Efficient biosynthesis of uridine diphosphate glucose from maltodextrin by multiple enzymes immobilized on magnetic nanoparticles

Uridine diphosphate glucose (UDP-Glc) serves as a glucosyl donor in many enzymatic glycosylation processes. This paper describes a multiple enzyme, one-pot, biocatalytic system for the synthesis of UDP-Glc from low cost raw materials: maltodextrin and uridine triphosphate. Three enzymes needed for the synthesis of UDP-Glc (maltodextrin phosphorylase, glucose-1-phosphate thymidylytransferase, and pyrophosphatase) were expressed in Escherichia coli and then immobilized individually on amino-functionalized magnetic nanoparticles. The conditions for biocatalysis were optimized and the immobilized multiple-enzyme biocatalyst could be easily recovered and reused up to five times in repeated syntheses of UDP-Glc. After a simple purification, approximately 630 mg of crystallized UDP-Glc was obtained from 1 l of reaction mixture, for a moderate yield of around 50% (UTP conversion) at very low cost.