title: IgM pyroglobulinemia with erythrocytosis presenting as hyperviscosity syndrome. II. Biochemical properties and mechanisms of pyrogel formation.
abstract: An immunoglobulin M with kappa light chains (IgMK) pyroglobulin from a patient with hyperviscosity syndrome, erythrocytosis and coagulation defects has been studied for its immunochemical properties. At physiologic temperatures the purified macropyroglobulin showed a striking tendency to aggregate in the pentamer as well as in the monomer form. This property was also observed in its H chains. Aggregate formation of the pentamers may have contributed to the blood viscosity and coagulation defects. Formation of pyrogel at 56degreesC was observed with pentamers as well as monomers, but not with separated H or L chains. Amino acid analysis showed quantitative abnormalities of aspartic acid, glycine, cystine and leucine within the H chains. Solubility of the pyrogel in sodium dodecyl sulfate, the pyroglobulin's tendency to aggregate and the cystine deficit of H chains implicate conformational changes leading to hydrophobic bonding at 56degreesC in the formation of pyrogel.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001809:Blood Viscosity; D005782:Gels; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007145:Immunoglobulin kappa-Chains; D010265:Paraproteinemias / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D010266:Paraproteins / Q000378:metabolism; D011086:Polycythemia / Q000150:complications*; D011750:Pyroglobulins / Q000378:metabolism; D008258:Waldenstrom Macroglobulinemia / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D005782:Gels; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D010266:Paraproteins; D011750:Pyroglobulins; C013230:pyrogel