Structure of human desArg-C5a

Acta Crystallogr D Biol Crystallogr. 2010 Feb;66(Pt 2):190-7. doi: 10.1107/S0907444909049051. Epub 2010 Jan 22.


The anaphylatoxin C5a is derived from the complement component C5 during activation of the complement cascade. It is an important component in the pathogenesis of a number of inflammatory diseases. NMR structures of human and porcine C5a have been reported; these revealed a four-helix bundle stabilized by three disulfide bonds. The crystal structure of human desArg-C5a has now been determined in two crystal forms. Surprisingly, the protein crystallizes as a dimer and each monomer in the dimer has a three-helix core instead of the four-helix bundle noted in the NMR structure determinations. Furthermore, the N-terminal helices of the two monomers occupy different positions relative to the three-helix core and are completely different from the NMR structures. The physiological significance of these structural differences is unknown.

MeSH terms

  • Complement C5a, des-Arginine / chemistry*
  • Complement C5a, des-Arginine / metabolism
  • Crystallography, X-Ray
  • Humans
  • Models, Molecular
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Receptor, Anaphylatoxin C5a / chemistry
  • Receptor, Anaphylatoxin C5a / metabolism


  • Complement C5a, des-Arginine
  • Receptor, Anaphylatoxin C5a