DOCSLIB.ORG

In Search for the Membrane Regulators of Archaea Marta Salvador-Castell, Maxime Tourte, Philippe Oger

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
In Search for the Membrane Regulators of Archaea Marta Salvador-Castell, Maxime Tourte, Philippe Oger In Search for the Membrane Regulators of Archaea Marta Salvador-Castell, Maxime Tourte, Philippe Oger To cite this version: Marta Salvador-Castell, Maxime Tourte, Philippe Oger. In Search for the Membrane Regula- tors of Archaea. International Journal of Molecular Sciences, MDPI, 2019, 20 (18), pp.4434. 10.3390/ijms20184434. hal-02283370 HAL Id: hal-02283370 https://hal.archives-ouvertes.fr/hal-02283370 Submitted on 12 Nov 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. International Journal of Molecular Sciences Review In Search for the Membrane Regulators of Archaea Marta Salvador-Castell 1,2 , Maxime Tourte 1,2 and Philippe M. Oger 1,2,* 1 Université de Lyon, CNRS, UMR 5240, F-69621 Villeurbanne, France 2 Université de Lyon, INSA de Lyon, UMR 5240, F-69621 Villeurbanne, France * Correspondence: [email protected] Received: 7 August 2019; Accepted: 6 September 2019; Published: 9 September 2019 Abstract: Membrane regulators such as sterols and hopanoids play a major role in the physiological and physicochemical adaptation of the different plasmic membranes in Eukarya and Bacteria. They are key to the functionalization and the spatialization of the membrane, and therefore indispensable for the cell cycle. No archaeon has been found to be able to synthesize sterols or hopanoids to date. They also lack homologs of the genes responsible for the synthesis of these membrane regulators. Due to their divergent membrane lipid composition, the question whether archaea require membrane regulators, and if so, what is their nature, remains open. In this review, we review evidence for the existence of membrane regulators in Archaea, and propose tentative location and biological functions. It is likely that no membrane regulator is shared by all archaea, but that they may use different polyterpenes, such as carotenoids, polyprenols, quinones and apolar polyisoprenoids, in response to specific stressors or physiological needs. Keywords: archaea; membrane organization; membrane modulators; polyterpenes; carotenoids; polyprenols; quinones; polyisoprenoids; adaptation 1. Introduction In 1972, Singer and Nicolson reconciled the numerous observations about cell membranes to construct the now well-established fluid mosaic model [1]. Since then, the ultrastructure of cell membranes has further evolved to accommodate the lipid phases, i.e., gel or liquid crystalline, lipid phase partition, membrane curvature and the presence of lipid membrane regulators, which are currently gaining much attention in membrane structuration, function and regulation [2–4]. Lipid membrane regulators allow to expand the functional state of the lipid membrane to broader environmental conditions. The best studied membrane regulator is cholesterol, a sterol derivative present in animal cell membranes [3,5–10]. Although Bacteria do not synthesize sterols, their hopanoids have been accepted as “sterol surrogates” [11,12]. Sterols or hopanoids are absent in Archaea, and whether Archaea have membrane regulators remains a hotly debated question. The current review sums up the data available on putative archaeal membrane regulators and poses the groundwork for their identification in Archaea. 2. Structure of Bacterial and Eukaryal Membrane Regulators Sterols are the most well-known lipid membrane regulators. The term sterols covers a variety of compounds synthesized from 2,3-epoxide-squalene and consisting of an aliphatic chain with 7–10 carbons and four flat fused rings, the outermost one exhibiting an sn-3 hydroxyl group [6]. The three major kingdoms of the Eukarya, e.g., mammals, fungi and plants, synthesize different types of sterols, cholesterol, ergosterol and sitosterols and stigmasterols respectively. Hopanoids are pentacyclic triterpenoids synthesized from squalene. Such term regroups C30 derivatives such as diploptene, a hydrophobic molecule, and C35 molecules such as bacteriohopane, and their Int. J. Mol. Sci. 2019, 20, 4434; doi:10.3390/ijms20184434 www.mdpi.com/journal/ijms Int. J. Mol. Sci. 2019, 20, 4434 2 of 26 derivatives [13]. In hydrophilic hopanoids, hydroxyl groups are bound to the branched aliphatic chain, whichresults therefore in an “inverted” results in polarity an “inverted” in comparison polarity to in sterols. comparison Sterols to and sterols. hopanoids Sterols belong and hopanoids to a much belonglarger togroup a much of natural larger groupcompounds of natural called compounds polyterpenes, called i.e., polyterpenes, hydrocarbon i.e., oligomers hydrocarbon resulting oligomers from resultingsuccessive from condensations successive condensations of isoprene precursors of isoprene, precursors,namely, isopentenyl namely, isopentenyl pyrophosphate pyrophosphate (IPP) and (IPP)dimethyallyl and dimethyallyl diphosphate diphosphate (DMAP) (DMAP) (Figure (Figure 1). Poly1).terpenes Polyterpenes represent represent one oneof the of thelargest largest class class of ofnaturally naturally occurring occurring compounds compounds and and are are widely widely distributed distributed in Eukaryotes, Bacteria asas wellwell asas Archaea.Archaea. AlthoughAlthough all all polyterpenes polyterpenes of theof threethe three domains domain of lifes of originate life originate from IPP from and DMAP,IPP and these DMAP, precursors these areprecursors synthesized are synthesized via two independent, via two independent, non-homologous non-homologous pathways: thepathways: methylerythritol the methylerythritol 4-phosphate 4- pathwayphosphate in pathway Bacteria andin Bacteria the mevalonate and the mevalonate pathway in Eukaryotespathway in andEukaryotes Archaea and [14 ,Archaea15]. [14,15]. FigureFigure 1. 1.Most Most representative representative polyterpenes polyterpenes and theirand biosynthetictheir biosynthetic link. Carbon link. Carbon nomenclature nomenclature and isoprene and conformationsisoprene conformations are indicated are as indicated mentioned as hereafter.mentioned hereafter. 3. Mechanisms of Membrane Regulation in Eukarya and Bacteria 3. Mechanisms of Membrane Regulation in Eukarya and Bacteria TheThe impact impact of of sterols, sterols, and and particularly particularly of cholesterol, of cholesterol, on lipid on membraneslipid membranes has been has largely been studied. largely Sterolsstudied. are Sterols oriented are perpendicular oriented perpendicular to the membrane to the surfacemembrane with surface the hydroxyl with facingthe hydroxyl the phospholipid facing the esterphospholipid carbonyl ester and carbonyl stabilize and the stabilize functional the phospholipid functional phospholipid liquid-crystalline liquid-crystalline phase, i.e., phase, decrease i.e., gel-to-liquid lipid phase transition temperature (Tm). Sterols modulate membrane parameters decrease gel-to-liquid lipid phase transition temperature (Tm). Sterols modulate membrane byparameters tightening by and tightening reducing and the averagereducing tilt the of phospholipidaverage tilt of acyl phospholipid chains [16], acyl therefore chains decreasing [16], therefore acyl chains’decreasing motion acyl [17 chains’] while motion increasing [17] the while viscosity increasi andng the the order viscosity of lipid and membranes the order [of18 lipid]. They membranes also limit lipid[18]. membraneThey also passivelimit lipid permeability membrane to passive ions and perm smalleability molecules to ions [17]. and Last, small cholesterol molecules is the [17]. essential Last, componentcholesterol ofis thethe thickeressential liquid-ordered component of phase the thicker present liquid-ordered in eukaryotic cell phase membranes, present previouslyin eukaryotic called cell “lipidmembranes, raft”, which previously is essential called for “lipid membrane raft”, which functional is essential differentiation. for membrane This functional cholesterol-induced differentiation. lipid phaseThis leadscholesterol-induced to a discontinuity lipid of thephase membrane leads boundaryto a discontinuity and, therefore, of the to amembrane line-tension boundary between bothand, phasestherefore, [19 ].to This a line-tension tension may between facilitate both cell membranephases [19]. bending This tension and, consequently, may facilitate cell cell processes membrane as fusionbending and and, fission, consequently, which are essentialcell processes for numerous as fusion physiological and fission, mechanisms which are essential including for cell numerous division, cellphysiological compartmentalization mechanisms or including vesicle formation. cell division, cell compartmentalization or vesicle formation. The hydrophobic hopanoid, diploptene, is placed in the midplane of the lipid bilayer with an average tilt angle of about 51° to the membrane plane, whereas bacteriohopanetetrol presents an Int. J. Mol. Sci. 2019, 20, x; doi: FOR PEER REVIEW www.mdpi.com/journal/ijms Int. J. Mol. Sci. 2019, 20, 4434 3 of 26 The hydrophobic hopanoid, diploptene, is placed in the midplane of the lipid bilayer with an average tilt angle of about 51◦ to the membrane plane, whereas bacteriohopanetetrol presents an orientation similar
Load more

Recommended publications
  • Bacterial Cell Membrane
    BACTERIAL CELL MEMBRANE Dr. Rakesh Sharda Department of Veterinary Microbiology NDVSU College of Veterinary Sc. & A.H., MHOW CYTOPLASMIC MEMBRANE ➢The cytoplasmic membrane, also called a cell membrane or plasma membrane, is about 7 nanometers (nm; 1/1,000,000,000 m) thick. ➢It lies internal to the cell wall and encloses the cytoplasm of the bacterium. ➢It is the most dynamic structure of a prokaryotic cell. Structure of cell membrane ➢The structure of bacterial plasma membrane is that of unit membrane, i.e., a fluid phospholipid bilayer, composed of phospholipids (40%) and peripheral and integral proteins (60%) molecules. ➢The phospholipids of bacterial cell membranes do not contain sterols as in eukaryotes, but instead consist of saturated or monounsaturated fatty acids (rarely, polyunsaturated fatty acids). ➢Many bacteria contain sterol-like molecules called hopanoids. ➢The hopanoids most likely stabilize the bacterial cytoplasmic membrane. ➢The phospholipids are amphoteric molecules with a polar hydrophilic glycerol "head" attached via an ester bond to two non-polar hydrophobic fatty acid tails. ➢The phospholipid bilayer is arranged such that the polar ends of the molecules form the outermost and innermost surface of the membrane while the non-polar ends form the center of the membrane Fluid mosaic model ➢The plasma membrane contains proteins, sugars, and other lipids in addition to the phospholipids. ➢The model that describes the arrangement of these substances in lipid bilayer is called the fluid mosaic model ➢Dispersed within the bilayer are various structural and enzymatic proteins, which carry out most membrane functions. ➢Some membrane proteins are located and function on one side or another of the membrane (peripheral proteins).
    [Show full text]
  • 126.-In-Vitro-Prototyping-Of-Limonene-Biosynthesis.Pdf
    Metabolic Engineering 61 (2020) 251–260 Contents lists available at ScienceDirect Metabolic Engineering journal homepage: www.elsevier.com/locate/meteng In vitro prototyping of limonene biosynthesis using cell-free protein synthesis T ∗ Quentin M. Dudley1, Ashty S. Karim, Connor J. Nash, Michael C. Jewett Department of Chemical and Biological Engineering and Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA ARTICLE INFO ABSTRACT Keywords: Metabolic engineering of microorganisms to produce sustainable chemicals has emerged as an important part of Cell-free metabolic engineering the global bioeconomy. Unfortunately, efforts to design and engineer microbial cell factories are challenging Limonene because design-build-test cycles, iterations of re-engineering organisms to test and optimize new sets of enzymes, iPROBE are slow. To alleviate this challenge, we demonstrate a cell-free approach termed in vitro Prototyping and Rapid Cell-free metabolic pathway prototyping Optimization of Biosynthetic Enzymes (or iPROBE). In iPROBE, a large number of pathway combinations can be Cell-free protein synthesis rapidly built and optimized. The key idea is to use cell-free protein synthesis (CFPS) to manufacture pathway Synthetic biology enzymes in separate reactions that are then mixed to modularly assemble multiple, distinct biosynthetic path- ways. As a model, we apply our approach to the 9-step heterologous enzyme pathway to limonene in extracts from Escherichia coli. In iterative cycles of design, we studied the impact of 54 enzyme homologs, multiple enzyme levels, and cofactor concentrations on pathway performance. In total, we screened over 150 unique sets of enzymes in 580 unique pathway conditions to increase limonene production in 24 h from 0.2 to 4.5 mM (23–610 mg/L).
    [Show full text]
  • Thermococcus Piezophilus Sp. Nov., a Novel Hyperthermophilic And
    1 Systematic and Applied Microbiology Achimer October 2016, Volume 39, Issue 7, Pages 440-444 http://dx.doi.org/10.1016/j.syapm.2016.08.003 http://archimer.ifremer.fr http://archimer.ifremer.fr/doc/00348/45949/ © 2016 Elsevier GmbH. All rights reserved. Thermococcus piezophilus sp. nov., a novel hyperthermophilic and piezophilic archaeon with a broad pressure range for growth, isolated from a deepest hydrothermal vent at the Mid-Cayman Rise ✯ Dalmasso Cécile 1, 2, 3, Oger Philippe 4, Selva Gwendoline 1, 2, 3, Courtine Damien 1, 2, 3, L'Haridon Stéphane 1, 2, 3, Garlaschelli Alexandre 1, 2, 3, Roussel Erwan 1, 2, 3, Miyazaki Junichi 5, Reveillaud Julie 1, 2, 3, Jebbar Mohamed 1, 2, 3, Takai Ken 5, Maignien Lois 1, 2, 3, Alain Karine 1, 2, 3, * 1 Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM) − UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Place Nicolas Copernic, F-29280 Plouzané, France 2 CNRS, IUEM − UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Place Nicolas Copernic, F-29280 Plouzané, France 3 Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Technopôle Pointe du diable, F-29280 Plouzané, France 4 Université de Lyon, INSA Lyon, CNRS UMR 5240, 11 Avenue Jean Capelle, F-69621 Villeurbanne, France 5 Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan * Corresponding author : Karine Alain, email address : [email protected] ✯ Note: The EMBL/GenBank/DDBJ 16S rRNA gene sequence accession number of strain CDGST is LN 878294.
    [Show full text]
  • Hydrogen Isotope Fractionation in Lipids of the Methane-Oxidizing Bacterium Methylococcus Capsulatus
    Geochimica et Cosmochimica Acta, Vol. 66, No. 22, pp. 3955–3969, 2002 Copyright © 2002 Elsevier Science Ltd Pergamon Printed in the USA. All rights reserved 0016-7037/02 $22.00 ϩ .00 PII S0016-7037(02)00981-X Hydrogen isotope fractionation in lipids of the methane-oxidizing bacterium Methylococcus capsulatus 1, 2 3 1 ALEX L. SESSIONS, *LINDA L. JAHNKE, ARNDT SCHIMMELMANN, and JOHN M. HAYES 1Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA 2Exobiology Branch, NASA-Ames Research Center, Moffett Field, CA 94035, USA 3Biogeochemical Laboratories, Department of Geological Sciences, Indiana University, Bloomington, IN 47405, USA (Received December 10, 2001; accepted in revised form June 7, 2002) Abstract—Hydrogen isotopic compositions of individual lipids from Methylococcus capsulatus, an aerobic, methane-oxidizing bacterium, were analyzed by hydrogen isotope-ratio-monitoring gas chromatography–mass spectrometry (GC-MS). The purposes of the study were to measure isotopic fractionation factors between methane, water, and lipids and to examine the biochemical processes that determine the hydrogen isotopic composition of lipids. M. capsulatus was grown in six replicate cultures in which the ␦D values of methane and water were varied independently. Measurement of concomitant changes in ␦D values of lipids allowed estimation of the proportion of hydrogen derived from each source and the isotopic fractionation associated with the utilization of each source. All lipids examined, including fatty acids, sterols, and hopanols, derived 31.4 Ϯ 1.7% of their hydrogen from methane. This was apparently true whether the cultures were harvested during exponential or stationary phase. Examination of the relevant biochemical pathways indicates that no hydrogen is transferred directly (with C-H bonds intact) from methane to lipids.
    [Show full text]
  • A Distinct Pathway for Tetrahymanol Synthesis in Bacteria
    A distinct pathway for tetrahymanol synthesis in bacteria Amy B. Banta1, Jeremy H. Wei1, and Paula V. Welander2 Department of Earth System Science, Stanford University, Stanford, CA 94305 Edited by John M. Hayes, Woods Hole Oceanographic Institution, Berkeley, CA, and approved September 25, 2015 (received for review June 11, 2015) Tetrahymanol is a polycyclic triterpenoid lipid first discovered in the physiological role of tetrahymanol in bacteria is unknown. Recent ciliate Tetrahymena pyriformis whose potential diagenetic product, studies have highlighted increased tetrahymanol production in gammacerane, is often used as a biomarker for water column strat- R. palustris TIE-1 under certain physiological conditions (e.g., ification in ancient ecosystems. Bacteria are also a potential source photoautotrophic growth) and also when cellular hopanoid lipid of tetrahymanol, but neither the distribution of this lipid in extant profiles are altered in gene deletion mutants (22, 23), but the bacteria nor the significance of bacterial tetrahymanol synthesis for physiological significance of these changes is not known. Further, interpreting gammacerane biosignatures is known. Here we couple the biochemical mechanism of tetrahymanol synthesis in bacteria comparative genomics with genetic and lipid analyses to link a pro- is unclear. In ciliates, squalene-tetrahymanol cyclase (Stc) cata- tein of unknown function to tetrahymanol synthesis in bacteria. This tetrahymanol synthase (Ths) is found in a variety of bacterial lyzes the cyclization of squalene directly to tetrahymanol (24), but genomes, including aerobic methanotrophs, nitrite-oxidizers, and neither of the two known bacterial tetrahymanol producers harbor sulfate-reducers, and in a subset of aquatic and terrestrial metage- a copy of Stc (10, 24).
    [Show full text]
  • Hopanoids Play a Role in Membrane Integrity and Ph Homeostasis in Rhodopseudomonas Palustris TIE-1ᰔ† Paula V
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Caltech Authors JOURNAL OF BACTERIOLOGY, Oct. 2009, p. 6145–6156 Vol. 191, No. 19 0021-9193/09/$08.00ϩ0 doi:10.1128/JB.00460-09 Copyright © 2009, American Society for Microbiology. All Rights Reserved. Hopanoids Play a Role in Membrane Integrity and pH Homeostasis in Rhodopseudomonas palustris TIE-1ᰔ† Paula V. Welander,1 Ryan C. Hunter,1 Lichun Zhang,2 Alex L. Sessions,2 Roger E. Summons,3 and Dianne K. Newman1,3,4* Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 68-380, Cambridge, Massachusetts 021391; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, MC100-23, 1200 E. California Boulevard, Pasadena, California 911252; Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E25-633, Cambridge, Massachusetts 021393; and Howard Hughes Medical Institute, 4 77 Massachusetts Avenue, 68-171, Cambridge, Massachusetts 02139 Downloaded from Received 3 April 2009/Accepted 6 July 2009 Sedimentary hopanes are pentacyclic triterpenoids that serve as biomarker proxies for bacteria and certain bacterial metabolisms, such as oxygenic photosynthesis and aerobic methanotrophy. Their parent molecules, the bacteriohopanepolyols (BHPs), have been hypothesized to be the bacterial equivalent of sterols. However, the actual function of BHPs in bacterial cells is poorly understood. Here, we report the physiological study of jb.asm.org a mutant in Rhodopseudomonas palustris TIE-1 that is unable to produce any hopanoids. The deletion of the gene encoding the squalene-hopene cyclase protein (Shc), which cyclizes squalene to the basic hopene struc- ture, resulted in a strain that no longer produced any polycyclic triterpenoids.
    [Show full text]
  • Update of the LIPID MAPS Comprehensive Classification System for Lipids1
    Update of the LIPID MAPS comprehensive classification system for lipids1 † Eoin Fahy,* Shankar Subramaniam, Robert C. Murphy,§ Masahiro Nishijima,** †† ††† Christian R. H. Raetz, Takao Shimizu,§§ Friedrich Spener,*** Gerrit van Meer, Michael J. O. Wakelam,§§§ and Edward A. Dennis2,**** † San Diego Supercomputer Center,* Department of Bioengineering, and Department of Chemistry and Biochemistry and Department of Pharmacology of the School of Medicine,**** University of California, San Diego, La Jolla, CA 92093-0505; Department of Pharmacology,§ University of Colorado Denver, Aurora, CO 80045-0598; National Institute of Health Sciences,** Setagaya-ku, Tokyo 158-8501, Japan; Department †† of Biochemistry, Duke University Medical Center, Durham, NC 27710; Department of Biochemistry and Molecular Biology,§§ Faculty of Medicine, University of Tokyo, Tokyo 113-0033, Japan; Department of Molecular Biosciences,*** University of Graz, 8010 Graz, Austria; Bijvoet Center and Institute of ††† Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands; and The Babraham Institute,§§§ Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom Abstract In 2005, the International Lipid Classification Nomenclature Committee (ILCNC) developed a “Com- and Nomenclature Committee under the sponsorship of prehensive Classification System for Lipids” that was pub- the LIPID MAPS Consortium developed and established a lished in 2005 (1). For the purpose of classification, we “ ” Comprehensive Classification System for Lipids based define lipids as hydrophobic or amphipathic small mole- on well-defined chemical and biochemical principles and cules that may originate entirely or in part by carbanion- using an ontology that is extensible, flexible, and scalable. This classification system, which is compatible with contem- based condensations of thioesters (fatty acyls, glycerolipids, porary databasing and informatics needs, has now been ac- glycerophospholipids, sphingolipids, saccharolipids, and cepted internationally and widely adopted.
    [Show full text]
  • Menthol Smokers: Metabolomic Profiling and Smoking Behavior
    Published OnlineFirst September 14, 2016; DOI: 10.1158/1055-9965.EPI-16-0124 Research Article Cancer Epidemiology, Biomarkers Menthol Smokers: Metabolomic Profiling & Prevention and Smoking Behavior Ping-Ching Hsu1,2, Renny S. Lan1, Theodore M. Brasky1, Catalin Marian1,3, Amrita K. Cheema4, Habtom W. Ressom4, Christopher A. Loffredo4, Wallace B. Pickworth5, and Peter G. Shields1 Abstract Background: The use of menthol in cigarettes and mar- tial least squares-discriminant analysis (PLS-DA) was carried keting is under consideration for regulation by the FDA. out for the classification of metabolomics profiles. However, the effects of menthol on smoking behavior and Results: MG boost was positively correlated with CO boost, carcinogen exposure have been inconclusive. We previously nicotine boost, average puff volume, puff duration, and total reported metabolomic profiling for cigarette smokers, and smoke exposure. Classification using PLS-DA, MG was the top novelly identified a menthol-glucuronide (MG) as the most metabolite discriminating metabolome of menthol versus non- significant metabolite directly related to smoking. Here, MG menthol smokers. Among menthol smokers, 42 metabolites were is studied in relation to smoking behavior and metabolomic significantly correlated with MG boost, which linked to cellular profiles. functions, such as of cell death, survival, and movement. Methods: This is a cross-sectional study of 105 smokers who Conclusions: Plasma MG boost is a new smoking behavior smoked two cigarettes in the laboratory one hour apart. Blood biomarker that may provide novel information over self-reported nicotine, MG, and exhaled carbon monoxide (CO) boosts were use of menthol cigarettes by integrating different smoking mea- determined (the difference before and after smoking).
    [Show full text]
  • Development of Compound-Specific Hydrogen Isotope Ratio Analysis Of
    Development of Compound-Specific Hydrogen Isotope Ratio Analysis of Biomarkers and their Application as New Proxy for Reconstruction of Palaeoenvironment and Palaeoclimate Entwicklung komponentenspezifischer Wasserstoffisotopen- Analyse von Biomarkern und deren Anwendung als neuartiger Proxy zur Rekonstruktion von Paläoumwelt und Paläoklima Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakultät der Friedrich-Schiller-Universität Jena von Diplom Geologe Jens Radke geboren am 20.2.1967 in Bremerhaven Gutachter: 1. Prof.Dr.R.Gaupp 2. PD.Dr.G.Gleixner Tag der öffentlichen Verteidigung: 18.1.2006 Printed on 100% recycled paper (after ISO9706, 133 CIE, DIN 6738 LDK 24-85) Content Content ABSTRACT KURZFASSUNG ABBREVIATIONS 1 INTRODUCTION ......................................................................................................... 1 2 FRACTIONATION OF WATER ISOTOPES IN THE ENVIRONMENT ........................................ 2 2.1 Fractionation of water isotopes in the climate system......................................... 2 2.2 Fractionation of hydrogen in the biosynthesis of plant biomass.......................... 3 3 SEDIMENTS AND METHODS........................................................................................ 6 3.1 Sediment samples and stratigraphic framework ................................................. 6 3.2 Sample preparation for bulk and compound specific analysis ............................ 8 3.2.1 Sample
    [Show full text]
  • Plant-Derived Triterpenoid Biomarkers and Their Applications In
    Plant-derived triterpeonid biomarkers: chemotaxonomy, geological alteration, and vegetation reconstruction Res. Org. Geochem. 35, 11 − 35 (2019) Reviews-2015 Taguchi Award Plant-derived triterpenoid biomarkers and their applications in paleoenvironmental reconstructions: chemotaxonomy, geological alteration, and vegetation reconstruction Hideto Nakamura＊ （Received November 22, 2019; Accepted December 27, 2019） Abstract Triterpenoids and their derivatives are ubiquitous in sediment samples. Land plants are major sources of non- hopanoid triterpenoids; these terpenoids comprise a vast number of chemotaxonomically distinct biomolecules. Hence, geologically occurring plant-derived triterpenoids (geoterpenoids) potentially record unique characteristics of paleovegetation and sedimentary environments, and serve as source-specific markers for studying paleoenviron- ments. This review is aimed at explaining the origin of triterpenoids and their use as biomarkers in elucidating paleo- environments. Herein, application of plant-derived triterpenoids is discussed in terms of: (i) their biosynthetic pathways. These compounds are primarily synthesized via oxidosqualene cyclase (OSCs) and serve as precursors for a variety of membrane sterols and steroid hormones. Studies on OSCs and resulting compounds have helped elucidate the diversity and origin of the parent terpenoids. (ii) their chemotaxonomic significance. Geochemically important classes of triterpenoid skeletons are useful in gathering and substantiating information on botanical ori- gin of
    [Show full text]
  • Fats and Fatty Acid in Human Nutrition
    ISSN 0254-4725 91 FAO Fats and fatty acids FOOD AND NUTRITION PAPER in human nutrition Report of an expert consultation 91 Fats and fatty acids in human nutrition − Report of an expert consultation Knowledge of the role of fatty acids in determining health and nutritional well-being has expanded dramatically in the past 15 years. In November 2008, an international consultation of experts was convened to consider recent scientific developments, particularly with respect to the role of fatty acids in neonatal and infant growth and development, health maintenance, the prevention of cardiovascular disease, diabetes, cancers and age-related functional decline. This report will be a useful reference for nutrition scientists, medical researchers, designers of public health interventions and food producers. ISBN 978-92-5-106733-8 ISSN 0254-4725 9 7 8 9 2 5 1 0 6 7 3 3 8 Food and Agriculture I1953E/1/11.10 Organization of FAO the United Nations FAO Fats and fatty acids FOOD AND NUTRITION in human nutrition PAPER Report of an expert consultation 91 10 − 14 November 2008 Geneva FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2010 The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned.
    [Show full text]
  • (IPP)-Bypass Mevalonate Pathways for Isopentenol Production
    Metabolic Engineering 34 (2016) 25–35 Contents lists available at ScienceDirect Metabolic Engineering journal homepage: www.elsevier.com/locate/ymben Original Research Article Isopentenyl diphosphate (IPP)-bypass mevalonate pathways for isopentenol production Aram Kang a,b, Kevin W. George a,b, George Wang a,b, Edward Baidoo a,b, Jay D. Keasling a,b,c,d, Taek Soon Lee a,b,n a Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA 94608, USA b Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA c Department of Bioengineering, University of California, Berkeley, CA 94720, USA d Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA article info abstract Article history: Branched C5 alcohols are promising biofuels with favorable combustion properties. A mevalonate (MVA)- Received 8 September 2015 based isoprenoid biosynthetic pathway for C5 alcohols was constructed in Escherichia coli using genes Received in revised form from several organisms, and the pathway was optimized to achieve over 50% theoretical yield. Although 2 November 2015 the MVA pathway is energetically less efficient than the native methylerythritol 4-phosphate (MEP) Accepted 7 December 2015 pathway, implementing the MVA pathway in bacterial hosts such as E. coli is advantageous due to its lack Available online 17 December 2015 of endogenous regulation. The MVA and MEP pathways intersect at isopentenyl diphosphate (IPP), the Keywords: direct precursor to isoprenoid-derived C5 alcohols and initial precursor to longer chain terpenes, which Isopentenol makes independent regulation of the pathways difficult. In pursuit of the complete “decoupling” of the Isoprenol MVA pathway from native cellular regulation, we designed novel IPP-bypass MVA pathways for C Mevalonate pathway 5 alcohol production by utilizing promiscuous activities of two enzymes, phosphomevalonate decarbox- Biofuel Phosphomevalonate decarboxylase ylase (PMD) and an E.
    [Show full text]