Patent ID: 7901912

Claim:
A method for enzymatically producing uridine 5′-diphospho-N-acetylgalactosamine (UDP-GalNAc) from uridine 5′-monophosphate (UMP) and N-acetylgalactosamine (GalNAc), the method comprising the steps of: preparing a fusion gene by ligating a gene that encodes for human GalNAc kinase to a 3′-downstream region of a gene that encodes for Escherichia coli uridine 5′-diphospho-N-acetylglucosamine (UDP-GlcNAc) pyrophosphorylase, wherein the gene that encodes for human GalNAc kinase is GALK2 and wherein the gene that encodes for Escherichia coli UDP-GlcNAc pyrophosphorylase is glmU; expressing a fusion protein comprising the enzymes GalNAc kinase and UDP-GlcNAc pyrophosphorylase through transformation of the fusion gene to Escherichia coli; producing N-acetylgalactosamine 1-P (GalNAc 1-P) by enzymatic phosphorylation of GalNAc in a reaction mixture containing the expressed fusion protein and yeast cells having an adenosine 5′-triphosphate (ATP) and uridine 5′-triphosphate (UTP) production/regeneration system; producing UTP by enzymatic phosphorylation of UMP employing the UTP production/regeneration system of the yeast cells; enzymatically producing the UDP-GalNAc from the GalNAc 1-P and UTP; and isolating and purifying the UDP-GalNAc from the reaction mixture.