Large Scale Production of Recombinant α-1,2-Mannosyltransferase from E. coli for the Study of Acceptor Specificity and Use of the Recombinant Whole Cells in Synthesis

We report the first large scale heterologous expression of a recombinant yeast α-1,2-mannosyltransferase in E. coli. The enzyme was isolated from 10-L and 50-L fermentations, purified and used for mannosylation reactions. The specificity of the recombinant enzyme was extensively studied by using mannose derivatives, oligosaccharides, and analogs as acceptors, and the results show that the enzyme exhibits high activities toward ManOMe and disaccharides connected by an α-1,2-mannosidic linkage. The recombinant E. coli cells were also used as a catalyst for glycosylation reaction, and mannosylation of saccharides and glycopeptides proceeded in moderate to good yields.