Figure 6.

The β-hairpin loop protects the N184-glycan of procatZ from complex glycosylation. CHO cells transfected with wt-procatZ, Δloop^*, and Δloop cDNA were pulsed for 5 min and chased for 3 h. Secreted procatZ was collected from the medium by anti-HA immunoprecipitation, probed for the sensitivity to endoH and PN-Gase F, and analyzed by SDS-PAGE/fluorography. Numbers indicate doubly-, singly-, and nonglycosylated procatZ after endoH treatment. The graph plots the percentages of endoH-resistant oligosaccharides for the three procatZ mutants as determined by densitometry.