Structures of the carbohydrate moieties of two monoclonal human .lambda.-type immunoglobulin light chains

Abstract

Human Bence Jones proteins of .lambda. type, Wh and Nei, both of which belong to subgroup II, contain an Asn-linked sugar chain. Their carbohydrate moieties were liberated as oligosaccharides by hydrazinolysis and labeled by reduction with NaB3H4 after N-acetylation. Structural studies of each oligosaccharide by sequential exoglycosidase digestion in combination with methylation analysis revealed that Wh .lambda. contains the mono- and disialylated oligosaccharides, while Nei .lambda. contains the 2 acidic oligosaccharides. These oligosaccharides are different from the oligosaccharides found in another .lambda.-type Bence Jones protein, Sm .lambda., by Chandrasekaran et al. and Garver et al.