Normal levels of serum glycoproteins maintained in beta-1,4-galactosyltransferase I-knockout mice

The galactose-mediated clearance of serum glycoproteins from the circulatio n was evaluated using beta-1,4-galactosyltransferase (beta-1,4-GalT) I-knoc kout mice. Partial structural study of the oligosaccharides released from m ouse serum glycoproteins revealed that 77.4% of the oligosaccharides from b eta-1,4-GalT I+/+ mouse contain galactose, while 7.7% of those from beta-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 rece ptor-mediated system is not functioning in the clearance of endogenous seru m glycoproteins. (C) 1999 Federation of European Biochemical Societies.