Preparation of GDP-L-fucose by using microbial enzymes.

Guanosine diphosphate fucose (GDP-fucose) is the substrate for the fucosyl transferases involved in the biosynthesis of blood group substances and other tissue antigens.In mammals,1'2) higher plants3>4) and certain bacteria5>6) this sugar nucleotide is synthesized by complicated enzyme systems.Evidence is presented showing that GDP-4-keto-6-deoxy-D-mannose is an intermediate in the conversion of GDP-mannoseto GDP-fucose and this conversion requires NADPH.The preparation of GDPfucose was reported using cell-free extracts of Aerobacter aerogenes.5)The chemical synthesis of this nucleotide was also reported.7)However, these preparative methods are not efficient and provide only a small amount of GDPfucose.This nucleotide has been used as an analytical reagent for identification of rare blood groups such as the Bombay type.In the present work, we describe the