FIGURE 5.

Generation of T-antigen (Galβ1–3GalNAc) by co-expression of C1GALT1. A, co-expression of EPO-Fc with the machinery for O-GalNAc formation is shown. B, co-expression of EPO-Fc with the machinery for O-GalNAc formation, human C1GALT1, and its specific chaperone COSMC is shown. C, co-expression of EPO-Fc with the machinery for O-GalNAc formation and Drosophila C1GALT1 is shown. The spectra show the O-glycosylated EPO-Fc Ser-126-containing peptide (¹¹⁷EAISPPDAASAAPLR¹³¹). The arrow points at the peptide with one hydroxyproline residue. Unrelated peaks are denoted by an asterisk.