Waller M, Conrad D H, Carlo J R
Int Arch Allergy Appl Immunol. 1981;66(1):59-67. doi: 10.1159/000232800.
Chymotrypsin hydrolysis of the IgG anti-Rh antibodies Ri results in both bivalent and univalent antibody fragments. The bivalent fragments coated on Rh-positive erythrocytes are agglutinable by albumin and other serum proteins in 3% polyethylene glycol. The bivalent structure of the 5S fragment is essential for expression of this site since 5S fragments produced by trypsin and pepsin are also agglutinable, while univalent fragments produced by papain and subtilisin are not. The agglutination by albumin of the 5S fragments is not caused by residual enzyme. The reaction appears to be irreversible in that once albumin has reacted with the 5S fragment, either in the fluid phase or at the cell surface, fresh addition of albumin and PEG will not result in agglutination. The nonantibody reaction of albumin and the other serum proteins with these 5S IgG fragments is believed to be caused by hydrophobic bonding involving the intrachain disulfide in the 5S fragment and hydrophobic areas of other proteins.
胰凝乳蛋白酶对IgG抗Rh抗体Ri的水解产生了二价和单价抗体片段。包被在Rh阳性红细胞上的二价片段可被白蛋白和其他血清蛋白在3%聚乙二醇中凝集。5S片段的二价结构对于该位点的表达至关重要，因为胰蛋白酶和胃蛋白酶产生的5S片段也可被凝集，而木瓜蛋白酶和枯草杆菌蛋白酶产生的单价片段则不能。白蛋白对5S片段的凝集不是由残留酶引起的。该反应似乎是不可逆的，因为一旦白蛋白与5S片段在液相或细胞表面发生反应，再新鲜添加白蛋白和聚乙二醇不会导致凝集。白蛋白和其他血清蛋白与这些5S IgG片段的非抗体反应被认为是由涉及5S片段链内二硫键和其他蛋白质疏水区域的疏水键合引起的。
