Mengyang Xue

University of California, Davis, Davis, California, United States

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Publications (16)58.49 Total impact

  • Yanhong Li · Mengyang Xue · Xue Sheng · Hai Yu · Jie Zeng · Vireak Thon · Peng G. Wang · Xi Chen

    No preview · Conference Paper · Nov 2015
  • Rui Zhang · Jiali Wang · Mengyang Xue · Feng Xu · Yuguo Chen
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    ABSTRACT: The human aldehyde dehydrogenase 2 (ALDH2) is the most effective enzyme in the detoxification of alcohol metabolite acetaldehyde. The ALDH2*2 mutation is caused by a single nucleotide substitution which results in a nearly inactive form of ALDH2 enzyme. The ALDH2 genotype has been used as a surrogate of alcohol use to get causal inferences of alcohol in related diseases implementing Mendelian randomization approach. In addition, ALDH2 enzyme has significant effect on different diseases, indicating the potential therapeutic value of ALDH2 regulators including both activators like Alda-1 and inhibitors such as daidzin and daidzein. In this review, we systematically discuss the implications of ALDH2 genotype and ALDH2 enzyme regulators, highlighting their epidemiological and clinical importance, respectively.
    No preview · Article · Jul 2015 · Current drug targets
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    ABSTRACT: Lacto-N-neotetraose and its sialyl and fucosyl derivatives including Lewis x (Lex) pentasaccharide, sialyl Lewis x (sLex) hexasaccharide and internally sialylated derivatives were enzymatically synthesized from readily available lactoside, commercially available uridine 5'-diphosphate-glucose (UDP-Glc) and corresponding monosaccharides using highly efficient sequential one-pot multienzyme (OPME) strategy. The OPME strategy which combines bacterial glycosyltransferases and sugar nucleotide generation enzymes provides an easy access to the biologically important complex oligosaccharides in preparative scales. Moreover, the same OPME strategy can be used for the regioselective introduction of sialic acid to the internal galactose unit of LNnT in a designed glycosylation route by simply changing the glycosylation sequence.
    Full-text · Article · Mar 2015 · Chemical Communications
  • Jiali Wang · Baoshan Liu · Hui Han · Qiuhuan Yuan · Mengyang Xue · Feng Xu · Yuguo Chen
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    ABSTRACT: Although hyperglycemia is common in patients with acute myocardial infarction (MI), the underlying mechanisms are largely unknown. Insulin signaling plays a key role in the regulation of glucose homeostasis. In this study, we test the hypothesis that rapid alteration of insulin signaling pathways could be the potential contributor to acute hyperglycemia after MI. Male rats were used to produce MI by ligation of the left anterior descending coronary artery. Plasma glucose and insulin levels were significantly higher in MI rats than those in controls. Insulin-stimulated tyrosine phosphorylation of insulin receptor substrate 1(IRS1) was significantly reduced in liver of MI rats compared with controls, followed by decreased attachment of phosphatidylinositol 3-kinase (PI3K) p85 subunit with IRS1 and Akt phosphorylation. However, insulin-stimulated signaling was not significantly altered in skeletal muscle after MI. The relative mRNA levels of PEPCK and G6Pase were slightly higher in liver of MI rats than those in controls. Rosiglitazone (ROSI) markedly restored hepatic insulin signaling, inhibited gluconeogenesis and reduced plasma glucose levels in MI rats. Insulin resistance develops rapidly in liver but not skeletal muscle after MI, which contributes to acute hyperglycemia. Therapy aimed at potentiating hepatic insulin signaling may be beneficial for MI-induced hyperglycemia.
    No preview · Article · Feb 2015 · Molecular Medicine
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    ABSTRACT: Arabidopsis thaliana glucuronokinase (AtGlcAK) was cloned and shown to be able to use various uronic acids as substrates to produce the corresponding uronic acid-1-phosphates. AtGlcAK or Bifidobacterium infantis galactokinase (BiGalK) was used with a UDP-sugar pyrophosphorylase, an inorganic pyrophosphatase, with or without a glycosyltransferase for highly efficient synthesis of UDP-uronic acids and glucuronides. These improved cost-effective one-pot multienzyme (OPME) systems avoid the use of nicotinamide adenine dinucleotide (NAD+)-cofactor in dehydrogenase-dependent UDP-glucuronic acid production processes and can be broadly applied for synthesizing various glucuronic acid-containing molecules.
    Full-text · Article · Feb 2015 · Chemical Communications
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    ABSTRACT: Two novel synthetic α2-6-linked disialyl hexasaccharides, disialyllacto-N-neotetraose (DSLNnT) and α2-6-linked disialyllacto-N-tetraose (DS'LNT), were readily obtained by highly efficient one-pot multienzyme (OPME) reactions. The sequential OPME systems described herein allowed the use of an inexpensive disaccharide and simple monosaccharides to synthesize the desired complex oligosaccharides with high efficiency and selectivity. DSLNnT and DS'LNT were shown to protect neonatal rats from necrotizing enterocolitis (NEC) and are good therapeutic candidates for preclinical experiments and clinical application in treating NEC in preterm infants.
    Full-text · Article · Jun 2014 · Angewandte Chemie International Edition in English
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    ABSTRACT: Globotriose is involved in numerous pathogenic processes and drug development strategies. Recent studies have demonstrated that globotriosylceramide could be used in colon cancer therapy and as a crucial indicator for susceptibility to HIV-1 infection. Therefore, the cost-effective and facile approaches for large-scale production of globotiose as potential drugs are highly required. Here, a multi-enzyme one-pot system containing a galactokinase (SpGalK, E.C., a UDP-glucose pyrophosphorylase (SpGalU, E.C., a α-1,4-galactosyltransferase (LgtC, E.C. and a commercial inorganic pyrophosphatase (PPase, EC was designed to achieve globotriose on preparative scales. This method exploits a cheaper initial substrate, galactose, for donor UDP-galactose production. More importantly, the substrate specificity of SpGalK and SpGalU is highly promiscuous and various UDP-galactose derivatives obtained could be used as the donor substrates for LgtC. This pointcut of rapid preparation of globotriose derivatives is proposed for the first time. Finally, three globotriose analogs were achieved by this one-pot multi-enzyme system in our study.
    No preview · Article · Apr 2014 · European Journal of Medicinal Chemistry
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    ABSTRACT: Enzymatic synthesis of globotriose and its derivatives.
    No preview · Article · Jan 2014
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    ABSTRACT: A novel N-acetylglucosamine-1-phosphate pyrophosphorylase was identified from Campylobacter jejuni NCTC 11168. An unprecedented degree of substrate promiscuity has been revealed by systematic studies on its substrate specificities towards sugar-1-P and NTP. The yields of the synthetic reaction of seven kinds of sugar nucleotides catalyzed by the enzyme were up to 60%. In addition, the yields of the other nine were around 20%. With this enzyme, three novel sugar nucleotide analogs were synthesized on a preparative scale and well characterized.
    No preview · Article · Jun 2013 · Bioorganic & medicinal chemistry letters
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    ABSTRACT: 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.
    No preview · Article · May 2013 · Bioorganic & medicinal chemistry letters
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    ABSTRACT: 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.
    No preview · Article · Mar 2013 · Carbohydrate research
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    ABSTRACT: Glycopeptides are very useful substrates for the synthesis of various complex glycoproteins and glycopeptides that are indispensable materials for the structural and functional investigation of glycoproteins. This report provides an efficient and time- and cost-saving strategy for the large-scale production of a sialylglycopeptide (SGP) that carries an intact N-linked disialyl-biantennary complex-type sialyloligosaccharide. Consequently, 680 mg of SGP was obtained from 100 egg yolks after phenol treatment, Sephadex G-50 gel filtration, and filtration through graphitized carbon cartridges. The chemical structure and the glycosylation site of the isolated SGP were identified by NMR and ESI-MS/MS, and the purity measured with HPLC was over 95%.
    No preview · Article · May 2012 · Journal of Carbohydrate Chemistry
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    ABSTRACT: Nucleotide sugars are essential glycosyl donors for Leloir-type glycosyltransferases. The UDP-N-acetylgalactosamine pyrophosphorylase (UDP-GalNAc PP; AGX1) from Homo sapiens catalyzes the synthesis of UDP-N-acetylgalactosamine from N-acetylgalactosamine 1-phosphate and UTP. In this Letter, we systematically studied nucleotide substrate specificity of AGX1 during its uridyltransfer reaction, and described the capability of AGX1 to catalyze dUTP and dTTP to their corresponding nucleotide sugars for the first time. Furthermore, using such a eukaryotic enzyme, we synthesized dUDP-GalNAc and dTDP-GalNAc in multiple mg scale in vitro efficiently and rapidly.
    No preview · Article · Apr 2012 · Bioorganic & medicinal chemistry letters
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    ABSTRACT: 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.
    No preview · Article · Apr 2012 · Bioorganic & medicinal chemistry letters
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    ABSTRACT: 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.
    No preview · Article · Aug 2011 · Carbohydrate research
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    ABSTRACT: UDP-hexose 4-epimerases are critical in galactose metabolism and often important in lipopolysaccharide biosynthesis as well. Three groups of these enzymes have been reported based on their substrate specificity towards non-acetylated substrates (group 1), dual specificity towards N-acetylated and non-acetylated substrates (group 2) and specificity towards N-acetylated substrates (group 3). We recently reported the structure of a novel UDP-GalNAc 4-epimerase called WbgU and based on the structure proposed a model of specific substrate recognition by UDP-GalNAc 4-epimerases. In this work, we present an analysis of the proposed model of substrate recognition using site-directed mutagenesis of WbgU and crystal structure of the His305Ala mutant. This investigation reveals that the wild-type activity of WbgU is retained in most single-point mutants targeting the active site. However, a graded loss in activity is observed in double-and triple-point mutants with the quadruple-point mutant being completely inactive corroborating the proposed rationale of substrate recognition. Furthermore, crystal structure of the His305Ala mutant shows that the structure is significantly similar to the wild-type WbgU, albeit a loss in the critical hydrogen bond network seated at His305 and ensuing minor conformational changes. It is inferred that the specific and non-specific interactions throughout the active site confer it sufficient elasticity to sustain wild-type activity for several of the single-point mutations.
    Full-text · Article · Jul 2011 · Biochemical and Biophysical Research Communications

Publication Stats

42 Citations
58.49 Total Impact Points


  • 2014-2015
    • University of California, Davis
      • Department of Chemistry
      Davis, California, United States
  • 2011-2015
    • Shandong University
      • • Key Laboratory for Cardiovascular Remodelling and Function Research
      • • State Key Laboratory for Microbial Technology
      • • Department of Chemical Engineering
      Chi-nan-shih, Shandong Sheng, China