Phorylase Has Been Forthcominglately
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Articles Catalytic Cycling in Β-Phosphoglucomutase: a Kinetic
9404 Biochemistry 2005, 44, 9404-9416 Articles Catalytic Cycling in â-Phosphoglucomutase: A Kinetic and Structural Analysis†,‡ Guofeng Zhang, Jianying Dai, Liangbing Wang, and Debra Dunaway-Mariano* Department of Chemistry, UniVersity of New Mexico, Albuquerque, New Mexico 87131-0001 Lee W. Tremblay and Karen N. Allen* Department of Physiology and Biophysics, Boston UniVersity School of Medicine, Boston, Massachusetts 02118-2394 ReceiVed March 26, 2005; ReVised Manuscript ReceiVed May 18, 2005 ABSTRACT: Lactococcus lactis â-phosphoglucomutase (â-PGM) catalyzes the interconversion of â-D-glucose 1-phosphate (â-G1P) and â-D-glucose 6-phosphate (G6P), forming â-D-glucose 1,6-(bis)phosphate (â- G16P) as an intermediate. â-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 â-PGM activation by the Mg2+ cofactor, â-PGM activation by Asp8 phosphorylation, and the role of cap domain closure in substrate discrimination. First, the 1.90 Å resolution X-ray crystal structure of the Mg2+-â-PGM complex is examined in the context of + + previously reported structures of the Mg2 -R-D-galactose-1-phosphate-â-PGM, Mg2 -phospho-â-PGM, and Mg2+-â-glucose-6-phosphate-1-phosphorane-â-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. -
Monophosphate- Binding Protein Complex with Subsequent Poly(A) RNA Synthesis in Embryonic Chick Cartilage
Specific nuclear binding of adenosine 3',5'-monophosphate- binding protein complex with subsequent poly(A) RNA synthesis in embryonic chick cartilage. W M Burch Jr, H E Lebovitz J Clin Invest. 1980;66(3):532-542. https://doi.org/10.1172/JCI109885. Research Article We used embryonic chick pelvic cartilage as a model to study the mechanism by which cyclic AMP increases RNA synthesis. Isolated nuclei were incubated with [32P]-8-azidoadenosine 3,5'-monophosphate ([32P]N3cAMP) with no resultant specific nuclear binding. However, in the presence of cytosol proteins, nuclear binding of [32P]N3cAMP was demonstrable that was specific, time dependent, and dependent on a heat-labile cytosol factor. The possible biological significance of the nuclear binding of the cyclic AMP-protein complex was identified by incubating isolating nuclei with either cyclic AMP or cytosol cyclic AMP-binding proteins prepared by batch elution DEAE cellulose chromatography (DEAE peak cytosol protein), or both, in the presence of cold nucleotides and [3H]uridine 5'-triphosphate. Poly(A) RNA production occurred only in nuclei incubated with cyclic AMP and the DEAE peak cytosol protein preparation. Actinomycin D inhibited the incorporation of [3H]uridine 5'-monophosphate into poly(A) RNA. The newly synthesized poly(A) RNA had a sedimentation constant of 23S. Characterization of the cytosol cyclic AMP binding proteins using [32P]N3-cAMP with photoaffinity labeling three major cAMP-binding complexes (41,000, 51,000, and 55,000 daltons). The 51,000 and 55,000 dalton cyclic AMP binding proteins were further purified by DNA-cellulose chromatography. In the presence of cyclic AMP they stimulated poly(A) RNA synthesis in isolated nuclei. -
Glycogenesis
Glycogenesis Glycogen is the storage form of glucose in animals and humans which is analogous to the starch in plants. Glycogen is synthesized and stored mainly in the liver and the muscles. Structurally, glycogen is very similar to amylopectin with alpha acetal linkages, however, it has even more branching and more glucose units are present than in amylopectin. Various samples of glycogen have been measured at 1,700-600,000 units of glucose. The structure of glycogen consists of long polymer chains of glucose units connected by an alpha acetal linkage. All of the monomer units are alpha-D-glucose, and all the alpha acetal links connect C # 1 of one glucose to C # 4 of the next glucose. The branches are formed by linking C # 1 to a C # 6 through acetal linkages. In glycogen, the branches occur at intervals of 8-10 glucose units (in amylopectin the branches are separated by 12-20 glucose units). Carbon # 1 is called the anomeric carbon and is the center of an acetal functional group. The Alpha position is defined as the ether oxygen being on the opposite side of the ring as the C # 6. In the chair structure this results in a downward projection. Plants make starch and cellulose through the photosynthesis processes. Animals and human in turn eat plant materials and products. Digestion is a process of hydrolysis where the starch is broken ultimately into the various monosaccharides. A major product is of course glucose which can be used immediately for metabolism to make energy. The glucose that is not used immediately is converted in the liver and muscles into glycogen for storage by the process of glycogenesis. -
Expression of a Phosphoglucomutase Gene in Rainbow Trout (Polymorphism/Developmental Rate/Glycolysis/Salmo Gairdneri) FRED W
Proc. Natt Acad. Sci. USA Vol. 80, pp. 1397-1400, March 1983 Genetics Adaptive significance of differences in the tissue-specific expression of a phosphoglucomutase gene in rainbow trout (polymorphism/developmental rate/glycolysis/Salmo gairdneri) FRED W. ALLENDORF, KATHY L. KNUDSEN, AND ROBB F. LEARY Department of Zoology,, University of Montana, Missoula, Montana 59812 Communicated by G. Ledyard Stebbins, November 17, 1982 ABSTRACT We have investigated the phenotypic effects of fold increase in the expression of a phosphoglucomutase (PGM; a mutant allele that results in the expression of a phosphogluco- a-D-glucose-1,6-bisphosphate:a-D-glucose-l-phosphate phos- mutase locus (Pgml) in the liver of rainbow trout. Embryos with photransferase EC 2.7.5. 1) locus, Pgml, in liver tissue (14, 15). liver Pgml expression hatch earlier than embryos without liver The results of inheritance experiments are consistent with a sin- Pgml expression. These differences apparently result from in- gle regulatory gene, Pgml-t, with additive inheritance being re- creased flux through glycolysis in embryos with liver PGM1 ac- sponsible for the differences in the expression of this locus (15). tivity while they are dependent on the yolk for energy. Fish with We report here that the presence or absence of PGM1 in the liver PGM1 activity are also more developmentally buffered, as liver rise to indicated by less fluctuating asymmetry of five bilateral meristic gives important differences in several phenotypic traits. The more rapidly developing individuals begin exogenous characteristics of adaptive significance (developmental rate, de- feeding earlier and achieve a size advantage that is maintained velopmental stability, body size, and age at first maturity). -
Lecture 8 - Glycogen Metabolism
Lecture 8 - Glycogen Metabolism Chem 454: Regulatory Mechanisms in Biochemistry University of Wisconsin-Eau Claire Introduction Glycogen Text A storage form of glucose 2 Introduction Glycogen is stored primarily in the liver and Text skeletal muscles. Liver - used for maintaining blood glucose levels Muscles - used to meet energy needs of the muscles 3 Introduction Glycogen Text degradation occurs in three steps 4 Introduction Glycogen Text synthesis uses activated precursor UDP–glucose 5 Introduction Regulation of glycogen metabolism is Text complex. Allosteric regulation to meet the needs of the cell Hormonal regulation to meet the needs of the organsim 6 1. Glycogen Breakdown Requires three enzymes and produces Text glucose 6–phosphate Glycogen Phosphorylase Debranching Enzyme Phosphoglucomutase In the liver, an additional enzyme produces free glucose Glucose 6–phosphatase 7 1.1 Phosphorylase Cleavage uses orthophosphate in Text phosphorolysis reactions glycogen + Pi glucose 1-phosphate + glycogen n residues n-1 residues 8 1.2 Debranching Enzyme Two enzymes Text activities are needed to deal with the α–1,6 branch points 9 1.3 Phosphoglucomutase Mechanism is like that of phosphoglycerate Text mutase 10 1.4 Glucose 6-phosphatase Enzyme is found primarily in the liver and is Text used to release glucose into the bloodstream glucose 6-phosphate + H2O glucose + Pi 11 1.5 Mechanism for Phosphorolysis Text 12 1.5 Mechanism for Phosphorolysis Pyridoxyl phosphate Text coenzyme 13 1.5 Mechanism for Phosphorolysis Text 14 2. Regulation of Phosphorylase Phosphorylase is regulated by several Text allosteric effectors that signal the energy state of the cell It is also regulated by reversible phosphorylation in response to the hormones insulin, epinephrine, and glucagon 15 2.1 Muscle Phosphorylase Text 16 2.1 Muscle Phosphorylase Text 17 2.1 Muscle Phosphorylase Text 18 2.2 Liver Phosphorylase Text 19 2.3 Phosphorylase Kinase Text 20 3. -
Geochemical Influences on Nonenzymatic Oligomerization Of
bioRxiv preprint doi: https://doi.org/10.1101/872234; this version posted December 11, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Geochemical influences on nonenzymatic oligomerization of prebiotically relevant cyclic nucleotides Authors: Shikha Dagar‡, Susovan Sarkar‡, Sudha Rajamani‡* ‡ Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India Correspondence: [email protected]; Tel.: +91-20-2590-8061 Running title: Cyclic nucleotides and emergence of an RNA World Key words: Dehydration-rehydration cycles, lipid-assisted oligomerization, cyclic nucleotides, analogue environments Dagar, S. 1 bioRxiv preprint doi: https://doi.org/10.1101/872234; this version posted December 11, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Abstract The spontaneous emergence of RNA on the early Earth continues to remain an enigma in the field of origins of life. Few studies have looked at the nonenzymatic oligomerization of cyclic nucleotides under neutral to alkaline conditions, in fully dehydrated state. Herein, we systematically investigated the oligomerization of cyclic nucleotides under prebiotically relevant conditions, where starting reactants were subjected to repeated dehydration-rehydration (DH- RH) regimes, like they would have been on an early Earth. DH-RH conditions, a recurring geological theme, are driven by naturally occurring processes including diurnal cycles and tidal pool activity. These conditions have been shown to facilitate uphill oligomerization reactions in terrestrial geothermal niches, which are hypothesized to be pertinent sites for the emergence of life. -
Chem331 Glycogen Metabolism
Glycogen metabolism Glycogen review - 1,4 and 1,6 α-glycosidic links ~ every 10 sugars are branched - open helix with many non-reducing ends. Effective storage of glucose Glucose storage Liver glycogen 4.0% 72 g Muscle glycogen 0.7% 245 g Blood Glucose 0.1% 10 g Large amount of water associated with glycogen - 0.5% of total weight Glycogen stored in granules in cytosol w/proteins for synthesis, degradation and control There are very different means of control of glycogen metabolism between liver and muscle Glycogen biosynthetic and degradative cycle Two different pathways - which do not share enzymes like glycolysis and gluconeogenesis glucose -> glycogen glycogenesis - biosynthetic glycogen -> glucose 1-P glycogenolysis - breakdown Evidence for two paths - Patients lacking phosphorylase can still synthesize glycogen - hormonal regulation of both directions Glycogenolysis (glycogen breakdown)- Glycogen Phosphorylase glycogen (n) + Pi -> glucose 1-p + glycogen (n-1) • Enzyme binds and cleaves glycogen into monomers at the end of the polymer (reducing ends of glycogen) • Dimmer interacting at the N-terminus. • rate limiting - controlled step in glycogen breakdown • glycogen phosphorylase - cleavage of 1,4 α glycosidic bond by Pi NOT H2O • Energy of phosphorolysis vs. hydrolysis -low standard state free energy change -transfer potential -driven by Pi concentration -Hydrolysis would require additional step s/ cost of ATP - Think of the difference between adding a phosphate group with hydrolysis • phosphorylation locks glucose in cell (imp. for muscle) • Phosphorylase binds glycogen at storage site and the catalytic site is 4 to 5 glucose residues away from the catalytic site. • Phosphorylase removes 1 residue at a time from glycogen until 4 glucose residues away on either side of 1,6 branch point – stericaly hindered by glycogen storage site • Cleaves without releasing at storage site • general acid/base catalysts • Inorganic phosphate attacks the terminal glucose residue passing through an oxonium ion intermediate. -
Supplementary Information
Supplementary information (a) (b) Figure S1. Resistant (a) and sensitive (b) gene scores plotted against subsystems involved in cell regulation. The small circles represent the individual hits and the large circles represent the mean of each subsystem. Each individual score signifies the mean of 12 trials – three biological and four technical. The p-value was calculated as a two-tailed t-test and significance was determined using the Benjamini-Hochberg procedure; false discovery rate was selected to be 0.1. Plots constructed using Pathway Tools, Omics Dashboard. Figure S2. Connectivity map displaying the predicted functional associations between the silver-resistant gene hits; disconnected gene hits not shown. The thicknesses of the lines indicate the degree of confidence prediction for the given interaction, based on fusion, co-occurrence, experimental and co-expression data. Figure produced using STRING (version 10.5) and a medium confidence score (approximate probability) of 0.4. Figure S3. Connectivity map displaying the predicted functional associations between the silver-sensitive gene hits; disconnected gene hits not shown. The thicknesses of the lines indicate the degree of confidence prediction for the given interaction, based on fusion, co-occurrence, experimental and co-expression data. Figure produced using STRING (version 10.5) and a medium confidence score (approximate probability) of 0.4. Figure S4. Metabolic overview of the pathways in Escherichia coli. The pathways involved in silver-resistance are coloured according to respective normalized score. Each individual score represents the mean of 12 trials – three biological and four technical. Amino acid – upward pointing triangle, carbohydrate – square, proteins – diamond, purines – vertical ellipse, cofactor – downward pointing triangle, tRNA – tee, and other – circle. -
RSC Article Template
Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics This journal is © The Owner Societies 2013 Supplimentary Information Figure Legends: S1: Raman spectra of RNA building blocks and related compounds. All spectra are the average of 3 Raman spectra and have been baseline corrected, buffer subtracted and scaled to an effective 5 concentration of 50 mM. (a) Adenine related molecules: adenine (black), adenosine (red) and adenosine monophosphate (blue). The measured concentrations were 47.81 mM, 46.40 mM and 56.75 mM, respectively. (b) Cytosine related molecules: cytosine (black), cytidine (red) and cytidine monophosphate (blue). The measured concentrations were 47.70 mM, 56.74 mM and 55.38 mM, respectively. (c) Guanine related molecules: guanine (black), guanosine (red) and guanosine 10 monophosphate (blue). The measured concentrations were 46.19 mM, 63.90 mM and 46.67 mM, respectively. (d) Uracil related molecules: uracil (black), uridine (red) and uridine monophosphate (blue). The measured concentrations were 48.09 mM, 48.32 mM and 67.64 mM, respectively. (e) Ribose and phosphate molecules: ribose (black), ribose phosphate (red) and sodium phosphate (blue). The measured concentrations were 287.08 mM, 434.58 mM and 47.75 mM, respectively. 15 S2: Second derivative spectra of the measured RNA Raman spectra; SL-HIV1 (black), SL-APTR (red) and SL-SARS (blue). The positions of peaks discussed in the text are noted. Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics This journal is © The -
Already Estimated Levels of Phosphorylase, Phosphoglucomutase, and UDPG Glycogen Transglucosylase
ENZYMES IN A GLYCOGEN STORAGE MYOPATHY* BY JOSEPH LARNER AND CARLOS VILLAR-PALASI DEPARTMENT OF PHARMACOLOGY, SCHOOL OF MEDICINE, WESTERN RESERVE 17NIVERSITY Communicated by Harland G. Wood, June 22, 1959 McArdle has reported a "myopathy due to a defect in muscle glycogen break- down"' which appears to be a type of glycogen storage disease distinct from the previously reported classes.2 Schmid and Mahler' using muscle homogenates from a patient similar to the one described by McArdle have found that lactate is formed from added glucose 1-phosphate at a rate comparable to that of controls, but addition of muscle glycogen did not increase production of lactate. The con- tent of glycogen in the muscles of this patient ranged from 2.4 to 3.0 per cent. Estimation of phosphorylase indicated a markedly reduced activity of this enzyme. Recently it has become apparent4-8 that there is a uridine linked pathway of glycogen synthesis present in animal tissues which involves two enzymes UDPGt pyrophosphorylase, and UDPG glycogen transglucosylase. It was therefore of interest to determine the enzymes of the uridine linked pathway in the muscle of a patient with McArdle's disease. Schmid, Robbins, Traut, and Lipmann9 have already estimated levels of phosphorylase, phosphoglucomutase, and UDPG glycogen transglucosylase. We report here further results with a sample of the same muscle biopsy, including confirmation of the extremely low phosphorylase activity, and in addition normal activities of UDPG pyrophosphorylase, amylo- 1,6-glucosidase, and phosphoglucomutase. Materials and Methods.- The biopsy of the patient with the disease was obtained from the back. Two control biopsies of rectus and pectoral muscles were obtained during surgical procedures.: Homogenates of the rapidly frozen tissue (1:10 w/v) were made in 0.05 M Tris 0.005 M EDTA pH 8. -
Guanosine-Based Nucleotides, the Sons of a Lesser God in the Purinergic Signal Scenario of Excitable Tissues
International Journal of Molecular Sciences Review Guanosine-Based Nucleotides, the Sons of a Lesser God in the Purinergic Signal Scenario of Excitable Tissues 1,2, 2,3, 1,2 1,2, Rosa Mancinelli y, Giorgio Fanò-Illic y, Tiziana Pietrangelo and Stefania Fulle * 1 Department of Neuroscience Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy; [email protected] (R.M.); [email protected] (T.P.) 2 Interuniversity Institute of Miology (IIM), 66100 Chieti, Italy; [email protected] 3 Libera Università di Alcatraz, Santa Cristina di Gubbio, 06024 Gubbio, Italy * Correspondence: [email protected] Both authors contributed equally to this work. y Received: 30 January 2020; Accepted: 25 February 2020; Published: 26 February 2020 Abstract: Purines are nitrogen compounds consisting mainly of a nitrogen base of adenine (ABP) or guanine (GBP) and their derivatives: nucleosides (nitrogen bases plus ribose) and nucleotides (nitrogen bases plus ribose and phosphate). These compounds are very common in nature, especially in a phosphorylated form. There is increasing evidence that purines are involved in the development of different organs such as the heart, skeletal muscle and brain. When brain development is complete, some purinergic mechanisms may be silenced, but may be reactivated in the adult brain/muscle, suggesting a role for purines in regeneration and self-repair. Thus, it is possible that guanosine-50-triphosphate (GTP) also acts as regulator during the adult phase. However, regarding GBP, no specific receptor has been cloned for GTP or its metabolites, although specific binding sites with distinct GTP affinity characteristics have been found in both muscle and neural cell lines. -
Developmental Disorder Associated with Increased Cellular Nucleotidase Activity (Purine-Pyrimidine Metabolism͞uridine͞brain Diseases)
Proc. Natl. Acad. Sci. USA Vol. 94, pp. 11601–11606, October 1997 Medical Sciences Developmental disorder associated with increased cellular nucleotidase activity (purine-pyrimidine metabolismyuridineybrain diseases) THEODORE PAGE*†,ALICE YU‡,JOHN FONTANESI‡, AND WILLIAM L. NYHAN‡ Departments of *Neurosciences and ‡Pediatrics, University of California at San Diego, La Jolla, CA 92093 Communicated by J. Edwin Seegmiller, University of California at San Diego, La Jolla, CA, August 7, 1997 (received for review June 26, 1997) ABSTRACT Four unrelated patients are described with a represent defects of purine metabolism, although no specific syndrome that included developmental delay, seizures, ataxia, enzyme abnormality has been identified in these cases (6). In recurrent infections, severe language deficit, and an unusual none of these disorders has it been possible to delineate the behavioral phenotype characterized by hyperactivity, short mechanism through which the enzyme deficiency produces the attention span, and poor social interaction. These manifesta- neurological or behavioral abnormalities. Therapeutic strate- tions appeared within the first few years of life. Each patient gies designed to treat the behavioral and neurological abnor- displayed abnormalities on EEG. No unusual metabolites were malities of these disorders by replacing the supposed deficient found in plasma or urine, and metabolic testing was normal metabolites have not been successful in any case. except for persistent hypouricosuria. Investigation of purine This report describes four unrelated patients in whom and pyrimidine metabolism in cultured fibroblasts derived developmental delay, seizures, ataxia, recurrent infections, from these patients showed normal incorporation of purine speech deficit, and an unusual behavioral phenotype were bases into nucleotides but decreased incorporation of uridine.