earticle

영어

UDP-D-glucose is then used as a glucosyl donor for the biosynthesis of various carbohydrates, such as the cell envelope of Escherichia coli, lipopolysaccharide, capsular polysaccharide, and membranederived oligosaccharides. In addition, it is an essential intermediate for the growth on galactose and trehalose, including the synthesis of rehalose. UDP-D-glucose is also considered to be the glucosyl donor for glycogen synthesis in mammalian cells, but ADP-D-glucose or UDP-D-glucose can serve as glucosyl donors in eukaryotic microorganisms and plants. So to synthesize UDP-glucose from UMP via UDP and UTP, three enzymes TMK (thymidine monophosphate kinase), ACK (acetate kinase) and Gal-U (Glucose-1-phosphate uridylyltransferase gene) are needed. a one-pot reaction system with ATP regeneration was designed, in which easily available UMP and glucose-1-phosphate were used as starting materials. Enzyme immobilization is a method to keep enzyme molecules cofined or localized in a certain defined region of space with retention of their catalytic activities. In comparison with their native form, immobilized enzymes offer several advantages, such as enhanced stability, easier product recovery and purification, the possibility of repeated usage, and continuous process technology. so UDP-glucose synthase was immobilized as a cross-linked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and cross-linking with glutaraldehyde. The effects of precipitation and cross-linking on CLEA activity were investigated and the immobilized enzymes were characterized.