DTDP-activated deoxysugar synthesis

This complex synthesis was accomphshed following the definition of sequential cascade reactions combining multiple biocatalytic reactions without the necessity of intermediate work-up. The central intermediate of dTDP-activated deoxysugar synthesis was produced in an enzyme module system with sucrose synthase... 

Fig. 23. Enzymatic synthesis of dTDP-activated deoxysugars with dTDP-Glc 4,6 dehydratase (EC 4.2.1.46) [331]...

P., Drager, G., Kirschning, A., and Piepersberg, W. (2005) An enzyme module system for the synthesis of dTDP-activated deoxysugars from dTMP and sucrose. GhemBioGhem, 6, 1423-1430. 

However, the alternative way to produce activated deoxysugars is by chemical synthesis, with all its formerly described disadvantages. In this review only a few examples will be mentioned. Chemical syntheses of the GDP-activated 6-deoxysugar L-fucose [158-161] and dTDP-activated 3,6 didesoxyglucose... 

However, nucleoside diphosphates (NDP) are still expensive substrates, which can be obtained from much more cheaper nucleoside monophosphates (NMP). In this respect we have combined the SuSy-catalyzed cleavage of sucrose with the enzymatic formation of NDPs from NMPs catalyzed by nucleoside monophosphate kinase (NMPK, EC 2.7.4.4) or myokinase (MK, EC 2.7.4.3), including in situ regeneration of ATP with pyruvate kinase (PK, EC 2.7.1.40) (Fig. 20) [272]. Testing the substrate spectrum of four different kinases disclosed that none of them accepted dTMP as substrate [272], However, dUMP was well accepted by NMPK and dUDP-activated glucose could also substitute dTDP-activated glucose as precursor for the synthesis of activated deoxysugars (see below). The excellent enzyme stabilities under synthesis... 

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