Study on the specificity and thrombogenicproperty of anficardiolipin antibodies in serafrom patients with the antiphospholipid syndrome.

1)从外周血淋巴细胞中建立了9个依赖于抗心磷脂抗体(ACL)的IgM单抗。2)APS患者和APS易感小鼠来源的单抗ACL与β2-GPI结构域缺失突变体的反应性。大多数单抗ACL被认为识别与Beta2-GPI第4结构域相关的表位(S)。3)利用GENETYX-SV/R和QUANTA/CHARMm，从因子H的三级结构模拟人β2-GPI的三维结构，这是为了分析肽和蛋白的空间结构。4)为了鉴定致病ACL识别的表位，用抗β2-GPI的单抗搜索随机多肽文库，分别与人的单克隆ACL EY1C8和EY2C9结合的多肽具有共同的基序。与鼠抗人Beta2-GPI单抗WBCAL-1反应的多肽具有重叠的一致序列。5)为了阐明抗Beta2-GPI的单抗识别的表位，在人Beta2-GPI的三级结构模型中搜索与所鉴定的基序相似的结构。EY1C8和EY2C9可能识别的表位位于Beta2-GPI的第4个结构域，该表位被不含Beta2-GPI的第3个结构域覆盖，COF-18识别的表位位于Beta2-GPI的第5个结构域的磷脂结合部位附近，这可能解释了COF-18抑制Beta2-GPI与阴离子磷脂结合的原因。

1) Nine clones of IgM monoclonal beta2-glycoprotein I (beta2-GPI) dependent anticardiolipin antibodies (aCL) were established from peripheral blood lymphocytes. These monoclonal aCL recognized beta2-GPI structurally altered by binding to anionic phospholipids.2) Reactivity of monoclonal aCL derived from patients with the APS and from APS prone mice with domain deleted mutants of beta2-GPI.Most of monoclonal aCL were considered to recognize epitope (s) related to 4th domain of beta2-GPI.3) Three dimensional structure of human beta2-GPI was analogized from the tertial structure of the Factor H,using GENETYX-SV/R and QUANTA/CHARMm, which were developed to analyze tertial structure of peptides and proteins.4) To identify the epitopes recognized by pathogenic aCL,random peptide libraries were searched with monoclonal antibodies against beta2-GPI.Peptides bound to EY1C8 and EY2C9, human monoclonal aCL,had consensus motifs respectively. Peptides reacted with WBCAL-1, a mouse monoclonal anti-human beta2-GPI antibody, had overlapping consesus sequences.5)To clarify the epitope recognized by monoclonal antibody aganist beta2-GPI,tertial structure model of human beta2-GPI was searched for structures similar to the identified motifs. The putative epitope recognized by EY1C8 and EY2C9 were identified on the 4th domain of beta2-GPI.The epitope was covered by 3rd domain in free from beta2-GPI.The epitope recognized by Cof-18 was near the phospholipid binding site on the 5th domain of beta2-GPI.This may explain the inhibition of the binding of beta2-GPI to anionic phospholipids by Cof-18.