2 Deuteration
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Espalhamento Raman em Policristais de L-alanina deuterados sob pressÃo. / Raman spectroscopy on deuterated L-alanine crystals under hydrostatic pressure.
Nesta DissertaÃÃo sÃo apresentados os resultados oriundos do estudo do efeito da aplicaÃÃo de pressÃo hidrostÃtica sobre cristais de L-alanina deuterada. A L-alanina à um dos vinte aminoÃcidos formadores das proteÃnas, sendo entre os quirais o mais simples deles. A L-alanina cristaliza-se numa estrutura ortorrÃmbica (D24) com quatro molÃculas por
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/07/2008
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2. Procedure for C2 deuteration of nucleic acids and determination of A psi 31 pseudouridine conformation by nuclear Overhauser effect in yeast tRNAPhe.
Nuclear Overhauser effect (NOE) combined with semispecific deuteration provides a general strategy for identification of exchangeable protons in nucleic base pairs, and has been extended to NOEs involving purine C2 protons in tRNA. Deuterated tri-ethyl orthoformate was condensed with 5(4)-amino imidazole 4(5)-carboxamide to yield C2 deuterated hypoxanthine.
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3. Whole-body irradiation of deuterated mice by the 10B(n, alpha)7Li reaction.
Specific pathogen-free mice, 8-12 wk of age, were supplied with either acidified tap water or acidified 30 atom % 2H2O in tap water. Thirteen days later, when body water deuterium was about 20 atom %, mice were irradiated either by neutrons or by x-rays after intraperitoneal injection of boric acid. Mortality from whole-body neutron-boron radiation, unlike m
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4. Determination of retinal Schiff base configuration in bacteriorhodopsin
Resonance Raman spectra of the BR568, BR548, K625, and L550 intermediates of the bacteriorhodopsin photocycle have been obtained in 1H2O and 2H2O by using native purple membrane as well as purple membrane regenerated with 14,15-13C2 and 12,14-2H2 isotopic derivatives of retinal. These derivatives were selected to determine the contribution of the C14—C15 s
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5. An efficient and economic site-specific deuteration strategy for NMR studies of homologous oligonucleotide repeat sequences.
We describe herein the use of a 2H-labeling strategy to achieve specific assignments of considerably overlapped cross peaks in the 1H-NMR spectrum of a DNA trinucleotide repeat sequence. Our strategy focuses on site-specific 2H-labeling of base moieties to simplify the NMR spectral regions which contain the major portion of the structural information. To ach
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6. Thermal stability of poly(A) and poly(U) complexes in H2O and D2O: isotopic effects on critical temperatures and transition widths.
This is a study of the effect of total and partial deuteration of solvent on critical temperatures and profiles of all four reactions occurring in poly(A) x n poly(U) (n = 1 or 2) aqueous systems. The study was done at observational times not longer than hydrogen exchange times at base pairs in helically ordered structures, and it was extended to a wide rang
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7. Preparation and characterization of a uniformly 2 H/ 15 N-labeled RNA oligonucleotide for NMR studies.
An RNA oligonucleotide that contains the binding site for Escherichia coli ribosomal protein S8 was prepared with uniform 15N isotopic enrichment and uniform deuterium enrichment at all non-exchangeable sites using enzymatic methods. The RNA binding site, which contains 44 nt, forms a hairpin in solution and requires Mg2+for proper folding. The longitudinal
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8. Insight into the mechanism of aromatic hydroxylation by toluene 4-monooxygenase by use of specifically deuterated toluene and p-xylene
The present studies address the mechanism of aromatic hydroxylation used by the natural and G103L isoforms of the diiron enzyme toluene 4-monooxygenase. These isoforms have comparable catalytic parameters but distinct regiospecificities for toluene hydroxylation. Hydroxylation of ring-deuterated p-xylene by the natural isoform revealed a substantial inverse
The National Academy of Sciences.
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9. Neutron scattering in the plane of membranes: structure of alamethicin pores.
A technique of neutron in-plane scattering for studying the structures of peptide pores in membranes is described. Alamethicin in the inserted state was prepared and undeuterated and deuterated dilauroyl phosphatidylcholine (DLPC) hydrated with D2O or H2O. Neutron in-plane scattering showed a strong dependence on deuteration, clearly indicating that water is
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10. Specific deuteration of dichlorobenzoate during reductive dehalogenation by Desulfomonile tiedjei in D2O.
Desulfomonile tiedjei DCB-1 is a strict anaerobe capable of reductively dechlorinating meta-chlorobenzoates. To probe the mechanism of this aryl dechlorination, we incubated cell suspensions of D. tiedjei in D2O and with 2,5-dichlorobenzoate. The deuterium was incorporated into the dechlorination product exclusively at the position of dehalogenation, as show
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11. Resonance coherent anti-Stokes Raman scattering spectra of fluorescent biological chromophores: Vibrational evidence for hydrogen bonding of flavin to glucose oxidase and for rapid solvent exchange
Coherent anti-Stokes Raman scattering (CARS) spectra are reported for flavin adenine dinucleotide (FAD) and glucose oxidase (β-D-glucose:oxygen 1-oxidoreductase; EC 1.1.3.4), in resonance with the 450 nm flavin absorption band. Several isoalloxazine ring modes were observed (1635, 1584, 1507, 1416, and 1359 cm-1). A 12 cm-1 increase in one component of the
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12. Guanine and 7-methylguanine amino proton exchange rates as a function of buffer pK: implications for the exchange mechanism.
Using the stopped-flow kinetic method we have measured the deuteration rate of the amino protons in 2'deoxyguanosine 5'monophosphate and 7-methylguanosine 5'monophosphate. For both compounds the exchange rates are accelerated with increasing concentration of a large number of buffers with widely differing pKs. The results obtained, in conjunction with a theo