title: IgM molecules with and without J chain in serum and after purification, studied by ultracentrifugation, electrophoresis, and electron microscopy.
abstract: IgM molecules in pure IgM preparations and in the corresponding sera from three patients with Waldenström's macroglobulinemia have been studied by analytical ultracentrifugation, rate zonal ultracentrifugation, agarose-polyacrylamide gel electrophoresis, and electron microscopy. One of the IgM preparations was without J chain, while the two others contained J chain. The experiments revealed that IgM with J chain consisted of pentameric molecules; whereas in IgM preparations without J chain the dominating molecules were hexamers, but also pentamers, tetramers, and even smaller molecules were found. In both types of IgM the molecules formed a wide range of aggregates, which were usually more abundant in the purified IgM than in serum. Some of the aggregates were kept together by noncovalent forces only.
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis; D007143:Immunoglobulin Heavy Chains / Q000032:analysis; D007144:Immunoglobulin J-Chains / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis* / Q000302:isolation & purification; D008854:Microscopy, Electron; D008968:Molecular Conformation; D011108:Polymers; D014461:Ultracentrifugation; D008258:Waldenstrom Macroglobulinemia / Q000276:immunology*
chemical_list: D007143:Immunoglobulin Heavy Chains; D007144:Immunoglobulin J-Chains; D007075:Immunoglobulin M; D011108:Polymers