Localization of the phosphocholine-binding sites on C-reactive protein by immunoelectron microscopy

Academic Article


  • C-reactive protein (CRP) was reacted with monoclonal IgG antibody or Fab antibody fragments directed against the phosphocholine- (PC) binding site or a second unrelated site. The resulting immune complexes were viewed by a negative stain immunoelectron microscopy technique. Monoclonal anti-PC-binding site antibody bound to a single epitope on each of the five CRP subnits. The orientation of the PC-binding sites was determined to be slightly medial to one of the planar faces (A-face) of the molecule. The second monoclonal antibody, which was not PC-binding site related, bound to epitopes (one per CRP subunit) that were located slightly lateral to the other planar face (B-face) of the CRP molecule, i.e., opposite of the PC-binding site. Thus, the PC-binding site and the non-PC-binding site are oriented nearly perpendicular but on opposite sides with respect to the plane of the CRP molecule. The functional significance of this configuration is discussed.
  • Published In

    Pubmed Id

  • 25873071
  • Author List

  • Roux KH; Kilpatrick JM; Volanakis JE; Kearney JF
  • Start Page

  • 2411
  • End Page

  • 2415
  • Volume

  • 131
  • Issue

  • 5