| Title | Kininogen domain 3 contains regions recognized by antiphosphatidylethanolamine antibodies. | | Author(s) | Katsunuma J, Sugi T, Inomo A, Matsubayashi H, Izumi SI, Makino T | | Institution | Department of Obstetrics and Gynecology, Center for Growth and Reproductive Medicine, Tokai University School of Medicine, Kanagawa, Japan. | | Source | J Thromb Haemost 2003 Jan; 1(1):132-8. | | MeSH | Abortion, Habitual
Adult
Amino Acid Sequence
Binding Sites
Binding, Competitive
Enzyme-Linked Immunosorbent Assay
Epitope Mapping
Epitopes
Female
Humans
Immunoglobulin G
Kininogens
Molecular Sequence Data
Peptides
Pregnancy
Protein Binding
Protein Structure, Tertiary
| | Abstract | Antiphosphatidylethanolamine antibodies (APE) have been described in patients with thrombotic diseases and recurrent pregnancy loss (RPL). It has been reported that certain APE are not specific for phosphatidylethanolamine (PE) per se, but are directed to PE-binding plasma proteins, called kininogens. Our recent in vitro data suggest that APE may recognize the domain 3 (D3) region of kininogens. In this study, we have used synthetic peptides that span the D3 of kininogens in inhibition and direct binding studies to identify epitopes that are sites for binding APE. Our present data demonstrate that among 24 RPL patients who were positive for kininogen-dependent immunoglobulin (IgG) APE, 17 patients (70.8%) recognized the LDC27 peptide. We mapped the APE-binding region on D3 using plasma from a RPL patient (X) who had a high titer of IgG APE that recognized LDC27. APE of patient X recognized a 13-residue segment in LDC27, named CNA13. Leu331-Met357 (LDC27) and Cys333-Lys345 (CNA13) are located on the carboxyl-terminal portion of kininogen D3, which is known as the major kininogen heavy chain cell attachment site where it overlaps its cysteine protease inhibitory region. Because APE interferes with the balance of hemostasis in vitro, APE may therefore induce a similar condition in patients thereby causing thrombosis and RPL. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 12871550 |
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