25249-56-3Relevant academic research and scientific papers
ACTIVATED N-ACETYLATED SUGARS AND OLIGOSACCHARIDES
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Page/Page column 20, (2017/01/02)
The invention relates to production of uridine-5'diphospho-N-acetylglucosamine and uridine-5'diphospho-N-acetylgalactosamine. The invention further relates to the production of lacto-/V-triose II and globotetraose.
On the phosphorylase activity of GH3 enzymes: A β-N-acetylglucosaminidase from Herbaspirillum seropedicae SmR1 and a glucosidase from Saccharopolyspora erythraea
Ducatti, Diogo R.B.,Carroll, Madison A.,Jakeman, David L.
, p. 106 - 112 (2016/10/22)
A phosphorolytic activity has been reported for beta-N-acetylglucosaminidases from glycoside hydrolase family 3 (GH3) giving an interesting explanation for an unusual histidine as catalytic acid/base residue and suggesting that members from this family may be phosphorylases [J. Biol. Chem. 2015, 290, 4887]. Here, we describe the characterization of Hsero1941, a GH3 beta-N-acetylglucosaminidase from the endophytic nitrogen-fixing bacterium Herbaspirillum seropedicae SmR1. The enzyme has significantly higher activity against pNP-beta-D-GlcNAcp (Km?=?0.24?mM, kcat?=?1.2 s?1, kcat/Km?=?5.0?mM?1s?1) than pNP-beta-D-Glcp (Km?=?33?mM, kcat?=?3.3?×?10?3s?1, kcat/Km?=?9?×?10?4?mM?1s?1). The presence of phosphate failed to significantly modify the kinetic parameters of the reaction. The enzyme showed a broad aglycone site specificity, being able to hydrolyze sugar phosphates beta-D-GlcNAc 1P and beta-D-Glc 1P, albeit at a fraction of the rate of hydrolysis of aryl glycosides. GH3 beta-glucosidase EryBI, that does not have a histidine as the general acid/base residue, also hydrolyzed beta-D-Glc 1P, at comparable rates to Hsero1941. These data indicate that Hsero1941 functions primarily as a hydrolase and that phosphorolytic activity is likely adventitious. The prevalence of histidine as a general acid/base residue is not predictive, nor correlative, with GH3 beta-N-acetylglucosaminidases having phosphorolytic activity.
Biosynthesis of the carbamoylated D-gulosamine moiety of streptothricins: Involvement of a guanidino-N-glycosyltransferase and an N-acetyl-D-gulosamine deacetylase
Guo, Zhengyan,Li, Jine,Qin, Hua,Wang, Min,Lv, Xun,Li, Xuebing,Chen, Yihua
, p. 5175 - 5178 (2015/04/27)
Streptothricins (STNs) are atypical aminoglycosides containing a rare carbamoylated D-gulosamine (D-GulN) moiety, and the antimicrobial activity of STNs has been exploited for crop protection. Herein, the biosynthetic pathway of the carbamoylated D-GulN moiety was delineated. An N-acetyl-D-galactosamine is first attached to the streptolidine lactam by the glycosyltransferse StnG and then epimerized to N-acetyl-D-gulosamine by the putative epimerase StnJ. After carbamoylation by the carbamoyltransferase StnQ, N-acetyl-D-GulN is deacetylated by StnI to furnish the carbamoylated D-GulN moiety. In vitro studies characterized two novel enzymes: StnG is an unprecedented GT-A fold N-glycosyltransferase that glycosylates the imine nitrogen atom of guanidine, and StnI is the first reported N-acetyl-D-GulN deacetylase. The dynamic duo: Two novel enzymes, StnG and StnI, have been found to be involved in the biosynthetic pathway of the carbamoylated D-gulosamine moiety in streptothricins. StnG is a GT-A fold glycosyltransferase that catalyzes the unprecedented attachment of a sugar to the imine nitrogen atom of a guanidine group; StnI catalyzes the deacetylation of the N-acetyl-D-gulosamine moiety.
Facile enzymatic synthesis of sugar 1-phosphates as substrates for phosphorylases using anomeric kinases
Liu, Yuan,Nishimoto, Mamoru,Kitaoka, Motomitsu
, p. 1 - 4 (2015/02/19)
Three sugar 1-phosphates that are donor substrates for phosphorylases were produced at the gram scale from phosphoenolpyruvic acid and the corresponding sugars by the combined action of pyruvate kinase and the corresponding anomeric kinases in good yields. These sugar 1-phosphates were purified through two electrodialysis steps. α-d-Galactose 1-phosphate was finally isolated as crystals of dipotassium salts. α-d-Mannose 1-phosphate and 2-acetamido-2-deoxy-α-d-glucose 1-phosphate were isolated as crystals of bis(cyclohexylammonium) salts.
Substrate specificity of galactokinase from Streptococcus pneumoniae TIGR4 towards galactose, glucose, and their derivatives
Zou, Yang,Wang, Wenjun,Cai, Li,Chen, Leilei,Xue, Mengyang,Zhang, Xiaomei,Shen, Jie,Chen, Min
body text, p. 3540 - 3543 (2012/07/03)
Galactokinases (GalKs) have attracted significant research attention for their potential applications in the enzymatic synthesis of unique sugar phosphates. The galactokinase (GalKSpe4) cloned from Streptococcus pneumoniae TIGR4 presents a remarkably broad substrate range including 14 diverse natural and unnatural sugars. TLC and MS studies revealed that GalKSpe4 had relaxed activity towards galactose derivatives with modifications on the C-6, 4- or 2-positions. Additionally, GalKSpe4 can also tolerate glucose while glucose derivatives with modifications on the C-6, 4- or 2-positions were unacceptable. More interestingly, GalKSpe4 can phosphorylate l-mannose in moderate yield (43%), while other l-sugars such as l-Gal cannot be recognized by this enzyme. These results are very significant because there is rarely enzyme reported that can phosphorylate such uncommon substrates as l-mannose.
In vitro validation of acetyltransferase activity of GlmU as an antibacterial target in Haemophilus influenzae
Buurman, Ed T.,Andrews, Beth,Gao, Ning,Hu, Jun,Keating, Thomas A.,Lahiri, Sushmita,Otterbein, Ludovic R.,Patten, Arthur D.,Stokes, Suzanne S.,Shapiro, Adam B.
experimental part, p. 40734 - 40742 (2012/06/29)
GlmU is a bifunctional enzyme that is essential for bacterial growth, converting D-glucosamine 1-phosphate into UDP-GlcNAc via acetylation and subsequent uridyl transfer. A biochemical screen of AstraZeneca's compound library using GlmU of Escherichia coli identified novel sulfonamide inhibitors of the acetyltransferase reaction. Steady-state kinetics, ligand-observe NMR, isothermal titration calorimetry, and x-ray crystallography showed that the inhibitors were competitive with acetyl-CoA substrate. Iterative chemistry efforts improved biochemical potency against Gram-negative isozymes 300-fold and afforded antimicrobial activity against a strain of Haemophilus influenzae lacking its major efflux pump. Inhibition of precursor incorporation into bacterial macromolecules was consistent with the antimicrobial activity being caused by disruption of peptidoglycan and fatty acid biosyntheses. Isolation and characterization of two different resistant mutant strains identified the GlmU acetyltransferase domain as the molecular target. These data, along with x-ray co-crystal structures, confirmed the binding mode of the inhibitors and explained their relative lack of potency against Gram-positive GlmU isozymes. This is the first example of antimicrobial compounds mediating their growth inhibitory effects specifically via GlmU.
Wide sugar substrate specificity of galactokinase from Streptococcus pneumoniae TIGR4
Chen, Min,Chen, Lei-Lei,Zou, Yang,Xue, Mengyang,Liang, Min,Jin, Lan,Guan, Wan-Yi,Shen, Jie,Wang, Wenjun,Wang, Lei,Liu, Jun,Wang, Peng George
experimental part, p. 2421 - 2425 (2011/12/15)
Galactokinases (GALK) have attracted significant research attention for their potential application in the enzymatic synthesis of unique sugar phosphates. The galactokinase (GalKSpe4) cloned from Streptococcus pneumoniae TIGR4 had a temperature optimum of 45 °C, and a pH optimum of 8.0. The substrate specificity and kinetics studies revealed that GalKSpe4 had moderate activity toward glucose, in contrast with very low or no activity observed in other previously reported GALKs. Most interestingly, GalKSpe4 exhibited activity for GalNAc, which had never been recorded in other GALKs found by now. This is the first time to report that bacterial GALK can recognize GalNAc.
Identification and characterization of a strict and a promiscuous N-acetylglucosamine-1-P uridylyltransferase in Arabidopsis
Yang, Ting,Echols, Merritt,Martin, Andy,Bar-Peled, Maor
experimental part, p. 275 - 284 (2012/05/20)
UDP-GlcNAc is an essential precursor for glycoprotein and glycolipid synthesis. In the present study, a functional nucleotidyltransferase gene from Arabidopsis encoding a 58.3 kDa GlcNAc1pUT-1 (N-acetylglucosamine-1-phosphate uridylyltransferase) was identified. In the forward reaction the enzyme catalyses the formation of UDP-N-acetylglucosamine and PPi from the respective monosaccharide 1-phosphate and UTP. The enzyme can utilize the 4-epimer UDP-GalNAc as a substrate as well. The enzyme requires divalent ions (Mg2+ or Mn2+) for activity and is highly active between pH 6.5 and 8.0, and at 30-37°C. The apparent Km values for the forward reaction were 337 μM (GlcNAc-1-P) and 295 μM (UTP) respectively. Another GlcNAc1pUT-2, which shares 86%amino acid sequence identity with GlcNAc1pUT-1, was found to convert, in addition to GlcNAc-1-P and GalNAc-1-P, Glc-1-P into corresponding UDP-sugars, suggesting that subtle changes in the UT family cause different substrate specificities. A three-dimensional protein structure model using the human AGX1 as template showed a conserved catalytic fold and helped identify key conserved motifs, despite the high sequence divergence. The identification of these strict and promiscuous gene products open a window to indentify new roles of amino sugar metabolism in plants and specifically their role as signalling molecules. The ability of GlcNAc1pUT-2 to utilize three different substrates may provide further understanding as to why biological systems have plasticity. The Authors.
One-step synthesis of labeled sugar nucleotides for protein O-GlcNAc modification studies by chemical function analysis of an archaeal protein
Mizanur, Rahman M.,Jaipuri, Firoz A.,Pohl, Nicola L.
, p. 836 - 837 (2007/10/03)
Herein we present the chemical function analysis of a recombinant sugar nucleotidyltransferase from the hyperthermophile Pyrococcus furiosus and its use in the one-pot synthesis of chloroacetyl- and alkyne-tagged analogues of uridinediphospho-N-acetylglucosamine (UDP-GlcNAc). The gene was originally annotated as a glucose-1-phosphate deoxythymidylyltransferase; however, kinetic analysis of a panel of sugar-1-phosphates with the protein shows that it is better described as a bifunctional protein that synthesizes UDP-GlcNAc from glucosamine-1-phosphate and acetyl coenzyme A (CoA). A new mass-spectrometry-based assay for the rapid analysis of the acyltransferase activity demonstrates that the enzyme can also accept cheaper truncated N-acetylcysteamine thioester substrates in place of the natural acetyl CoA. The enzyme can tolerate alkyne or chloride substitutions in the acyl moiety, thereby allowing the facile synthesis of tagged sugar nucleotides for future use in protein O-GlcNAc modification studies. Copyright
Two-step enzymatic synthesis of UDP-N-acetylgalactosamine
Bourgeaux, Vanessa,Piller, Friedrich,Piller, Veronique
, p. 5459 - 5462 (2007/10/03)
UDP-GalNAc has been synthesised with high yield from GalNAc, UTP and ATP using recombinant human GalNAc kinase GK2 and UDP-GalNAc pyrophosphorylase AGX1. Both enzymes have been prepared in one step from 1 L cultures of transformed Escherichia coli and the UDP-GalNAc produced has been purified by a simple procedure. The method described is a rapid and efficient means to produce UDP-GalNAc as well as analogues like UDP-N-azidoacetylgalactosamine (UDP-GalNAz).
