Epitopes on beta2-GPI recognized by anticardiolipin antibodies.
Anticardiolipin antibodies (aCL) found in sera from patients with antiphospholipid syndrome recognize a cryptic epitope that appears on the beta2-glycoprotein I (beta2-GPI) molecule when beta2-GPI interacts with a lipid membrane composed of negatively charged phospholipid or when beta2-GPI is adsorbed on a polyoxygenated polystyrene plate. A homology based model of beta2-GPI was constructed based on the NMR coordinates of sushi domains of human factor H. The conformation was like a cylinder consisting of five domains, its IV and V domains being glued by electrostatic interaction. We used phage-displayed random peptide libraries to search the epitopes of human aCL. Structures similar to consensus sequences selected by a biopanning method was found on domain IV of beta2-GPI.
Koike
T
T
Department of Medicine II, Hokkaido University School of Medicine, Sapporo, Japan. tkoike@med.hokudai.ac.jp
Ichikawa
K
K
Kasahara
H
H
Atsumi
T
T
Tsutsumi
A
A
Matsuura
E
E
D000595:Amino Acid Sequence; D017153:Antibodies, Anticardiolipin / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000276:immunology*; D001324:Autoantigens / Q000737:chemistry / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D006023:Glycoproteins / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000276:immunology / Q000378:metabolism; D011487:Protein Conformation; D053482:beta 2-Glycoprotein I
D017153:Antibodies, Anticardiolipin; D001324:Autoantigens; D000939:Epitopes; D006023:Glycoproteins; D010743:Phospholipids; D053482:beta 2-Glycoprotein I