Human complement factor H: an additional gene product of 43 kDa isolated from human plasma shows cofactor activity for the cleavage of the third component of complement

Eur J Immunol. 1989 Sep;19(9):1765-8. doi: 10.1002/eji.1830190936.


In addition to the 150-kDa factor H protein, we have previously described a 43-kDa factor H molecule in human plasma, which probably represents a translational product of the additional 1.8-kb mRNA for factor H. This factor H was isolated from human plasma by means of immunoaffinity chromatography and high-performance liquid chromatography. When tested for its functional activity, this purified 43-kDa H protein was shown to act as cofactor for factor I- mediated cleavage of fluid-phase C3b to iC3b.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Blotting, Western
  • Complement Activation*
  • Complement C3 / metabolism*
  • Complement C3b Inactivator Proteins / isolation & purification
  • Complement C3b Inactivator Proteins / physiology*
  • Complement Factor H
  • Complement Pathway, Alternative*
  • Humans
  • Molecular Weight


  • Antibodies, Monoclonal
  • CFH protein, human
  • Complement C3
  • Complement C3b Inactivator Proteins
  • Complement Factor H