The galactose-mediated clearance of serum glycoproteins from the circulation was evaluated using β-1,4-galactosyltransferase (β-1,4-GalT) I- knockout mice. Partial structural study of the oligosaccharides released from mouse serum glycoproteins revealed that 77.4% of the oligosaccharides from β-1,4-GalT I(+/+) mouse contain galactose, while 7.7% of those from β-1,4- GalT I(-/-) mouse were galactosylated. Under the conditions, no significant change in serum protein concentrations was observed between the normal and mutant mice. The results indicate that the hepatic asialoglycoprotein receptor-mediated system is not functioning in the clearance of endogenous serum glycoproteins.
- Serum glycoprotein