DOCSLIB.ORG

Promoted More Effectively by D-Allose Than by Glucose (Regulation/Malonate/Cyclohexlmide/Mannose) DONNA B

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Promoted More Effectively by D-Allose Than by Glucose (Regulation/Malonate/Cyclohexlmide/Mannose) DONNA B Proc. Natl. Acad. Sci. USA Vol. 83, pp. 5858-5860, August 1986 Biochemistry Hexose transport control in a fibroblast metabolic mutant can be promoted more effectively by D-allose than by glucose (regulation/malonate/cyclohexlmide/mannose) DONNA B. ULLREY AND HERMAN M. KALCKAR Unit of Biochemistry in the Department of Chemistry, Boston University, Boston, MA 02215 Contributed by Herman M. Kalckar, April 28, 1986 ABSTRACT By studying the energy-requiring control of transport system (4), was able to induce a well-expressed the hexose transport system (the transport "curb") in a lung transport curb in various types of fibroblasts (5, 6, *). In the fibroblast mutant called the phosphoglucose isomerase mutant PGI mutant that is unable to respond to mannose or D- (because it is devoid of the enzyme phosphoglucose isomerase) glucosamine, D-allose turns out to develop a curb that, much the following features were noted. The aldohexose D-allose, if like glucose, is abolished by malonate. In the parental line, added over 20 hr to a culture of the mutant, promotes the 023, in which several D-aldohexoses are able to develop a development of an intense curb ofthe hexose transport system, hexose transport curb (1), D-allose also brings about a greatly surpassing that brought about by incubation with pronounced transport curb, which also seems to be energy glucose. The allose-mediated curb can be circumvented by requiring. As will be discussed in this paper, D-allose, in various metabolic inhibitors as well as by the presence of other amounts as low as 1 mM, exerts a highly pronounced curb in aldohexoses such as mannose. the PGI mutant surpassing that brought about by glucose. A regulatory energy-requiring system that we have called the hexose transport "curb" has been examined in a cultured MATERIALS AND METHODS hamster fibroblast mutant, DS7, devoid of the enzyme phosphoglucose isomerase (D-glucose-6-phosphate ketol- Cells used were a Chinese hamster lung fibroblast line lacking isomerase, EC 5.3.1.9) (the PGI mutant). The parental line of PGI (DS7) and its parental line (023) (see ref. 6). Both were the mutant, 023, uses glucose readily for energy metabolism. tested by the 4',6-diamidino-2-phenylindole stain method and The transport curb in 023 is promoted by feeding with glucose were found free of mycoplasma (D. V. Young, Bioassay as well as with mannose or D-glucosamine. In DS7, the PGI Systems Research Corp.). The cells were grown in Dulbec- mutant, the two latter hexoses can be used in energy co's modified Eagle's medium (DMEM) with 10% fetal metabolism, yet no transport curb ensues. Conversely, bovine serum. Before the uptake test the cells were rinsed glucose, unable to serve in energfymetabolism ofthis mutant, twice with sugar-free DMEM; the cells were then given remains a promoter of the curb of its transport system. The modified DMEM without pyruvate and with various sugars all-cis aldohexose D-allose has turned out to be the most replacing glucose and supplemented with 10% dialyzed fetal effective promoter of the hexose transport curb. This curb bovine serum (Sigma) for 16-20 hr. Chx (Sigma) was used at can be released by various metabolic inhibitors, such as 35 gM (7). Other additions are indicated for the individual malonate or cycloheximide (Chx). Addition of mannose in experiments. Sugars and malonate were obtained from Sig- excess will also prevent the allose-induced transport curb in ma. the PGI mutant. 3-O-Methylglucose Transport. Cultures were rinsed three A comparison of the down-regulatory patterns of the times with sugar-free and serum-free medium. They were hexose transport system, which we call the "mediated curb," then preloaded with 50 mM 3-O-methylglucose in DMEM between a fibroblast mutant, defective in PGI (the PGI without glucose or serum for 30 min at 370C. The cells were mutant), and its parental line shows the following differences. next rinsed rapidly with 10 ml of phosphate-buffered saline In the parental line, like fibroblast cultures from other (PBS) and then incubated 20 sec at 220C with 3-0- hamster lines (tumorigenic or not), glucose and other ['4C]methylglucose containing L-[3H]glucose to check for aldohexoses, such as D-glucosamine or D-mannose, "in- completeness of washing. After the transport test the cells duce" a marked curb of their own transport system (1, 2). were rinsed rapidly with ice-cold PBS. In some experiments Cultures deprived of sugars or fed fructose instead of D- the cold PBS contained 0.1 mM phloretin. The cells were aldohexose consistently showed much higher rates ofhexose extracted with ethanol and the extracts were assayed for transport (1). radioactivity in a scintillation counter. The results were The transport curb is energy-requiring and it also depends expressed as pmol/mg of cell protein per 20 sec (from on protein synthesis, since the curb is released by inhibitors duplicate samples). of oxidative phosphorylation as well as by inhibitors of Galactose Uptake Test. Cultures were rinsed three times protein synthesis (1-3). with PBS at 370C, incubated 5 or 10 min at 370C with 0.1 mM The D-aldohexoses that can induce a transport curb in the [14C]galactose, rinsed, and analyzed as described (2, 7). The PGI mutant are much more restricted. Neither D-glUCOS- results are expressed as nmol/mg of cell protein per 5 or 10 amine nor mannose was able to elicit a transport curb; only in the tables. Radiochemicals were glucose or galactose has retained this ability (1, 2). min, as stated respective Surprisingly enough, the all-cis hexose D-allose, suppos- from New England Nuclear. edly a nonmetabolizable hexose, albeit a ligand ofthe hexose Abbreviations: Chx, cycloheximide; PGI, phosphoglucose isomer- ase. The publication costs of this article were defrayed in part by page charge *Ullrey, D. B. & Kalckar, H. M. (1986) 86th Meeting of the payment. This article must therefore be hereby marked "advertisement" American Society of Microbiology, March 23-28, 1986, abstr. in accordance with 18 U.S.C. §1734 solely to indicate this fact. K195, p. 226. 5858 Downloaded by guest on October 1, 2021 Biochemistry: Ullrey and Kalckar Proc. Natl. Acad. Sci. USA 83 (1986) 5859 Table 1. Regulation of hexose uptake in 023 and DS7 cultures Table 3. Glucose and allose curb of hexose transport in the PGI mutant nmol/mg of protein per 10 min 3-O-[14C]Methylglucose transport, Sugar DS7 023 Sugar pmol/mg of protein per 20 sec Ratio Fructose (22 mM) 5.34 4.79 First incubation (18 hr) D-Glucosamine (5 mM) 4.36 2.12 None 35.94 Glucose (22 mM) 1.81 2.25 Fructose (22 mM) 47.62 Allose (22 mM) 1.06 1.30 Glucose (22 mM) 13.36 Allose (22 mM) 8.34 Near-confluent cultures were fed various hexoses with 10% Allose (5 mM) 8.18 dialyzed fetal calf serum over 20 hr. Uptake tests were performed Second incubation (7 hr)* with 0.1 mM [U-_4C]galactose at 370C for 10 min. Fructose (22 mM) 45.95 1.02 + Chx 47.06 RESULTS AND DISCUSSION Glucose (22 mM) 20.51 + Chx 55.00 2.68 Table 1 indicates that allose elicits an even stronger transport Allose (22 mM) 17.39 2.62 curb than glucose in the PGI mutant and the parental strain. + Chx 45.63 The fact that the allose-induced transport curb is released by Confluent DS7 cultures were maintained for 18 hr in sugar-free malonate (Table 2) indicates that this is a true curb and not medium containing L-glutamine and supplemented with 10% dialyzed simple toxicity. This is supported by the prevention of the fetal calf serum. Subsequently, 22 mM hexoses were added with or establishment of the allose-induced curb by Chx (Table 3). without 35 uM Chx; this refeeding period spanned only 7 hr. Confluent DS7 cultures were incubated for 18 hr in growth Transport tests were then carried out with 0.01 mM 3-0-[14C]- medium containing fructose, glucose, allose, or no sugar. The methylglucose for 20 sec at 23°C. sugar concentrations were 22 mM; however, an extra pair of *Sugar and 35 ,M Chx were added to original sugar-free samples for allose incubation mixtures with only 5 mM of this sugar was 7 hr. added (Table 3, top). A second set of hexose-starved DS7 cultures was exposed to Chx (35 gM) over 7 hr in the It should be emphasized here that the intense transport presence of 22 mM fructose, glucose, or allose and then curb that develops after 20 hr of exposure to D-allose is not analyzed. It can be seen in Table 3, bottom, that Chx is able a plain toxic action by this sugar but a regulatory effect. This to forestall the onset of the hexose transport curb, including appears from the fact that the additional presence of meta- that elicited by allose. bolic inhibitors over the same extended span of time still Table 4 illustrates the competition between allose and permitted the culture to manifest unbridled transport, as mannose. Since this mutant catabolizes mannose rapidly (1, determined in the transport test. 2), a large excess of this sugar was used. In the presence of In general, the biochemical literature on D-allose seems 22 mM mannose, allose fails to elicit a transport curb. The rather sparse. In an important study about 10 years ago (4) it lactic acid generated per mg of cell protein over 18 hr was found that D-allose (3H-labeled) acts as a transport ligand amounted to 3.7-4.3 ,umol from pyruvate and an additional in the hexose transport system ofadipose fat cells.
Load more

Recommended publications
  • Electronic Supplementary Information
    Electronic Supplementary Material (ESI) for Chemical Science. This journal is © The Royal Society of Chemistry 2019 Electronic Supplementary Information Poly(ionic liquid)s as a Distinct Receptor Material to Create Highly- Integrated Sensing Platform for Efficiently Identifying a Myriad of Saccharides Wanlin Zhang, Yao Li, Yun Liang, Ning Gao, Chengcheng Liu, Shiqiang Wang, Xianpeng Yin, and Guangtao Li* *Corresponding authors: Guangtao Li ([email protected]) S1 Contents 1. Experimental Section (Page S4-S6) Materials and Characterization (Page S4) Experimental Details (Page S4-S6) 2. Figures and Tables (Page S7-S40) Fig. S1 SEM image of silica colloidal crystal spheres and PIL inverse opal spheres. (Page S7) Fig. S2 Adsorption isotherm of PIL inverse opal. (Page S7) Fig. S3 Dynamic mechanical analysis and thermal gravimetric analysis of PIL materials. (Page S7) Fig. S4 Chemical structures of 23 saccharides. (Page S8) Fig. S5 The counteranion exchange of PIL photonic spheres from Br- to DCA. (Page S9) Fig. S6 Reflection and emission spectra of spheres for saccharides. (Page S9) Table S1 The jack-knifed classification on single-sphere array for 23 saccharides. (Page S10) Fig. S7 Lower detection concentration at 10 mM of the single-sphere array. (Page S11) Fig. S8 Lower detection concentration at 1 mM of the single-sphere array. (Page S12) Fig. S9 PIL sphere exhibiting great pH robustness within the biological pH range. (Page S12) Fig. S10 Exploring the tolerance of PIL spheres to different conditions. (Page S13) Fig. S11 Exploring the reusability of PIL spheres. (Page S14) Fig. S12 Responses of spheres to sugar alcohols. (Page S15) Fig.
    [Show full text]
  • WO 2013/070444 Al 16 May 2013 (16.05.2013) W P O P C T
    (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2013/070444 Al 16 May 2013 (16.05.2013) W P O P C T (51) International Patent Classification: (81) Designated States (unless otherwise indicated, for every A23G 4/00 (2006.01) kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, (21) International Application Number: BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, PCT/US20 12/062043 DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, (22) International Filing Date: HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, 26 October 2012 (26.10.2012) KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, (25) Filing Language: English NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, (26) Publication Language: English RW, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, (30) Priority Data: ZM, ZW. 61/556,546 7 November 20 11 (07. 11.201 1) US (84) Designated States (unless otherwise indicated, for every (71) Applicant (for all designated States except US): WVI. kind of regional protection available): ARIPO (BW, GH, WRIGLEY JR. COMPANY [US/US]; 1132 Blackhawk GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ, Street, Chicago, IL 60642 (US).
    [Show full text]
  • Monosaccharides: a Tof-SIMS Reference Accession #: 01592, 01593, 01594, 01595, 01596, 01597, 01598, Spectra Database
    Monosaccharides: A ToF-SIMS reference Accession #: 01592, 01593, 01594, 01595, 01596, 01597, 01598, spectra database. II. Positive polarity 01599, 01600, 01601, 01602, a) 01603, 01604, 01605, 01606, Laetitia Bernard, Rowena Crockett, and Maciej Kawecki 01607, 01608, 01609, 01610 Laboratory of Nanoscale Materials Science, Empa, CH-8600 Dübendorf, Switzerland Technique: SIMS (Received 20 August 2019; accepted 30 October 2019; published 3 December 2019) Host Material: Silicon (100) wafer The number of time-of-flight secondary ion mass spectrometry studies on biological tissues and Instrument: IONTOF TOF-SIMS.5 cells has strongly increased since the development of primary ion sources that allow not only ele- Major Species in Spectra: C, H, O, (N) mental but also molecular analysis. Substantial fragmentation during ionic bombardment results in a Minor Species in Spectra: Na, K large number of peaks, rendering data analysis complex. Complete and trustable sets of reference spectra for the main biological building blocks, i.e., amino acids, monosaccharides, fatty acids, and Published Spectra: 19 nucleotides, are required. This work aims to provide an accurate and extensive library of reference Spectra in Electronic Record: 19 + spectra for monosaccharides, measured with the Bi3 primary ion. Here (Paper II), the positive polar- Published Figures: 20 ity spectra and lists of associated characteristic fragments are presented. Published by the AVS. Spectral Category: Reference https://doi.org/10.1116/1.5125103 Keywords: ToF-SIMS, carbohydrate, sugar, monosaccharide, mass spectrometry, fragmentation INTRODUCTION Fluka and all others from Sigma Aldrich. Each powder was dissolved in freshly de-ionized H2O (resistivity >18.2 MΩ cm) Monosaccharides are the building blocks of structural polymers at a concentration of 0.1M.
    [Show full text]
  • Food Carbohydrates: Monosaccharides and Oligosaccharides
    Paper No. 01 Paper Title: Food Chemistry Module-04: Food carbohydrates: Monosaccharides and Oligosaccharides Monosaccharides The simplest form of carbohydrates is the monosaccharide. Monosaccharides are either aldoses or ketoses. Aldoses such as glucose consists of a carbon backbone and a carbonyl group (C=O) located at the end of the chain. Ketoses such as fructose consists of a carbon backbone with a carbonyl group located at any other carbon in the chain. The remaining carbon atoms are bound to hydroxyl groups (-OH). Monosaccharide classifications based on the number of carbons Number Category of Examples Name Carbons 4 Tetrose Erythrose, Threose 5 Pentose Arabinose, Ribose, Ribulose, Xylose, Xylulose, Lyxose Allose, Altrose, Fructose, Galactose, Glucose, Gulose, Idose, 6 Hexose Mannose, Sorbose, Talose, Tagatose 7 Heptose Sedoheptulose, Mannoheptulose Monosaccharides Three common sugars glucose, galactose and fructose share the same molecular formula: C6H12O6. Because of their six carbon atoms, each is a hexose. Although all three share the same molecular formula, the arrangement of atoms differs in each case. Substances such as these three, which have identical molecular formulas but different structural formulas, are known as structural isomers. Glucose "Blood sugar" is the immediate source of energy for cellular respiration. Glucose, which is also referred to as dextrose, is a moderately sweet sugar found in vegetables and fruit. When glucose is fermented by the enzyme zymase, in yeast, it results in the formation of carbon dioxide and ethyl alcohol. It is the basic structure to which all carbohydrates are reduced to in the end, for transport via the bloodstream and use by the cells of the body.
    [Show full text]
  • 25 05.Html.Ppt [Read-Only]
    25.5 A Mnemonic for Carbohydrate Configurations The Eight D-Aldohexoses CH O H OH CH2OH The Eight D-Aldohexoses All CH O Altruists Gladly Make Gum In H OH Gallon CH2OH Tanks The Eight D-Aldohexoses All Allose CH O Altruists Altrose Gladly Glucose Make Mannose Gum Gulose In Idose H OH Gallon Galactose CH2OH Tanks Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose Gulose Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose Gulose HO H Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose H OH Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose HO H Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose Gulose HO H Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose H OH Gulose HO H Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose HO H Gulose HO H Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose Mannose H OH Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose Glucose H OH Mannose H OH Gulose H OH Idose H OH Galactose CH2OH Talose The Eight D-Aldohexoses Allose CH O Altrose
    [Show full text]
  • United States Patent (19 11) 4,312,979 Takemoto Et Al
    United States Patent (19 11) 4,312,979 Takemoto et al. 45 Jan. 26, 1982 54 POLYSACCHARIDES CONTAINING 58) Field of Search ......................... 536/1, 18, 114, 4; ALLOSE 435/101 (75) Inventors: Hisao Takemoto; Tatsuo Igarashi, (56) References Cited both of Shin-Nanyo, Japan U.S. PATENT DOCUMENTS 73 Assignee: Toyo Soda Manufacturing Co., Ltd., 3,711,462 l/1973 Abdo et al. ............................. 536/1 Tokyo, Japan 4,186,025 l/1980 Kang et al. ............................. 536/1 Primary Examiner-Johnnie R. Brown (21) Appl. No.: 30,444 Attorney, Agent, or Firm-Scully, Scott, Murphy & Presser 22 Filed: Apr. 16, 1979 57 ABSTRACT 30 Foreign Application Priority Data A new polysaccharide including allose as a constituent Apr. 20, 1978 JP Japan .................................. 53.45918 sugar and further characterized by galactose as a major Dec. 5, 1978 JP Japan ................................ 53-149715 constituent sugar is described. The polysaccharide is produced extracellularly by cultivation of Pseudomonas 51) Int. Cl. ............................................... CO7H1/08 viscogena strains in nutrient medium. 52 U.S. C. ...... 0 a a 4 536/1; 435/72; 435/101; 536/114 6 Claims, 2 Drawing Figures U.S. Patent Jan. 26, 1982 Sheet 1 of 2 4,312,979 8 O O Sn Cd O ar - O - 3 CD won L Cd O CO ve O Cd Cd cN O O O N O O o O o O O. d o o O a. 3 c) do N. ud to at Y on 9 (%) AONWLLIWSNW U.S. Patent Jan. 26, 1982 Sheet 2 of 2 4,312,979 3 s 8 un co, t OO O) O S s S 8 & O O O O O r ONWSOS9W 4,312,979 1.
    [Show full text]
  • Biochemistry Introductory Lecture Dr
    Biochemistry Introductory lecture Dr. Munaf S. Daoud Carbohydrates (CHO) Definition: Aldehyde or Ketone derivatives of the higher polyhydric alcohols or compounds which yield these derivatives on hydrolysis. Classification: (mono, di, oligo, poly) saccharide. Monosaccharides: Can be classified as trioses, tetroses, pentoses, hexoses and heptoses depending upon the number of carbon atoms, and as aldoses or ketoses, depending upon whether they have an aldehyde or ketone group. Aldehyde (-CHO) Aldoses Ketone (-C=O) Ketoses Polysaccharides (glycans): Homopolysaccharides (homoglycans): e.g. starch, glycogen, inulin, cellulose, dextrins, dextrans. Heteropolysaccharides (heteroglycans): e.g. mucopolysaccharides (MPS) or glycosaminoglycans. Function of CHO: 1) Chief source of energy (immediate and stored energy). 2) Constituent of compound lipids and conjugated protein. 3) Structural element like cellulose. 4) Drugs like cardiac glycosides and antibodies. 5) Lactating mammary gland (Lactose in milk). 6) Synthesis of other substances like fatty acids, cholesterol, amino acids…etc. by their degradation products. 7) Constituent of mucopolysaccharides. 1 1) Stereo-isomerism Stereo-isomers: D-form, L-form 2) Optical isomers (optical activity) Enantiomers: dextrorotatory (d or + sign) Levorotatory (l or – sign) Racemic (d l) 3) Cyclic structures or open chain 4) Anomers and Anomeric carbon OH on carbon number 1, if below the plane then its -form, if above the plane then -form. Mutarotation: the changes of the initial optical rotation that takes place
    [Show full text]
  • R and S Nomemclature Problem 3 - Classify the Absolute Configuration of All Chiral Centers As R Or S in the Molecules Below
    1 Lecture 16 Problem 1 - Draw a 3D structure and its mirror image for each of the following molecules. Are they different (enantiomers) or identical (superimposable)? Build models of each and see if your pencil and paper analysis is correct. See if you can use your hands to help your analysis. a. 1-bromopentane d. 1,1-dibromocyclopentane b. 2-bromopentane e. cis-1,2-dibromocyclopentane c. 3-bromopentane f. trans-1,2-dibromocyclopentane Problem 2 - Which molecules below have stereogenic centers? How many? Are they all chiral centers? a. b. c. d. e. Cl OH Br Br Cl Br Br f. g. h. i. j. Br Br Br Br R and S Nomemclature Problem 3 - Classify the absolute configuration of all chiral centers as R or S in the molecules below. Use hands (or model atoms) to help you see these configurations whenever the low priority group is facing towards you (the wrong way). Find the chiral centers, assign the priorities and make your assignments. a. b. c. d. CH3 Cl H H H3C H H H H3C Br Cl C HO C CH3 I H H3C H CH3 C H H H H3C H e. O f. g. h. H Br Br OH H H H CH3 C H3C CH3 CH3 C H3C H H H H C H Cl 3 i. j. k. l. Cl CH2CH3 Br H3CH2C H C Br H CH3 Cl S CH3 D CH3 H CH3 O H 2 Lecture 16 Pi Bond Priority Problem 4 - Evaluate the order of priority in each part.
    [Show full text]
  • Pyranose Ring Conformation: 1 Pyranose Ring Conformation: 4 #06
    #06. 2012-01-20 Quiz 1: Thursday 26 Jan 2012 from 11 AM to 12 noon GG Building Ground Floor #06. 2012-01-20 Last class... Clarification on torsion potential: periodicity 2 and 3 Conformer selection, active/inactive conformations, activation by ligands, etc. - alternative models Inter- and intra-molecular interactions Non-covalent / non-bonded interactions Bonded and non-bonded atoms Hard-sphere approximation Steric effect Preference of trans over gauche conformation for bulky groups #06. 2012-01-20 Monosubstituted cyclohexanes Me Me Bulky group is axially Bulky group is equatorially oriented: gauche to both oriented: trans to both vicinal carbon atoms vicinal carbon atoms #06. 2012-01-20 Monosubstituted cyclohexanes Me Me Bulky group is axially Bulky group is equatorially oriented: gauche to both oriented: trans to both vicinal carbon atoms vicinal carbon atoms #06. 2012-01-20 Cis 1,2-disubstituted cyclohexane Me 4 5 6 Me 3 2 1 #06. 2012-01-20 Trans 1,4-disubstituted cyclohexane 4 5 6 Me Me 3 2 1 #06. 2012-01-20 What governs the conformational preferences? Conformation “a” Conformation “b” Unfolded Folded (protein, DNA, RNA) Monomers (homo/hetero) Oligomer(s) (protein, lipid) A + B A·B (binding) ∆∆∆G = ∆∆∆H – T ∆∆∆S Steric criterion – (approximation of) van der Waals interactions Often, van der Waals contribution is not predominant #06. 2012-01-20 Conformation of 1,3,5-trineopentylbenzene CH 2-tBu tBu-H2C CH 2-tBu Two neopentyl groups are on one side, All the three neopentyl groups are on third on the other side of the ring the same side of the ring view along the plane of the ring Nishio & Hirota (1989) Tetrahedron 45:7201 #06.
    [Show full text]
  • Puckering Free Energy of Pyranoses: an NMR and Metadynamics--Umbrella Sampling Investigation
    Puckering Free Energy of Pyranoses: an NMR and Metadynamics–Umbrella Sampling Investigation E. Autieri, M. Sega,∗ and F. Pederiva Department of Physics and I.N.F.N., University of Trento, via Sommarive 14, 38123 Trento, Italy G. Guella Department of Physics, University of Trento, via Sommarive 14, 38123 Trento, Italy Abstract We present the results of a combined metadynamics–umbrella sampling investigation of the puckered conformers of pyranoses described using the gromos 45a4 force field. The free energy landscape of Cremer–Pople puckering coordinates has been calculated for the whole series of α and β aldohexoses, showing that the current force field parameters fail in reproducing proper puckering free energy differences between chair conformers. We suggest a modification to the gromos 45a4 parameter set which improves considerably the agreement of simulation results with theoretical and experimental estimates of puckering free energies. We also report on the experimental measurement of altrose conformers populations by means of NMR spectroscopy, which show good agreement with the predictions of current theoretical models. arXiv:1006.2515v1 [physics.chem-ph] 13 Jun 2010 1 I. INTRODUCTION Within the framework of classical force fields, the number of computer experiments on sac- charides has grown considerably in recent years, and various systems have been addressed1–27. Devising a realistic model of monosaccharides is obviously a decisive step in order for carbo- hydrates simulations to have enough predictive power. The accurate description of monosac- charides with classical force fields is not an easy task, because of the delicate interplay of different factors such as the presence of a high number of intramolecular hydrogen bonds, the competition of these hydrogen bonds with water-sugar ones and important steric and electrostatic effects between ring substituents in spatial proximity (see for example Ref.
    [Show full text]
  • Reduced Calorie D-Aldohexose Monosaccharides
    Europaisches Patentamt 19 European Patent Office Office europeen des brevets © Publication number: 0 478 580 B1 12 EUROPEAN PATENT SPECIFICATION @ Date of publication of patent specification © int. ci.5: A23L 1/236, C13K 13/00 06.10.93 Bulletin 93/40 (2j) Application number : 90908336.2 (22) Date of filing : 07.05.90 (86) International application number : PCT/US90/02534 (87) International publication number : WO 90/15545 27.12.90 Gazette 90/29 (54) REDUCED CALORIE D-ALDOHEXOSE MONOSACCHARIDES. (30) Priority : 22.06.89 US 369985 (73) Proprietor: UOP 25 East Algonquin Road Des Plaines, Illinois 60017-5017 (US) (43) Date of publication of application 08.04.92 Bulletin 92/15 (72) Inventor : ARENA, Blaise, J. 621 Parsons © Publication of the grant of the patent : Des Plaines, IL 60016 (US) 06.10.93 Bulletin 93/40 Inventor : ARNOLD, Edward, C. 941 East Hillside Naperville, IL 60540 (US) @ Designated Contracting States : AT BE CH DE DK ES FR GB IT LI LU NL SE (74) Representative : Brock, Peter William U RQU HART-DYKES & LORD 91 Wimpole References cited : Street EP-A- 257 626 London W1M 8AH (GB) US-A- 3 667 969 US-A- 4 262 032 JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE vol.21, December 1970, BARK- ING, GB, pages 650-653; "Organoleptic effect in sugar structures", see the whole document CO o 00 If) 00 Note : Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted.
    [Show full text]
  • REPORTS Two-Step Synthesis of Carbohydrates
    R ESEARCH A RTICLES and Mgm1 have been demonstrated and in- additional evolutionary connection between 10. More information about Fzo1 is available at volve the outer membrane fusion protein Ugo1 DRPs and endosymbiotic organelles is that their http://db.yeastgenome.org/cgi-bin/SGD/homolog/ nrHomolog?locusϭYBR179C#summary. (7, 8). The exact nature of the interactions be- division also has evolved to require the action of 11. G. J. Praefcke, H. T. McMahon, Nature Rev. Mol. Cell tween Fzo1, Ugo1, and Mgm1 and their specif- a DRP (25). Biol. 5, 133 (2004). ic roles in mitochondrial fusion remain largely DRPs most commonly have been shown to 12. S. Frank et al., Dev. Cell 1, 515 (2001). unknown. However, Ugo1 functions as an function in membrane fission events, such as 13. M. Karbowski et al., J. Cell Biol. 159, 931 (2002). 14. M. Karbowski et al., J. Cell Biol. 164, 493 (2004). adaptor between Fzo1 and Mgm1 (18). Fzo1 mitochondrial and chloroplast division and en- 15. C. Alexander et al., Nature Genet. 26, 211 (2000). interactions with inner membrane components docytosis (26). However, the actions of two 16. C. Delettre et al., Nature Genet. 26, 207 (2000). may be required in a mechanical manner for the DRPs, Fzo1 on the outer membrane and Mgm1 17. S. Zuchner et al., Nature Genet. 36, 449 (2004). formation of regions of close inner and outer on the inner membrane, are required for mito- 18. H. Sesaki, R. E. Jensen, J. Biol. Chem. 279, 28298 (2004). 19. Materials and methods are available as supporting membrane contact within mitochondria.
    [Show full text]