TDP-D-glucose

TDP-D-glucose is initially attacked by enzyme-NAD+ (enzyme protein containing one mole of firmly bound NAD+) at carbon 4 to yield TDP-D-xylo-4-hexulose and accompanying formation of enzyme NADH. The 4-ulose rearranges by / -elimination of water between carbons 5 and 6 to form an unsaturated glucoseen. This unsaturated 5,6-glucoseen serves as hydrogen acceptor for enzyme-NADH to restore enzyme-NAD+ and leads to the end product of the reaction TDP-6-deoxy-D-xylo-4-hexulose. 

Considering this property of 4-uloses to be applicable to the postulated intermediate TDP-D-xylo-4-hexulose formed in the enzymatic reaction, we decided to verify this reaction mechanism by the use of specifically labeled substrate. For this purpose TDP-D-glucose-4T was prepared in the following way. 

The first two enzymatic steps are common to the biosynthesis of all 6DOHs and lead to the biosynthesis of the intermediate TDP-4-keto-6-deoxy-D-glucose. These enzymatic reactions have been extensively studied in different sugar biosynthesis pathways, such as tylosin or mithramycin [13]. 

Thymidine D-Glucose TDP-6-deoxy-D-xylo-4-hexulose (4-keto-6-deoxy-D-glucose)... 

D., Uou, K.-K., Lee, H.-C., Sohng, J.-K. et al. (2010) One-pot enzymatic synthesis of deoxy-thymidine-diphosphate (TDP)-2-deoxy-a-d-glucose using phos-phomannomutase. J. Mol. Catal. E ... 

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