Chapter 23 Nucleic Acids
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A Guardian of the Development of Diabetic Retinopathy
Diabetes Volume 67, April 2018 745 Sirt1: A Guardian of the Development of Diabetic Retinopathy Manish Mishra, Arul J. Duraisamy, and Renu A. Kowluru Diabetes 2018;67:745–754 | https://doi.org/10.2337/db17-0996 Diabetic retinopathy is a multifactorial disease, and the molecular mechanism of the development of diabetic reti- exact mechanism of its pathogenesis remains obscure. nopathy remains to be established. Sirtuin 1 (Sirt1), a multifunctional deacetylase, is impli- Sirtuin 1 (Sirt1), a member of the silent information cated in the regulation of many cellular functions and in regulator 2 family, is a class III histone deacetylase that gene transcription, and retinal Sirt1 is inhibited in di- interacts with target proteins and regulates many cellular abetes. Our aim was to determine the role of Sirt1 in the functions including cell proliferation, apoptosis, and inflam- development of diabetic retinopathy and to elucidate the matory responses (6–8). Sirt1 is mainly a nuclear protein, Sirt1 molecular mechanism of its downregulation. Using - and its activity depends on cellular NAD availability (9). It is overexpressing mice that were diabetic for 8 months, Sirt1 expressed throughout the retina, and upregulation of COMPLICATIONS structural, functional, and metabolic abnormalities were protects against various ocular diseases including retinal investigated in vascular and neuronal retina. The role of degeneration, cataract, and optic neuritis (10). Our previous epigenetics in Sirt1 transcriptional suppression was inves- work has shown that Sirt1 expression and activity are de- tigated in retinal microvessels. Compared with diabetic wild-type mice, retinal vasculature from diabetic Sirt1 mice creased in the retina and its capillary cells in diabetes (11). -
Cytosine-Rich
Proc. Natl. Acad. Sci. USA Vol. 93, pp. 12116-12121, October 1996 Chemistry Inter-strand C-H 0 hydrogen bonds stabilizing four-stranded intercalated molecules: Stereoelectronic effects of 04' in cytosine-rich DNA (base-ribose stacking/sugar pucker/x-ray crystallography) IMRE BERGERt, MARTIN EGLIt, AND ALEXANDER RICHt tDepartment of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139; and tDepartment of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611-3008 Contributed by Alexander Rich, August 19, 1996 ABSTRACT DNA fragments with stretches of cytosine matic cytosine ring systems from intercalated duplexes (Fig. 1A). residues can fold into four-stranded structures in which two Second, unusually close intermolecular contacts between sugar- parallel duplexes, held together by hemiprotonated phosphate backbones in the narrow grooves are observed, with cytosine-cytosine+ (C C+) base pairs, intercalate into each inter-strand phosphorus-phosphorus distances as close as 5.9 A other with opposite polarity. The structural details of this (5), presumably resulting in unfavorable electrostatic repulsion if intercalated DNA quadruplex have been assessed by solution not shielded by cations or bridging water molecules. NMR and single crystal x-ray diffraction studies of cytosine- The close contacts between pairs of antiparallel sugar- rich sequences, including those present in metazoan telo- phosphate backbones from the two interdigitated duplexes are meres. A conserved feature of these structures is the absence a unique characteristic of four-stranded intercalated DNA. of stabilizing stacking interactions between the aromatic ring Indeed, the unusually strong nuclear overhauser effect signals systems of adjacent C-C+ base pairs from intercalated du- between inter-strand sugar Hi' protons and Hi' and H4' plexes. -
Watson Andcrick1 Consists of Two Polynucleotide Chains, Which Are
73474CHEMISTRY: DONOHUE AND STENT PiRoc. N. A. S. 2 E. Klenk, Z. physiol. Chem., 268, 50,1941. 3 K. Meyer, Advances in Protein Chemistry, 2, 249, 1945. 4K. Meyer, E. Chaffee, G. L. Hobby, and M. H. Dawson, J. Exptl. Med., 73, 309, 1941. 5 M. M. Rapport, A. Linker, and K. Meyer, J. Biol. Chem., 192, 283, 1951. 6 J. Werner and L. Odin, Acta Soc. med. Upsaliensis, 57, 230, 1952. 7 L. A. Elson and W. T. J. Morgan, Biochem. J., 27, 1924, 1933. 8 S. Gardell, Acta chem. Scand., 7, 207, 1953. 9 M. McLeod and R. Robison, Biochem. J., 23, 517, 1929. 10 0. Schales and S. S. Schales, Arch. Biochem., 8, 285, 1948. 11 We are indebted to Dr. Calderon Howe, of the Department of Microbiology, Columbia Uni- versity College of Physicians and Surgeons, New York, for these studies. 12 We wish to thank Dr. Baruch S. Blumberg for performing the ultracentrifugation studies. 13 G. Blix, E. Lindberg, L. Odin, and I. Werner, Nature, 175, 340, 1955. 14 W. T. J. Morgan and L. A. Elson, Biochem. J., 28, 988, 1934. 16 A. Gottschalk, Yale J. Biol. and Med., 28, 525, 1956. 16 E. Klenk, H. Faillard, F. Weygand, and H. H. Schbne, Z. physiol. Chem., 304, 35, 1956. 17 J. S. D. Bacon and J. Edelman, Biochem. J., 48, 114, 1951. 18 S. M. Partridge, Biochem. J., 42, 238, 1948. 19 P. J. Stoffyn and R. W. Jeanloz, Arch. Biochem., 52, 373, 1954. 20 J. Immers and E. Vasseur, Acta chem. Scand., 6, 363, 1952. -
REDUCTION of PURINE CONTENT in COMMONLY CONSUMED MEAT PRODUCTS THROUGH RINSING and COOKING by Anna Ellington (Under the Directio
REDUCTION OF PURINE CONTENT IN COMMONLY CONSUMED MEAT PRODUCTS THROUGH RINSING AND COOKING by Anna Ellington (Under the direction of Yen-Con Hung) Abstract The commonly consumed meat products ground beef, ground turkey, and bacon were analyzed for purine content before and after a rinsing treatment. The rinsing treatment involved rinsing the meat samples using a wrist shaker in 5:1 ratio water: sample for 2 or 5 minutes then draining or centrifuging to remove water. The total purine content of 25% fat ground beef significantly decreased (p<0.05) from 8.58 mg/g protein to a range of 5.17-7.26 mg/g protein after rinsing treatments. After rinsing and cooking an even greater decrease was seen ranging from 4.59-6.32 mg/g protein. The total purine content of 7% fat ground beef significantly decreased from 7.80 mg/g protein to a range of 5.07-5.59 mg/g protein after rinsing treatments. A greater reduction was seen after rinsing and cooking in the range of 4.38-5.52 mg/g protein. Ground turkey samples showed no significant changes after rinsing, but significant decreases were seen after rinsing and cooking. Bacon samples showed significant decreases from 6.06 mg/g protein to 4.72 and 4.49 after 2 and 5 minute rinsing and to 4.53 and 4.68 mg/g protein after 2 and 5 minute rinsing and cooking. Overall, this study showed that rinsing foods in water effectively reduces total purine content and subsequent cooking after rinsing results in an even greater reduction of total purine content. -
Differential Effects of the Poly (ADP-Ribose)Polymerase (PARP
British Journal of Cancer (2001) 84(1), 106–112 © 2001 Cancer Research Campaign doi: 10.1054/ bjoc.2000.1555, available online at http://www.idealibrary.com on http://www.bjcancer.com Differential effects of the poly (ADP-ribose) polymerase (PARP) inhibitor NU1025 on topoisomerase I and II inhibitor cytotoxicity in L1210 cells in vitro KJ Bowman*, DR Newell, AH Calvert and NJ Curtin Cancer Research Unit, University of Newcastle upon Tyne Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK Summary The potent novel poly(ADP-ribose) polymerase (PARP) inhibitor, NU1025, enhances the cytotoxicity of DNA-methylating agents and ionizing radiation by inhibiting DNA repair. We report here an investigation of the role of PARP in the cellular responses to inhibitors of topoisomerase I and II using NU1025. The cytotoxicity of the topoisomerase I inhibitor, camptothecin, was increased 2.6-fold in L1210 cells by co-incubation with NU1025. Camptothecin-induced DNA strand breaks were also increased 2.5-fold by NU1025 and exposure to camptothecin-activated PARP. In contrast, NU1025 did not increase the DNA strand breakage or cytotoxicity caused by the topoisomerase II inhibitor etoposide. Exposure to etoposide did not activate PARP even at concentrations that caused significant levels of apoptosis. Taken together, these data suggest that potentiation of camptothecin cytotoxicity by NU1025 is a direct result of increased DNA strand breakage, and that activation of PARP by camptothecin-induced DNA damage contributes to its repair and consequently cell survival. However, in L1210 cells at least, it would appear that PARP is not involved in the cellular response to etoposide-mediated DNA damage. -
Alternative Biochemistries for Alien Life: Basic Concepts and Requirements for the Design of a Robust Biocontainment System in Genetic Isolation
G C A T T A C G G C A T genes Review Alternative Biochemistries for Alien Life: Basic Concepts and Requirements for the Design of a Robust Biocontainment System in Genetic Isolation Christian Diwo 1 and Nediljko Budisa 1,2,* 1 Institut für Chemie, Technische Universität Berlin Müller-Breslau-Straße 10, 10623 Berlin, Germany; [email protected] 2 Department of Chemistry, University of Manitoba, 144 Dysart Rd, 360 Parker Building, Winnipeg, MB R3T 2N2, Canada * Correspondence: [email protected] or [email protected]; Tel.: +49-30-314-28821 or +1-204-474-9178 Received: 27 November 2018; Accepted: 21 December 2018; Published: 28 December 2018 Abstract: The universal genetic code, which is the foundation of cellular organization for almost all organisms, has fostered the exchange of genetic information from very different paths of evolution. The result of this communication network of potentially beneficial traits can be observed as modern biodiversity. Today, the genetic modification techniques of synthetic biology allow for the design of specialized organisms and their employment as tools, creating an artificial biodiversity based on the same universal genetic code. As there is no natural barrier towards the proliferation of genetic information which confers an advantage for a certain species, the naturally evolved genetic pool could be irreversibly altered if modified genetic information is exchanged. We argue that an alien genetic code which is incompatible with nature is likely to assure the inhibition of all mechanisms of genetic information transfer in an open environment. The two conceivable routes to synthetic life are either de novo cellular design or the successive alienation of a complex biological organism through laboratory evolution. -
Human Hypoxanthine (Guanine) Phosphoribosyltransferase: An
Proc. NatL Acad. Sci. USA Vol. 80, pp. 870-873, Febriary 1983 Medical Sciences Human hypoxanthine (guanine) phosphoribosyltransferase: An amino acid substitution in a mutant form of the enzyme isolated from a patient with gout (reverse-phase HPLC/peptide mapping/mutant enzyme) JAMES M. WILSON*t, GEORGE E. TARRt, AND WILLIAM N. KELLEY*t Departments of *Internal Medicine and tBiological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 Communicated by James B. Wyngaarden, November 3, 1982 ABSTRACT We have investigated the molecular basis for a tration ofenzyme protein. in both erythrocytes (3) and lympho- deficiency ofthe enzyme hypoxanthine (guanine) phosphoribosyl- blasts (4); (ii) a normal Vm., a normal Km for 5-phosphoribosyl- transferase (HPRT; IMP:pyrophosphate-phosphoribosyltransfer- 1-pyrophosphate, and a 5-fold increased Km for hypoxanthine ase, EC 2.4.2.8) in a patient with a severe form of gout. We re-. (unpublished data); (iii) a normal isoelectric point (3, 4) and ported in previous studies the isolation of a unique structural migration during nondenaturing polyacrylamide gel electro- variant of HPRT from this patient's erythrocytes and cultured phoresis (4); and (iv) -an apparently smaller subunit molecular lymphoblasts. This enzyme variant, which is called HPRTOnd0., weight as evidenced by an increased mobility during Na- is characterized by a decreased concentration of HPRT protein DodSO4/polyacrylamide gel electrophoresis (3, 4). in erythrocytes and lymphoblasts, a normal Vm.., a 5-fold in- Our study ofthe tryptic peptides and amino acid composition creased Km for hypoxanthine, a normal isoelectric point, and an of apparently smaller subunit molecular weight. Comparative pep- HPRTLondon revealed a single amino acid substitution (Ser tide mapping-experiments revealed a single abnormal tryptic pep- Leu) at position 109. -
Evidence Suggests That RNA Was a Product of Evolution
Putting together the pieces: Evidence suggests that RNA was a product of evolution Brian Cafferty and Nicholas V. Hud, Georgia Institute of Technology, Atlanta, GA, USA For the past four decades, prebiotic chemists have attempted to demonstrate the formation of RNA polymers by plausible prebiotic reactions. There have been notable advances, but to be certain, the spontaneous formation of RNA remains a grand challenge in origins of life research. From a different perspective, there are reasons to seriously consider the possibility that RNA is a product of evolution. If so, there may have never been a prebiotic mechanism that produced RNA polymers. We subscribe to this latter view and hypothesize that RNA is the penultimate member of continuous lineage of genetic polymers, with DNA being the ultimate member of this lineage. In this essay, we briefly summarize the case for why RNA is likely the descendant of one or more pre-RNA polymers that spontaneous assembled on the prebiotic earth. Nucleosides are each an assemblage of a nucleobase and a ribose sugar, whereas nucleotides, the monomeric units of RNA, are phosphorylated nucleosides (Figure 1). Prebiotic chemists have typically sought to form RNA in a seQuential fashion, starting with the formation of nucleotides, followed by their polymerization (Figure 1). However, of the four canonical RNA bases (adenine, cytosine, guanine, uracil), only adenine has been found to react with ribose in a model prebiotic reaction to produce nucleosides in appreciable yields (i.e., about 2%). The other three canonical nucleobases do not produce nucleosides when dried and heated with ribose. This apparent roadblock in RNA synthesis motivated the Orgel laboratory and, more recently, Sutherland and co-workers, to investigate the possibility that the nucleobases were first formed on a pre-existing sugar. -
An O(N5) Algorithm for MFE Prediction of Kissing Hairpins and 4-Chains in Nucleic Acids
JOURNAL OF COMPUTATIONAL BIOLOGY Volume 16, Number 6, 2009 # Mary Ann Liebert, Inc. Pp. 803–815 DOI: 10.1089/cmb.2008.0219 An O(n5) Algorithm for MFE Prediction of Kissing Hairpins and 4-Chains in Nucleic Acids HO-LIN CHEN,1 ANNE CONDON,2 and HOSNA JABBARI2 ABSTRACT Efficient methods for prediction of minimum free energy (MFE) nucleic secondary struc- tures are widely used, both to better understand structure and function of biological RNAs and to design novel nano-structures. Here, we present a new algorithm for MFE secondary structure prediction, which significantly expands the class of structures that can be handled in O(n5) time. Our algorithm can handle H-type pseudoknotted structures, kissing hairpins, and chains of four overlapping stems, as well as nested substructures of these types. Key words: kissing hairpins, pseudoknot, RNA, secondary structure prediction. 1. INTRODUCTION ur knowledge of the amazing variety of functions played by RNA molecules in the cell Ocontinues to expand, with the functions determined in part by structure (Lee et al., 1997). Additionally, DNA and RNA sequences are designed to form novel structures for a wide range of applications, such as algorithmic DNA self-assembly (He et al., 2008; Rothemund et al., 2004), detection of low concentrations of other molecules of interest (Dirks and Pierce, 2004) or to exhibit motion (Simmel and Dittmer, 2005). In order to improve our ability to determine function from DNA or RNA sequences, and also to aid in the design of nucleic acids with novel structural or functional properties, accurate and efficient methods for predicting nucleic acid structure are very valuable. -
Inhibition by Cyclic Guanosine 3':5'-Monophosphate of the Soluble DNA Polymerase Activity, and of Partially Purified DNA Polymer
Inhibition by Cyclic Guanosine 3':5'-Monophosphate of the Soluble DNA Polymerase Activity, and of Partially Purified DNA Polymerase A (DNA Polymerase I) from the Yeast Saccharomyces cere visiae Hans Eckstein Institut für Physiologische Chemie der Universität, Martinistr. 52-UKE, D-2000 Hamburg 20 Z. Naturforsch. 36 c, 813-819 (1981); received April 16/July 2, 1981 Dedicated to Professor Dr. Joachim Kühnauon the Occasion of His 80th Birthday cGMP, DNA Polymerase Activity, DNA Polymerase A, DNA Polymerase I, Baker’s Yeast DNA polymerase activity from extracts of growing yeast cells is inhibited by cGMP. Experiments with partially purified yeast DNA polymerases show, that cGMP inhibits DNA polymerase A (DNA polymerase I from Chang), which is the main component of the soluble DNA polymerase activity in yeast extracts, by competing for the enzyme with the primer- template DNA. Since the enzyme is not only inhibited by 3',5'-cGMP, but also by 3',5'-cAMP, the 3': 5'-phosphodiester seems to be crucial for the competition between cGMP and primer. This would be inconsistent with the concept of a 3'-OH primer binding site in the enzyme. The existence of such a site in the yeast DNA polymerase A is indicated from studies with various purine nucleoside monophosphates. When various DNA polymerases are compared, inhibition by cGMP seems to be restricted to those enzymes, which are involved in DNA replication. DNA polymerases with an associated nuclease activity are not inhibited, DNA polymerase B from yeast is even activated by cGMP. Though some relations between the cGMP effect and the presumed function of the enzymes in the living cell are apparent, the biological meaning of the observations in general remains open. -
Gout: a Low-Purine Diet Makes a Difference
Patient HANDOUT Gout: A Low-Purine Diet Makes a Difference Gout occurs when high levels of uric acid in your blood cause crystals to form and build up around a joint. Your body produces uric acid when it breaks down purines. Purines occur naturally in your body, but you also get them from certain foods and drinks. By following a low-purine diet, you can help your body control the production of uric acid and lower your chances of having another gout attack. Purines are found in many healthy foods and drinks. The purpose of a low-purine diet is to lower the amount of purine that you consume each day. Avoid Beer High-Purine Foods Organ meats (e.g., liver, kidneys), bacon, veal, venison Anchovies, sardines, herring, scallops, mackerel Gravy (purines leach out of the meat during cooking so gravy made from drippings has a higher concentration of purines) Limit Moderate- Chicken, beef, pork, duck, crab, lobster, oysters, shrimp : 4-6 oz daily Purine Foods Liquor: Limit alcohol intake. There is evidence that risk of gout attack is directly related to level of alcohol consumption What Other Dietary Changes Can Help? • Choose low-fat or fat-free dairy products. Studies show that low- or non-fat milk and yogurt help reduce the chances of having a gout attack. • Drink plenty of fluids (especially water) which can help remove uric acid from your body. Avoid drinks sweetened with fructose such as soft drinks. • Eat more non-meat proteins such as legumes, nuts, seeds and eggs. • Eat more whole grains and fruits and vegetables and less refined carbohydrates, such as white bread and cakes. -
Expanding the Genetic Code Lei Wang and Peter G
Reviews P. G. Schultz and L. Wang Protein Science Expanding the Genetic Code Lei Wang and Peter G. Schultz* Keywords: amino acids · genetic code · protein chemistry Angewandte Chemie 34 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/anie.200460627 Angew. Chem. Int. Ed. 2005, 44,34–66 Angewandte Protein Science Chemie Although chemists can synthesize virtually any small organic molecule, our From the Contents ability to rationally manipulate the structures of proteins is quite limited, despite their involvement in virtually every life process. For most proteins, 1. Introduction 35 modifications are largely restricted to substitutions among the common 20 2. Chemical Approaches 35 amino acids. Herein we describe recent advances that make it possible to add new building blocks to the genetic codes of both prokaryotic and 3. In Vitro Biosynthetic eukaryotic organisms. Over 30 novel amino acids have been genetically Approaches to Protein encoded in response to unique triplet and quadruplet codons including Mutagenesis 39 fluorescent, photoreactive, and redox-active amino acids, glycosylated 4. In Vivo Protein amino acids, and amino acids with keto, azido, acetylenic, and heavy-atom- Mutagenesis 43 containing side chains. By removing the limitations imposed by the existing 20 amino acid code, it should be possible to generate proteins and perhaps 5. An Expanded Code 46 entire organisms with new or enhanced properties. 6. Outlook 61 1. Introduction The genetic codes of all known organisms specify the same functional roles to amino acid residues in proteins. Selectivity 20 amino acid building blocks. These building blocks contain a depends on the number and reactivity (dependent on both limited number of functional groups including carboxylic steric and electronic factors) of a particular amino acid side acids and amides, a thiol and thiol ether, alcohols, basic chain.