Comparison of the carbohydrate moieties of recombinant soluble Fc? receptor (sFc? RII/sCD23) expressed inSaccharomyces cerevisiae and Chinese hamster ovary cells. Different O-glycosylation sites are used by yeast and mammalian cells

Abstract
Recombinant human soluble low affinity receptor for the Fc portion of IgE (sFcεRII/sCD23) was produced inSaccharomyces cerevisiae or Chinese hamster ovary cells and subjected to carbohydrate analysis. Applied methods included analytical SDS-PAGE, reversed phase HPLC, methylation analysis and sequential degradation with exoglycosidases. The results revealed that sFcεRII derived from Chinese hamster ovary cells is glycosylated exclusively at Ser-147, containing mainly the trisaccharide Sia(α2–3)Gal(β1–3)GalNAc, whereas the yeast derived glycoprotein was glycosylated at Ser-167 and contained only α-mannosyl residues. It is shown here for the first time that different amino acids of a given protein can be O-glycosylated when expressed in yeast or Chinese hamster ovary cells.