The factor H variant associated with age-related macular degeneration (H384) and the non-disease associated form bind differentially to C-reactive protein, fibromodulin, DNA and necrotic cells.

Research output: Contribution to journalArticle

Abstract

Recently, a polymorphism in the complement regulator factor H (FH) gene has been associated with age-related macular degeneration. When histidine instead of tyrosine is present at position 384 in the seventh complement control protein (CCP) domain of FH, the risk for age-related macular degeneration is increased. It was recently shown that these allotypic variants of FH, in the context of a recombinant construct corresponding to CCPs 6 - 8, recognize polyanionic structures differently, which may lead to altered regulation of the alternative pathway of complement. We show now that His-384, corresponding to the risk allele, binds C-reactive protein (CRP) poorly compared with the Tyr-384 form. We also found that C1q and phosphorylcholine do not compete with FH for binding to C-reactive protein. The interaction with extracellular matrix protein fibromodulin, which we now show to be mediated, at least in part, by CCP6 - 8 of FH, occurs via the polypeptide of fibromodulin and not through its glycosaminoglycan modifications. The Tyr-384 variant of FH bound fibromodulin better than the His-384 form. Furthermore, we find that CCP6 - 8 is able to interact with DNA and necrotic cells, but in contrast the His-384 allotype binds these ligands more strongly than the Tyr-384 variant. The variations in binding affinity of the two alleles indicate that complement activation and local inflammation in response to different targets will differ between His/His and Tyr/Tyr homozygotes.

Details

Authors
  • Andreas Holmér
  • Leendert Trouw
  • Simon J Clark
  • Jonatan Sjolander
  • Dick Heinegård
  • Robert B Sim
  • Anthony J Day
  • Anna Blom
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Basic Medicine
  • Basic Medicine
  • Medicinal Chemistry
Original languageEnglish
Pages (from-to)10894-10900
JournalJournal of Biological Chemistry
Volume282
Issue number15
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Protein Chemistry (013017510), Clinical Chemistry, Malmö (013016000), Department of Experimental Medical Science (013210000), Connective Tissue Biology (013230151)

Related research output

Andreas Holmér, 2007, Clinical Chemistry, Malmö. 167 p.

Research output: ThesisDoctoral Thesis (compilation)

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