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Totani M, Nakamichi A, Kadokawa JI. Enzymatic Assembly of Chitosan-Based Network Polysaccharides and Their Encapsulation and Release of Fluorescent Dye. Molecules 2024; 29:1804. [PMID: 38675624 DOI: 10.3390/molecules29081804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
We prepared network polysaccharide nanoscopic hydrogels by crosslinking water-soluble chitosan (WSCS) with a carboxylate-terminated maltooligosaccharide crosslinker via condensation. In this study, the enzymatic elongation of amylose chains on chitosan-based network polysaccharides by glucan phosphorylase (GP) catalysis was performed to obtain assembly materials. Maltoheptaose (Glc7) primers for GP-catalyzed enzymatic polymerization were first introduced into WSCS by reductive amination. Crosslinking of the product with the above-mentioned crosslinker by condensation was then performed to produce Glc7-modified network polysaccharides. The GP-catalyzed enzymatic polymerization of the α-d-glucose 1-phosphate monomer from the Glc7 primers on the network polysaccharides was conducted, where the elongated amylose chains formed double helices. Enzymatic disintegration of the resulting network polysaccharide assembly successfully occurred by α-amylase-catalyzed hydrolysis of the double helical amyloses. The encapsulation and release of a fluorescent dye, Rhodamine B, using the CS-based network polysaccharides were also achieved by means of the above two enzymatic approaches.
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Affiliation(s)
- Masayasu Totani
- Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
| | - Aina Nakamichi
- Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
| | - Jun-Ichi Kadokawa
- Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
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Ciarkowska A, Ostrowski M, Kozakiewicz A. Biochemical Characterization of Recombinant UDPG-Dependent IAA Glucosyltransferase from Maize ( Zea mays). Int J Mol Sci 2021; 22:ijms22073355. [PMID: 33805949 PMCID: PMC8037650 DOI: 10.3390/ijms22073355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/16/2022] Open
Abstract
Here, we report a biochemical characterization of recombinant maize indole-3-acetyl-β-d-glucose (IAGlc) synthase which glucosylates indole-3-acetic acid (IAA) and thus abolishes its auxinic activity affecting plant hormonal homeostasis. Substrate specificity analysis revealed that IAA is a preferred substrate of IAGlc synthase; however, the enzyme can also glucosylate indole-3-butyric acid and indole-3-propionic acid with the relative activity of 66% and 49.7%, respectively. KM values determined for IAA and UDP glucose are 0.8 and 0.7 mM, respectively. 2,4-Dichlorophenoxyacetic acid is a competitive inhibitor of the synthase and causes a 1.5-fold decrease in the enzyme affinity towards IAA, with the Ki value determined as 117 μM, while IAA-Asp acts as an activator of the synthase. Two sugar-phosphate compounds, ATP and glucose-1-phosphate, have a unique effect on the enzyme by acting as activators at low concentrations and showing inhibitory effect at higher concentrations (above 0.6 and 4 mM for ATP and glucose-1-phosphate, respectively). Results of molecular docking revealed that both compounds can bind to the PSPG (plant secondary product glycosyltransferase) motif of IAGlc synthase; however, there are also different potential binding sites present in the enzyme. We postulate that IAGlc synthase may contain more than one binding site for ATP and glucose-1-phosphate as reflected in its activity modulation.
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Affiliation(s)
- Anna Ciarkowska
- Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland;
- Correspondence: ; Tel.: +48-56-611-4520
| | - Maciej Ostrowski
- Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland;
| | - Anna Kozakiewicz
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland;
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Lomas JS, Joubert L. On the importance of intramolecular hydrogen bond cooperativity in d-glucose - an NMR and QTAIM approach. Magn Reson Chem 2017; 55:893-901. [PMID: 28432857 DOI: 10.1002/mrc.4599] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/15/2017] [Accepted: 04/18/2017] [Indexed: 05/16/2023]
Abstract
The idea that hydrogen bond cooperativity is responsible for the structure and reactivity of carbohydrates is examined. Density functional theory and gauge-including atomic orbital calculations on the known conformers of the α and β anomers of d-glucopyranose in the gas phase are used to compute proton NMR chemical shifts and interatomic distances, which are taken as criteria for probing intramolecular interactions. Atom-atom interaction energies are calculated by the interacting quantum atoms approach in the framework of the quantum theory of atoms in molecules. Association of OH1 in the counterclockwise conformers with a strong acceptor, pyridine, is accompanied by cooperative participation from OH2, but there is no significant change in the bonding of the two following 1,2-diol motifs. The OH6... O5 (G-g+/cc/t and G+g-/cc/t conformers) or OH6... O4 (Tg+/cc/t conformer) distance is reduced, and the OH6 proton is slightly deshielded. In the latter case, this shortening and the associated increase in the OH6-O4 interaction energy may be interpreted as a small cooperative effect, but intermolecular interaction energies are practically the same for all three conformers. In most of the pyridine complexes, one ortho proton interacts with the endocyclic oxygen O5. Analogous results are obtained when the clockwise conformer, G-g+/cl/g-, detected for the α anomer, and a hypothetical conformer, Tt/cl/g-, are complexed with pyridine through OH6. Generally, the cooperative effect does not go beyond the first two OH groups of a chain. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- John S Lomas
- ITODYS (CNRS UMR-7086), Univ Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France
| | - Laurent Joubert
- Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, F-76821, Mont St Aignan Cedex, France
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Abstract
Enzymes in the α-d-phosphohexomutases superfamily catalyze the reversible conversion of phosphosugars, such as glucose 1-phosphate and glucose 6-phosphate. These reactions are fundamental to primary metabolism across the kingdoms of life and are required for a myriad of cellular processes, ranging from exopolysaccharide production to protein glycosylation. The subject of extensive mechanistic characterization during the latter half of the 20th century, these enzymes have recently benefitted from biophysical characterization, including X-ray crystallography, NMR, and hydrogen-deuterium exchange studies. This work has provided new insights into the unique catalytic mechanism of the superfamily, shed light on the molecular determinants of ligand recognition, and revealed the evolutionary conservation of conformational flexibility. Novel associations with inherited metabolic disease and the pathogenesis of bacterial infections have emerged, spurring renewed interest in the long-appreciated functional roles of these enzymes.
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Affiliation(s)
| | | | - Lesa J Beamer
- University of Missouri, Columbia, MO, United States.
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Zhou W, You C, Ma H, Ma Y, Zhang YHP. One-Pot Biosynthesis of High-Concentration α-Glucose 1-Phosphate from Starch by Sequential Addition of Three Hyperthermophilic Enzymes. J Agric Food Chem 2016; 64:1777-1783. [PMID: 26832825 DOI: 10.1021/acs.jafc.5b05648] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
α-Glucose 1-phosphate (G1P) is synthesized from 5% (w/v) corn starch and 1 M phosphate mediated by α-glucan phosphorylase (αGP) from the thermophilic bacterium Thermotoga maritima at pH 7.2 and 70 °C. To increase G1P yield from corn starch containing branched amylopectin, a hyper-thermostable isoamylase from Sulfolobus tokodaii was added for simultaneous starch gelatinization and starch-debranching hydrolysis at 85 °C and pH 5.5 before αGP use. The pretreatment of isoamylase increased G1P titer from 120 mM to 170 mM. To increase maltose and maltotriose utilization, the third thermostable enzyme, 4-glucanotransferase (4GT) from Thermococcus litoralis, was added during the late stage of G1P biotransformation, further increasing G1P titer to 200 mM. This titer is the highest G1P level obtained on starch or its derived products (maltodextrin and soluble starch). This study suggests that in vitro multienzyme biotransformation has an advantage of great engineering flexibility in terms of space and time compared with microbial fermentation.
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Affiliation(s)
- Wei Zhou
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences , 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Chun You
- Cell Free Bioinnovations Inc. , 1800 Kraft Drive, Suite 222, Blacksburg, Virginia 24060, United States
| | - Hongwu Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences , 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences , 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Y-H Percival Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences , 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Cell Free Bioinnovations Inc. , 1800 Kraft Drive, Suite 222, Blacksburg, Virginia 24060, United States
- Biological Systems Engineering Department, Virginia Tech , 304 Seitz Hall, Blacksburg, Virginia 24061, United States
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Loranger MW, Beaton SA, Lines KL, Jakeman DL. Thiophosphate and thiophosphonate analogues of glucose-1-phosphate: synthesis and enzymatic activity with a thymidylyltransferase. Carbohydr Res 2013; 379:43-50. [PMID: 23872276 DOI: 10.1016/j.carres.2013.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 11/17/2022]
Abstract
Synthetic methods were investigated for the preparation of O and S-glucosyl thiophosphates and glucosyl 1C-thiophosphonate. Four protected glucosyl thiophosphate compounds were synthesized and characterized as precursors to glucose 1-thiophosphate. The effect of various reaction conditions and the nature of the carbohydrate and thiophosphate protecting groups and how they impact both the yields and α/β diastereoselectivity of the glucosyl thiophosphate products were explored. A novel isomerization from an O-linked to S-linked glucosyl thiophosphate was observed. α-D-Glucose-1C-thiophosphonate was synthesized and evaluated as a substrate for the thymidylyltransferase, Cps2L. Tandem mass spectrometric analysis determined the position of sulfur in the sugar nucleotide product.
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Affiliation(s)
- Matthew W Loranger
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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Kharel MK, Lian H, Rohr J. Characterization of the TDP-D-ravidosamine biosynthetic pathway: one-pot enzymatic synthesis of TDP-D-ravidosamine from thymidine-5-phosphate and glucose-1-phosphate. Org Biomol Chem 2011; 9:1799-808. [PMID: 21264378 PMCID: PMC4482361 DOI: 10.1039/c0ob00854k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ravidomycin V and related compounds, e.g., FE35A-B, exhibit potent anticancer activities against various cancer cell lines in the presence of visible light. The amino sugar moieties (D-ravidosamine and its analogues, respectively) in these molecules contribute to the higher potencies of ravidomycin and analogues when compared to closely related compounds with neutral or branched sugars. Within the ravidomycin V biosynthetic gene cluster, five putative genes encoding NDP-D-ravidosamine biosynthetic enzymes were identified. Through the activities of the isolated enzymes in vitro, it is demonstrated that ravD, ravE, ravIM, ravAMT and ravNMT encode TDP-D-glucose synthase, TDP-4-keto-6-deoxy-D-glucose-4,6-dehydratase, TDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase, TDP-3-keto-6-deoxy-D-galactose-3-aminotransferase, and TDP-3-amino-3,6-dideoxy-D-galactose-N,N-dimethyl-transferase, respectively. A protocol for a one-pot enzymatic synthesis of TDP-D-ravidosamine has been developed. The results presented here now set the stage to produce TDP-D-ravidosamine routinely for glycosylation studies.
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Affiliation(s)
- Madan K. Kharel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Hui Lian
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Jürgen Rohr
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
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Olsson R, Giesler R, Loring JS, Persson P. Adsorption, desorption, and surface-promoted hydrolysis of glucose-1-phosphate in aqueous goethite (α-FeOOH) suspensions. Langmuir 2010; 26:18760-18770. [PMID: 21087005 DOI: 10.1021/la1026152] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Adsorption, desorption, and precipitation reactions at environmental interfaces govern the fate of phosphorus in terrestrial and aquatic environments. Typically, a substantial part of the total pool of phosphorus consists of organophosphate, and in this study we have focused on the interactions between glucose-1-phosphate (G1P) and goethite (α-FeOOH) particles. The adsorption and surface-promoted hydrolysis reactions have been studied at room temperature as a function of pH, time, and total concentration of G1P by means of quantitative batch experiments in combination with infrared spectroscopy. A novel simultaneous infrared and potentiometric titration (SIPT) technique has also been used to study the rates and mechanisms of desorption of the surface complexes. The results have shown that G1P adsorption occurs over a wide pH interval and at pH values above the isoelectric point of goethite (IEP(goethite) = 9.4), indicating a comparatively strong interaction with the particle surfaces. As evidenced by IR spectroscopy, G1P formed pH-dependent surface complexes on goethite, and investigations of both adsorption and desorption processes were consistent with a model including three types of surface complexes. These complexes interact monodentately with surface Fe but differ in hydrogen bonding interactions via the auxiliary oxygens of the phosphate group. The apparent desorption rates were shown to be influenced by reaction pathways that include interconversion of surface species, which highlights the difficulty in determining the intrinsic desorption rates of individual surface complexes. Desorption results have also indicated that the molecular structures of surface complexes and the surface charge are two important determinants of G1P desorption rates. Finally, this study has shown that surface-promoted hydrolysis of G1P by goethite is base-catalyzed but that the extent of hydrolysis was small.
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Affiliation(s)
- Rickard Olsson
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
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9
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Kim H, Choi J, Kim T, Lokanath NK, Ha SC, Suh SW, Hwang HY, Kim KK. Structural basis for the reaction mechanism of UDP-glucose pyrophosphorylase. Mol Cells 2010; 29:397-405. [PMID: 20238176 DOI: 10.1007/s10059-010-0047-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 12/18/2009] [Accepted: 12/30/2009] [Indexed: 10/19/2022] Open
Abstract
UDP-glucose pyrophosphorylases (UGPase; EC 2.7.7.9) catalyze the conversion of UTP and glucose-1-phosphate to UDP-glucose and pyrophosphate and vice versa. Prokaryotic UGPases are distinct from their eukaryotic counterparts and are considered appropriate targets for the development of novel antibacterial agents since their product, UDP-glucose, is indispensable for the biosynthesis of virulence factors such as lipopolysaccharides and capsular polysaccharides. In this study, the crystal structures of UGPase from Helicobacter pylori (HpUGPase) were determined in apo- and UDP-glucose/Mg(2+)-bound forms at 2.9 A and 2.3 A resolutions, respectively. HpUGPase is a homotetramer and its active site is located in a deep pocket of each subunit. Magnesium ion is coordinated by Asp130, two oxygen atoms of phosphoryl groups, and three water molecules with octahedral geometry. Isothermal titration calorimetry analyses demonstrated that Mg(2+) ion plays a key role in the enzymatic activity of UGPase by enhancing the binding of UGPase to UTP or UDP-glucose, suggesting that this reaction is catalyzed by an ordered sequential Bi Bi mechanism. Furthermore, the crystal structure explains the specificity for uracil bases. The current structural study combined with functional analyses provides essential information for understanding the reaction mechanism of bacterial UGPases, as well as a platform for the development of novel antibacterial agents.
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Affiliation(s)
- Hun Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, 440-746, Korea.
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10
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Hasunuma T, Harada K, Miyazawa SI, Kondo A, Fukusaki E, Miyake C. Metabolic turnover analysis by a combination of in vivo 13C-labelling from 13CO2 and metabolic profiling with CE-MS/MS reveals rate-limiting steps of the C3 photosynthetic pathway in Nicotiana tabacum leaves. J Exp Bot 2010; 61:1041-51. [PMID: 20026474 PMCID: PMC2826653 DOI: 10.1093/jxb/erp374] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 11/22/2009] [Accepted: 11/24/2009] [Indexed: 05/05/2023]
Abstract
Understanding of the control of metabolic pathways in plants requires direct measurement of the metabolic turnover rate. Sugar phosphate metabolism, including the Calvin cycle, is the primary pathway in C(3) photosynthesis, the dynamic status of which has not been assessed quantitatively in the leaves of higher plants. Since the flux of photosynthetic carbon metabolism is affected by the CO(2) fixation rate in leaves, a novel in vivo (13)C-labelling system was developed with (13)CO(2) for the kinetic determination of metabolic turnover that was the time-course of the (13)C-labelling ratio in each metabolite. The system is equipped with a gas-exchange chamber that enables real-time monitoring of the CO(2) fixation rate and a freeze-clamp that excises a labelled leaf concurrently with quenching the metabolic reactions by liquid nitrogen within the photosynthesis chamber. Kinetic measurements were performed by detecting mass isotopomer abundance with capillary electrophoresis-tandem mass spectrometry. The multiple reaction monitoring method was optimized for the determination of each compound for sensitive detection because the amount of some sugar phosphates in plant cells is extremely small. Our analytical system enabled the in vivo turnover of sugar phosphates to be monitored in fresh tobacco (Nicotiana tabacum) leaves, which revealed that the turnover rate of glucose-1-phosphate (G1P) was significantly lower than that of other sugar phosphates, including glucose-6-phosphate (G6P). The pool size of G1P is 12 times lower than that of G6P. These results indicate that the conversion of G6P to G1P is one of the rate-limiting steps in the sugar phosphate pathway.
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Affiliation(s)
- Tomohisa Hasunuma
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa-shi, Kyoto 619-0292 Japan
| | - Kazuo Harada
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shin-Ichi Miyazawa
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa-shi, Kyoto 619-0292 Japan
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Chikahiro Miyake
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa-shi, Kyoto 619-0292 Japan
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Katzenellenbogen E, Kocharova NA, Korzeniowska-Kowal A, Gamian A, Bogulska M, Szostko B, Shashkov AS, Knirel YA. Immunochemical studies of the lipopolysaccharides of Hafnia alvei PCM 1219 and other strains with the O-antigens containing D-glucose 1-phosphate and 2-deoxy-2-[(R)-3-hydroxybutyramido]-D-glucose. Arch Immunol Ther Exp (Warsz) 2009; 56:347-52. [PMID: 18836891 PMCID: PMC2768797 DOI: 10.1007/s00005-008-0034-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Introduction: Hafnia alveiis the only species of the genus Hafnia, which belongs to the family of Enterobacteriaceae. These Gram-negative bacteria are commonly distributed in the natural environment and are often the cause of human opportunistic infections. Their lipopolysaccharides (LPSs) are important surface antigens which are responsible for the serological specificity and numerous cross-reactions with other enterobacterial genera. So far, 29 different O-polysaccharide (OPS, O-antigen) structures in Hafnias LPSs have been established and for some of them the molecular basis of the serological activity has been elucidated. Materials and Methods: OPS from H. alvei strain PCM 1219 was obtained by mild acid hydrolysis of the LPS followed by gel permeation chromatography of carbohydrate material on Sephadex G-50 column. The polysaccharide structure was determined using chemical methods as well as 13C NMR and 1H NMR spectroscopy. For serological studies, SDS-PAGE, immunoblotting, and passive hemagglutination tests were used. Results: The serological studies revealed a cross-reactivity of the LPSs of H. alvei PCM 1219 and a group of H. alvei strains with an O-antigen containing D-glucose 1-phosphate and [(R)-3-hydroxybutyramido]-D-glucose. The following structure of the OPS was established: where Acyl stands for (R)-3-hydroxybutyryl and the degree of O-acetylation is ~70%. The structure of the core oligosaccharide was found to be typical of the genus Hafnia. Conclusions: Based on the OPS structure and serological results it was concluded that H. alvei strain PCM 1219 should be classified in the same serogroup as the H. alvei type strain ATCC 13337 and five other strains containing D-glucose 1-phosphate and 2-deoxy-2-[(R)-3-hydroxybutyramido]-D-glucose in their O-antigens.
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Affiliation(s)
- Ewa Katzenellenbogen
- Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114, Wrocław, Poland.
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Kaneko Y, Beppu K, Kadokawa JI. Amylose Selectively Includes One from a Mixture of Two Resemblant Polyethers in Vine-Twining Polymerization. Biomacromolecules 2007; 8:2983-5. [PMID: 17880135 DOI: 10.1021/bm700670m] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this paper, we describe that amylose almost selectively includes poly(tetrahydrofuran) (PTHF) from a mixture of poly(oxetane) (POXT) and PTHF having resemblant chemical structures and molecular weights in vine-twining polymerization. This was performed by the phosphorylase-catalyzed enzymatic polymerization of alpha-D-glucose 1-phosphate from maltoheptaose as a primer in the presence of a mixture of POXT and PTHF to produce an amylose-PTHF inclusion complex.
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Affiliation(s)
- Yoshiro Kaneko
- Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima, Japan
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Nihira T, Nakajima M, Inoue K, Nishimoto M, Kitaoka M. Colorimetric quantification of alpha-D-galactose 1-phosphate. Anal Biochem 2007; 371:259-61. [PMID: 17709092 DOI: 10.1016/j.ab.2007.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 07/09/2007] [Accepted: 07/13/2007] [Indexed: 10/23/2022]
Affiliation(s)
- Takanori Nihira
- National Food Research Institute, Tsukuba, Ibaraki 305-8642, Japan
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Affiliation(s)
- Nobuyuki Morimoto
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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Abstract
ADP-Glc pyrophosphorylase (PPase), a key regulatory enzyme in the biosynthetic pathway of starch and bacterial glycogen, catalyzes the synthesis of ADP-Glc from Glc-1-P and ATP. A homology model of the three-dimensional structure of the Escherichia coli enzyme complexed with ADP-Glc has been generated to study the substrate-binding site in detail. A set of amino acids in the model has been identified to be in close proximity to the glucose moiety of the ADP-Glc ligand. The role of these amino acids (Glu(194), Ser(212), Tyr(216), Asp(239), Phe(240), Trp(274), and Asp(276)) was studied by site-directed mutagenesis through the characterization of the kinetic properties and thermal stability of the designed mutants. All purified alanine mutants had 1 or 2 orders of magnitude lower apparent affinity for Glc-1-P compared with the wild type, indicating that the selected set of amino acids plays an important role in their interaction with the substrate. These amino acids, which are conserved within the ADP-Glc PPase family, were replaced with other residues to investigate the effect of size, hydrophobicity, polarity, aromaticity, or charge on the affinity for Glc-1-P. In this study, the architecture of the Glc-1-P-binding site is characterized. The model overlaps with the Glc-1-P site of other PPases such as Pseudomonas aeruginosa dTDP-Glc PPase and Salmonella typhi CDP-Glc PPase. Therefore, the data reported here may have implications for other members of the nucleotide-diphosphoglucose PPase family.
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Affiliation(s)
- Clarisa Maria Bejar
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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Pluzhnikov KA, Bocharov DN, Kononova NV, Sukhanov SV, Balashova TA, Arsen'ev AS, Grishin EV. [Identification and structural analysis of a glycophospholipid component from the venom of ant Paraponera clavata]. Bioorg Khim 2006; 32:530-7. [PMID: 17042271 DOI: 10.1134/s1068162006050116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The venom of South American ant Paraponera clavata and its low-molecular-mass fraction were shown to possess insectotoxic and pore-forming activities. A number of glycophospholipid components were isolated from this ant venom by means of gel filtration and reversed-phase chromatography. Some of the compounds cause conductivity fluctuations in lipid bilayer membranes within the ranges 3-25 pS and 200-400 pS at concentrations of 10(-6) to 10(-7) M. N-Acetylglucosamine, a fatty acid, and phosphoric acid residues were found in their structures. A full structure, 3-myristoyl-2-acetamido-2-deoxy-alpha-D-glucopyranosyl phosphate, was elucidated for one of the compounds by the use of 1H, 13C, and 31P NMR spectroscopy and mass spectrometry.
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17
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Baxter NJ, Olguin LF, Goličnik M, Feng G, Hounslow AM, Bermel W, Blackburn GM, Hollfelder F, Waltho JP, Williams NH. A Trojan horse transition state analogue generated by MgF3- formation in an enzyme active site. Proc Natl Acad Sci U S A 2006; 103:14732-7. [PMID: 16990434 PMCID: PMC1595420 DOI: 10.1073/pnas.0604448103] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Identifying how enzymes stabilize high-energy species along the reaction pathway is central to explaining their enormous rate acceleration. beta-Phosphoglucomutase catalyses the isomerization of beta-glucose-1-phosphate to beta-glucose-6-phosphate and appeared to be unique in its ability to stabilize a high-energy pentacoordinate phosphorane intermediate sufficiently to be directly observable in the enzyme active site. Using (19)F-NMR and kinetic analysis, we report that the complex that forms is not the postulated high-energy reaction intermediate, but a deceptively similar transition state analogue in which MgF(3)(-) mimics the transferring PO(3)(-) moiety. Here we present a detailed characterization of the metal ion-fluoride complex bound to the enzyme active site in solution, which reveals the molecular mechanism for fluoride inhibition of beta-phosphoglucomutase. This NMR methodology has a general application in identifying specific interactions between fluoride complexes and proteins and resolving structural assignments that are indistinguishable by x-ray crystallography.
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Affiliation(s)
- Nicola J. Baxter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Luis F. Olguin
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Marko Goličnik
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Guoqiang Feng
- Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom; and
| | - Andrea M. Hounslow
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Wolfgang Bermel
- Bruker BioSpin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany
| | - G. Michael Blackburn
- Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom; and
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
- To whom correspondence may be addressed. E-mail:
, , or
| | - Jonathan P. Waltho
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
- To whom correspondence may be addressed. E-mail:
, , or
| | - Nicholas H. Williams
- Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom; and
- To whom correspondence may be addressed. E-mail:
, , or
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18
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Aragão D, Marques AR, Frazão C, Enguita FJ, Carrondo MA, Fialho AM, Sá-Correia I, Mitchell EP. Cloning, expression, purification, crystallization and preliminary structure determination of glucose-1-phosphate uridylyltransferase (UgpG) from Sphingomonas elodea ATCC 31461 bound to glucose-1-phosphate. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:930-4. [PMID: 16946483 PMCID: PMC2242879 DOI: 10.1107/s1744309106030107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Accepted: 08/01/2006] [Indexed: 05/11/2023]
Abstract
The cloning, expression, purification, crystallization and preliminary crystallographic analysis of glucose-1-phosphate uridylyltransferase (UgpG) from Sphingomonas elodea ATCC 31461 bound to glucose-1-phosphate are reported. Diffraction data sets were obtained from seven crystal forms in five different space groups, with highest resolutions ranging from 4.20 to 2.65 A. The phase problem was solved for a P2(1) crystal form using multiple isomorphous replacement with anomalous scattering from an osmium derivative and a SeMet derivative. The best native crystal in space group P2(1) has unit-cell parameters a = 105.5, b = 85.7, c = 151.8 A, beta = 105.2 degrees . Model building and refinement are currently under way.
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Affiliation(s)
- D. Aragão
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble CEDEX, France
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, P-2781-901 Oeiras, Portugal
| | - A. R. Marques
- Biological Sciences Research Group, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - C. Frazão
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, P-2781-901 Oeiras, Portugal
| | - F. J. Enguita
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, P-2781-901 Oeiras, Portugal
| | - M. A. Carrondo
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, P-2781-901 Oeiras, Portugal
| | - A. M. Fialho
- Biological Sciences Research Group, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - I. Sá-Correia
- Biological Sciences Research Group, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - E. P. Mitchell
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble CEDEX, France
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19
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Vorob'eva EV, Krasikova IN, Dmitrenok AS, Dmitrenok PS, Isakov VV, Nedashkovskaia OI, Solov'eva TF. [An unusual lipid A from a marine bacterium Chryseobacterium scophtalmum CIP 104199T]. Bioorg Khim 2006; 32:538-45. [PMID: 17042272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The hydrolysis of defatted cells of the marine bacterium Chryseobacterium scophtalmum CIP 104199T with 10% acetic acid (3 h, 100 degrees C) led to an unusual lipid A (LA) (yield 0.6%), obtained for the first time. Using chemical analysis, FAB MS, and NMR spectroscopy, it was shown to be D-glucosamine 1-phosphate acylated with (R)-3-hydroxy-15-methylhexadecanoic and (R)-3-hydroxy-13-methyltetradecanoic acids at the C2 and C3 atoms, respectively. It is similar to the monosaccharide biosynthetic precursor of lipopolysaccharide (LPS), so-called lipid X (LX). Unlike LX, LA can be isolated by the treatment of bacteria with organic solvents only after the preliminary acidic hydrolysis of the cells, which suggests that LA might be strongly, probably chemically, linked to other components of the outer membrane. However, LPS cannot be such a component, because extraction with phenol-water or phenol-chloroform-petroleum ether mixtures in high yields (5.34% and 0.5%, respectively) leads to preparations that do not contain 3-deoxy-D-manno-oct-2-ulopyranosonic acid, 3-hydroxyalkanoic acids, or LA.
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20
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Oikonomakos NG, Tiraidis C, Leonidas DD, Zographos SE, Kristiansen M, Jessen CU, Nørskov-Lauritsen L, Agius L. Iminosugars as Potential Inhibitors of Glycogenolysis: Structural Insights into the Molecular Basis of Glycogen Phosphorylase Inhibition. J Med Chem 2006; 49:5687-701. [PMID: 16970395 DOI: 10.1021/jm060496g] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Iminosugars DAB (5), isofagomine (9), and several N-substituted derivatives have been identified as potent inhibitors of liver glycogen phosphorylase a (IC(50) = 0.4-1.2 microM) and of basal and glucagon-stimulated glycogenolysis (IC(50) = 1-3 microM). The X-ray structures of 5, 9, and its N-3-phenylpropyl analogue 8 in complex with rabbit muscle glycogen phosphorylase (GPb) shows that iminosugars bind tightly at the catalytic site in the presence of the substrate phosphate and induce conformational changes that characterize the R-state conformation of the enzyme. Charged nitrogen N1 is within hydrogen-bonding distance with the carbonyl oxygen of His377 (5) and in ionic contact with the substrate phosphate oxygen (8 and 9). Our findings suggest that the inhibitors function as oxocarbenium ion transition-state analogues. The conformational change to the R state provides an explanation for previous findings that 5, unlike inhibitors that favor the T state, promotes phosphorylation of GPb in hepatocytes with sequential inactivation of glycogen synthase.
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Affiliation(s)
- Nikos G Oikonomakos
- Institute of Organic and Pharmaceutical Chemistry, The National Hellenic Research Foundation, Athens 11635, Greece.
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21
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Kato M, Sah AK, Tanase T, Mikuriya M. Tetranuclear Copper(II) Complexes Bridged by α-d-Glucose-1-Phosphate and Incorporation of Sugar Acids through the Cu4 Core Structural Changes. Inorg Chem 2006; 45:6646-60. [PMID: 16903719 DOI: 10.1021/ic060202h] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tetranuclear copper(II) complexes containing alpha-D-glucose-1-phosphate (alpha-D-Glc-1P), [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(bpy)4(H2O)2]X3 [X = NO3 (1a), Cl (1b), Br (1c)], and [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(phen)4(H2O)2](NO3)3 (2) were prepared by reacting the copper(II) salt with Na2[alpha-D-Glc-1P] in the presence of diimine ancillary ligands, and the structure of 2 was characterized by X-ray crystallography to comprise four {Cu(phen)}2+ fragments connected by the two sugar phosphate dianions in 1,3-O,O' and 1,1-O mu4-bridging fashion as well as a mu-hydroxo anion. The crystal structure of 2 involves two chemically independent complex cations in which the C2 enantiomeric structure for the trapezoidal tetracopper(II) framework is switched according to the orientation of the alpha-D-glucopyranosyl moieties. Temperature-dependent magnetic susceptibility data of 1a indicated that antiferromagnetic spin coupling is operative between the two metal ions joined by the hydroxo bridge (J = -52 cm(-1)) while antiferromagnetic interaction through the Cu-O-Cu sugar phosphate bridges is weak (J = -13 cm(-1)). Complex 1a readily reacted with carboxylic acids to afford the tetranuclear copper(II) complexes, [Cu4{mu-(alpha-D-Glc-1P)}2(mu-CA)2(bpy)4](NO3)2 [CA = CH3COO (3), o-C6H4(COO)(COOH) (4)]. Reactions with m-phenylenediacetic acid [m-C6H4(CH2COOH)2] also gave the discrete tetracopper(II) cationic complex [Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)(CH2COOH))2(bpy)4](NO3)2 (5a) as well as the cluster polymer formulated as {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)2)(bpy)4](NO3)2}n (5b). The tetracopper structure of 1a is converted into a symmetrical rectangular core in complexes 3, 4, and 5b, where the hydroxo bridge is dissociated and, instead, two carboxylate anions bridge another pair of Cu(II) ions in a 1,1-O monodentate fashion. The similar reactions were applied to incorporate sugar acids onto the tetranuclear copper(II) centers. Reactions of 1a with delta-D-gluconolactone, D-glucuronic acid, or D-glucaric acid in dimethylformamide resulted in the formation of discrete tetracopper complexes with sugar acids, [Cu4{mu-(alpha-D-Glc-1P)}2(mu-SA)2(bpy)4](NO3)2 [SA = D-gluconate (6), D-glucuronate (7), D-glucarateH (8a)]. The structures of 6 and 7 were determined by X-ray crystallography to be almost identical with that of 3 with additional chelating coordination of the C-2 hydroxyl group of D-gluconate moieties (6) or the C-5 cyclic O atom of D-glucuronate units (7). Those with D-glucaric acid and D-lactobionic acid afforded chiral one-dimensional polymers, {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-D-glucarate)(bpy)4](NO3)2}n (8b) and {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-D-lactobionate)(bpy)4(H2O)2](NO3)3}n (9), respectively, in which the D-Glc-1P-bridged tetracopper(II) units are connected by sugar acid moieties through the C-1 and C-6 carboxylate O atoms in 8b and the C-1 carboxylate and C-6 alkoxy O atoms of the gluconate chain in 9. When complex 7 containing d-glucuronate moieties was heated in water, the mononuclear copper(II) complex with 2-dihydroxy malonate, [Cu(mu-O2CC(OH)2CO2)(bpy)] (10), and the dicopper(II) complex with oxalate, [Cu2(mu-C2O4)(bpy)2(H2O)2](NO3)2 (11), were obtained as a result of oxidative degradation of the carbohydrates through C-C bond cleavage reactions.
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Affiliation(s)
- Merii Kato
- Department of Chemistry, Faculty of Science, Nara Women's University, Kitauoya-higashi-machi, Nara 630-8285, Japan
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22
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Maruta K, Watanabe H, Nishimoto T, Kubota M, Chaen H, Fukuda S, Kurimoto M, Tsujisaka Y. Acceptor specificity of trehalose phosphorylase from Thermoanaerobacter brockii: Production of novel nonreducing trisaccharide, 6-O-α-D-galactopyranosyl trehalose. J Biosci Bioeng 2006; 101:385-90. [PMID: 16781466 DOI: 10.1263/jbb.101.385] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 02/02/2006] [Indexed: 11/17/2022]
Abstract
We investigated the acceptor specificity of a thermostable trehalose phosphorylase from Thermoanaerobacter brockii ATCC 35047 (TbTP) was examined using beta-D-glucose-1-phosphate (beta-G1P) as a glucosyl donor and oligosaccharides as the acceptor. Oligosaccharides with a reducing-end glucose residue as the C-6 substituent (e.g., isomaltose, gentiobiose, melibiose, isomaltotriose, and isopanose) were found to be successful acceptors. The transfer products of isomaltose, gentiobiose, and melibiose were isolated and characterized as 6-O-alpha-D-glucopyranosyl trehalose (alpha-GlcTre), 6-O-beta-D-glucopyranosyl trehalose (beta-GlcTre), and 6-O-alpha-D-galactopyranosyl trehalose (alpha-GalTre), respectively. To produce alpha-GalTre, a novel nonreducing trisaccharide, the reaction conditions of alpha-GalTre were examined using trehalose as a glucosyl donor. As a result, the yield of alpha-GalTre reached 40.5%.
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Affiliation(s)
- Kazuhiko Maruta
- Amase Institute, Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
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23
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Dinev Z, Wardak AZ, Brownlee RTC, Williams SJ. A convenient gram-scale synthesis of uridine diphospho(13C6)glucose. Carbohydr Res 2006; 341:1743-7. [PMID: 16603138 DOI: 10.1016/j.carres.2006.02.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 02/20/2006] [Accepted: 02/24/2006] [Indexed: 10/24/2022]
Abstract
A simple gram-scale synthesis of uridine diphospho(13C6)glucose is presented from D-(13C6)glucose. The critical step uses a 1H-tetrazole-catalyzed coupling of 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl-1-phosphate and UMP-morpholidate. The uridine diphospho(13C6)glucose was used in the structural identification of (1-->3)-beta-D-glucan from Lolium multiflorum.
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Affiliation(s)
- Zoran Dinev
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
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24
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Abstract
This report describes a procedure combining six enzymes native to Escherichia coli or Salmonella typhi, such as thymidine kinase (TK), thymidylate kinase (TMK), nucleoside diphosphate kinase (NDK), pyruvate kinase (PK; for ATP regeneration), TDP-glucose synthetase (RfbA), and TDP-glucose 4,6-dehydratase (RfbB), with five enzymes from Streptomyces fradiae, such as TylX3, TylC1, TylC3, TylK, and TylC2, that resulted in the biosynthesis of TDP-l-mycarose from glucose-1-phosphate and thymidine. This two-stage one-pot approach can be readily applied to the synthesis of other unusual sugars.
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Affiliation(s)
- Haruko Takahashi
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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25
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Mok MTS, Edwards MR. Critical sources of error in colorimetric assay for UDP-N-acetylglucosamine pyrophosphorylase. Anal Biochem 2005; 343:341-3. [PMID: 15992757 DOI: 10.1016/j.ab.2005.05.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 04/27/2005] [Accepted: 05/16/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Myth T S Mok
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.
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26
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Zhang G, Dai J, Wang L, Dunaway-Mariano D, Tremblay LW, Allen KN. Catalytic Cycling in β-Phosphoglucomutase: A Kinetic and Structural Analysis,. Biochemistry 2005; 44:9404-16. [PMID: 15996095 DOI: 10.1021/bi050558p] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lactococcus lactis beta-phosphoglucomutase (beta-PGM) catalyzes the interconversion of beta-d-glucose 1-phosphate (beta-G1P) and beta-d-glucose 6-phosphate (G6P), forming beta-d-glucose 1,6-(bis)phosphate (beta-G16P) as an intermediate. Beta-PGM conserves the core domain catalytic scaffold of the phosphatase branch of the HAD (haloalkanoic acid dehalogenase) enzyme superfamily, yet it has evolved to function as a mutase rather than as a phosphatase. This work was carried out to identify the structural basis underlying this diversification of function. In this paper, we examine beta-PGM activation by the Mg(2+) cofactor, beta-PGM activation by Asp8 phosphorylation, and the role of cap domain closure in substrate discrimination. First, the 1.90 A resolution X-ray crystal structure of the Mg(2+)-beta-PGM complex is examined in the context of previously reported structures of the Mg(2+)-alpha-d-galactose-1-phosphate-beta-PGM, Mg(2+)-phospho-beta-PGM, and Mg(2+)-beta-glucose-6-phosphate-1-phosphorane-beta-PGM complexes to identify conformational changes that occur during catalytic turnover. The essential role of Asp8 in nucleophilic catalysis was confirmed by demonstrating that the D8A and D8E mutants are devoid of catalytic activity. Comparison of the ligands to Mg(2+) in the different complexes shows that a single Mg(2+) coordination site must alternatively accommodate water, phosphate, and the phosphorane intermediate during catalytic turnover. Limited involvement of the HAD family metal-binding loop in Mg(2+) anchoring in beta-PGM is consistent with the relatively loose binding indicated by the large K(m) for Mg(2+) activation (270 +/- 20 microM) and with the retention of activity found in the E169A/D170A double loop mutant. Comparison of the relative positions of cap and core domains in the different complexes indicated that interaction of cap domain Arg49 with the "nontransferring" phosphoryl group of the substrate ligand might stabilize the cap-closed conformation, as required for active site desolvation and alignment of Asp10 for acid-base catalysis. Kinetic analyses of the specificity of beta-PGM toward phosphoryl group donors and the specificity of phospho-beta-PGM toward phosphoryl group acceptors were carried out. The results support a substrate induced-fit mechanism of beta-PGM catalysis, which allows phosphomutase activity to dominate over the intrinsic phosphatase activity. Last, we present evidence that the autophosphorylation of beta-PGM by the substrate beta-G1P accounts for the origin of phospho-beta-PGM in the cell.
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Affiliation(s)
- Guofeng Zhang
- Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
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27
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Abstract
The novel tetranuclear copper(II) complexes with alpha-d-glucose-1-phosphates, [Cu(4)(mu-OH)(alpha-d-Glc-1P)(2)(L)(4)(H(2)O)(2)](NO(3))(3) (L = bpy (1), phen (2)), were prepared and characterized by X-ray crystallography. Complex 1 was further transformed into the ATP stabilized tetracopper(II) complex of [Cu(4)(ATP)(2)(bpy)(4)] (4), where ATP is adenosine 5'-triphosphate.
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Affiliation(s)
- Merii Kato
- Department of Chemistry, Faculty of Science, Nara Women's University, Kitauoya-higashi-machi, Nara 630-8285, Japan
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28
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Abstract
An electrospray ionization mass spectrometry-based assay has been developed to study the class of enzymes called sugar nucleotidyltransferases that couple sugar-1-phosphates and nucleotide triphosphates to form Leloir pathway glycosyl donors. The recombinant Escherichia coli and the commercially available yeast uridine-diphosphoglucose pyrophosphorylases were used as model systems. This technique allows the simultaneous and direct detection of the substrates and products without separation and, as described, is as sensitive as traditional coupled techniques. More importantly, the assay is capable of easily measuring kinetic values and inhibition constants for a range of natural and nonnatural substrates. This new assay was used to show for the first time that the reaction of the commercially available yeast uridine-diphosphoglucose pyrophosphorylase preparation is competitively inhibited by adenosine 5'-triphosphate (ATP), an observation that indicates a single active site that accepts both uridine 5'-triphosphate and ATP substrates.
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Affiliation(s)
- Corbin J Zea
- Department of Chemistry and the Plant Sciences Institute, Iowa State University, Ames, IA 50011, USA
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29
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Varrot A, Yip VLY, Li Y, Rajan SS, Yang X, Anderson WF, Thompson J, Withers SG, Davies GJ. NAD+ and metal-ion dependent hydrolysis by family 4 glycosidases: structural insight into specificity for phospho-beta-D-glucosides. J Mol Biol 2005; 346:423-35. [PMID: 15670594 DOI: 10.1016/j.jmb.2004.11.058] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Revised: 11/14/2004] [Accepted: 11/23/2004] [Indexed: 11/17/2022]
Abstract
The import of disaccharides by many bacteria is achieved through their simultaneous translocation and phosphorylation by the phosphoenolpyruvate-dependent phosphotransferase system (PEP-PTS). The imported phospho-disaccharides are, in some cases, subsequently hydrolyzed by members of the unusual glycoside hydrolase family GH4. The GH4 enzymes, occasionally found also in bacteria such as Thermotoga maritima that do not utilise a PEP-PTS system, require both NAD(+) and Mn(2+) for catalysis. A further curiosity of this family is that closely related enzymes may show specificity for either alpha-d- or beta-d-glycosides. Here, we present, for the first time, the three-dimensional structure (using single-wavelength anomalous dispersion methods, harnessing extensive non-crystallographic symmetry) of the 6-phospho-beta-glycosidase, BglT, from T.maritima in native and complexed (NAD(+) and Glc6P) forms. Comparison of the active-center structure with that of the 6-phospho-alpha-glucosidase GlvA from Bacillus subtilis reveals a striking degree of structural similarity that, in light of previous kinetic isotope effect data, allows the postulation of a common reaction mechanism for both alpha and beta-glycosidases. Given that the "chemistry" occurs primarily on the glycone sugar and features no nucleophilic attack on the intact disaccharide substrate, modulation of anomeric specificity for alpha and beta-linkages is accommodated through comparatively minor structural changes.
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Affiliation(s)
- Annabelle Varrot
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5YW, UK
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30
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Bobrovnik SA. [A new thermodynamic function, which allows easy determination of the direction of a reaction and its energetic characteristics]. Ukr Biokhim Zh (1999) 2005; 77:110-2. [PMID: 16335278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A new thermodynamic function, namely a universal variable Q, is suggested for the description of reversible chemical reactions. According to the definition, if the reaction is represented by the equation aA + bB = gG + hH, and K is the equilibrium constant, the universal variable Q is: Q = aG(g)aH(h)/(aA(a)aB(b)K). Then, Q is a dimensionless variable, which has the following properties: Q = 1 for the state of equilibrium, Q < 1 for spontaneous reactions, and Q > 1 for the reverse reaction. Knowledge of Q allows determination of the Gibbs energy and standard Gibbs energy by the same formula deltaG = RTlnQ.
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31
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Oh J, Lee SG, Kim BG, Sohng JK, Liou K, Lee HC. One-pot enzymatic production of dTDP-4-keto-6-deoxy-D-glucose from dTMP and glucose-1-phosphate. Biotechnol Bioeng 2004; 84:452-8. [PMID: 14574703 DOI: 10.1002/bit.10789] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An enzymatic production method for dTDP-4-keto-6-deoxy-D-glucose, a key intermediate of various deoxysugars in antibiotics, was developed starting from dTMP, acetyl phosphate, and glucose-1-phosphate. Four enzymes, i.e., TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-D-glucose 4,6-dehydratase' were overexpressed using T7 promoter system in the E. coli BL21 strain, and the dTDP-4-keto-6-deoxy-D-glucose was synthesized by using the enzyme extracts in one-pot batch system. When 20 mM dTMP of initial concentration was used, Mg2+ ion, acetyl phosphate, and glucose-1-phosphate concentrations were optimized. About 95% conversion yield of dTDP-4-keto-6-deoxy-D-glucose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 60 mM acetyl phosphate, 80 mM glucose-1-phosphate, and 20 mM MgCl(2). The rate-limiting step in this multiple enzyme reaction system was the dTDP-glucose synthase reaction. Using the reaction scheme, about 1 gram of purified dTDP-4-keto-6-deoxy-D-glucose was obtained in an overall yield of 81% after two-step purification, i.e., anion exchange chromatography and gel filtration.
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Affiliation(s)
- Jongmin Oh
- Institute of Molecular Biology and Genetics and School of Chemical Engineering, Seoul National University, Seoul 151-742, South Korea
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32
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Wittayanukulluk A, Jiang D, Regnier FE, Hem SL. Effect of microenvironment pH of aluminum hydroxide adjuvant on the chemical stability of adsorbed antigen. Vaccine 2004; 22:1172-6. [PMID: 15003645 DOI: 10.1016/j.vaccine.2003.09.037] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Revised: 09/25/2003] [Accepted: 09/25/2003] [Indexed: 11/28/2022]
Abstract
The rate of acid-catalyzed hydrolysis of glucose-1-phosphate (G1P) when adsorbed to aluminum hydroxide adjuvant was significantly slower than the rate of hydrolysis of a solution of G1P at the same pH. It was concluded that the positively charged aluminum hydroxide adjuvant (iep 11.4) electrostatically attracted anions including hydroxyls to form a double layer surrounding the adjuvant particles. Thus, the pH of the microenvironment surrounding the aluminum hydroxide adjuvant was higher than the bulk pH. Adsorbed G1P hydrolyzed at a rate associated with the pH of the microenvironment of the surface of the adjuvant rather than with the pH of the bulk solution. Comparison of the rate constant for the hydrolysis of adsorbed G1P to the pH-stability profile of G1P in solution revealed that adsorbed G1P hydrolyzed at a rate associated with a pH that was approximately two pH units higher than the bulk pH. The results suggest that the chemical stability of antigens that degrade by pH-dependent mechanisms can be optimized by modifying the surface charge of the aluminum-containing adjuvant to produce the pH of maximum stability in the microenvironment of the adjuvant.
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Affiliation(s)
- Arunee Wittayanukulluk
- Industrial and Physical Pharmacy Department, Purdue University, West Lafayette, IN 47907, USA
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33
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Abstract
Enzyme-substrate complexes of phosphomannomutase/phosphoglucomutase (PMM/PGM) reveal the structural basis of the enzyme's ability to use four different substrates in catalysis. High-resolution structures with glucose 1-phosphate, glucose 6-phosphate, mannose 1-phosphate, and mannose 6-phosphate show that the position of the phosphate group of each substrate is held constant by a conserved network of hydrogen bonds. This produces two distinct, and mutually exclusive, binding orientations for the sugar rings of the 1-phospho and 6-phospho sugars. Specific binding of both orientations is accomplished by key contacts with the O3 and O4 hydroxyls of the sugar, which must occupy equatorial positions. Dual recognition of glucose and mannose phosphosugars uses a combination of specific protein contacts and nonspecific solvent contacts. The ability of PMM/PGM to accommodate these four diverse substrates in a single active site is consistent with its highly reversible phosphoryl transfer reaction and allows it to function in multiple biosynthetic pathways in P. aeruginosa.
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Affiliation(s)
- Catherine Regni
- Department of Biochemistry, 117 Schweitzer Hall, University of Missouri-Columbia, Columbia, MO 65211, USA
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34
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Clarke JL, Mason PJ. Murine hexose-6-phosphate dehydrogenase: a bifunctional enzyme with broad substrate specificity and 6-phosphogluconolactonase activity. Arch Biochem Biophys 2003; 415:229-34. [PMID: 12831846 DOI: 10.1016/s0003-9861(03)00229-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Murine hexose-6-phosphate dehydrogenase has been purified from liver microsomes by affinity chromatography on 2('),5(')-ADP-Sepharose. The purified enzyme has 6-phosphogluconolactonase activity and glucose-6-phosphate dehydrogenase activity and has a native molecular mass of 178 kDa and a subunit molecular mass of 89 kDa. Glucose 6-phosphate, galactose 6-phosphate, 2-deoxyglucose 6-phosphate, glucosamine 6-phosphate, and glucose 6-sulfate are substrates for murine hexose-6-phosphate dehydrogenase, with either NADP or deamino-NADP as coenzyme. This study confirms that hexose-6-phosphate dehydrogenase is a bifunctional enzyme which can catalyze the first two reactions of the pentose phosphate pathway.
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Affiliation(s)
- Julia L Clarke
- Department of Haematology, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom
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35
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Yaylayan VA, Machiels D, Istasse L. Thermal decomposition of specifically phosphorylated D-glucoses and their role in the control of the Maillard reaction. J Agric Food Chem 2003; 51:3358-3366. [PMID: 12744667 DOI: 10.1021/jf034037p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
One of the main shortcomings of the information available on the Maillard reaction is the lack of knowledge to control the different pathways, especially when it is desired to direct the reaction away from the formation of carcinogenic and other toxic substances to more aroma and color generation. The use of specifically phosphorylated sugars may impart some elements of control over the aroma profile generated by the Maillard reaction. Thermal decomposition of 1- and 6-phosphorylated glucoses was studied in the presence and absence of ammonia and selected amino acids through pyrolysis/gas chromatography/mass spectrometry using nonpolar PLOT and medium polar DB-1 columns. The analysis of the data has indicated that glucose-1-phosphate relative to glucose undergoes more extensive phosphate-catalyzed ring opening followed by formation of sugar-derived reactive intermediates as was indicated by a 9-fold increase in the amount of trimethylpyrazine and a 5-fold increase in the amount of 2,3-dimethylpyrazine, when pyrolyzed in the presence of glycine. In addition, glucose-1-phosphate alone generated a 6-fold excess of acetol as compared to glucose. On the other hand, glucose-6-phosphate enhanced retro-aldol reactions initiated from a C-6 hydroxyl group and increased the subsequent formation of furfural and 4-cyclopentene-1,3-dione. Furthermore, it also stabilized 1- and 3-deoxyglucosone intermediates and enhanced the formation of six carbon atom-containing Maillard products derived directly from them through elimination reactions such as 1,6-dimethyl-2,4-dihydroxy-3-(2H)-furanone (acetylformoin), 2-acetylpyrrole, 5-methylfurfural, 5-hydroxymethylfurfural, and 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (Furaneol), due to the enhanced leaving group ability of the phosphate moiety at the C-6 carbon. However, Maillard products generated through the nucleophilic action of the C-6 hydroxyl group such as 2-acetylfuran and 2,3-dihydro-3,5-dihydroxy-4H-pyran-4-one were retarded, due to the blocked nucleophilic atom at C-6.
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Affiliation(s)
- Varoujan A Yaylayan
- Department of Food Science and Agricultural Chemistry, McGill University, 21111 Lakeshore, Ste. Anne de Bellevue, Quebec, Canada, H9X 3V9.
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36
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Bedford CT, Hickman AD, Logan CJ. Structure-activity studies of glucose transfer: determination of the spontaneous rates of hydrolysis of uridine 5'-diphospho-alpha-D-glucose (UDPG) and uridine 5'-diphospho-alpha-D-glucuronic acid (UDPGA). Bioorg Med Chem 2003; 11:2339-45. [PMID: 12713846 DOI: 10.1016/s0968-0896(03)00065-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The pH-rate profiles for the hydrolysis of uridine 5'-diphospho-alpha-D-glucose (UDPG) and uridine 5'-diphospho-alpha-D-glucuronic acid (UDPGA) in aqueous solution have been measured. The results obtained and a comparison with other data suggests that the mechanism of hydrolysis of each activated glycosyl-donor at pH 1-4 probably involves the slow ionisation, via an S(N)1 process, of the neutral molecule to a glycosyl ion and UDP. From these data, the catalytic power (k(cat)/k(uncat)) of the glycosyltransferases has been estimated for the first time to be in the order of 10(11-13).
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Affiliation(s)
- Colin T Bedford
- School of Biosciences, University of Westminster, 115New Cavendish Street, London W1W 6UW, UK.
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37
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Okada H, Fukushi E, Onodera S, Nishimoto T, Kawabata J, Kikuchi M, Shiomi N. Synthesis and structural analysis of five novel oligosaccharides prepared by glucosyltransfer from beta-D-glucose 1-phosphate to isokestose and nystose using Thermoanaerobacter brockii kojibiose phosphorylase. Carbohydr Res 2003; 338:879-85. [PMID: 12681912 DOI: 10.1016/s0008-6215(03)00020-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Five novel oligosaccharides (tetra-, penta- and hexa-saccharides) were synthesized by glucosyltransfer from beta-D-glucose 1-phosphate to isokestose (O-beta-D-fructofuranosyl-(2-->1)-O-beta-D-fructofuranosyl-(2-->1)-alpha-D-glucopyranoside) or nystose (O-beta-D-fructofuranosyl-(2-->1)-O-beta-D-fructofuranosyl-(2-->1)-O-beta-D-fructofuranosyl-(2-->1)-alpha-D-glucopyranoside) using Thermoanaerobacter brockii kojibiose phosphorylase. The oligosaccharides were identified as 2(2-alpha-D-glucopyranosyl)(m)isokestose; [O-alpha-D-glucopyranosyl-(1-->2)](m)-O-[beta-D-fructofuranosyl-(2-->1)](2)-alpha-D-glucopyranoside: m=1, 2, and 3, and 2(2-alpha-D-glucopyranosyl)(n)nystose; [O-alpha-D-glucopyranosyl-(1-->2)](n)-O-[beta-D-fructofuranosyl-(2-->1)](3)-alpha-D-glucopyranoside: n=1 and 2 using gas liquid chromatography analysis of the methyl derivatives, and MALDI-TOF-MS and NMR measurements of the newly formed oligosaccharides. 1H, 13C NMR signals of each saccharide were assigned using 2D-NMR techniques, including COSY, HSQC, HSQC-TOCSY, HMBC, CH(2)-selected E-HSQC, and CH(2)-selected E-HSQC-TOCSY.
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Affiliation(s)
- Hideki Okada
- Department of Food Production and Utility Development, Graduate School of Dairy Science Research, Rakuno Gakuen University, Ebetsu 069-8501, Japan
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38
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Abstract
Enzymes provide enormous rate enhancements, unmatched by any other type of catalyst. The stabilization of high-energy states along the reaction coordinate is the crux of the catalytic power of enzymes. We report the atomic-resolution structure of a high-energy reaction intermediate stabilized in the active site of an enzyme. Crystallization of phosphorylated beta-phosphoglucomutase in the presence of the Mg(II) cofactor and either of the substrates glucose 1-phosphate or glucose 6-phosphate produced crystals of the enzyme-Mg(II)-glucose 1,6-(bis)phosphate complex, which diffracted x-rays to 1.2 and 1.4 angstroms, respectively. The structure reveals a stabilized pentacovalent phosphorane formed in the phosphoryl transfer from the C(1)O of glucose 1,6-(bis)phosphate to the nucleophilic Asp8 carboxylate.
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Affiliation(s)
- Sushmita D Lahiri
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118-2394, USA
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39
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Affiliation(s)
- Jeremy Knowles
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
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40
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Rabuka D, Hindsgaul O. Synthesis and NMR characterization of the six regioisomeric monophosphates of octyl beta-D-galactopyranosyl-(1 --> 4)-2-acetamido-2-deoxy-beta-D-glucopyranoside. Carbohydr Res 2002; 337:2127-51. [PMID: 12433477 DOI: 10.1016/s0008-6215(02)00178-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
All six regioisomeric monophosphates of octyl beta-D-galactopyranosyl-(1 --> 4)-2-acetamido-2-deoxy-beta-D-glucopyranoside have been chemically synthesized and characterized by high-resolution 1H, 13C and 31P NMR spectroscopy. Phosphorylation causes characteristic downfield shifts of the nucleus at the substituted site in the 1H and 13C NMR signals and resulted in a unique 31P signal for each compound.
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Affiliation(s)
- David Rabuka
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2
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41
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Jankovics H, Nagy L, Buzás N, Pellerito L, Barbieri R. Coordination properties of adenosine-5'-monophosphate and related ligands towards Me2Sn(IV)2+ in aqueous solution. J Inorg Biochem 2002; 92:55-64. [PMID: 12230988 DOI: 10.1016/s0162-0134(02)00470-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The coordination of Me2Sn(IV)2+ to adenosine-5'-monophosphate (AMP) and the related compounds D-ribose-5-phosphate (R5P), D-glucose-1-phosphate (G1P) and D-glucose-6-phosphate (G6P) in aqueous solution was investigated by means of potentiometric titration, and 1H-, 31P-NMR and Mössbauer spectroscopic methods in the pH range 2-11 (I=0.1 M NaClO4, 298 K). The complex of AMP and Me2Sn(IV)2+ precipitated at low pH was characterised by elemental analysis, FT-IR and Mössbauer spectroscopic methods. From a comparison of the pK values obtained in the presence and absence of metal ion and the stability constants for the different systems, the coordination of [N] is excluded, while bidentate coordination of the phosphate group is presumed. Mössbauer spectroscopic measurements recorded in the glassy state confirmed bidentate coordination of the phosphate and the formation of mixed hydroxo complexes in the weakly acidic, neutral and strongly basic pH range. With increasing pH, the phosphate groups were replaced by the deprotonated alcoholic [O] atoms of the sugar moiety. The solid complex proved to be tbp structure with bidentate phosphate coordination.
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Affiliation(s)
- H Jankovics
- Research Group on Biocoordination Chemistry of the Hungarian Academy of Sciences, University of Szeged, Szeged, Hungary
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42
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Egloff MP, Uppenberg J, Haalck L, van Tilbeurgh H. Crystal structure of maltose phosphorylase from Lactobacillus brevis: unexpected evolutionary relationship with glucoamylases. Structure 2001; 9:689-97. [PMID: 11587643 DOI: 10.1016/s0969-2126(01)00626-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Maltose phosphorylase (MP) is a dimeric enzyme that catalyzes the conversion of maltose and inorganic phosphate into beta-D-glucose-1-phosphate and glucose without requiring any cofactors, such as pyridoxal phosphate. The enzyme is part of operons that are involved in maltose/malto-oligosaccharide metabolism. Maltose phosphorylases have been classified in family 65 of the glycoside hydrolases. No structure is available for any member of this family. RESULTS We report here the 2.15 A resolution crystal structure of the MP from Lactobacillus brevis in complex with the cosubstrate phosphate. This represents the first structure of a disaccharide phosphorylase. The structure consists of an N-terminal complex beta sandwich domain, a helical linker, an (alpha/alpha)6 barrel catalytic domain, and a C-terminal beta sheet domain. The (alpha/alpha)6 barrel has an unexpected strong structural and functional analogy with the catalytic domain of glucoamylase from Aspergillus awamori. The only conserved glutamate of MP (Glu487) superposes onto the catalytic residue Glu179 of glucoamylase and likely represents the general acid catalyst. The phosphate ion is bound in a pocket facing the carboxylate of Glu487 and is ideally positioned for nucleophilic attack of the anomeric carbon atom. This site is occupied by the catalytic base carboxylate in glucoamylase. CONCLUSIONS These observations strongly suggest that maltose phosphorylase has evolved from glucoamylase. MP has probably conserved one carboxylate group for acid catalysis and has exchanged the catalytic base for a phosphate binding pocket. The relative positions of the acid catalytic group and the bound phosphate are compatible with a direct-attack mechanism of a glycosidic bond by phosphate, in accordance with inversion of configuration at the anomeric carbon as observed for this enzyme.
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Affiliation(s)
- M P Egloff
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique, Unite Mixte de Recherche 6098, Université d'Aix-Marseille, I et II, Case 925, 13288, Marseille, France
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43
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Mazhul' VM, Zaĭtseva EM, Mitskevich LG, Fedurkina NV, Kurganov BI. [Phosphorescent analysis of the intramolecular dynamics of the muscle glycogen phosphorylase b]. Biofizika 1999; 44:1010-6. [PMID: 10707275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Large-scale functionally significant changes in the intramolecular dynamics of muscle glycogen phosphorylase b (EC 2.4.1.1) in solution upon ligand binding, transition from dimeric to tetrameric form, temperature denaturation and aggregation were registered at room temperature using the tryptophan phosphorescence technique. It was shown that binding of glucose-1-phosphate (substrate, 0.25-4 mM) and glucose (competitive inhibitor, 0.5-8 mM) to the active site and temperature-induced protein aggregation decrease large-scale structural fluctuations of the protein matrix at the level of domains and subunits; whereas the transition of glycogen phosphorylase b to tetrameric form (R-conformation) leads to a dramatic increase in the structural flexibility of the peripheral parts of the protein globule.
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Affiliation(s)
- V M Mazhul'
- Institute of Photobiology, Belorussian Academy of Sciences, Minsk, Belarus
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44
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Affiliation(s)
- H Deng
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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45
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Bartl F, Palm D, Schinzel R, Zundel G. Proton relay system in the active site of maltodextrinphosphorylase via hydrogen bonds with large proton polarizability: an FT-IR difference spectroscopy study. European Biophysics Journal 1999; 28:200-7. [PMID: 10232933 DOI: 10.1007/s002490050200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Maltodextrinphosphorylase (MDP) was studied in the pH range 5.4-8.4 by Fourier transform infrared (FT-IR) spectroscopy. The pK(a) value of the cofactor pyridoxalphosphate (PLP) was found between 6.5 and 7.0, which closely resembles the second pK(a) of free PLP.FT-IR difference spectra of the binary complex of MDP + alpha-D-glucose-1-methylenephosphonate (Glc-1-MeP) minus native MDP were taken at pH 6.9. Following binary complex formation, two Lys residues, tentatively assigned to the active site residues Lys533 and Lys539, became deprotonated, and PLP as well as a carboxyl group, most likely of Glu637, protonated. A system of hydrogen bonds which shows large proton polarizability due to collective proton tunneling was observed connecting Lys533, PLP, and Glc-1-MeP. A comparison with model systems shows, furthermore, that this hydrogen bonded chain is highly sensitive to local electrical fields and specific interactions, respectively. In the binary complex the proton limiting structure with by far the highest probability is the one in which Glc-1-MeP is singly protonated. In a second hydrogen bonded chain the proton of Lys539 is shifted to Glu637. In the binary complex the proton remains located at Glu637. In the ternary complex composed of phosphorylase, glucose-1-phosphate (Glc-1-P), and the nonreducing end of a polysaccharide chain (primer), a second proton may be shifted to the phosphate group of Glc-1-P. In the doubly protonated phosphate group the loss of mesomeric stabilization of the phosphate ester makes the C1-O1 bond of Glc-1-P susceptible to bond cleavage. The arising glucosyl carbonium ion will be a substrate for nucleophilic attack by the nonreducing terminal glucose residue of the polysaccharide chain.
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Affiliation(s)
- F Bartl
- Humboldt University of Berlin, Institute of Medical Physics and Biophysics, Germany.
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46
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Marwood RD, Riley AM, Correa V, Taylor CW, Potter BV. Simplification of adenophostin A defines a minimal structure for potent glucopyranoside-based mimics of D-myo-inositol 1,4,5-trisphosphate. Bioorg Med Chem Lett 1999; 9:453-8. [PMID: 10091701 DOI: 10.1016/s0960-894x(99)00006-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The synthesis of 1-O-[(3S,4R)-3-hydroxytetrahydrofuran-4-yl]-alpha-D-glucopyranosid e 3,4,3'-trisphosphate (7), a novel Ca2+ mobilising agonist at the Ins(1,4,5)P3 receptor, designed by excision of two motifs of adenophostin A is reported, defining a potential minimal structure for potent glucopyranoside-based agonists of Ins(1,4,5)P3 receptors.
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Affiliation(s)
- R D Marwood
- Department of Pharmacy and Pharmacology, University of Bath, UK
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47
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Oikonomakos NG, Zographos SE, Johnson LN, Papageorgiou AC, Acharya KR. The binding of 2-deoxy-D-glucose 6-phosphate to glycogen phosphorylase b: kinetic and crystallographic studies. J Mol Biol 1995; 254:900-17. [PMID: 7500360 DOI: 10.1006/jmbi.1995.0665] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Kinetic and crystallographic studies have characterized the effect of 2-deoxy-glucose 6-phosphate on the catalytic and structural properties of glycogen phosphorylase b. Previous work on the binding of glucose 6-phosphate, a potent physiological inhibitor of the enzyme, to T state phosphorylase b in the crystal showed that the inhibitor binds at the allosteric site and induces substantial conformational changes that affect the subunit-subunit interface. The hydrogen-bond from the O-2 hydroxyl of glucose 6-phosphate to the main-chain oxygen of Val40' represents the only hydrogen bond from the sugar to the other subunit, and this interaction appears important for promoting a more "tensed" structure than native T state phosphorylase b. 2-Deoxy-glucose 6-phosphate acts competitively with both the activator AMP and the substrate glucose 1-phosphate, with Ki values of 0.53 mM and 1.23 mM, respectively. The binding of 2-deoxy-glucose 6-phosphate to T state glycogen phosphorylase b in the crystal, has been investigated and the complex phosphorylase b: 2-deoxy-glucose 6-phosphate has been refined to give a crystallographic R factor of 17.3%, for data between 8 A and 2.3 A. 2-Deoxy-glucose 6-phosphate binds at the allosteric site as the a anomer and adopts a different conformation compared to glucose 6-phosphate. The two conformations differ by 160 degrees in the torsion angle about the C-5-C-6 bond. The contacts from the phosphate group are essentially identical to those made by the phosphate of glucose 6-phosphate but the 2-deoxy glucosyl moiety binds in a quite different orientation compared to the glucosyl of glucose 6-phosphate. 2-Deoxy-glucose 6-phosphate can be accommodated in the allosteric site with very little change in the protein, while structural comparisons show that the phosphorylase b: 2-deoxy-glucose 6-phosphate complex structure is overall more similar to a glucose-like complex than to the Glc-6-P complex structure.
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Affiliation(s)
- N G Oikonomakos
- Institute of Biological Research & Biotechnology, National Hellenic Research Foundation, Athens, Greece
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48
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Zographos SE, Oikonomakos NG, Dixon HB, Griffin WG, Johnson LN, Leonidas DD. Sulphate-activated phosphorylase b: the pH-dependence of catalytic activity. Biochem J 1995; 310 ( Pt 2):565-70. [PMID: 7654195 PMCID: PMC1135932 DOI: 10.1042/bj3100565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The pH-dependence of sulphate-activated phosphorylase b has been studied in the direction of glycogen synthesis. The bell-shaped curve of the pH-dependence of the catalytic constant for the AMP-activated enzyme showed pK values of 6.1 and 7.3, but the curve for the enzyme activated by 0.9 M ammonium sulphate showed a drop of activity on the acid side at much higher pH values. Its bell was centred at pH 7.8 but it was too narrow to be characterized by only two pK values. The narrowness of the curve could be explained by positive co-operativity, but not its unusually steep acid side. We suggest that the fall on the acid side is due to more than one hydronation (addition of H+). The points can be fitted by a curve with two de-activating hydronations and a de-activating dehydronation having identical titration pK values of 7.5, and hence molecular values of 7.0, 7.5 and 8.0. If both 0.9 M ammonium sulphate and 5 mM AMP are added, the bell is as broad as with AMP alone, but is somewhat raised in pH optimum. The results are discussed in the light of new structural data from crystallographic studies on binary complexes of the enzyme.
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Affiliation(s)
- S E Zographos
- Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece
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49
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Abstract
The ionization state of the substrate alpha-D-glucopyranosyl phosphate bound at the active site of glycogen phosphorylase has been probed by a number of techniques. Values of Ki determined for a series of substrate analogue inhibitors in which the phosphate moiety bears differing charges suggest that the enzyme will bind both the monoanionic and dianionic substrates with approximately equal affinity. These results are strongly supported by 31P- and 19F-NMR studies of the bound substrate analogues alpha-D-glucopyranosyl 1-methylenephosphonate and 2-deoxy-2-fluoro-alpha-D-glucopyranosyl phosphate, which also suggest that the substrate can be bound in either ionization state. The pH-dependences of the inhibition constants K1 for these two analogues, which have substantially different phosphate pK2 values (7.3 and 5.9 respectively), are found to be essentially identical with the pH-dependence of K(m) values for the substrate, inhibition decreasing according to an apparent pKa value of 7.2. This again indicates that there is no specificity for monoanion or dianion binding and also reveals that binding is associated with the uptake of a proton. As the bound substrate is not protonated, this proton must be taken up by the proton.
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Affiliation(s)
- I P Street
- Department of Chemistry, University of British Columbia, Vancouver, Canada
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Bungum B, Hole EO, Sagstuen E, Lindgren M. Electron paramagnetic resonance of X-irradiated sodium and potassium salts of glucose-1-phosphate. Identification of PO3(2-) radicals at room temperature. Radiat Res 1994; 139:194-202. [PMID: 8052695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Single crystals of the disodium and dipotassium salt of glucose-1-phosphate, X-irradiated at 80 K or at 280 K, show the presence of PO3(2-) radicals at 295 K, formed by scission of the phosphate-ester bond at the phosphate side. The 31P hyperfine coupling constants were measured using X- and Q-band EPR spectroscopy. Typical values for these coupling constants are a magnitude of = 68 mT and a perpendicular = 53 mT. The g values were almost isotropic, slightly smaller than that of the free electron spin (g = 2.0023). There is no substantial reorientation of the phosphate group in the crystalline lattice upon radical formation. Directly after irradiation at 77 K the PO3(2-) radicals are not present, but their characteristic resonance grows in upon thermal annealing of the crystals. The radicals are probably formed from a carbon-centered radical precursor by secondary reactions resulting in the loss of the phosphate group, leaving a (diamagnetic) modified carbohydrate molecule behind. The alternative process of reductive cleavage of the phosphate-ester bond by electrons released from traps in the crystal upon thermal annealing is considered less likely. A second phosphate-centered species, with a magnitude of about 21 mT and a perpendicular about 15 mT, was detected in the dipotassium salt of glucose-1-phosphate only. Possible structures for this species are discussed.
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Affiliation(s)
- B Bungum
- Department of Physics, University of Oslo, Norway
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