Epitope domain and plasminogen activating site (s) in streptokinase molecule

我们以前报道过，从一名链球菌后肾小球肾炎（PSGN）患者身上提取的a，M型12型链球菌分离物（菌株A374）中制备的针对SKase的单克隆抗体（N-59）识别出了一个同样存在于SKase中的表位，该表位来自C组链球菌（菌株H46A），而不是PSGN分离物。然而，另一种针对A374株的SKase（肾炎株相关SKase， NSA-SKase）制备的单抗RU-1仅与同源SKase反应，而与H46A株的普通SKase （C-SKase）不反应。此外，测定了菌株A374的NSA-SKase的完整氨基酸序列，发现RU-1 mAb仅与NSA-SKase反应的表位结构域定位在164 ~ 236残基。采用引脚技术和ELISA法测定了与RU-1单抗反应的NSA-SKase分子内部区域所涉及的表位结构域。结果表明，RU-1 mAb与残基177 ~ 185 （PSLKERYHL）反应，与RU-1 mAb反应的最小表位结构域为残基177 ~ 180 （PSLK）。另一方面，N-59 mAb与几乎所有的SKase （C-SKase）反应。分析了C-SKase与N-59单抗反应的表位结构域。结果表明，N-59 mAb可识别C-SKase分子中324-332 （RDLYDPRDK）残基，最小表位结构域为324-331 （RDLYDPRD）残基。

We have previously reported that a monoclonal antibody (mAb), N-59, prepared against streptokinase (SKase) from a group A,M type 12 streptococcal isolate (strain A374) from a patient with poststreptococcal glomerulonephritis (PSGN) recognized an epitope also present in SKase from a group C Streptococcus (strain H46A) which is not a PSGN isolate.However, another mAb, RU-1, prepared against SKase (nephritis strain-assiciated SKase, NSA-SKase) from strain A374 reacted only with the homologous SKase and not with common-SKase (C-SKase) from strain H46A.In addition, the complete amino acid sequence of the NSA-SKase of strain A374 was determined, and the epitope domain specific for RU-1 mAb reacted only with the NSA-SKase was localized to residues 164-236.Both pin technology and ELISA test were used to the determination of epitope domain involved in the internal region of NSA-SKase molecule reacted with RU-1 mAb. As the results, RU-1 mAb reacted with residues 177-185 (PSLKERYHL), and the minimum epitope domain, which reacts with RU-1 mAb, was residues 177-180 (PSLK).The other side, N-59 mAb reacted with almost all of SKase (C-SKase). The epitope domain of C-SKase reacted with N-59 mAb was analyzed. As the results, N-59 mAb recognized residues 324-332 (RDLYDPRDK) in C-SKase molecule, and the minimum epitope domain was residues 324-331 (RDLYDPRD).