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Here, we report a practical sugar nucleotide production strategy that combined a high-concentrated multi-enzyme catalyzed reaction and a robust chromatography-free selective precipitation purification process. Twelve sugar nucleotides were synthesized on a gram scale with a purity up to 98%.

Glucose-1-phosphate thymidylyltransferase (Cps23FL) from Streptococcus pneumonia serotype 23F is the initial enzyme that catalyses the thymidylyl transfer reaction in prokaryotic deoxythymidine diphosphate-l-rhamnose (dTDP-Rha) biosynthetic pathway. In this study, the broad substrate specificity of Cps23FL towards six glucose-1-phosphates and nine nucleoside triphosphates as substrates was systematically explored, eventually providing access to nineteen sugar nucleotide analogs.

Biomimetic synthesis routes towards the important natural d-mannosyl donor guanosine 5′-diphospho-d-mannose (GDP-Man) rely on kinase-catalyzed nucleotide triphosphate (NTP)-dependent phosphorylations of d-mannose (Man), to give d-mannose 6-phosphate or α-d-mannose 1-phosphate (αMan 1-P) as an intermediate product. A GDP-Man synthesis not requiring the kinase/NTP system would be practical and cost-effective. Here, we have developed a multienzyme cascade towards GDP-Man, characterized in that αMan 1-P was obtained by a diastereoselective phosphatase-catalyzed phosphorylation of Man. α-d-Glucose 1-phosphate (αGlc 1-P), prepared in situ through phosphorylase-catalyzed conversion of sucrose in the presence of inorganic phosphate, was used as an expedient phosphoryl donor. The incipient αMan 1-P and guanosine triphosphate (GTP) were converted into GDP-Man by a highly manno compared to gluco selective nucleotidyltransferase. Pyrophosphatase was additionally required to hydrolyze the pyrophosphate released from the GTP, thus driving the reaction towards GDP-Man. The enzymatic cascade was operated with the αMan 1-P and the GDP-Man formation decoupled from one another (sequential mode) or having all steps run concurrently (simultaneous mode). Detailed time course analysis revealed that kinetic pull due to the constant removal of the intermediate αMan 1-P in simultaneous-mode reactions was important to promote phosphorylation of Man from αGlc 1-P in high efficiency, avoiding loss of sugar 1-phosphates by hydrolysis. Under optimized conditions for the one-pot transformation involving four enzymes, 100 mM (67 g L?1) GDP-Man was prepared from 140 mM sucrose and phosphate, using 400 mM Man as the phosphoryl acceptor. The product was recovered by anion-exchange and size-exclusion chromatography in ≥95% purity in about 50% yield (100 mg). These results demonstrate for the first time the practical use of a phosphorylase-phosphatase combi-catalyst as an alternative to the canonical kinase for the anomeric phosphorylation of the sugar substrate in nucleoside diphospho-sugar synthesis. Phosphorylation from inorganic phosphate via the intermediate αGlc 1-P rather than from NTP, particularly GTP, appears advantageous specifically in cases where the sugar acceptor is a bulk commodity that can be applied in suitable excess to the phosphatase reaction. (Figure presented.).

An N-acetylhexosamine 1-kinase from Bifidobacterium infantis (NahK-15697), a guanosine 5′-diphosphate (GDP)-mannose pyrophosphorylase from Pyrococcus furiosus (PFManC), and an Escherichia coli inorganic pyrophosphatase (EcPpA) were used efficiently for a one-pot three-enzyme synthesis of GDP-mannose, GDP-glucose, their derivatives, and GDP-talose. This study represents the first facile and efficient enzymatic synthesis of GDP-sugars and derivatives starting from monosaccharides and derivatives.

A series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (Manp-1P) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4 positions, in turn suggesting that these positions are buried inside the enzyme active site. Additionally, both the 6-methoxy and 6-deoxy Manp-1P derivatives are good or moderate substrates for GDP-ManPP, thus indicating that the C-6 hydroxy group of the Manp-1P substrate is not required for binding to the enzyme. When taken into consideration with other previously published work, it appears that this enzyme has potential utility for the chemoenzymatic synthesis of GDP-Manp analogues, which are useful probes for studying enzymes that employ this sugar nucleotide as a substrate.

Herein we present an analysis of the chemical function of a recombinant bifunctional phosphomannose isomerase/GDP-mannose pyrophosphorylase (manC) from Pyrococcus furiosus DSM 3638 and its use in the synthesis of guanidinediphospho-hexoses and a range of

GDP-2-, 3-, 4- or 6-azidomannoses can be successfully prepared from the corresponding azidomannose-1-phosphates and GTP using the enzyme GDP-Mannosepyrophosphorylase (GDP-ManPP) from Salmonella enterica and may serve as useful probes for mannosyltransferase activity. The Royal Society of Chemistry.

Figure presented The use of Leloir glycosyltransferases to prepare biologically relevant oligosaccharides and glycoconjugates requires access to sugar nucleoside diphosphates, which are notoriously difficult to efficiently synthesize and purify. We report a novel stereoselective route to UDP- and GDPα-D-mannose as well as UDP- and GDP-β-L-fucose via direct displacement of acylated glycosyl bromides with nucleoside 5′- diphosphates.

2-Deoxy-α-D-glucose-1-phosphate, 3-deoxy-α-D-arabino-hexose-1-phosphate, 4-deoxy-α-D-lyxo-hexose-1-phosphate, and α-D-lyxose-1-phosphate were synthesised chemically, and evaluated as substrates for a recombinant GDP-mannose pyrophosphorylase (Salmonella enterica, group B, cloned in Escherichia coli). The deoxy derivatives were all substrates for the enzyme, with slightly reduced V(max) values but significantly higher K(m) values than those recorded for the native substrate, mannose-1-phosphate. The pyrophosphorylase was used for the synthesis of GDP-mannose analogues GDP-2-deoxy-glucose and GDP-lyxose on a milligram scale. Copyright (C) 2000 Elsevier Science Ltd.

The aim of the presented work is the chemoenzymatic synthesis of GDP- mannose (GDP-Man). Mannose-1-phosphate (Man-1-P) is synthesised by a very convenient chemical method and is activated with GTP and recombinant GDP- mannose pyrophosphorylase (GDP-Man PP) to give GDP-Man. The productivity of the process is improved using reaction engineering techniques. Detailed kinetic studies, modelling of the reaction and simulations of different reaction systems revealed that besides a strong product inhibition the cofactor Mg2+ is a key switch for effective enzymatic synthesis. Using a two-stage cascade of enzyme membrane reactors, GDP-Man could be produced continuously with a space-time yield of 28 gL-1 d-1 and an enzyme consumption of 0.9 Ug-1, which means a six-fold improvement related to batch synthesis.

Guanosine 5'-diphosphomannose (GDP-mannose, 1) has been prepared via two routes from α-D-mannose 1-phosphate 5.The non-enzymic route involves coupling of the phosphate 5 to guanosine 5'-monophosphate dibutyl phosphinothioic anhydride (GMP-anhydride 11) to give compound 1 in 40percent yield.The enzymic routes require coupling of compound 5 with guanosine 5'-triphosphate (GTP) catalysed by GDP-mannose pyrophosphorylase (37percent).

Sialyl Lewis x and derivatives have been synthesized using 0-1,4-galactosyltransferase and recombinant α-2,3-sialyltransferase and α-l,3-fucosyltransferase. The enzymatic glycosylations have been achieved on preparative scales with in situ regeneration of UDP-galactose, CMP-N-acetylneuraminic acid, and GDP-fucose. Additionally, galactosyltransferase and fucosyltransferases have been studied with respect to their substrate specificity and inhibition. The enzymatic procedures have also been used in the synthesis of 2′-deoxy-LacNAc, 2′-amino-2′-deoxy-LacNAc, 2-azido-Lac, Lewis x, the Lewis x analog with GlcNAc replaced with 5-thioglucose, [Gal-l-13C]-LacNAc, [Gal-1-13C]-sialyl Lewis x, and the corresponding terminal glycal. The synthesized 13C-labeled sialyl Lewis x and intermediates (including Lewis x and sialyl LacNAc) were used for conformational study using NMR techniques combined with calculations based on GESA and MM2 programs. GESA calculation of sialyl Lewis x gave four minimum-energy conformers, and the two (A and B) consistent with NMR results were further refined with MM2 calculation. The one (A') with lower energy was picked as the preferred conformer which had all internuclear distances and glycosidic torsional angles consistent with the NMR analysis. The glycosidic torsional angle ψ of Gal-GlcNAc, for example, was determined to be 18° on the basis of the coupling between Gal-1-13C and GlcNAc, while the predicted value was 15°. The tetrasaccharide appears to form a well-defined hydrophilic surface along NeuAc-Gal- Fuc, and a hydrophobic face underneath NeuAc-Gal-GlcNAc. Comparing the conformation of sialyl Lewis x to sialyl Lewis a indicates that the recognition domain of sialyl Lewis x mainly comes from the sialic acid - galactose - fucose residues.

This paper compares enzymatic and chemical methods for the synthesis of cytidine 5'-triphosphate, guanosine 5'-triphosphate, and uridine 5'-triphosphate from the corresponding nucleoside monophosphates on scales of ~10 g. These nucleoside triphosphates are important as intermediates in Leloir pathway biosyntheses of complex carbohydrates; the nucleoside monophosphates are readily available commercially. The best route to CTP is based on phosphorylation of CMP using adenylate kinase (EC 2.7.4.3); the route to GTP involves phosphorylation of GMP using guanylate kinase (EC 2.7.4.8); chemical deamination of CTP (prepared enzymatically from CMP) is the best synthesis of UTP. For the 10-200-mmol-scale reactions described in this paper, it is more convenient to prepare phosphoenolpyruvate (PEP), used in the enzymatic preparations, from D-(-)-3-phosphoglyceric acid (3-PGA) in the reaction mixture rather than to synthesize PEP in a separate chemical step. The in situ conversion of 3-PGA to PEP requires the coupled action of phosphoglycerate mutase (EC 2.7.5.3) and enolase (EC 4.2.1.11). The enzyme-catalyzed syntheses of uridine 5'-diphosphoglucose (UDP-Glc), uridine 5'-diphosphoglucuronic acid (UDP-GlcUA), and guanosine 5'-diphosphomannose (GDP-Man) illustrate the use of the nucleoside triphosphates.

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