Similar combining sites of IgG1and IgG2aantibodies in individual mice as judged from affinity and rate constant measurements

摘要

AbstractWithin individual sera, mouse IgG1and IgG2asubclass antibodies against the antigenic detetminant oligio‐D‐Allanine are likely to have similar combining sites. The antibodies are characterized by two methods, by their rate of binding to antigen equipped sheep red blood cells and by the hapten inhibition of antigen binding. The two characteristics are shown to be independent. The subclass antibodies of thirteen different sera differ by a factor of about 10 in their rate constant and by a factor of about 50 in affinity for hapten. In contrast, IgG1and IgG2awithin the same serum have strikingly similar rate constants (factor 1.02–1.33) as well as very similar affinities (factor 1.1–2.7). Since it is higly improbable that correlation in two independent criteria occurs by chance, the IgG1and IgG2aantibodies are asssumed to have similar combinin