Idiotypic determinants with purified antibodies

As indicated earlier Kunkel et al. (3) observed that anti-A substance and antilevan, specifically purified from the serum of a single human donor, possessed unrelated idiotypic specificities. Similarly, Oudin and Michel (2) found that a rabbit antiserum directed to idiotypic determinants in rabbit antisalmonella antibody failed to react with anti-... 

Idiotypic specificities on free L chains have been localized to the variable half of the polypeptide chain by Tan and Epstein, who isolated such fragments from the urine of a patient with multiple myeloma (92). The corresponding, intact Bence Jones protein was also purified and used to prepare antibodies in rabbits which, after appropriate absorption, reacted with idiotypic determinants of the immunogen. A line of identity was obtained in the reaction of these anti-D antibodies with the Bence Jones protein and the fragment comprising the variable region. Thus, all the individually specific determinants appeared to be represented in the variable segment. 

Quantitative studies of antiidiotypic antibodies directed to specifically purified rabbit anti-p-azobenzoate antibody indicated that the combining site of the antibenzoate antibody is part of, or close to a major idiotypic determinant (84). The reaction of I-labeled F(ab )2 fragments of antibenzoate antibody with each of six antiidiotypic antisera tested was significantly inhibited by a large number of homologous haptens, i.e., by benzoate derivatives. There was a close correlation between the affinity of a hapten for the antibody and its capacity to prevent the combination of antibenzoate antibody with antiidiotypic antibody. Compounds unrelated to benzoate were not inhibitory. As much as 69% inhibition was observed when the hapten of highest affinity, p-(p -hydroxy)phenylazobenzoate, was tested at a concentration of 1.6 X 10- M. 

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