- Expanded investigations of the aglycon promiscuity and catalysis characteristic of flavonol 3-: O -rhamnosyltransferase AtUGT78D1 from Arabidopsis thaliana
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Rhamnosides usually possess better bioavailabilities and improved solubilities compared with their aglycons and are a major source of bioactive natural products. However, biosynthesis of rhamnosides is hindered by the commercially expensive UDP-rhamnose (UDP-Rha) donor and a lack of universal rhamnosyltransferases. In the present study, an efficient UDP-Rha production system via a two-step enzymatic reactions using UDP-glucose (UDP-Glc) as a substrate was constructed. Extensive in vitro enzymatic assays and preparative reactions using the obtained UDP-Rha/UDP-Glc highlighted the robust glycosylation promiscuity of the reported rhamnosyltransferase AtUGT78D1. Based on HPLC-UV and HR-MS analyses, 30 of the tested aromatic compounds belonging to 7 structural types, including flavonoids, flavonoid glycosides, phenylethyl chromones, benzophenones, coumarins, lignanoids, and anthraquinones, were accepted by AtUGT78D1 to conduct the corresponding rhamnosylation and/or glucosylation with one or more glycosyl substitutions at different positions. Further preparative reactions expanded the catalytic characteristic of AtUGT78D1 since it can catalyse the rhamnosylation at the 3-OH position of the flavonols, glucosylation at the 7-OH position of the flavone baicalein, and multiple hydroxyl substitutions for diverse types of aromatics. Interestingly, a unique reversible catalysis activity of AtUGT78D1 was observed, and it has been effectively used in one-pot rhamnosylation of the desired rhamnoside. The enzymatic rhamnosylations of diverse "drug-like" scaffolds as well as bidirectional catalysis for one-pot rhamnosylations by plant rhamnosyltransferase were rarely reported before, which indicated that AtUGT78D1 was expected to be a universal and effective tool for chemo-enzymatic synthesis of diverse bioactive rhamnosylated derivatives for drug discovery.
- Mo, Ting,Liu, Xiao,Liu, Yuyu,Wang, Xiaohui,Zhang, Le,Wang, Juan,Zhang, Zhongxiu,Shi, Shepo,Tu, Pengfei
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p. 84616 - 84626
(2016/11/02)
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- One-pot three-enzyme synthesis of UDP-Glc, UDP-Gal, and their derivatives
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A UTP-glucose-1-phosphate uridylyltransferase (SpGalU) and a galactokinase (SpGalK) were cloned from Streptococcus pneumoniae TIGR4 and were successfully used to synthesize UDP-galactose (UDP-Gal), UDP-glucose (UDP-Glc), and their derivatives in an efficient one-pot reaction system. The reaction conditions for the one-pot multi-enzyme synthesis were optimized and nine UDP-Glc/Gal derivatives were synthesized. Using this system, six unnatural UDP-Gal derivatives, including UDP-2-deoxy-Galactose and UDP-GalN3 which were not accepted by other approach, can be synthesized efficiently in a one pot fashion. More interestingly, this is the first time it has been reported that UDP-Glc can be synthesized in a simpler one-pot three-enzyme synthesis reaction system.
- Zou, Yang,Xue, Mengyang,Wang, Wenjun,Cai, Li,Chen, Leilei,Liu, Jun,Wang, Peng George,Shen, Jie,Chen, Min
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supporting information
p. 76 - 81
(2013/06/27)
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- Biosynthesis of nucleotide sugars by a promiscuous UDP-sugar pyrophosphorylase from Arabidopsis thaliana (AtUSP)
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Nucleotide sugars are activated forms of monosaccharides and key intermediates of carbohydrate metabolism in all organisms. The availability of structurally diverse nucleotide sugars is particularly important for the characterization of glycosyltransferases. Given that limited methods are available for preparation of nucleotide sugars, especially their useful non-natural derivatives, we introduced herein an efficient one-step three-enzyme catalytic system for the synthesis of nucleotide sugars from monosaccharides. In this study, a promiscuous UDP-sugar pyrophosphorylase (USP) from Arabidopsis thaliana (AtUSP) was used with a galactokinase from Streptococcus pneumoniae TIGR4 (SpGalK) and an inorganic pyrophosphatase (PPase) to effectively synthesize four UDP-sugars. AtUSP has better tolerance for C4-derivatives of Gal-1-P compared to UDP-glucose pyrophosphorylase from S. pneumoniae TIGR4 (SpGalU). Besides, the nucleotide substrate specificity and kinetic parameters of AtUSP were systematically studied. AtUSP exhibited considerable activity toward UTP, dUTP and dTTP, the yield of which was 87%, 85% and 84%, respectively. These results provide abundant information for better understanding of the relationship between substrate specificity and structural features of AtUSP.
- Liu, Jun,Zou, Yang,Guan, Wanyi,Zhai, Yafei,Xue, Mengyang,Jin, Lan,Zhao, Xueer,Dong, Junkai,Wang, Wenjun,Shen, Jie,Wang, Peng George,Chen, Min
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supporting information
p. 3764 - 3768
(2013/07/25)
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- Stereoselective chemical synthesis of sugar nucleotides via direct displacement of acylated glycosyl bromides
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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.
- Timmons, Shannon C.,Jakeman, David L.
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p. 1227 - 1230
(2007/10/03)
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- Unusually broad substrate tolerance of a heat-stable archaeal sugar nucleotidyltransferase for the synthesis of sugar nucleotides
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Herein, we report the first cloning, recombinant expression, and synthetic utility of a sugar nucleotidyltransferase from any archaeal source and demonstrate by an electrospray ionization mass spectrometry (ESI-MS)-based assay its unusual tolerance of heat, pH, and sugar substrates. The metalion-dependent enzyme from Pyrococcus furiosus DSM 3638 showed a relatively high degree of acceptance of glucose-1-phosphate (Glc1P), mannose-1-phosphate (Man1P), galactose-1-phosphate (Gal1P), fucose-1-phosphate, glucosamine-1-phosphate, galactosamine-1-phosphate, and N-acetylglucosamine-1-phosphate with uridine and deoxythymidine triphosphate (UTP and dTTP, respectively). The apparent Michaelis constants for Glc1P, Man1P, and Gal1P are 13.0 ± 0.7, 15 ± 1, and 22 ± 2 μM, respectively, with corresponding turnover numbers of 2.08, 1.65, and 1.32 s-1, respectively. An initial velocity study indicated an ordered bi-bi catalytic mechanism for this enzyme. The temperature stability and inherently broad substrate tolerance of this archaeal enzyme promise an effective reagent for the rapid chemoenzymatic synthesis of a range of natural and unnatural sugar nucleotides for in vitro glycosylation studies and highlight the potential of archaea as a source of new enzymes for synthesis.
- Mizanur, Rahman M.,Zea, Corbin J.,Pohl, Nicola L.
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p. 15993 - 15998
(2007/10/03)
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- Active-site engineering of nucleotidylyltransferases and general enzymatic methods for the synthesis of natural and "unnatural" UDP- and TDP-nucleotide sugars
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The present invention provides mutant nucleotidylyl-transferases, such as Ep, having altered substrate specificity; methods for their production; and methods of producing nucleotide sugars, which utilize these nucleotidylyl-transferases. The present invention also provides methods of synthesizing desired nucleotide sugars using natural and/or modified Ep or other nucleotidyltransferases; and nucleotide sugars sythesized by the present methods. The present invention further provides new glycosyl phosphates, and methods for making them.
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- Rapid conversion of unprotected galactose analogs to their UDP-derivatives for use in the chemoenzymatic synthesis of unnatural oligosaccharides
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The rapid conversion of D-galactose, its 2-deoxy, 3-deoxy, 4-deoxy and 6-deoxy derivatives and L-arabinose to their UDP-derivatives (2-7) is described. The procedure involves the in situ preparation of the per-O-trimethylsilylated glycopyranosyl iodides and their direct reaction with UDP. All six sugar nucleotides were active as substrates for β(1→4)-galactosyltransferase and were used to enzymatically prepare N-acetyllactosamine (8) and five of its analogs (9-13).
- Uchiyama, Taketo,Hindsgaul, Ole
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p. 1181 - 1190
(2007/10/03)
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- Novel aspects of interaction between UDP-Gal and GlcNAc β-1,4-galactosyltransferase: Tansferability and remarkable inhibitory activity of UDP-(mono-O-methylated Gal), UDP-Fuc and UDP-Man
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Four mono-O-methylated and one mono-O-acetylated UDP-D-Gal analogues and UDP-L-Fuc were synthesized. 2-O-Methyl-D-galactose residue was enzymatically transferred to give 2'-O-methyllactosaminide in high yield. UDP-Fuc and UDP-Man showed potent inhibitory
- Endo, Tsuyoshi,Kajihara, Yasuhiro,Kodama, Hisashi,Hashimoto, Hironobu
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p. 1939 - 1948
(2007/10/03)
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- Enzymic transfer of 6-modified D-galactosyl residues: Synthesis of biantennary penta- and hepta-saccharides having two 6-deoxy-D-galactose residues at the nonreducing end and evaluation of 6-deoxy-D-galactosyl transfer to glycoprotein using bovine β-(1 4)-galactosyltransferase and UDP-6-deoxy-D-galactose
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UDP-6-Deoxy-D-galactose and UDP-6-deoxy-6-fluoro-D-galactose were synthesized and their transfer to 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine) by β-(1 → 4)-galactosyltransferase was examined. The transfer rates of 6-deoxy-D-galactose and 6-deoxy-6-fluoro-D-galactose were 1.3 and 0.2% of that of D-galactosyl transfer, respectively. The 2-acetamido-4-O-(6-deoxy-β-D-galactopyranosyl)-2-deoxy-D-glucopyranos e (6'-deoxy-N-acetyllactosamine) and methyl 2-acetamido-4-O-(6-deoxy-6-fluoro-β-D-galactopyranosyl)-2-deoxy-D-glu copyranoside (6'-deoxy-6'-fluoro-N-acetyllactosamine) were synthesized enzymatically in 30 and 59% yields, respectively. Further, 6-deoxy-D-galactose could be completely transferred to N-linked type biantennary oligosaccharides having two N-acetyl-D-glucosaminyl residues at the nonreducing end to give the corresponding penta- and hepta-saccharides in 55 and 57% yields, respectively. An assay of 6-deoxy-D-galactosyl transfer using asialo agalacto α1-acid glycoprotein as an acceptor suggested that 6-deoxy-D-galactose was transferred to about 30% of the N-acetyl-D-glucosaminyl residues in the N-linked oligosaccharides of the glycoprotein.
- Kajihara,Endo,Ogasawara,Kodama,Hashimoto
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p. 273 - 294
(2007/10/02)
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- Synthesis of uridine 5′(α-D-fucopyranosyl diphosphate) and (digitoxigenin-3β-yl)-β-D-fucopyranoside and enzymatic β-D-fucosylation of cardenolide aglycones in Digitalis lanata
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The phosphorylation of 2,3,4-tri-Oacetyl-α-D-fucopyranose with o-phenylene phosphochloridate yielded α-D-fucopyranosyl phosphate which was used for condensation with undine 5′-monophosphomorpholidate to give uridine 5′-(α-D-fucopyranosyl diphosphate) (UDP-α-D-fucose). A crude enzyme preparation from young leaves of Digitalis lanata EHRH has been shown to catalyze the transfer of D-fucose from synthetic UDP-α-D-fucose to cardenolide aglycones, such as digitoxigenin. The reaction product was identified and characterized by chemical synthesis, HPLC, and spectral methods as the 3 β-O-β-D-fucopyranoside of digitoxigenin (digiproside). Copyright
- Faust,Theurer,Eger,Kreis
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p. 140 - 149
(2007/10/02)
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