Characterization of a new UDP-sugar pyrophosphorylase from Hordeum vulgare (barley).

The broad substrate spectrum of UDP-sugar pyrophosphorylases from plant salvage pathways is of high interest for the synthesis of expensive nucleotide sugars by straightforward enzyme cascade reactions in combination with monosaccharide kinases. We here present a new UDP-sugar pyrophosphorylase from Hordeum vulgare with favorable biochemical properties like broad pH and temperature tolerances as well as a broad substrate spectrum and high synthesis stability. Enzyme properties were determined and reaction conditions were optimized by high-through-put multiplexed capillary electrophoresis analysis. In combination with a galactokinase UDP-α-d-galactose (UDP-Gal) was efficiently synthesized with a space-time-yield of 17g/L*h for full conversion of 10mM substrate within 20min by 1.2U of each enzyme.