Structures of the asparagine-linked oligosaccharides of guinea-pig factor B of the alternative complement pathway

This paper describes the structures of the asparagine-linked oligosaccharides of two forms of guinea-pig Factor B of the alternative complement pathway with different M(r) values. Oligosaccharides were quantitatively liberated from both glycoproteins by hydrazinolysis, fractionated by paper electrophoresis and Bio-Gel P-4 column chromatography, and their structures determined by sequential exoglycosidase digestions in conjunction with methylation analysis. Both glycoproteins were shown to have the same biantennary complex-type oligosaccharides but it is suggested that they contain different numbers of oligosaccharide chains.