Increased transfer of oligosaccharide from oligosaccharide pyrophosphoryl dolichol to protein acceptors upon estrogen-induced chick oviduct differentiation.

In an earlier report (Lucas, J. J., and Levin, E. (1977 J. Biol. Chem. 252, 4330-4336), we showed that immature chick oviduct membranes could not transfer [14C]mannose from GDP-[14C]Man to endogenous oligosaccharide pyrophosphoryl dolichol or protein. Estrogen treatment of chicks however, stimulated [14C]mannose transfer to those acceptors. In order to determine whether the oligosaccharide transfer responsible for N-glycosylation of oviduct proteins is present in immature oviduct membranes exogenous carboxymethylated alpha-lactalbumin and radiolabeled oligosaccharide-lipid were added to oviduct membranes. Because purity of the oligosaccharide-lipid is essential for consistent transfer of oligosaccharide to carboxymethylated alpha-lactalbumin a high pressure liquid chromatography procedure has been developed for oligosaccharide-lipid purification. The data obtained indicate that immature chick oviduct membranes do have an enzyme capable of oligosaccharide transfer and that the activity is enhanced 3- to 4-fold by estrogen treatment of chicks. A Glc-oligosaccharide is transferred approximately 3-fold more effectively than the nonglycosylated Man-oligosaccharide by membrane preparations from immature chicks, estrogen-treated chicks, and mature hens.