title: Coexistence of multiple monoclonal immunoglobulins with identical constant regions in one patient.
abstract: Two populations of IgG molecules, designated F-IgG3(chi) and S-IgG3(chi), were isolated from a patient with multiple myeloma. The constant regions of the two molecules appear to be identical, since the heavy chains of both belong to the gamma 3 subclass and both molecules are positive for G3m(5), G3m(10), and G3m(11) but negative for G3m(21), Km(1) and Km(2) allotypes. In contrast, the two molecules have different variable regions, since (a) they do not share idiotypic determinant(s); (b) their light chains have different NH2 terminal amino acid sequences, and (c) both their heavy and light chains have different peptide maps and amino acid compositions. SDS-polyacrylamide gel electrophoresis showed that the F-IgG3(chi) molecules have two kinds of light chains. One, designated, chi n, has a normal molecular weight (approximately 23,000); the other, designated chi h, has a molecular weight of approximately 28,000.
mesh_terms: D000368:Aged; D000595:Amino Acid Sequence; D001798:Blood Proteins / Q000235:genetics / Q000276:immunology; D005260:Female; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000235:genetics / Q000302:isolation & purification; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007136:Immunoglobulins / Q000145:classification / Q000235:genetics*; D008970:Molecular Weight; D009101:Multiple Myeloma / Q000235:genetics / Q000276:immunology*; D010266:Paraproteins; D010455:Peptides / Q000032:analysis
chemical_list: D001798:Blood Proteins; D007126:Immunoglobulin Allotypes; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007136:Immunoglobulins; C009823:M-proteins (Myeloma); D010266:Paraproteins; D010455:Peptides