Takahashi I, Mizumo S, Kamiya T, Takamatsu J, Saito H
Japanese Red Cross Aichi Blood Centre.
Br J Haematol. 1994 Sep;88(1):166-73. doi: 10.1111/j.1365-2141.1994.tb04992.x.
We have determined the location of epitopes on the factor IX for three haemophilia B inhibitor antibodies (HB-1, HB-3, HB-7) and a monoclonal anti-factor IX inhibitory antibody (designated 65-10). The main binding region of HB-1, HB-3 and HB-7 was 155YVNSTEAETI164 (residues 155-164), 167NITQSTQSFN176 and 156VNSTEAETI164, respectively. The binding region of 65-10 was 168ITQSTQSFNDFTRVV182, which included the cleavage site (180R-V181) for activation by factor XIa. By neutralization experiments using two peptides, 156VNSTEAETI164 and 167NITQSTQSFN176, the degree of neutralization of anti-factor IX IgG purified by protein A was determined. Neutralization of three antibodies, HB-1, HB-3 and HB-7, in the presence of 10 mM of the peptides 156VNSTEAETI164 was 30.1%, 0% and 10.8%, respectively, and in the presence of 4 mM of 167NITQSTQSFN176 it was 0%, 13.5% and 17.3%, respectively. On the other hand, when plasmas of patients instead of purified IgG were used for neutralization, 10 mM of 156VNSTEAETI164 and 4 mM of 167NITQSTQSFN176 failed to neutralize the inhibitor in the plasmas.
我们已经确定了三种B型血友病抑制性抗体（HB - 1、HB - 3、HB - 7）和一种单克隆抗凝血因子IX抑制性抗体（命名为65 - 10）在凝血因子IX上的表位位置。HB - 1、HB - 3和HB - 7的主要结合区域分别为155YVNSTEAETI164（第155 - 164位氨基酸残基）、167NITQSTQSFN176和156VNSTEAETI164。65 - 10的结合区域为168ITQSTQSFNDFTRVV182，其中包括因子XIa激活的切割位点（180R - V181）。通过使用两种肽段156VNSTEAETI164和167NITQSTQSFN176进行中和实验，测定了通过蛋白A纯化的抗凝血因子IX IgG的中和程度。在存在10 mM肽段156VNSTEAETI164的情况下，三种抗体HB - 1、HB - 3和HB - 7的中和率分别为30.1%、0%和10.8%，在存在4 mM肽段167NITQSTQSFN176的情况下，中和率分别为0%、13.5%和17.3%。另一方面，当使用患者血浆而非纯化的IgG进行中和时，10 mM的156VNSTEAETI164和4 mM的167NITQSTQSFN176未能中和血浆中的抑制剂。
