title: Epitopes on beta2-GPI recognized by anticardiolipin antibodies.
abstract: 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.
authors.affiliation: Department of Medicine II, Hokkaido University School of Medicine, Sapporo, Japan. tkoike@med.hokudai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Koike
authors.forename: K
authors.initials: K
authors.lastname: Ichikawa
authors.forename: H
authors.initials: H
authors.lastname: Kasahara
authors.forename: T
authors.initials: T
authors.lastname: Atsumi
authors.forename: A
authors.initials: A
authors.lastname: Tsutsumi
authors.forename: E
authors.initials: E
authors.lastname: Matsuura
mesh_terms: 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
chemical_list: D017153:Antibodies, Anticardiolipin; D001324:Autoantigens; D000939:Epitopes; D006023:Glycoproteins; D010743:Phospholipids; D053482:beta 2-Glycoprotein I