Enzymatic synthesis of dTDP-4-amino-4,6-dideoxy-D-glucose using GerB (dTDP-4-keto-6-deoxy-D-glucose aminotransferase).

Over-expressed GerB (dTDP-4-keto-6-deoxy-d-glucose aminotransferase) of Streptomyces sp. GERI-155 was used in the enzymatic synthesis of dTDP-4-amino-4,6-dideoxy-D-glucose (2) from dTDP-4-keto-6-deoxy-D-glucose (1). [Carbohydrate structure: see text]. Five enzymes including dTMP kinase (TMK), acetate kinase (ACK), dTDP-glucose synthase (TGS), dTDP-glucose 4,6-dehydratase (DH), and dTDP-4-keto-6-deoxy-d-glucose aminotransferase (GerB) were used to synthesize 2 on a large scale from glucose-1-phosphate and TMP. A conversion yield of up to 57% was obtained by HPLC peak integration given a reaction time of 270min. After purification by two successive preparative HPLC systems, the final product was identified by HPLC and then analyzed by (1)H, (13)C, (1)H-(1)H COSY NMR spectrometry.