Chemical Composition of the Acrosomes of Ram Spermatozoa

Total Page:16

File Type:pdf, Size:1020Kb

Chemical Composition of the Acrosomes of Ram Spermatozoa CHEMICAL COMPOSITION OF THE ACROSOMES OF RAM SPERMATOZOA E. F. HARTREE and P. N. SRIVASTAVA A.R.C. Unit of Reproductive Physiology and Biochemistry, 307 Huntingdon Road, Cambridge {Received 27th May 1964) Summary. Material extracted from ram spermatozoa with 0\m=.\0125 n-NaOH was separated into lipid and glycoprotein fractions. By use of an anionic detergent (Hyamine 2389) acrosomes were separated from ram spermatozoa and also fractionated into lipid and glycoprotein. The chemical compositions of the two glycoprotein fractions, as well as of the two lipid fractions, show marked similarities. Taking into consideration the chemical changes that may occur during the isolation of these frac- tions it is deduced that they provide a reasonable approximation to the composition of the acrosomes. Ofthe amino acids glutamic acid predom- inates. The following sugars are present: mannose, galactose, fucose, glucosamine, galactosamine and sialic acid. The residue left after extract- ing ram spermatozoa with n-NaOH contains polysaccharide of which the constituent sugars are glucose, galactose and mannose. All the sialic acid of ram spermatozoa appears to be contained in the acrosome. The sialic acid content of the spermatozoa of other species has been measured and the possible role of sialic acid in sperm physiology is discussed. INTRODUCTION Clermont, Glegg & Leblond (1955) found that the component of the acrosome which is stained in the periodic acid-Schiff (pas) reaction could be removed from guinea-pig spermatozoa by extraction with 0-1 N-NaOH. Hathaway & Hartree (1963) showed that acrosomes can be removed from washed ram spermatozoa as effectively by 0-01 N-NaOH as by 0-1 N-NaOH; within that range of concentrations there was very little variation in the quantities of nitrogen and of orcinol-reactive sugar that passed into the alkaline extracts. This was taken as evidence that a discrete unit, the acrosome, was being dissolved. The possibility remained that material other than that present in the acrosome was simultaneously dissolved from the sperm cell in quantities which were also independent of the concentration of alkali. It was shown in the same paper that treatment of ram spermatozoa with hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide, ctab) caused membranous material, and in some cases apparently intact acrosomes, to be removed from the sperm head. Such detached elements, like the acrosomes of intact sperma¬ tozoa, were strongly stained by the pas and Giemsa techniques. 47 Downloaded from Bioscientifica.com at 09/30/2021 08:48:50AM via free access 48 E. F. Hartree and . Srivastava We have now examined the effects ofother detergents upon ram spermatozoa. We have improved the methods for detachment of morphologically intact acrosomes and have been able to obtain them as suspensions which are virtually free from spermatozoa. The chemical composition of such acrosomal prepara¬ tions, and that of the material extracted from spermatozoa by alkali, has been determined. The sialic acid content of the semen of a few other species has also been measured. MATERIALS AND METHODS Semen was collected twice weekly from a group of about twenty rams, and pooled. The spermatozoa were separated from the seminal plasma within 1 hr of collection and were washed with calcium-free Ringer solution as described by Hathaway & Hartree (1963). The final suspension was made up in Ringer solution to twice the original semen volume. Spermatozoa were stained with Giemsa solution as described by Hancock (1952) except that preparations were not fixed and the slides were left in the stain solution for 16 hr at 20° C. Bull and rabbit semen were dealt with in the same way. Epididymal bull semen was provided by Dr H. M. Dott and cock semen by Dr C. Polge. DETACHMENT OF ACROSOMES BY DETERGENTS A suspension of washed ram spermatozoa in Ringer solution was centrifuged and the cells were made up to the same volume with 0-9% sodium chloride (saline). Portions of this suspension were mixed with equal volumes of solutions of the detergents in saline and were incubated at 37° C for 45 min. Observations made on stained preparations of spermatozoa treated by such methods are given in Table 1. Teepol XL and ctab removed the great majority of acro¬ somes, but both acrosomes and tails showed serious damage. Manoxol OT and Hyamine 2389 gave better results : the former was more effective in removing acrosomes but the latter caused less damage to the tails (PI. 1, Fig. 1). When the Hyamine-containing suspension was centrifuged for 15 min at 1500 g the super¬ natant fluid contained shrunken but characteristically stained acrosomes (PI. 1, Fig. 2). Further experiments with Hyamine led to a procedure by which 70 to 90% of acrosomes could be detached without appreciable damage to the tails. This is described below (B). ISOLATION OF ACROSOMAL GLYCOPROTEIN FRACTIONS A. Isolation from an alkaline extract of spermatozoa A mixture of 40 ml of washed spermatozoa and 40 ml of 0-025 N-NaOH, having a pH of 11-4, was held at 37° C for 45 min and centrifuged at 6000g for 15 min. The almost clear supernatant fluid (75 ml) was brought to pH 6-5 with acetic acid and could be stored at —20° C if necessary. Each extract was mixed with four volumes of cold (—20° C) acetone, and centrifuged at 8000 g and 5° C for 10 min. The white sediment was suspended in about 10 ml of water and dialysed overnight at 5° C against 51. of distilled water. Lipid was removed from the dialysed solution by the procedure of Hartree & Mann (1961). The resulting precipitate was washed with chloroform and air-dried. This material Downloaded from Bioscientifica.com at 09/30/2021 08:48:50AM via free access PLATE 1 Magnification of spermatozoa: x920 in Figs. 1 and 2; x2200 in Figs. 3 and 4. All preparations were stained by the Giemsa method. Fig. 1. Ram spermatozoa treated with 0-025% Hyamine for 45 min at 37° C. Fig. 2. Shrunken acrosomes separated from suspension shown in Fig. 1. Fig. 3. As Fig. 1, using 0-05% Hyamine for 90 min. Fig. 4. Acrosomes separated from suspension shown in Fig. 3. (Facing p. 48) Downloaded from Bioscientifica.com at 09/30/2021 08:48:50AM via free access Chemical composition of ram acrosomes -a -o u 3 U S ( g •s 3|w S -S >s_bp ~3 "•¿ -a •S S c a S -a 5 c '> ta c o. OT3 " til 8" « ·ß.|c b s S s n u 1 ^ 5 ^ U d o « g a a-0 ¬ m3 ' ¡ OC S Su - 0 S « S c C u %r, sO ìn < ci rt SU tQ 9 »2 -û g o <3* T3 rt S '3 ei ^_Q - s« s P "e 9 S3 o. J3 "5 "3 ¬ I «fe ñ ü G M -à c c« M u c [ -t-» & 2- pu- .s « ¿--5^ •a-i?.? 3 S « * ; í S _. r! .a £ u 0 « 1 _, tZS iJJ O œ «- f-( "_ o a cm >,O.s .2* 3 V "o S m s -. o"S, -1 g-s 3 ai < Cß e H .rt t/j ss s 3 U Downloaded from Bioscientifica.com at 09/30/2021 08:48:50AM via free access 50 E. F. Hartree and . Srivastava will be referred to as glycoprotein A. The extracted lipid was obtained as a solution in chloroform-methanol. This was shaken with 0-2 vol of 0-01 M-MgCl2 to remove impurities and the lower layer was evaporated in a rotary evaporator. The lipid residue was stored in chloroform solution at —20° C (lipid A). The supernatant fluid from which the white sediment had been separated was concentrated to small bulk in a rotary evaporator and treated with an equal volume of 10% trichloroacetic acid. The solution remained clear and it was therefore assumed that all the protein had been precipitated by acetone. -Washed ram spermatozoa pH 11.4, Hyamine pH 6-1, centrifuge centrifuge I Supernatant Sedimenl Sediment solution (discarded) resuspend, acetcne at centrifuge 5°C, centrifuge Sediment Supernatant suspen¬ (discarded ) sion of acrosomes Supernatant Sediment solution Upoglycoprotein ethanci, (discarded) centrifuge chLoroform methanol - Supernatant Sediment Solution of Insoluble solution LIPID A residue (discarded) GLYCOPROTEIN A chloroform methanol Solution of Insoluble LIPID residue GLYCOPROTEIN Flow sheets for separation of lipids and glycoproteins. B. Isolation from detached acrosomes A suspension of washed ram spermatozoa (40 ml) in saline was incubated with an equal volume of 0-1% Hyamine, in 0-067 M-phosphate buffer pH 6-1, at 37° C for 90 min. At this stage some of the detached acrosomes were distorted but still clearly recognizable (PI. 1, Fig. 3). The suspension was centrifuged for 15 min at 1500g, the sediment was resuspended in fresh saline and centri¬ fuged again. The combined supernatant fluids contained acrosomes with very few (<1%) spermatozoa and sperm tails (PI. 1, Fig. 4). The sediment contained spermatozoa, of which about 80% were without acrosomes, and free acrosomes equivalent to about 20% of the spermatozoa. Thus the supernatant fluid con¬ tained in suspension approximately 60% of the acrosomes in the original sperm suspension. The supernatant fluid was treated with an equal volume of absolute ethanol, left overnight at 4° C, and centrifuged. The precipitate was resuspended in 7-5 ml ofwater and lipids were removed as described above. The final products were the air-dried glycoprotein and a solution oflipids in chloroform. These will Downloaded from Bioscientifica.com at 09/30/2021 08:48:50AM via free access Chemical composition of ram acrosomes 51 be referred to as glycoprotein and lipid respectively. When the lipid solutions were required for analysis, phosphate buffer was replaced by saline as a solvent for Hyamine.
Recommended publications
  • 1. Nucleotides A. Pentose Sugars – 5-Carbon Sugar 1) Deoxyribose – in DNA 2) Ribose – in RNA B. Phosphate Group C. Nitroge
    1. Nucleotides a. Pentose sugars – 5-Carbon sugar 1) Deoxyribose – in DNA 2) Ribose – in RNA b. Phosphate group c. Nitrogenous bases 1) Purines a) Adenine b) Guanine 2) Pyrimidines a) Cytosine b) Thymine 2. Types of Nucleic Acids a. DNA 1) Locations 2) Functions b. RNA 1) Locations 2) Functions E. High Energy Biomolecules 1. Adenosine triphosphate a. Uses 1) Active transport 2) Movement 3) Biosynthesis reactions b. Regeneration 1) ADP + Pi + Energy → ATP 4. Classes of proteins a. Structural – ex. Collagen, keratin b. Transport – Hemoglobin, many β-globulins c. Contractile – Actin and Myosin of muscle tissue d. Regulatory - Hormones e. Immunologic - Antibodies f. Clotting – Thrombin and Fibrin g. Osmotic - Albumin h. Catalytic – Enzymes 1) Characteristics of enzymes • Proteins (most); ribonucleoproteins (few/ribozymes) • Act as organic catalysts • Lower the activation energy of reactions • Not changed by the reaction • Bind to their substrates o Lock-and-key model of enzyme activity o Induced-fit model • Highly specific • Named by adding -ase to substrate name; e.g., maltose/maltase • May require cofactors which may be: o Nonprotein metal ions such as copper, manganese, potassium, sodium o Small organic molecules known as coenzymes. The B vitamins like thiamine (B1) riboflavin (B2) and nicotinamide are precursors of coenzymes. • May require activation; e.g., pepsinogen pepsin in stomach chief cells 4. Factors Affecting Enzyme Action • pH o pepsin (stomach) @ pH = 2; trypsin (small int.) @ pH = 8 • Temperature o Denatured by high temp’s. • Enzyme inhibitors o Competitive inhibitors o Noncompetitive inhibitors • Effect of substrate concentration and reversible reactions and the Law of Mass D.
    [Show full text]
  • Multi-Enzymatic Cascades in the Synthesis of Modified Nucleosides
    biomolecules Article Multi-Enzymatic Cascades in the Synthesis of Modified Nucleosides: Comparison of the Thermophilic and Mesophilic Pathways Ilja V. Fateev , Maria A. Kostromina, Yuliya A. Abramchik, Barbara Z. Eletskaya , Olga O. Mikheeva, Dmitry D. Lukoshin, Evgeniy A. Zayats , Maria Ya. Berzina, Elena V. Dorofeeva, Alexander S. Paramonov , Alexey L. Kayushin, Irina D. Konstantinova * and Roman S. Esipov Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya 16/10, 117997 GSP, B-437 Moscow, Russia; [email protected] (I.V.F.); [email protected] (M.A.K.); [email protected] (Y.A.A.); [email protected] (B.Z.E.); [email protected] (O.O.M.); [email protected] (D.D.L.); [email protected] (E.A.Z.); [email protected] (M.Y.B.); [email protected] (E.V.D.); [email protected] (A.S.P.); [email protected] (A.L.K.); [email protected] (R.S.E.) * Correspondence: [email protected]; Tel.: +7-905-791-1719 ! Abstract: A comparative study of the possibilities of using ribokinase phosphopentomutase ! nucleoside phosphorylase cascades in the synthesis of modified nucleosides was carried out. Citation: Fateev, I.V.; Kostromina, Recombinant phosphopentomutase from Thermus thermophilus HB27 was obtained for the first time: M.A.; Abramchik, Y.A.; Eletskaya, a strain producing a soluble form of the enzyme was created, and a method for its isolation and B.Z.; Mikheeva, O.O.; Lukoshin, D.D.; chromatographic purification was developed. It was shown that cascade syntheses of modified nu- Zayats, E.A.; Berzina, M.Y..; cleosides can be carried out both by the mesophilic and thermophilic routes from D-pentoses: ribose, Dorofeeva, E.V.; Paramonov, A.S.; 2-deoxyribose, arabinose, xylose, and 2-deoxy-2-fluoroarabinose.
    [Show full text]
  • DNA Stands for Deoxyribose Nucleic Acid
    DNA and Protein Synthesis DNA • DNA stands for deoxyribose nucleic acid. • This chemical substance is found in the nucleus of all cells in all living organisms • DNA controls all the chemical changes which take place in cells • The kind of cell which is formed, (muscle, blood, nerve etc) is controlled by DNA Ribose is a sugar, like glucose, but with only five carbon atoms in its molecule. Deoxyribose is almost the same but lacks one oxygen atom. The nitrogen bases are: o ADENINE (A) o THYMINE (T) o CYTOSINE (C) o GUANINE (G) Nucleotides • A molecule of DNA is formed by millions of nucleotides joined together in a long chain. • DNA is a very large molecule made up of a long chain of sub-units. • The sub-units are called nucleotides. • Each nucleotide is made up of a sugar called deoxyribose, a phosphate group -PO4 and an organic (Nitrogen) base: A, T, C, G BASE PAIRING RULE amount of C= amount of G AND amount of A= amount of T • Adenine always pairs with thymine, and guanine always pairs with cytosine. DNA STRUCTURE • The nucleotide bases will point to the inside of the DNA molecule while the outside (backbone) of the DNA molecule will be made of the sugar and phosphate molecules. • When complete the DNA molecule forms a double helix (two spiral sides wrapped together). • The paired strands are coiled into a spiral called A DOUBLE HELIX. Genes • Each chromosome contains hundreds of genes. • Most of your characteristics: hair color, height, how things taste to a person, are determined by the kinds of proteins cells make (gene).
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,604,000 B2 De Kort Et Al
    USOO8604000B2 (12) United States Patent (10) Patent No.: US 8,604,000 B2 de Kort et al. (45) Date of Patent: Dec. 10, 2013 (54) PALATABLE NUTRITIONAL COMPOSITION 2011/0027391 A1 2/2011 De Kort et al. COMPRISING ANUCLEOTDE AND/ORA 2013, OO12469 A1 1/2013 De Kort et al. NUCLEOSDE AND A TASTE MASKING 2013, OO18012 A1 1/2013 Hageman et al. AGENT FOREIGN PATENT DOCUMENTS (75) Inventors: Esther Jacqueline de Kort, Wageningen EP O 175468 A2 3, 1986 (NL); Martine Groenendijk, EP 1216 041 B1 6, 2002 EP 1282 365 B1 2, 2003 Barendrecht (NL); Patrick Joseph EP 1656 839 A1 5, 2006 Gerardus Hendrikus Kamphuis, EP 1666 092 A2 6, 2006 Utrecht (NL) EP 18OO 675 A1 6, 2007 JP 64-080250 A 3, 1989 (73) Assignee: N.V. Nutricia, Zoetermeer (NL) JP 06-237734. A 8, 1994 JP 10-004918 A 1, 1998 JP 10-136937 A 5, 1998 (*) Notice: Subject to any disclaimer, the term of this JP 11-071274. A 3, 1999 patent is extended or adjusted under 35 WO WO-0038829 A1 T 2000 U.S.C. 154(b) by 213 days. WO WO-01 (32034 A1 5, 2001 WO WO-02/088159 A1 11, 2002 WO WO-02/096464 A1 12/2002 (21) Appl. No.: 12/809,431 WO WO-03 (013276 A1 2, 2003 WO WO-03/041701 A2 5, 2003 (22) PCT Filed: Dec. 22, 2008 WO WO-2005/039597 A2 5, 2005 WO WO-2006/031683 A2 3, 2006 (86). PCT No.: PCT/NL2O08/050843 WO WO-2006,118665 A2 11/2006 WO WO-2006, 127620 A2 11/2006 S371 (c)(1), WO WO-2007/001883 A2 1, 2007 (2), (4) Date: Dec.
    [Show full text]
  • Nucleosides & Nucleotides
    Nucleosides & Nucleotides Biochemistry Fundamentals > Genetic Information > Genetic Information NUCLEOSIDE AND NUCLEOTIDES SUMMARY NUCLEOSIDES&NBSP; • Comprise a sugar and a base NUCLEOTIDES&NBSP; • Phosphorylated nucleosides (at least one phosphorus group) • Link in chains to form polymers called nucleic acids (i.e. DNA and RNA) N-BETA-GLYCOSIDIC BOND&NBSP; • Links nitrogenous base to sugar in nucleotides and nucleosides • Purines: C1 of sugar bonds with N9 of base • Pyrimidines: C1 of sugar bonds with N1 of base PHOSPHOESTER BOND • Links C3 or C5 hydroxyl group of sugar to phosphate NITROGENOUS BASES&NBSP; • Adenine • Guanine • Cytosine • Thymine (DNA) 1 / 8 • Uracil (RNA) NUCLEOSIDES • =sugar + base • Adenosine • Guanosine • Cytidine • Thymidine • Uridine NUCLEOTIDE MONOPHOSPHATES – ADD SUFFIX 'SYLATE' • = nucleoside + 1 phosphate group • Adenylate • Guanylate • Cytidylate • Thymidylate • Uridylate Add prefix 'deoxy' when the ribose is a deoxyribose: lacks a hydroxyl group at C2. • Thymine only exists in DNA (deoxy prefix unnecessary for this reason) • Uracil only exists in RNA NUCLEIC ACIDS (DNA AND RNA)&NBSP; • Phosphodiester bonds: a phosphate group attached to C5 of one sugar bonds with - OH group on C3 of next sugar • Nucleotide monomers of nucleic acids exist as triphosphates • Nucleotide polymers (i.e. nucleic acids) are monophosphates • 5' end is free phosphate group attached to C5 • 3' end is free -OH group attached to C3 2 / 8 FULL-LENGTH TEXT • Here we will learn about learn about nucleoside and nucleotide structure, and how they create the backbones of nucleic acids (DNA and RNA). • Start a table, so we can address key features of nucleosides and nucleotides. • Denote that nucleosides comprise a sugar and a base.
    [Show full text]
  • Part 1 in Our Series of Carbohydrate Lectures. in This Section, You Will Learn About Monosaccharide Structure
    Welcome to Part 1 in our series of Carbohydrate lectures. In this section, you will learn about monosaccharide structure. The building blocks of larger carbohydrate polymers. 1 First, let’s review why learning about carbohydrates is important. Carbohydrates are used by biological systems as fuels and energy resources. Carbohydrates typically provide quick energy and are one of the primary energy storage forms in animals. Carbohydrates also provide the precursors to other major macromolecules within the body, including the deoxyribose and ribose required for nucleic acid biosynthesis. Carbohydrates can also provide structural support and cushioning/shock absorption, as well as cell‐cell communication, identification, and signaling. 2 Carbohydrates, as their name implies, are water hydrates of carbon, and they all have the same basic core formula (CH2O)n and are always found in the ratio of 1 carbon to 2 hydrogens to 1 oxygen (1:2:1) making them easy to identify from their molecular formula. 3 Carbohydrates can be divided into subcategories based on their complexity. The simplest carbohydrates are the monosaccharides which are the simple sugars required for the biosynthesis of all the other carbohydrate types. Disaccharides consist of two monosaccharides that have been joined together by a covalent bond called the glycosidic bond. Oligosaccharides are polymers that consist of a few monosaccharides covalently linked together, and Polysaccharides are large polymers that contain hundreds to thousands of monosaccharide units all joined together by glycosidic bonds. The remainder of this lecture will focus on monosaccharides 4 Monosaccharides all have alcohol functional groups associated with them. In addition they also have one additional functional group, either an aldehyde or a ketone.
    [Show full text]
  • 8| Nucleotides and Nucleic Acids
    8| Nucleotides and Nucleic Acids © 2013 W. H. Freeman and Company CHAPTER 8 Nucleotides and Nucleic Acids Key topics: – Biological function of nucleotides and nucleic acids – Structures of common nucleotides – Structure of double‐stranded DNA – Structures of ribonucleic acids – Denaturation and annealing of DNA – Chemistry of nucleic acids; mutagenesis Functions of Nucleotides and Nucleic Acids • Nucleotide Functions: – Energy for metabolism (ATP) – Enzyme cofactors (NAD+) –Signal transduction (cAMP) • Nucleic Acid Functions: – Storage of genetic info (DNA) – Transmission of genetic info (mRNA) –Processing of genetic information (ribozymes) –Protein synthesis (tRNA and rRNA) Nucleotides and Nucleosides • Nucleotide = – Nitrogeneous base –Pentose – Phosphate • Nucleoside = – Nitrogeneous base –Pentose • Nucleobase = – Nitrogeneous base Phosphate Group •Negatively charged at neutral pH • Typically attached to 5’ position – Nucleic acids are built using 5’‐triphosphates •ATP, GTP, TTP, CTP – Nucleic acids contain one phosphate moiety per nucleotide •May be attached to other positions Other Nucleotides: Monophosphate Group in Different Positions Pentose in Nucleotides • ‐D‐ribofuranose in RNA • ‐2’‐deoxy‐D‐ribofuranose in DNA •Different puckered conformations of the sugar ring are possible Nucleobases •Derivatives of pyrimidine or purine • Nitrogen‐containing heteroaromatic molecules •Planar or almost planar structures •Absorb UV light around 250–270 nm Pyrimidine Bases • Cytosine is found in both DNA and RNA •Thymineis found only in DNA
    [Show full text]
  • Nucleotides and Nucleic Acids
    CHAPTER 8 Nucleotides and Nucleic Acids Functions of Nucleotides and Nucleic Acids • Nucleotide Functions: – Energy for metabolism (ATP) – Enzyme cofactors (NAD+) – Signal transduction (cAMP) • Nucleic Acid Functions: – Storage of genetic info (DNA) – Transmission of genetic info (mRNA) – Processing of genetic information (ribozymes) – Protein synthesis (tRNA and rRNA) Nucleotides and Nucleosides • Nucleotide = – Nitrogeneous base – Pentose – Phosphate • Nucleoside = – Nitrogeneous base – Pentose • Nucleobase = – Nitrogeneous base Phosphate Group • Negatively charged at neutral pH • Typically attached to 5’ position – Nucleic acids are built using 5’- triphosphates • ATP, GTP, TTP, CTP – Nucleic acids contain one phosphate moiety per nucleotide • May be attached to other positions Other Nucleotides: Monophosphate Group in Different Positions Pentose in Nucleotides • -D-ribofuranose in RNA • -2’-deoxy-D-ribofuranose in DNA • Different puckered conformations of the sugar ring are possible Purine Bases • Adenine and guanine are found in both RNA and DNA • Also good H-bond donors and acceptors • Adenine pKa at N1 is 3.8 • Guanine pKa at N7 is 2.4 • Neutral molecules at pH 7 • Derivatives of pyrimidine or purine • Nitrogen-containing heteroaromatic molecules • Planar or almost planar structures • Absorb UV light around 250–270 nm Pyrimidine Bases • Cytosine is found in both DNA and RNA • Thymine is found only in DNA • Uracil is found only in RNA • All are good H-bond donors and acceptors • Cytosine pKa at N3 is 4.5 • Thymine pKa at N3 is 9.5
    [Show full text]
  • Deoxyribose and Deoxysugar Derivatives from Photoprocessed Astrophysical Ice Analogues and Comparison to Meteorites
    ARTICLE https://doi.org/10.1038/s41467-018-07693-x OPEN Deoxyribose and deoxysugar derivatives from photoprocessed astrophysical ice analogues and comparison to meteorites Michel Nuevo 1,2, George Cooper3 & Scott A. Sandford 1 Sugars and their derivatives are essential to all terrestrial life. Their presence in meteorites, together with amino acids, nucleobases, amphiphiles, and other compounds of biological 1234567890():,; importance, may have contributed to the inventory of organics that played a role in the emergence of life on Earth. Sugars, including ribose (the sugar of RNA), and other sugar derivatives have been identified in laboratory experiments simulating photoprocessing of ices under astrophysical conditions. In this work, we report the detection of 2-deoxyribose (the sugar of DNA) and several deoxysugar derivatives in residues produced from the ultraviolet irradiation of ice mixtures consisting of H2O and CH3OH. The detection of deoxysugar derivatives adds to the inventory of compounds of biological interest that can form under astrophysical conditions and puts constraints on their abiotic formation pathway. Finally, we report that some of the deoxysugar derivatives found in our residues are also newly identified in carbonaceous meteorites. 1 NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035, USA. 2 BAER Institute, NASA Research Park, MS 18-4, Moffett Field, CA 94035, USA. 3 NASA Ames Research Center, MS 239-4, Moffett Field, CA 94035, USA. Correspondence and requests for materials should be addressed to M.N. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:5276 | https://doi.org/10.1038/s41467-018-07693-x | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-018-07693-x ugars (monosaccharides) and their derivatives are ubiqui- contamination.
    [Show full text]
  • Studies on the Prebiotic Origin of 2-Deoxy-D-Ribose
    Studies on the Prebiotic Origin of 2-Deoxy-D-ribose Andrew Mark Steer Doctor of Philosophy University of York Chemistry August 2017 Abstract DNA is an important biological structure necessary for cell proliferation. The origins of cell- like structures and the building blocks of DNA are therefore also of great concern. As of yet the prebiotic origin of 2-deoxy-D-ribose, the sugar of DNA, has no satisfactory explanation. This research attempts to provide a possible explanation to the chemical origin of 2-deoxy- D-ribose via an aldol reaction between acetaldehyde 1 and D-glyceraldehyde D-2 (Error! Reference source not found.). The sugar mixture is trapped with N,N-diphenylhydrazine 3 for ease of purification and characterisation. The reaction is promoted by amino acids, amino esters and amino nitriles consistently giving selectivities in favour of 2-deoxy-D- ribose. This is the first example of an amino nitrile promoted reaction. Potential prebiotic synthesis of 2-deoxy-D-ribose and subsequent trapping with N,N-diphenyl hydrazine 3. The research is developed further by exploring the formation of 2-deoxy-D-ribose in a “protocell” environment – a primitive cell. Here we suggest that primitive cells may have been simple hydrogel systems. A discussion of the characterisation and catalytic ability of small peptide-based supramolecular structures is included. ii Contents Abstract ............................................................................................................................ ii Contents .........................................................................................................................
    [Show full text]
  • Deoxyribose-5-Phosphate Aldolase As a Synthetic Catalyst'
    J. Am. Chem. SOC.1990, 112, 2013-2014 2013 chemical shift for the iminosilaacyl carbon at 6 299.07.3a3b Ad- Deoxyribose-5-phosphateAldolase as a Synthetic dition of 1 equiv of CN(XyI) to a benzene solution of 4, or reaction Catalyst' of 1 with 2 equiv of CN(Xyl), results in formation of a blue complex 5. The combustion analysis of isolated 5 is consistent Carlos F. Barbas, 111, Yi-Fong Wang, and Chi-Huey Wong* with a 1:2 adduct of 1 with isocyanide, Cp,Sc(CN(Xyl)),Si- (SiMe3)3. However, 'H NMR data for 5 indicate a complex Department of Chemistry structure and the presence of three inequivalent SiMe3 groups in The Research Institute of Scripps Clinic a 1 :1: 1 ratioss Formation of X-ray-quality, blue crystals from La Jolla, California 92037 diethvl ether allowed comdete characterization of this comwund. Received November 29, 1989 Tie crystal structure7'(Figure 1) shows that 5 is the pioduct of an isocyanide-coupling reaction that results in further rear- Enzyme-catalyzed stereocontrolled aldol condensations are rangements. The structure drawn in Scheme I reflects the ob- valuable in organic synthesis, particularly in the synthesis of served structural parameters. The chelate ring of 5 is derived from carbohydrates and related s~bstances?~~We report here an initial the two isoc anide groups and contains a Sc( 1)-N( 1) single bond study on the synthetic utility of a bacterial 2-deoxyribose-5- (2.133 (7) i),a longer (dative) Sc(l)-N(2) bond (2.324 (8) A), phosphate aldolase (DERA, EC 4.1.2.4) overexpressed in Es- and a C=C double bond (C(l)-C(2) = 1.375 (12) A).
    [Show full text]
  • Carbohydrates Hydrates of Carbon: General Formula Cn(H2O)N Plants
    Chapter 25: Carbohydrates hydrates of carbon: general formula Cn(H2O)n Plants: photosynthesis hν 6 CO2 + H2O C6H12O6 + 6 O2 Polymers: large molecules made up of repeating smaller units (monomer) Biopolymers: Monomer units: carbohydrates (chapter 25) monosaccharides peptides and proteins (chapter 26) amino acids nucleic acids (chapter 28) nucleotides 315 25.1 Classification of Carbohydrates: I. Number of carbohydrate units monosaccharides: one carbohydrate unit (simple carbohydrates) disaccharides: two carbohydrate units (complex carbohydrates) trisaccharides: three carbohydrate units polysaccharides: many carbohydrate units CHO H OH HO HO HO H HO HO O HO O glucose H OH HO HO OH HO H OH OH CH2OH HO HO HO O HO O HO HO O HO HO O HO HO HO O O O O O HO HO O HO HO HO O O HO HO HO galactose OH + glucose O glucose = lactose polymer = amylose or cellulose 316 160 II. Position of carbonyl group at C1, carbonyl is an aldehyde: aldose at any other carbon, carbonyl is a ketone: ketose III. Number of carbons three carbons: triose six carbons: hexose four carbons: tetrose seven carbons: heptose five carbons: pentose etc. IV. Cyclic form (chapter 25.5) CHO CHO CHO CHO CH2OH H OH HO H H OH H OH O CH2OH H OH H OH HO H HO H CH2OH H OH H OH H OH CH2OH H OH H OH CH OH 2 CH2OH glyceraldehyde threose ribose glucose fructose (triose) (tetrose) (pentose) (hexose) (hexose) 317 (aldohexose) (ketohexose) 25.2: Depicting carbohydrates stereochemistry: Fischer Projections: representation of a three-dimensional molecule as a flat structure.
    [Show full text]