Synthesis of GDP-Mannose in Recombinant Escherichia coli

摘要

Three recombinant Escherichia coli strains were constructed to produce guanosine 5'-diphosphate (GDP)-mannose, donor of GDP-fucose, which is an essential substrate for synthesis of fucosyloligosaccharides. Glucokinase (glk), phosphomannomutase (manB), and mannose-1-phosphate guanylytransferase (manC), are three crucial enzymes for the de novo GDP-mannose biosynthesis, were overexpressed in recombinant E.coli by constructing inducible overexpression vectors. The optimum expression conditions for GLK, ManB, and ManC in recombinant E.coli BL21 (DE3) were 25 ºC and 0.1 mM isopropyl-β-D-thioglucopyranoside. In this condition, the conversion rate was 30% from mannose to GDP-mannose.