complement C1q is a soluble pattern recognition molecule comprising six heterotrimeric subunits assembled from three polypeptide chains (A–C). Each heterotrimer forms a collagen-like stem prolonged by a globular recognition domain. These recognition domains sense a wide variety of ligands, including...

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Autores principales: Moreau, Christophe, Bally, Isabelle, Chouquet, Anne, Bottazzi, Barbara, Ghebrehiwet, Berhane, Gaboriaud, Christine, Thielens, Nicole
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4774423/
https://www.ncbi.nlm.nih.gov/pubmed/26973654
http://dx.doi.org/10.3389/fimmu.2016.00079
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author Moreau, Christophe
Bally, Isabelle
Chouquet, Anne
Bottazzi, Barbara
Ghebrehiwet, Berhane
Gaboriaud, Christine
Thielens, Nicole
author_facet Moreau, Christophe
Bally, Isabelle
Chouquet, Anne
Bottazzi, Barbara
Ghebrehiwet, Berhane
Gaboriaud, Christine
Thielens, Nicole
author_sort Moreau, Christophe
collection PubMed
description Complement C1q is a soluble pattern recognition molecule comprising six heterotrimeric subunits assembled from three polypeptide chains (A–C). Each heterotrimer forms a collagen-like stem prolonged by a globular recognition domain. These recognition domains sense a wide variety of ligands, including pathogens and altered-self components. Ligand recognition is either direct or mediated by immunoglobulins or pentraxins. Multivalent binding of C1q to its targets triggers immune effector mechanisms mediated via its collagen-like stems. The induced immune response includes activation of the classical complement pathway and enhancement of the phagocytosis of the recognized target. We report here, the first production of a single-chain recombinant form of human C1q globular region (C1q-scGR). The three monomers have been linked in tandem to generate a single continuous polypeptide, based on a strategy previously used for adiponectin, a protein structurally related to C1q. The resulting C1q-scGR protein was produced at high yield in stably transfected 293-F mammalian cells. Recombinant C1q-scGR was correctly folded, as demonstrated by its X-ray crystal structure solved at a resolution of 1.35 Å. Its interaction properties were assessed by surface plasmon resonance analysis using the following physiological C1q ligands: the receptor for C1q globular heads, the long pentraxin PTX3, calreticulin, and heparin. The 3D structure and the binding properties of C1q-scGR were similar to those of the three-chain fragment generated by collagenase digestion of serum-derived C1q. Comparison of the interaction properties of the fragments with those of native C1q provided insights into the avidity component associated with the hexameric assembly of C1q. The interest of this functional recombinant form of the recognition domains of C1q in basic research and its potential biomedical applications are discussed.
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spelling pubmed-47744232016-03-11 Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q Moreau, Christophe Bally, Isabelle Chouquet, Anne Bottazzi, Barbara Ghebrehiwet, Berhane Gaboriaud, Christine Thielens, Nicole Front Immunol Immunology Complement C1q is a soluble pattern recognition molecule comprising six heterotrimeric subunits assembled from three polypeptide chains (A–C). Each heterotrimer forms a collagen-like stem prolonged by a globular recognition domain. These recognition domains sense a wide variety of ligands, including pathogens and altered-self components. Ligand recognition is either direct or mediated by immunoglobulins or pentraxins. Multivalent binding of C1q to its targets triggers immune effector mechanisms mediated via its collagen-like stems. The induced immune response includes activation of the classical complement pathway and enhancement of the phagocytosis of the recognized target. We report here, the first production of a single-chain recombinant form of human C1q globular region (C1q-scGR). The three monomers have been linked in tandem to generate a single continuous polypeptide, based on a strategy previously used for adiponectin, a protein structurally related to C1q. The resulting C1q-scGR protein was produced at high yield in stably transfected 293-F mammalian cells. Recombinant C1q-scGR was correctly folded, as demonstrated by its X-ray crystal structure solved at a resolution of 1.35 Å. Its interaction properties were assessed by surface plasmon resonance analysis using the following physiological C1q ligands: the receptor for C1q globular heads, the long pentraxin PTX3, calreticulin, and heparin. The 3D structure and the binding properties of C1q-scGR were similar to those of the three-chain fragment generated by collagenase digestion of serum-derived C1q. Comparison of the interaction properties of the fragments with those of native C1q provided insights into the avidity component associated with the hexameric assembly of C1q. The interest of this functional recombinant form of the recognition domains of C1q in basic research and its potential biomedical applications are discussed. Frontiers Media S.A. 2016-03-02 /pmc/articles/PMC4774423/ /pubmed/26973654 http://dx.doi.org/10.3389/fimmu.2016.00079 Text en Copyright © 2016 Moreau, Bally, Chouquet, Bottazzi, Ghebrehiwet, Gaboriaud and Thielens. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Immunology
Moreau, Christophe
Bally, Isabelle
Chouquet, Anne
Bottazzi, Barbara
Ghebrehiwet, Berhane
Gaboriaud, Christine
Thielens, Nicole
Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title_full Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title_fullStr Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title_full_unstemmed Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title_short Structural and Functional Characterization of a Single-Chain Form of the Recognition Domain of Complement Protein C1q
title_sort structural and functional characterization of a single-chain form of the recognition domain of complement protein c1q
topic Immunology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4774423/
https://www.ncbi.nlm.nih.gov/pubmed/26973654
http://dx.doi.org/10.3389/fimmu.2016.00079
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