The glycosylation of recombinant b-glucocerebrosidase, the protein for enzyme replacement therapy of Gaucher disease, is shown to be a key factor for its functionality. Macrophages, the target cells for Gaucher disease internalize b-glucocerebrosidase through their mannose receptor. Three enzymes are available for treatment of Gaucher disease by enzyme replacement therapy (ERT). Taliglucerase, imiglucerase and velaglucerase are produced in different cell systems and over-go various post-translational or post-production glycosylation modifications to expose their mannose residues. For the first time, three enzyme glycosylation profiles were compared, using the same methodology. To understand the influence of the glycan pattern, we also measured functionality and uptake parameters of the three commercially available enzymes. Results show that the major differences in glycosylation profiles are in the variation of terminal residues and mannose chain length. The enzymatic activity and stability are not affected by these differences. Furthermore the cellular uptake and in-cell stability in rat and human macrophages are the same. Biodistribution studies showed that all b-glucocerebrosidase enzymes had a similar uptake trend, to the liver and spleen, the expected target organs. These results indicate that variations of glycosylation between the three available commercial b-glucocerebrosidase enzymes have no effect on their function or distribution.
