CATIONIC GLYCOPROTEINS IN SERA OF PATIENTS WITH ACUTE INFECTIONS IDENTIFIED AS KAPPA-LIGHT CHAIN GLYCOSYLATED IGG

In half of the sera from patients with acute bacterial infections and 15% of the sera from patients with acute viral infections glycoprotein s were found that form a scalariform pattern in the cationic range upo n isoelectric focusing. The cationic glycoproteins appeared with the c linical illness. After subsidence of the symptoms they disappeared wit hin 4 to 6 weeks. The proteins were identified as immunoglobulin G (Ig G) by determination of the NH2-terminal amino acid sequence. Remarkabl y, these IgG only contained light chains of the kappa type with high p roportions of carbohydrates. Both, N-glycosidic- and O-glycosidic-boun d glycans were present. The glycosylated light chains may render the c ationic IgG multireactive. Thus, it may be part of an early nonspecifi c immune defense mechanism.