Title : N-Glycosylation profiling of recombinant mouse
extracellular superoxide dismutase produced in Chinese hamster ovary cells
Abstract :
- Extracellular superoxide dismutase ( EC-SOD ), the major SOD isoenzyme in biological fluids, is known to be N-glycosylated and heterogeneous as was detected in most glycoproteins
- However, only one N-glycan structure has been reported in recombinant human EC-SOD produced in Chinese hamster ovary (CHO) cells
- Thus, a precise N-glycan profile of the recombinant EC-SOD is not available
- In this study, we report profiling of the N-glycan in the recombinant mouse EC-SOD produced in CHO cells using high-resolution techniques, including the liberation of N-glycans by treatment with PNGase F , fluorescence labeling by pyridylamination, characterization by anion-exchange, normal and reversed phase-HPLC separation, and mass spectrometry
- We succeeded in identifying 26 different types of N-glycans in the recombinant enzyme
- The EC-SOD N-glycans were basically core-fucosylated (98.3% of the total N-glycan content) , and were high mannose sugar chain, and mono-, bi-, tri-, and tetra-antennary complex sugar chains exhibiting varying degrees of sialylation
- Four of the identified N-glycans were uniquely modified with a sulfate group, a Lewis(x) structure, or an α-Gal epitope.
- The findings will shed new light on the structure-function relationships of EC-SOD N-glycans