151
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Likhodii SS, Cunnane SC. Utilization of carbon from dietary polyunsaturates for brain cholesterol synthesis during early postnatal development in the rat: a 13C NMR study. Magn Reson Med 1995; 34:803-13. [PMID: 8598807 DOI: 10.1002/mrm.1910340605] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Incorporation of 13C from a dietary precursor into cholesterol was studied in neonatal rats. Rats were given uniformly 13C-enriched polyunsaturated fatty acids intragastrically and total lipid extracts of liver and brain were analyzed by 13C-NMR 1, 4, 8, and 15 days later. 13C-enrichment was detected in brain but not in liver cholesterol. Maximal 13C-labeling was observed 4 days after injection of the label. Spectra revealed that 70% of newly incorporated 13C had 13C as an adjacent neighbor, the other 30% had 12C as the neighbor. Double quantum NMR revealed the arrangement in the cholesterol skeleton of the 13C-13C pairs transferred from precursors to cholesterol. Desmosterol, an intermediate of cholesterol synthesis, was identified in the spectra of brain lipids. Comparison of 13C-13C unit arrangements in both cholesterol and desmosterol allowed carbons 26 and 27 of desmosterol to be unambiguously assigned.
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Affiliation(s)
- S S Likhodii
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Canada
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152
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153
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154
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Kayahara T, Tamura T, Amuro Y, Higashino K, Igimi H, Uchida K. Delta 22-beta-muricholic acid in monoassociated rats and conventional rats. Lipids 1994; 29:289-96. [PMID: 8177022 DOI: 10.1007/bf02536334] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Bile acids were analyzed in the bile, small and large intestines, and feces of germ-free rats after a single inoculation with one of six intestinal bacteria that had been originally isolated from human feces. Bacteroides vulgatus and Bifidobacterium longum preferentially deconjugated tauro-beta-muricholic acid and taurocholic acid, respectively. Clostridium ramosum, Peptostreptococcus productus and Lactobacillus gasseri deconjugated both bile acids, but Escherichia coli did not deconjugate either one. Rats inoculated with bacteria that deconjugated tauro-beta-muricholic acid produced delta 22-beta-muricholic acid in the feces. In contrast, delta 22-cholic acid could not be detected in rats inoculated with bacteria that deconjugated taurocholic acid.
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Affiliation(s)
- T Kayahara
- Department of Bacteriology, Hyogo College of Medicine, Nishinomiya, Japan
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155
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Gorkovenko A, Roberts MF, White RH. Identification, Biosynthesis, and Function of 1,3,4,6-Hexanetetracarboxylic Acid in
Methanobacterium thermoautotrophicum
ΔH. Appl Environ Microbiol 1994; 60:1249-53. [PMID: 16349232 PMCID: PMC201466 DOI: 10.1128/aem.60.4.1249-1253.1994] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An unusual compound, 1,3,4,6-hexanetetracarboxylic acid, was identified by
1
H and
13
C two-dimensional nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry as one of the major components of the small-molecule pool in
Methanobacterium thermoautotrophicum
ΔH under optimal conditions of cell growth. Incorporation of
13
C- and
2
H-labeled acetates was consistent with the biosynthesis of this tetracarboxylic acid from α-ketoglutarate, two molecules of acetyl-coenzyme A, and one molecule of CO
2
, as established for the tetracarboxylic acid moiety of methanofuran.
13
CO
2
pulse-
12
CO
2
chase methodology was used to establish the turnover rate for this compound. In contrast to the two other major solutes in this bacterium, cyclic 2,3-diphosphoglycerate and glutamate, which are key metabolic intermediates, this free tetracarboxylic acid was metabolically inactive, with a half-life that exceeded the cell doubling time. Hence, this molecular pool cannot serve as a metabolic intermediate in cell biosynthesis. The functional role of free tetracarboxylate as a conservative part of a system that maintains high positive internal osmotic pressure in this bacterium is proposed.
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Affiliation(s)
- A Gorkovenko
- Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02167
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156
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Fennell TR, Sumner SC. Identification of metabolites of carcinogens by 13C NMR spectroscopy. Drug Metab Rev 1994; 26:469-81. [PMID: 8082580 DOI: 10.3109/03602539409029809] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- T R Fennell
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709
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157
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Hensens OD. Modern spectroscopic approaches to structure elucidation. BIOTECHNOLOGY (READING, MASS.) 1994; 26:389-444. [PMID: 7749313 DOI: 10.1016/b978-0-7506-9003-4.50020-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- O D Hensens
- Merck Research Laboratories, Rahway, New Jersey, USA
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158
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Determination of proton densities on silica gel catalyst supports by n-quantum coherence in NMR. Anal Chim Acta 1993. [DOI: 10.1016/0003-2670(93)80266-n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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159
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Gorkovenko A, Roberts MF. Cyclic 2,3-diphosphoglycerate as a component of a new branch in gluconeogenesis in Methanobacterium thermoautotrophicum delta H. J Bacteriol 1993; 175:4087-95. [PMID: 8320225 PMCID: PMC204838 DOI: 10.1128/jb.175.13.4087-4095.1993] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A unique compound, cyclic 2,3-diphosphoglycerate (cDPG), is the major soluble carbon and phosphorus solute in Methanobacterium thermoautotrophicum delta H under optimal conditions of cell growth. It is a component of an unusual branch in gluconeogenesis in these bacteria. [U-13C]acetate pulse-[12C]acetate chase methodology was used to observe the relationship between cDPG and other metabolites (2-phosphoglycerate and 2,3-diphosphoglycerate [2-PG and 2,3-DPG, respectively]) of this branch. It was demonstrated that cells could grow exponentially under conditions in which 2-PG and 2,3-DPG, rather than cDPG, were the major solutes. While the total concentration of these three phosphorylated molecules was maintained, rapid interconversion of 13C label among them was observed. Label flow from 2-PG to 2,3-DPG to cDPG to polymer is the usual direction in this pathway in exponentially growing cells, while the reverse reactions sometimes predominate in the stationary phase. Evidence of the presence of a polymeric compound in this pathway was provided by 13C nuclear magnetic resonance (one-dimensional and two-dimensional INADEQUATE) studies of solubilized cell debris.
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Affiliation(s)
- A Gorkovenko
- Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02167
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160
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161
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Tycko R, Smith SO. Symmetry principles in the design of pulse sequences for structural measurements in magic angle spinning nuclear magnetic resonance. J Chem Phys 1993. [DOI: 10.1063/1.465078] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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162
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163
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Shimamura A, Uezono Y, Tsumori H, Mukasa H. Assignment of 13C NMR signals for reduced nigerooligosaccharides prepared by partial acid hydrolysis of (1 → 3)-α-d-glucan. Carbohydr Res 1992. [DOI: 10.1016/s0008-6215(00)90936-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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164
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Torres A, Nakashima T, McClung R, Muhandiram D. Improvement of INADEQUATE using compensated delays and pulses. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0022-2364(92)90158-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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165
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Abstract
Three isotope-edited n.m.r. methods have been applied to selectively 13C-substituted monosaccharides and nucleosides to simplify their spectra and/or measure 1H-1H, 13C-1H, or 13H-13C spin-couplings detected via the labeled site. 1D INADEQUATE spectra allowed the selective detection of the natural-abundance carbons that are spin-coupled to the labeled carbon, and adjustment of the mixing time permitted further discrimination between one-bond and longer-range 13C-13C coupling pathways. Geminal and vicinal 13C-1H coupling constants were determined from the analysis of 1H-1H COSY cross-peaks for those protons coupled to the labeled carbon. Long-range 13C-(HETCOR) and 1H-detected (HMBC) 13C-1H chemical-shift correlation spectra permitted the selective observation of those protons coupled to the labeled site, and JH,H values were measured from data projections. The implications of these methods for structural studies of more complex systems is briefly discussed.
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Affiliation(s)
- J Wu
- Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556
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166
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Shimamura A, Tsumori H, Mukasa H. Assignment of 13C-n.m.r. signals for reduced isomaltooligosaccharides. Carbohydr Res 1991. [DOI: 10.1016/0008-6215(91)80022-f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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167
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Hoberg H, Bärhausen D, Mynott R, Schroth G. Neuartige Ni0-katalysierte reaktionen zwischen 1,3-butadien und phenylisocyanat. J Organomet Chem 1991. [DOI: 10.1016/0022-328x(91)83030-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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168
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Hopf H, Kretschmer O, Ernst L, Witte L. Alkine und Cumulene, XXII. Die thermische Di- und Trimerisierung vontert-Butylallen. ACTA ACUST UNITED AC 1991. [DOI: 10.1002/cber.19911240430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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169
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170
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Burghardt I, Böhlen J, Bodenhausen G. Broadband multiple‐quantum nuclear magnetic resonance with frequency‐modulated ‘‘chirp’’ pulses: Applications to pairs of scalar‐coupled spinI=1/2 nuclei. J Chem Phys 1990. [DOI: 10.1063/1.459348] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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171
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172
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173
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Udagawa A, Yamamoto Y, Inoue Y, Chûjô R. Structural Determination of 4-Vinylcyclohexene Oxide Using 2D INADEQUATE NMR Spectroscopy and MNDO Calculation. Polym J 1990. [DOI: 10.1295/polymj.22.719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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174
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175
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176
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Boudot D, Canet D, Brondeau J, Boubel J. DANTE-Z. A new approach for accurate frequency selectivity using hard pulses. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0022-2364(89)90207-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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177
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Swapna G, Lakshmi A, Rao JM, Kunwar A. Mechanistic implications of photoannelation reaction of 4,4dimethyl-cyclohex-2-ene-1-one and acrylonitrile — regio and stereochemistry of the major photoadduct by 1H and 13C NMR spectroscopy. Tetrahedron 1989. [DOI: 10.1016/s0040-4020(01)80042-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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178
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179
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Two-dimensional NMR spectra of 17?-(1-aziridinylmethyl)-5?-androstan-17?-ol. Chem Heterocycl Compd (N Y) 1988. [DOI: 10.1007/bf00633497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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180
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Kurata K, Shiraishi K, Takato T, Taniguchi K, Suzuki M. A New Feeding-Deterrent Diterpenoid from the Brown AlgaDilophus okamuraiDawson. CHEM LETT 1988. [DOI: 10.1246/cl.1988.1629] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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181
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Hayashi T, Inoue Y, Chûjô R, Asakura T. Pentad Assignments of Methine Carbon Resonances in Stereoregular Ethylene–Propylene Copolymer Based on Two-Dimensional INADEQUATE NMR Spectrum. Polym J 1988. [DOI: 10.1295/polymj.20.895] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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182
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183
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Shaka A, Lee C, Pines A. Iterative schemes for bilinear operators; application to spin decoupling. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-2364(88)90178-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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184
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Kessler H, Gehrke M, Griesinger C. Zweidimensionale NMR-Spektroskopie, Grundlagen und Übersicht über die Experimente. Angew Chem Int Ed Engl 1988. [DOI: 10.1002/ange.19881000407] [Citation(s) in RCA: 169] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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185
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Kessler H, Gehrke M, Griesinger C. Two-Dimensional NMR Spectroscopy: Background and Overview of the Experiments [New Analytical Methods (36)]. ACTA ACUST UNITED AC 1988. [DOI: 10.1002/anie.198804901] [Citation(s) in RCA: 361] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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186
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Guerriero A, D'Ambrosio M, Pietra F. Slowly Interconverting Conformers of The Briarane Diterpenoids Verecynarmin B, C, and D, Isolated from the nudibranch molluscArmina maculata and the pennatulacean octocoralVeretillum cynomorium of East Pyrenean waters. Helv Chim Acta 1988. [DOI: 10.1002/hlca.19880710221] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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187
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Analysis of 1H NMR spectra with the combined use of zero- and double-quantum coherence. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-2364(88)90107-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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188
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Abdel-Sayed AN, Bauer L. Assignment of 13C and 1H cmemical shifts of 1,2-disubstituted adamantanes by one-and two-dimensional NMR spectroscopy. Tetrahedron 1988. [DOI: 10.1016/s0040-4020(01)90331-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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189
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190
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Lee M, Huss S, Gosselin G, Imbach JL, Hartley JA, Lown JW. Structure and conformation of the branch core triribonucleotide containing 2'-5' and 3'-5' phosphodiester linkages (A 2'p5'G 3'p5'C) i solution, essential for yeast mRNA splicing, deduced from 1H-NMR. J Biomol Struct Dyn 1987; 5:651-68. [PMID: 3078236 DOI: 10.1080/07391102.1987.10506418] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The non-exchangeable 1H-NMR signals of the branch core trinucleotide of the lariat branch site (A2'p5'G3'p5'C, 1) and its derivatives 2 and 3 are completely assigned using one- and two-dimensional NMR techniques including NOE, COSY, NOESY, 1H-1H INADEQUATE and 2D-J-resolved spectroscopy. From the vicinal coupling constants in the individual ribose rings, NOE data and T1 measurements, the following properties of the trimers are deduced. (i) The unique stacking behavior of the trimers is S2'N3'N, and the sugar rings exist predominantly in the N-conformation (3'-endo-2'-exo). (ii) The sugar-base orientations appear to be anti. (iii) The branched trimers exist in solution as single-stranded right-handed conformations resembling A-RNA with stacking between the adenine and guanine residues in aqueous solution at 21 degrees C and pH 7.2. (iv) The calculated values for the torsion angles epsilon t and gamma+ for the trimers are 201-203 degrees and 71-86%, respectively, while the percent beta t values are higher for the guanine (87-92%) than the cytosine residues (73-77%). The computer generated depiction of the triribonucleotide 1 is also shown. These subtle structural features may act as recognition signals for this critical lariat branch site which is essential for the second step in yeast mRNA splicing.
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Affiliation(s)
- M Lee
- Department of Chemistry, University of Alberta, Edmonton, Canada
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191
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Abstract
The 1H-n.m.r. spectra (200 MHz) of protonated (pD 3.9) and non-protonated (pD 11.9) tobramycin have been analysed completely by 2D methods. The 3JH,H values are consistent with an essentially undistorted 4C1 conformation for each of the three moieties and are practically independent of the state of protonation. The resonances in the 13C-n.m.r. spectrum (50 MHz) have been reassigned at both pD values on the basis of 2D1H-13C chemical-shift correlation and 1D selective INEPT measurements.
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Affiliation(s)
- L Szilágyi
- Department of Organic Chemistry, Lajos Kossuth University, Debrecen, Hungary
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192
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Günther H, Moskau D, Bast P, Schmalz D. Moderne NMR-Spektroskopie von Organolithium-Verbindungen. Angew Chem Int Ed Engl 1987. [DOI: 10.1002/ange.19870991205] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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193
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Hikichi K, Hiraoki T, Ikura M, Higuchi K, Eguchi K, Ohuchi M. Two-Dimensional INADEQUATE NMR Spectra of Ethylene-Propylene Copolymer. Polym J 1987. [DOI: 10.1295/polymj.19.1317] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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194
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Early TA, John BK, Johnson LF. Observation of homonuclear double-quantum correlations in plastic crystals using cross polarization and magic-angle spinning. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0022-2364(87)90321-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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195
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Lee M, Chang DK, Pon RT, Lown JW. Sequence dependent conformation and local geometry of the conserved branch site sequence element d(TpApCpTpApApC), essential for yeast mRNA splicing, deduced from high resolution 1H-NMR. J Biomol Struct Dyn 1987; 5:35-46. [PMID: 3271467 DOI: 10.1080/07391102.1987.10506373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The conserved sequence element and branch site splice signal d(TpApCpTpApApC) has been synthesized by a solid phase procedure. All the non-exchangeable protons have been assigned using a combination of one-dimensional and two-dimensional 1H-NMR analytical procedures. On the basis of the low NOE intensities in the 1D-NOE and NOESY experiments, the heptamer exists in solution as a random coil. The deoxyribose rings towards the 5' terminus exist predominantly in the S form (2'-endo-3'-exo) while residues on or adjacent to the 2' branch site in the eventual lariat structure [A(6) of TACTAAC] show more N-character (3'endo-2'-exo). In addition unique propeller twisting at contiguous AT base pairs in the consensus 5'-splice site occurs in the region in which there is partial complementarity with the branch splice signal TACTAAC. These subtle structural features, if carried over to the corresponding RNA, may have significance either as a recognition signals or for stereochemical reasons in the formation of the lariat intermediate in the maturation process of mRNA.
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Affiliation(s)
- M Lee
- Department of Chemistry University of Alberta, Edmonton, Canada
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196
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Debart F, Rayner B, Imbach JL, Lee M, Chang DK, Pon RT, Lown JW. Structure and conformation of the duplex consensus 5'-splice site d[(CpApGpGpTpApApGpT).(ApCpTpTpApCpCpTpG)] deduced from high field 1H-NMR of the non-exchangeable and imino protons. J Biomol Struct Dyn 1987; 5:47-65. [PMID: 3271468 DOI: 10.1080/07391102.1987.10506374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The complementary consensus donor exon intron junction d(ApCpTpTpApCpCpTpG) has been synthesized by a solid phase procedure. The non-exchangeable proton assignments were obtained using one- and two-dimensional NMR techniques including NOE, COSY, NOESY and 1H-1H-INADEQUATE. The non self-complementary nonamer exists as a random coil form in aqueous buffer at 21 degrees C as evidenced by the temperature variable 1H-NMR and NOE measurements. The nonamer was annealed to the primary consensus donor junction d(CpApGpGpTpApApGpT) and confirmation of complete annealing was obtained by detection and assignment of base pair imino protons in D2O/H2O mixtures. Application of one- and two-dimensional NMR techniques permitted the complete assignment of all the non-exchangeable protons in the duplex nonamer. These data, together with determination of vicinal coupling constants in the individual deoxyribose moieties, permits the following conclusions on the structure and conformation of the consensus donor junction: (i) it exists in aqueous solution in a conformation that belongs to the B family (ii) the sugar-base orientations are anti (iii) the deoxyribose units exist predominantly in the S conformation (2'-endo-3'-exo) (iv) the contiguous A.T base pairs d[T(5)-A(6)-A(7)].d[T(12)-T(13)-A(14)], two positions removed downstream from the splice site (5'-CAG decreases GTAAGT-3'), are uniquely propeller twisted. The propeller twisting occurs in the region in which there is partial complementarity with the branch site splice signal TACTAAC. The cross-correlation rates were used to derive the interproton distances between adjacent AH2 protons of 4.00 A in the T(5)-A(6).T(13)-A(14) step and of 3.87 A in the A(6)-A(7).T(12)-T(13) step. This structural and conformational feature if carried over into the primary RNA transcripts may serve as a recognition signal for this critical site in the genome.
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Affiliation(s)
- F Debart
- Laboratoire de Chimie Bio-Organique U.A. 488 du CNRS Université des Sciences, Montpellier, France
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197
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Buddrus J, Bauer H. Bestimmung des Kohlenstoffgerüsts organischer Verbindungen durch Doppelquanten-Kohärenz-13C-NMR-Spektroskopie, die INADEQUATE-Pulsfolge. Angew Chem Int Ed Engl 1987. [DOI: 10.1002/ange.19870990707] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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198
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Beale JM, Cottrellt CE, Keller PJ, Floss HG. Development of triple-quantum “INADEQUATE” for biosynthetic studies. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0022-2364(87)90165-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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199
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Jensen DJ, Delayre JL, Narayana PA. An incremental phase shifter and frequency modulator for magnetic resonance imaging and spectroscopy. IEEE Trans Biomed Eng 1987; 34:310-3. [PMID: 3504205 DOI: 10.1109/tbme.1987.326047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Debart F, Rayner B, Imbach JL, Chang DK, Lown JW. Structure and conformation of the duplex consensus acceptor exon:intron junction d[(CpTpApCpApGpGpT). (ApCpCpTpGpTpApG)] deduced from high-field 1H-NMR of non-exchangeable and imino protons. J Biomol Struct Dyn 1986; 4:343-63. [PMID: 3271448 DOI: 10.1080/07391102.1986.10506354] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The complementary consensus acceptor exon:intron junction d(ApCpCpTpGpTpApG) has been synthesized by a modified phosphotriester method. The non self-complementary octamer exists in the random coil form in aqueous buffer at 20 degrees C as evidenced by temperature variable 1H-NMR and NOE measurements. The non-exchangeable proton assignments were secured using a combination of techniques including two-dimensional COSY, NOESY and 1H-1H-INADEQUATE. The octamer was annealed with the primary consensus sequence d(CpTpApCpApGpGpT). Confirmation of complete duplex formation was confirmed by detection and assignment of imino protons in D2O:H2O mixtures. Assignment of the non-exchangeable proton signals in the duplex consensus junction was then secured by a combination of two-dimensional COSY correlations, NOESY and NOE experiments. Determination of individual vicinal coupling constants in the component deoxyribose moieties permitted deduction of the population of S conformations in this sequence. It is concluded that the consensus acceptor junction exists in solution in a conformation belonging to the B family, and that the bases are oriented anti. In addition the deoxyribose moieties in the 5' regions exist predominantly in the S form (2'endo-3'exo) whereas those residues on or adjacent to the junction on the primary strand show more N character (2'exo-3'endo). The contiguous bases A5-G6 (adjacent to the junction) and A15-G16 are stacked more closely than the other neighbor bases in this duplex sequence. These subtle structural and conformational differences in the exon:intron junction may serve as recognition signals for these critical sites in the genome.
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Affiliation(s)
- F Debart
- Laboratoire de Chimie Bio-Organique, CNRS Université des Sciences et Techniques du Languedoc, Montpellier, France
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