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Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion
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Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

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Structural and functional anatomy of the globular domain of complement protein C1q

Uday Kishore1, Rohit Ghai, Trevor J Greenhough

  • 1Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK. ukishore@hotmail.com

Immunology Letters
|September 25, 2004
PubMed

Insights

Complement C1q, a key immune system protein, recognizes diverse ligands through its globular domain (gC1q). Recent research reveals this domain

Area of Science:

  • Immunology
  • Structural Biology
  • Biochemistry

Background:

  • C1q initiates the classical complement pathway, bridging innate and adaptive immunity.
  • C1q functions as a pattern recognition molecule, binding various ligands via its globular head (gC1q).
  • The gC1q domain comprises heterotrimeric A, B, and C chains (ghA, ghB, ghC).

Purpose of the Study:

  • To investigate the modular organization and ligand specificity of the C1q gC1q domain.
  • To elucidate the structure-function relationships within the gC1q domain.
  • To explore how molecular structure influences C1q's versatile ligand recognition.

Main Methods:

  • Recombinant expression of ghA, ghB, and ghC chains.
  • X-ray crystallography of the gC1q domain.
  • Molecular modeling and protein engineering studies.

Main Results:

  • The gC1q domain exhibits a modular organization.
  • Individual ghA, ghB, and ghC chains display differential ligand specificities.
  • Structural and modeling studies reveal how modularity, charge, and spatial arrangement enable versatile ligand binding.

Conclusions:

  • The gC1q domain's structure supports its broad ligand recognition capabilities.
  • Understanding C1q's structure-function relationship provides insights into complement activation.
  • Further research is needed to address emerging questions regarding gC1q function.

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