Optimization of gram-scale synthesis of UDP-galactose via one-pot multienzyme approach

Student Name: Kevin Feng
UCD Department: Chemistry
UCD Mentor: Dr. Xi Chen

Uridine 5’diphopho-α-D-galactopyranoside (UDP-Gal) is a sugar nucleotide commonly used by animals, plants, and bacteria as the activated donor of galactose (Gal).   The salvage pathway is the simplest route to synthesize UDP-Gal and involves three different enzymes: Streptococcus pneumoniae TIGR4 galactokinase (SpGalK), Bifidobacterium longum UDP-sugar pyrophosphorylase (BLUSP), and Pasteurella multocida inorganic pyrophosphatase (PmPpA)1.  The optimum conditions for the entire reaction pathway in a one-pot multienzyme system were determined.  Then, using these conditions, synthesis of UDP-Gal was scaled-up to the gram-scale.  Production of UDP-Gal was successfully attempted using 1 g of Gal and a reaction yield of 70% was obtained.  No isolation yield was determined because of incomplete purification.