Three M components IgA lambda, + IgG kappa n + IgG kappa h in one patient. II. Structurally different kappa n and kappa h chains associated with H(gamma) chains sharing idiotypic determinants.
Structural analysis of purified IgG kappa h and IgG kappa n molecules of DA myeloma paraproteins indicated that the two IgG had different electrophoretic mobility and that L-kappa h had an unusually heavy m.w. (30,000). Peptide mapping showed the existence of additional peptides in the L-kappa h map when compared to the L-kappa n map. Total amino acid analysis showed that L-kappa h contained two additional cysteine residues and certain other amino acids than L-kappa n contained. Sequence of the first 25 NH2-terminal amino acids showed differences at positions 4, 5, 15, 18, and 21, but both L-kappa h and L-kappa n belong to the same V kappa IV subgroup. IgG kappa n but not IgG kappa h reacted with anti-gamma 1 antiserum, indicating that H chains of these two paraproteins were also different. Sera from rabbits immunized with IgG kappa n or IgG kappa h, and rendered specific for idiotypic determinants by appropriate absorption, were used for idiotype characterization of these components. Immunodiffusion, immunoelectrophoresis, and direct hemagglutination demonstrated that IgG kappa h and IgG kappa n cross-reacted partially. Inhibition tests disclosed that the main anti-idiotypic antibody was directed against a conformation structure of the complete IgG kappa h molecule, whereas cross-reaction was due to partial idiotypic similarity between H chains of the IgG kappa h and IgG kappa n. In addition, each of these paraproteins seemed also to bear private idiotypes on their H and L chains.
D000596:Amino Acids / Q000032:analysis; D003429:Cross Reactions; D000939:Epitopes; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000032:analysis; D007074:Immunoglobulin G / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000032:analysis; D007142:Immunoglobulin gamma-Chains / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000276:immunology; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis
D000596:Amino Acids; D000939:Epitopes; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G; D007130:Immunoglobulin Idiotypes; D007142:Immunoglobulin gamma-Chains; D007145:Immunoglobulin kappa-Chains; D010446:Peptide Fragments