Some correlations between specificity and sequence of the first complementary determining segments of human kappa light chains

Examination of the sequences of the first complementarity determining segments of the light chains of two IgM cold agglutinins against blood group I, four monoclonal IgM antibodies against IgG proteins, and of three Bence Jones proteins provides clues for predicting which residues contribute to antibody specificity and indicates that these predictions may be tested by evaluating recovery of antibody activity and specificity when various light chains are recombined with homologous and heterologous heavy chains.