Reduced paucimannosidic N-glycan formation by suppression of a specific β-hexosaminidase from Nicotiana benthamiana

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• 作者：Yun-Ji Shin ; Alexandra Castilho ; Martina Dicker ; Flavio Sá ; dio ; Ulrike Vavra ; Clemens Grü ; nwald-Gruber ; Tae-Ho Kwon ; Friedrich Altmann ; Herta Steinkellner and Richard Strasser
• 刊名：Plant Biotechnology Journal
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：15
• 期：2
• 页码：197-206
• 全文大小：991K
• ISSN：1467-7652

文摘

Plants are attractive hosts for the production of recombinant glycoproteins for therapeutic use. Recent advances in glyco-engineering facilitate the elimination of nonmammalian-type glycosylation and introduction of missing pathways for customized N-glycan formation. However, some therapeutically relevant recombinant glycoproteins exhibit unwanted truncated (paucimannosidic) N-glycans that lack GlcNAc residues at the nonreducing terminal end. These paucimannosidic N-glycans increase product heterogeneity and may affect the biological function of the recombinant drugs. Here, we identified two enzymes, β-hexosaminidases (HEXOs) that account for the formation of paucimannosidic N-glycans in Nicotiana benthamiana, a widely used expression host for recombinant proteins. Subcellular localization studies showed that HEXO1 is a vacuolar protein and HEXO3 is mainly located at the plasma membrane in N. benthamiana leaf epidermal cells. Both enzymes are functional and can complement the corresponding HEXO-deficient Arabidopsis thaliana mutants. In planta expression of HEXO3 demonstrated that core α1,3-fucose enhances the trimming of GlcNAc residues from the Fc domain of human IgG. Finally, using RNA interference, we show that suppression of HEXO3 expression can be applied to increase the amounts of complex N-glycans on plant-produced human α1-antitrypsin.