DOCSLIB.ORG

Acetate Metabolism: the Physiological Role of ADP-Forming Acetyl-Coa Synthetase and Acetate Kinase in Entamoeba Histolytica

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Acetate Metabolism: the Physiological Role of ADP-Forming Acetyl-Coa Synthetase and Acetate Kinase in Entamoeba Histolytica Clemson University TigerPrints All Dissertations Dissertations 8-2017 Acetate Metabolism: The physiological role of ADP-forming acetyl-CoA synthetase and acetate kinase in Entamoeba histolytica Thanh Dang Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_dissertations Recommended Citation Dang, Thanh, "Acetate Metabolism: The hp ysiological role of ADP-forming acetyl-CoA synthetase and acetate kinase in Entamoeba histolytica" (2017). All Dissertations. 1976. https://tigerprints.clemson.edu/all_dissertations/1976 This Dissertation is brought to you for free and open access by the Dissertations at TigerPrints. It has been accepted for inclusion in All Dissertations by an authorized administrator of TigerPrints. For more information, please contact [email protected]. Acetate Metabolism: The Physiological Role of ADP-forming Acetyl-CoA Synthetase and Acetate Kinase in Entamoeba histolytica _____________________________________________________________________ A Dissertation Presented to the Graduate School of Clemson University _____________________________________________________________________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Biochemistry and Molecular Biology _____________________________________________________________________ by Thanh Dang August 2017 _____________________________________________________________________ Accepted by: Cheryl Ingram-Smith, Committee Chair James C. Morris Kerry S. Smith Lesly Temesvari ABSTRACT Entamoeba histolytica is a protozoan parasite that causes amoebic colitis and liver abscess in approximately 90 million people each year, resulting in 50,000-100,000 fatalities. Even though Entamoeba poses a significant public health problem worldwide, research dedicated to understanding the biology of this unique protozoan has been limited. This amitochondriate parasite lacks many essential biosynthesis pathways including the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. As a result, substrate level phosphorylation plays a necessary role in ATP production. Unlike the standard glycolytic pathway, E. histolytica glycolysis requires pyrophosphate (PPi) by replacing ATP–dependent phosphofructokinase and pyruvate kinase with PPi–dependent phosphofructokinase and phosphate pyruvate dikinase. E. histolytica infects and colonizes the human colon where glucose is limited and short chain fatty acids (acetate, propionate, and butyrate) are plentiful. Acetate is also a major end product that is excreted when E. histolytica is grown axenically on glucose. Acetate has been demonstrated to act as carbon and energy source for cellular growth in other organisms, acetogenesis can regenerate NAD+, recycle coenzyme A, and produce ATP when the TCA cycle or oxidative phosphorylation does not operate or when the carbon flux into the cell exceed its capacity. In E. histolytica, acetate can be generated by acetate kinase (ACK) and ADP– forming acetyl–CoA synthetase (ACD). ACK converts acetyl phosphate + orthophosphate (Pi) to acetate + PPi. Previous biochemical and kinetic characterization of II recombinant ACK showed that it strongly prefers the acetate/PPi-forming direction. We hypothesized that ACK may function to supply PPi for the PPi oriented glycolytic pathway in E. histolytica. Recombinant ACD displayed high activity in both directions of the reaction to convert acetyl-CoA + orthophosphate + ADP to acetate + ATP + CoA. ACD may function to extend the glycolytic pathway to increase ATP production by 40% per molecule of glucose, or in the alternative direction to convert acetate to acetyl-CoA to meet the cell’s metabolic needs. Using reverse genetics, an Ehacd silenced strain displayed a growth defect in normal high glucose media, while Ehack silenced cells showed enhance growth in medium without added tryptone and glucose. The presence of acetate and butyrate showed no effect on E. histolytica growth in the absence of glucose regardless of ACK or ACD activity. The presence of propionate, however, improved E. histolytica growth and impaired growth of the Ehacd silenced strain implicated ACD as the cause of this improvement. Our data suggest ACD plays a role in increasing ATP production during growth on glucose and utilization of propionate as a growth substrate. Our data do not support the previously hypothesized role for ACK but instead suggest it possesses a novel function. The basis for E. histolytica ACK’s divergence from all other ACKs in phosphoryl substrate utilization was also explored. Currently, E. histolytica ACK is the only known ACK that uses pyrophosphate (PPi) or inorganic phosphate (Pi) as the phosphoryl donor or acceptor. All other known ACKs utilize ATP or ADP. In silico structural comparison and modeling of E. histolytica ACK against other ACKs identified structural differences III that could affect substrate binding and selection. ACK variants were generated to test these predictions. Inhibition and structural activity relationship studies revealed an occlusion in the ADENOSINE motif of E. histolytica ACK reduced ATP and ADP binding affinity. However, alterations to alleviate the constriction did not confer activity with ATP or ADP. Our results suggest controlling access of the adenosine pocket influences phosphoryl substrate binding but is not the sole determinant of enzyme activity. IV DEDICATION I would like to dedicate this to my Mom, Dad, and Joanne. Without your support and encouragement, this would not have been possible. I am blessed and thankful for having such a loving family. V ACKNOWLEDGEMENT I would like to thank my advisor, Dr. Cheryl Ingram-Smith. You are kind, patient, and understanding. I am truly grateful for the opportunity to work and learn from you. The lessons I gained here will stay with me for the rest of my career. Additionally, I would like to thank my committee members. Dr. Kerry Smith: thank you for the valuable discussions and insightful inputs during our numerous joint lab meetings. Dr. Lesly Temesvari: thank you for your advice and expertise toward my Entamoeba research. Dr. James Morris: thank you for your constant wisdom and wild ideas that have kept my perspective in check. I would also like to acknowledge the students from both the Ingram-Smith and Smith labs. Without everyone’s advice and helpful technical assistance, I would have made more mistakes, repeated more experiments, and not learned as much as I have. Thank you Cheryl Jones, Jordan Wesel, and Diana Nguyen, my fellow Ingram-Smith lab mates, for being a platform to screen new ideas and experimental designs. From the Smith lab, thank you Tonya Taylor, Katie Glenn, and Satyanarayana Lagishetty for being so welcoming and of great assistance during my graduate career. Lastly, I would like to extend a special thanks to Brenda Welter and Hollie Hendrick from Dr. Temesvari’s lab. Your assistance was critical to my work with Entamoeba histolytica. I would like to also express great thanks to the faculty, staff, and graduate students from Clemson University Genetics and Biochemistry department and the Eukaryotic Pathogens Innovation Center. In particular, I would like to thank Logan VI Crowe, Sophie Altamirano, Michael Harris, Jimmy Suryadi, and Steven Cogill for their support and advice in matters of science and life. Most of all, without everyone’s technical assistance, valuable input, and words of encouragement, graduate school would not have been as enjoyable and achievable. So, thank you! VII TABLE OF CONTENTS Page TITLE PAGE....................................................................................................................... I ABSTRACT........................................................................................................................II DEDICATION....................................................................................................................V ACKNOWLEDGEMENT ................................................................................................ VI LIST OF TABLES..............................................................................................................X LIST OF FIGURES .......................................................................................................... XI CHAPTER I. Literature Review.........................................................................................1 Introduction......................................................................................1 Acetate Metabolism .........................................................................3 Acetate metabolism in bacteria............................................4 Acetyl-phosphate in signal transduction..................9 Acetate metabolism in eukaryotes .....................................11 Entamoeba histolytica....................................................................16 Metabolism ........................................................................20 Acetate Kinase ...............................................................................28 ATP-acetate kinase ............................................................28 PPi-acetate kinase ..............................................................37 References.......................................................................................41 II. Investigation of pyrophosphate versus ATP substrate selection in the Entamoeba histolytica acetate kinase ...............................58 Abstract..........................................................................................58
Load more

Recommended publications
  • METACYC ID Description A0AR23 GO:0004842 (Ubiquitin-Protein Ligase
    Electronic Supplementary Material (ESI) for Integrative Biology This journal is © The Royal Society of Chemistry 2012 Heat Stress Responsive Zostera marina Genes, Southern Population (α=0.
    [Show full text]
  • Phosphatidylinositol-3-Kinase in Tomato (Solanum Lycopersicum. L) Fruit and Its Role in Ethylene Signal Transduction and Senescence
    Phosphatidylinositol-3-Kinase in Tomato (Solanum lycopersicum. L) Fruit and Its Role in Ethylene Signal Transduction and Senescence by Mohd Sabri Pak Dek A Thesis presented to The University of Guelph In partial fulfilment of requirements for the degree of Doctor of Philosophy in Plant Agriculture Guelph, Ontario, Canada © Mohd Sabri Pak Dek,June, 2015 ABSTRACT PHOSPHATIDYLINOSITOL-3-KINASE IN TOMATO (SOLANUM LYCOPERSICUM. L) FRUIT AND ITS ROLE IN ETHYLENE SIGNAL TRANSDUCTION AND SENESCENCE Mohd Sabri Pak Dek Co-Advisors: University of Guelph, 2015 Professor G. Paliyath Professor J. Subramanian The ripening process is initiated by ethylene through a signal transduction cascade leads to the expression of ripening-related genes and catabolism of membrane, cell wall, and storage components. One of the minor components in membrane phospholipids is phosphatidylinositol (PI). Phosphatidylinositol-3-kinase (PIK) is an enzyme that phosphorylates PI at the 3-OH position of inositol head group to produce phosphatidylinositol 3-phosphate (PI3P). Phosphorylation of PI may be an early event in the ethylene signal transduction pathway that generates negatively charged domains on the plasma membrane. PI3P domains may potentially serve as a docking site for phospholipase D (PLD) after ethylene stimulation. It is hypothesized that ethylene stimulation may activate PI3K resulting in enhanced level of phosphorylated phosphatidylinositol. However, the properties and function of PI3K is not well understood in plants. In the present study, the effect of PI3K inhibition during tomato fruit ripening was evaluated. This study demonstrated that PI3K activity is required for normal ripening process of the fruit. Inhibition of PI3K activity using wortmannin significantly reduced tomato ripening process.
    [Show full text]
  • A New Insight Into Role of Phosphoketolase Pathway in Synechocystis Sp
    www.nature.com/scientificreports OPEN A new insight into role of phosphoketolase pathway in Synechocystis sp. PCC 6803 Anushree Bachhar & Jiri Jablonsky* Phosphoketolase (PKET) pathway is predominant in cyanobacteria (around 98%) but current opinion is that it is virtually inactive under autotrophic ambient CO2 condition (AC-auto). This creates an evolutionary paradox due to the existence of PKET pathway in obligatory photoautotrophs. We aim to answer the paradox with the aid of bioinformatic analysis along with metabolic, transcriptomic, fuxomic and mutant data integrated into a multi-level kinetic model. We discussed the problems linked to neglected isozyme, pket2 (sll0529) and inconsistencies towards the explanation of residual fux via PKET pathway in the case of silenced pket1 (slr0453) in Synechocystis sp. PCC 6803. Our in silico analysis showed: (1) 17% fux reduction via RuBisCO for Δpket1 under AC-auto, (2) 11.2–14.3% growth decrease for Δpket2 in turbulent AC-auto, and (3) fux via PKET pathway reaching up to 252% of the fux via phosphoglycerate mutase under AC-auto. All results imply that PKET pathway plays a crucial role under AC-auto by mitigating the decarboxylation occurring in OPP pathway and conversion of pyruvate to acetyl CoA linked to EMP glycolysis under the carbon scarce environment. Finally, our model predicted that PKETs have low afnity to S7P as a substrate. Metabolic engineering of cyanobacteria provides many options for producing valuable compounds, e.g., acetone from Synechococcus elongatus PCC 79421 and butanol from Synechocystis sp. strain PCC 68032. However, certain metabolites or overproduction of intermediates can be lethal. Tere is also a possibility that required mutation(s) might be unstable or the target bacterium may even be able to maintain the fux distribution for optimal growth balance due to redundancies in the metabolic network, such as alternative pathways.
    [Show full text]
  • Structure-Function Analysis of the Catalytic Domain of the Histidine Kinase Chea
    Loyola University Chicago Loyola eCommons Dissertations Theses and Dissertations 1997 Structure-Function Analysis of the Catalytic Domain of the Histidine Kinase Chea Dolph David Ellefson Loyola University Chicago Follow this and additional works at: https://ecommons.luc.edu/luc_diss Part of the Microbiology Commons Recommended Citation Ellefson, Dolph David, "Structure-Function Analysis of the Catalytic Domain of the Histidine Kinase Chea" (1997). Dissertations. 3425. https://ecommons.luc.edu/luc_diss/3425 This Dissertation is brought to you for free and open access by the Theses and Dissertations at Loyola eCommons. It has been accepted for inclusion in Dissertations by an authorized administrator of Loyola eCommons. For more information, please contact [email protected]. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. Copyright © 1997 Dolph David Ellefson LOYOLA UNIVERSITY MEDICAL CENTER LIBRARY LOYOLA UNIVERSITY OF CHICAGO STRUCTURE-FUNCTION ANALYSIS OF THE CATALYTIC DOMAIN OF THE HISTIDINE KINASE CHEA A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF MICROBIOLOGY AND IMMUNOLOGY BY DOLPH DAVID ELLEFSON CHICAGO, ILLINOIS MAY, 1997 Copyright by Dolph David Ellefson, 1997 All Rights Reserved ii ACKNOWLEDGEMENTS I would like to thank my director, Dr. Alan J. Wolfe, for his support, advice, and encouragment during the many years in his laboratory. In his laboratory, I was given a rare opportunity to explore a new arena of science and interact with a field of gifted researchers who I would not known otherwise. I would also like to thank the members of my committee, Ors.
    [Show full text]
  • Characterization of the Ergosterol Biosynthesis Pathway in Ceratocystidaceae
    Journal of Fungi Article Characterization of the Ergosterol Biosynthesis Pathway in Ceratocystidaceae Mohammad Sayari 1,2,*, Magrieta A. van der Nest 1,3, Emma T. Steenkamp 1, Saleh Rahimlou 4 , Almuth Hammerbacher 1 and Brenda D. Wingfield 1 1 Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; [email protected] (M.A.v.d.N.); [email protected] (E.T.S.); [email protected] (A.H.); brenda.wingfi[email protected] (B.D.W.) 2 Department of Plant Science, University of Manitoba, 222 Agriculture Building, Winnipeg, MB R3T 2N2, Canada 3 Biotechnology Platform, Agricultural Research Council (ARC), Onderstepoort Campus, Pretoria 0110, South Africa 4 Department of Mycology and Microbiology, University of Tartu, 14A Ravila, 50411 Tartu, Estonia; [email protected] * Correspondence: [email protected]; Fax: +1-204-474-7528 Abstract: Terpenes represent the biggest group of natural compounds on earth. This large class of organic hydrocarbons is distributed among all cellular organisms, including fungi. The different classes of terpenes produced by fungi are mono, sesqui, di- and triterpenes, although triterpene ergosterol is the main sterol identified in cell membranes of these organisms. The availability of genomic data from members in the Ceratocystidaceae enabled the detection and characterization of the genes encoding the enzymes in the mevalonate and ergosterol biosynthetic pathways. Using Citation: Sayari, M.; van der Nest, a bioinformatics approach, fungal orthologs of sterol biosynthesis genes in nine different species M.A.; Steenkamp, E.T.; Rahimlou, S.; of the Ceratocystidaceae were identified.
    [Show full text]
  • CO2-Fixing One-Carbon Metabolism in a Cellulose-Degrading Bacterium
    CO2-fixing one-carbon metabolism in a cellulose- degrading bacterium Clostridium thermocellum Wei Xionga, Paul P. Linb, Lauren Magnussona, Lisa Warnerc, James C. Liaob,d, Pin-Ching Manessa,1, and Katherine J. Choua,1 aBiosciences Center, National Renewable Energy Laboratory, Golden, CO 80401; bDepartment of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095; cNational Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401; and dAcademia Sinica, Taipei City, Taiwan 115 Edited by Lonnie O. Ingram, University of Florida, Gainesville, FL, and approved September 23, 2016 (received for review April 6, 2016) Clostridium thermocellum can ferment cellulosic biomass to for- proposed pathway involving CO2 utilization in C. thermocellum is mate and other end products, including CO2. This organism lacks the malate shunt and its variant pathway (7, 14), in which CO2 is formate dehydrogenase (Fdh), which catalyzes the reduction of first incorporated by phosphoenolpyruvate carboxykinase (PEPCK) 13 CO2 to formate. However, feeding the bacterium C-bicarbonate to form oxaloacetate and then is released either by malic enzyme or and cellobiose followed by NMR analysis showed the production via oxaloacetate decarboxylase complex, yielding pyruvate. How- of 13C-formate in C. thermocellum culture, indicating the presence ever, other pathways capable of carbon fixation may also exist but of an uncharacterized pathway capable of converting CO2 to for- remain uncharacterized. mate. Combining genomic and experimental data, we demon- In recent years, isotopic tracer experiments followed by mass strated that the conversion of CO2 to formate serves as a CO2 spectrometry (MS) (15, 16) or NMR measurements (17) have entry point into the reductive one-carbon (C1) metabolism, and emerged as powerful tools for metabolic analysis.
    [Show full text]
  • A Thesis Entitled Phor, Phop and Mshc
    A Thesis entitled PhoR, PhoP and MshC: Three essential proteins of Mycobacterium tuberculosis by Erica Loney Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Chemistry __________________________________ Dr. Donald R. Ronning, Committee Chair __________________________________ Dr. John J. Bellizzi, Committee Member __________________________________ Dr. Ronald Viola, Committee Member __________________________________ Dr. Patricia R. Komuniecki, Dean College of Graduate Studies The University of Toledo May 2014 Copyright 2014, Erica Loney This document is copyrighted material. Under copyright law, no parts of this document may be produced without the expressed permission of the author. An Abstract of PhoR, PhoP and MshC: Three essential proteins of Mycobacterium tuberculosis by Erica Loney Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Chemistry The University of Toledo May 2014 The tuberculosis (TB) pandemic is responsible for 1.6 million deaths annually, most of which occur in developing nations. TB is treatable, though patient non- compliance, co-infection with HIV, and the long, 6-9 month treatment regimen have resulted in the emergence of drug-resistant TB. For these reasons, the development of novel anti-tuberculin drugs is essential. Three proteins – PhoR, PhoP, and MshC – of Mycobacterium tuberculosis (M.tb), the causative agent of TB, are the focus of this thesis. The PhoPR two-component system is a phosphorelay system responsible for the virulence of M.tb. The histidine kinase PhoR responds to a yet-unknown environmental stimulus and autophosphorylates a conserved histidine. The phosphate is transferred to an aspartate of the response regulator PhoP, which then forms a head-to-head homodimer and initiates the transcription of 114 virulence genes.
    [Show full text]
  • Part I Principles of Enzyme Catalysis
    j1 Part I Principles of Enzyme Catalysis Enzyme Catalysis in Organic Synthesis, Third Edition. Edited by Karlheinz Drauz, Harald Groger,€ and Oliver May. Ó 2012 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2012 by Wiley-VCH Verlag GmbH & Co. KGaA. j3 1 Introduction – Principles and Historical Landmarks of Enzyme Catalysis in Organic Synthesis Harald Gr€oger and Yasuhisa Asano 1.1 General Remarks Enzyme catalysis in organic synthesis – behind this term stands a technology that today is widely recognized as a first choice opportunity in the preparation of a wide range of chemical compounds. Notably, this is true not only for academic syntheses but also for industrial-scale applications [1]. For numerous molecules the synthetic routes based on enzyme catalysis have turned out to be competitive (and often superior!) compared with classic chemicalaswellaschemocatalyticsynthetic approaches. Thus, enzymatic catalysis is increasingly recognized by organic chemists in both academia and industry as an attractive synthetic tool besides the traditional organic disciplines such as classic synthesis, metal catalysis, and organocatalysis [2]. By means of enzymes a broad range of transformations relevant in organic chemistry can be catalyzed, including, for example, redox reactions, carbon–carbon bond forming reactions, and hydrolytic reactions. Nonetheless, for a long time enzyme catalysis was not realized as a first choice option in organic synthesis. Organic chemists did not use enzymes as catalysts for their envisioned syntheses because of observed (or assumed) disadvantages such as narrow substrate range, limited stability of enzymes under organic reaction conditions, low efficiency when using wild-type strains, and diluted substrate and product solutions, thus leading to non-satisfactory volumetric productivities.
    [Show full text]
  • ENZYMES: Catalysis, Kinetics and Mechanisms N
    ENZYMES: Catalysis, Kinetics and Mechanisms N. S. Punekar ENZYMES: Catalysis, Kinetics and Mechanisms N. S. Punekar Department of Biosciences & Bioengineering Indian Institute of Technology Bombay Mumbai, Maharashtra, India ISBN 978-981-13-0784-3 ISBN 978-981-13-0785-0 (eBook) https://doi.org/10.1007/978-981-13-0785-0 Library of Congress Control Number: 2018947307 # Springer Nature Singapore Pte Ltd. 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd.
    [Show full text]
  • Expression, Purification and Characterisation of Full-Length
    B doi:10.1016/S0022-2836(02)00424-2 available online at http://www.idealibrary.com on w J. Mol. Biol. (2002) 320, 201–213 Expression, Purification and Characterisation of Full-length Histidine Protein Kinase RegB from Rhodobacter sphaeroides Christopher A. Potter1, Alison Ward1, Cedric Laguri2 Michael P. Williamson2, Peter J.F. Henderson1 and Mary K. Phillips-Jones1* 1Division of Microbiology The global redox switch between aerobic and anaerobic growth in School of Biochemistry and Rhodobacter sphaeroides is controlled by the RegA/RegB two-component Molecular Biology, University system, in which RegB is the integral membrane histidine protein kinase, of Leeds, Leeds LS2 9JT, UK and RegA is the cytosolic response regulator. Despite the global regulatory importance of this system and its many homologues, there have been no 2Department of Molecular reported examples to date of heterologous expression of full-length RegB Biology and Biotechnology or any histidine protein kinases. Here, we report the amplified expression University of Sheffield of full-length functional His-tagged RegB in Escherichia coli, its purifi- Sheffield S10 2TN, UK cation, and characterisation of its properties. Both the membrane-bound and purified solubilised RegB protein demonstrate autophosphorylation activity, and the purified protein autophosphorylates at the same rate under both aerobic and anaerobic conditions confirming that an additional regulator is required to control/inhibit autophosphorylation. The intact protein has similar activity to previously characterised soluble forms, but is dephosphorylated more rapidly than the soluble form (half- life ca 30 minutes) demonstrating that the transmembrane segment present in the full-length RegB may be an important regulator of RegB activity.
    [Show full text]
  • Biosynthesis of New Alpha-Bisabolol Derivatives Through a Synthetic Biology Approach Arthur Sarrade-Loucheur
    Biosynthesis of new alpha-bisabolol derivatives through a synthetic biology approach Arthur Sarrade-Loucheur To cite this version: Arthur Sarrade-Loucheur. Biosynthesis of new alpha-bisabolol derivatives through a synthetic biology approach. Biochemistry, Molecular Biology. INSA de Toulouse, 2020. English. NNT : 2020ISAT0003. tel-02976811 HAL Id: tel-02976811 https://tel.archives-ouvertes.fr/tel-02976811 Submitted on 23 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THÈSE En vue de l’obtention du DOCTORAT DE L’UNIVERSITÉ DE TOULOUSE Délivré par l'Institut National des Sciences Appliquées de Toulouse Présentée et soutenue par Arthur SARRADE-LOUCHEUR Le 30 juin 2020 Biosynthèse de nouveaux dérivés de l'α-bisabolol par une approche de biologie synthèse Ecole doctorale : SEVAB - Sciences Ecologiques, Vétérinaires, Agronomiques et Bioingenieries Spécialité : Ingénieries microbienne et enzymatique Unité de recherche : TBI - Toulouse Biotechnology Institute, Bio & Chemical Engineering Thèse dirigée par Gilles TRUAN et Magali REMAUD-SIMEON Jury
    [Show full text]
  • Catalase: Bioinformatics Analyses of One of the Key Enzymes in Hydrogen Peroxide Metabolism
    6–71RYHPEHU 2019, Brno, Czech Republic Catalase: Bioinformatics analyses of one of the key enzymes in hydrogen peroxide metabolism Michaela Kameniarova, Romana Kopecka Department of Molecular Biology and Radiobiology Mendel University in Brno Zemedelska 1, 613 00 Brno CZECH REPUBLIC [email protected] Abstract: Catalases (CAT) are family of important antioxidant enzymes present in different isoforms and responsible for scavenging of hydrogen peroxide in almost all aerobically living organisms. In plants, they were found both in unicellular and multicellular species. Here, we performed bioinformatics analysis and analysed catalase evolutionary relationship and expression patterns. By comparing expression profiles of CATs and expression profiles of genes related to abiotic stimuli we found that almost 50% of light signalling genes were co-expressed with CATs. Further, by datamining in available resources and structural modelling we pinpointed candidate amino acid residues responsible for CAT thermostability. Key Words: catalase, H2O2, phylogenetics, abiotic stress, stability INTRODUCTION Plants contain several types of enzymes involved in H2O2 metabolism. These include catalases, ascorbate peroxidases, peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione S- transferases, but only catalases do not require additional cellular reductants (Mhamdi et al. 2010). Catalases are present almost in all aerobically respiring organisms. Within the cell environment, catalases are localized in all major sites of H2O2 production, mostly at peroxisomes, but they were detected in cytosol, mitochondria, and chloroplasts as well (Sharma and Ahmad 2014). Catalases (CAT, 1.11.1.6) are antioxidant enzymes that catalyse decomposition of hydrogen peroxide to water and molecular oxygen (2H2O2 → 2H2O + O2), an important process in defending cells against oxidative damage caused by reactive oxygen species (ROS; Alfonso-Prieto et al.
    [Show full text]