Figure 6.
Released 2-AB–labeled N-glycan analysis of CHO-sKlotho (A) and HEK-sKlotho (B). N-Glycans released from CHO- and HEK-sKlotho were subjected to HILIC-FLD glycan analysis as described under “Experimental procedures” and in Fig. S1. A, CHO-sKlotho is heavily sialylated (black trace) and efficiently desialylated by sialidase A digestion (blue trace). B, HEK-sKlotho was found to contain unique N-glycans with LacdiNAc moieties with both sialyation and sulfation (black trace). Exoglycosidase β-N-acetylhexosaminidasef (New England BioLabs; 16-h incubation at 37 °C prior to chromatography) specifically removed one terminal HexNAc from the LacdiNAc (GalNAcβ1–4GlcNAc)-containing N-glycan structures in various proportions due to interference from terminal fucosylation, sialyation, and sulfation (red trace).