Plasma 3S gamma-1-globulin: identity with erythrocyte carbonic anhydrase B.
The 3S (gamma1), 2S (gamma2), and 0.5S (gamma2) fractions of human plasma are heterogeneous in protein composition. Although each fraction contained a relatively small amount of protein antigenically related to the immunoglobulin light chains, most of the proteins were unrelated to immunogloublin G or its light chains. Of the 3S (gamma1)-globulins the greater part was immunochemically identical to carbonic anhydrase B and had carbonic anhydrase activity. These findings explain earlier reports of an immunochemical similarity between 3S (gamma1)-globulins and immunoglobulin light chains in spite of marked differences in amino acid and peptide composition between the two. Apparently not all plasma gamma-globulins are necessarily immunoglobulins.
D002256:Carbonic Anhydrases / Q000097:blood*; D002850:Chromatography, Gel; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007456:Iodine Isotopes; D005719:gamma-Globulins / Q000032:analysis*
D007456:Iodine Isotopes; D005719:gamma-Globulins; D002256:Carbonic Anhydrases