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Creator | Title | Description | Subject | Date |
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Poulter, Charles Dale | (S)-Geranylgeranylglyceryl phosphate synthase. Purification and characterization of the first pathway-specific enzyme in archaebacterial membrane lipid biosynthesis | The first pathway-specific step in the biosynthesis of the core membrane diether lipids in archaebacteria is the alkylation of the primary hydroxyl group in (S)-glyceryl phosphate by geranylgeranyl diphosphate. The reaction is catalyzed by (S)-3-O-geranylgeranylglyceryl phosphate ((S)-GGGP) synthase... | Polyacrylamide gel; Molecular weight | 1993-10-15 |
2 |
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Poulter, Charles Dale; Davis, Darrell R. | 15N labeled e. coli tRNAMet, tRNAGlu, tRNATyr, and tRNAPhe. Double resonance and two dimensional NMR of H-N1 units in pseudouridine | The N1 imino units in Escherichia coli tRNAfMet, tRNAGlu, tRNAPhe, and tRNATyr were studied by 1H-15N NMR using three different techniques to suppress signals of protons not attached to 15N. Two of the procedures, Fourier internuclear difference spectroscopy and two-dimensional forbidden echo spectr... | Escherichia coli; Magnetic resonance spectroscopy; Nucleic acid conformation | 1985-08-15 |
3 |
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Poulter, Charles Dale; Davis, Darrell R. | 15N-labeled Escherichia coli tRNAfMet, tRNAGlu, tRNATyr, and tRNAPhe. Double resonance and two-dimensional NMR of N1-labeled pseudouridine. | The N1 imino units in Escherichia coli tRNAfMet, tRNAGlu, tRNAPhe, and tRNATyr were studied by 1H-15N NMR using three different techniques to suppress signals of protons not attached to 15N. Two of the procedures, Fourier internuclear difference spectroscopy and two-dimensional forbidden echo spectr... | Escherichia coli; Magnetic resonance spectroscopy; Nitrogen; Nucleic acid conformation | 1985-08-15 |
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Poulter, Charles Dale; Davis, Darrell R. | 15N-labeled tRNA. Identification of 4-thiouridine in Escherichia coli tRNASer1 and tRNATyr2 by 1H-15N two-dimensional NMR spectroscopy. | Uridine is uniquely conserved at position 8 in elongator tRNAs and binds to A14 to form a reversed Hoogsteen base pair which folds the dihydrouridine loop back into the core of the L-shaped molecule. On the basis of 1H NMR studies, Hurd and co-workers (Hurd, R. E., Robillard, G. T., and Reid, B. R. ... | Magnetic resonance spectroscopy | 1986-09-15 |
5 |
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Poulter, Charles Dale; Davis, Darrell R. | 15N-labeled tRNA. Identification of dihydrouridine in Escherichia coli tRNAfMet, tRNALys, and tRNAPhe by 1H-15N two-dimensional NMR. | The N3 imino units of dihydrouridine were identified in samples of 15N-labeled Escherichia coli tRNAfMet, tRNALys, and tRNAPhe by 1H-15N two-dimensional NMR. The peaks for dihydrouridine had high field 1H (9.7-9.8 ppm) and 15N (147.8-149.5 ppm) chemical shifts. Assignments were made by 1H-15N chemic... | Hydrogen Bonding; Magnetic Resonance Spectroscopy; Magnetic Resonance Spectroscopy | 1986-03-15 |
6 |
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Miller, Joel Steven | 1H NMR investigation of the magnetic spin configuration in the molecule-based ferrimagnet [MnTFPP][TCNE] | 1H NMR line-shape measurements have been performed in the linear chain molecule-based ferrimagnet [MnTFPP][TCNE].xPhMe (TFPP=tetrakis(4-fluorophenyl)porphinato; TCNE=tetracyanoethylene) as a function of temperature. Hyperfine shifts of opposite sign were observed indicating the presence of two oppo... | Magnetization; Magnets; Paramagnetic | 2002 |
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Morse, Michael David | The 3d?Ni(?F)3d10Cu???*? manifold of excited electronic states of NiCu | Diatomic NiCu has been supersonically cooled in a molecular beam and investigated by resonant two-photon ionization spectroscopy. A total of nine band systems connecting the ground 3d?Ni3??Cu??, X 2?5/2 state to the 3d?Ni(3F)3d??Cu??*?? manifold of states have been found, and bands of eight of these... | | 1992 |
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Morse, Michael David | The 846 nm A? ???u ? ??? band system of jet-cooled V? | The 846 nm band system of jet-cooled 5?V2 has been recorded using resonant two-photon ionization spectroscopy, and is assigned as the A ? 3?u- +X ??g- band system. Both the ?'= 1u? ?" = 1g and ?'= Ou+ ??? = 0g+ subbands of the O-O band have been rotationally resolved and analyzed. Although the trans... | | 1992 |
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Morse, Michael David | The ?IIou ?X ???g band system of jet-cooled Ti? | A band of jet-cooled ??Ti? has been located in the near infrared by resonant two-photon ionization spectroscopy. Rotational analysis has shown the band to be an ?? =O* ???=1 transition, which is consistent with the 3??g, ground state proposed by Bauschlicher ef al. [J. Chem. Phys. 95, 1057 ( 1991)]... | | 1992 |
10 |
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Miller, Joel Steven | [Et4N]2[TCNE]2 (TCNE = tetracyanoethylene) - an example of an exceptionally long 2.827 Ã CC bond | Interest in organic compounds exhibiting unusually long CC bonds has been the subject of several recent studies.1-3 The longest sp3-sp3 C-C single bond reported to date is 1.73 A°,1,2 whereas several [TCNE]22- (TCNE = tetracyanoethylene) dimers have been recently reported to form cation-assisted, l... | Synthesis; Crystal; Solution | 2001 |
11 |
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Morse, Michael David | A pair potentials study of matrix-isolated atomic zinc. II. Intersystem crossing in rare-gas clusters and matrices | The mechanism of 4p 1P1?4p 3PJ intersystem crossing (ISC) following excitation of the 4p 1P1 level of matrix-isolated atomic zinc is investigated using a pair potentials approach. This is achieved by extending earlier ISC calculations on the Zn?RG2 and Zn?RG3 complexes to the square planar Zn?RG4 ... | | 1998 |
12 |
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Voth, Gregory Alan | Ab initio calculations of reactive pathways for ?-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (?-HMX) | Using the BLYP and B3LYP level of density functional theory, four possible decomposition reaction pathways of HMX in the gas phase were investigated: N?NO2 bond dissociation, HONO elimination, C?N bond scission of the ring, and the concerted ring fission. The energetics of each of these four mechan... | Ab initio calculations; Reactive pathways; HMX | 2000 |
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Armentrout, Peter B. | Activation of methane by gold cations: guided ion beam and theoretical studies | The potential energy surface for activation of methane by the third-row transition metal cation, Au+, is studied experimentally by examining the kinetic energy dependence of this reaction using guided ion beam tandem mass spectrometry. A flow tube ion source produces Au+ primarily in its 1S0 (5d10) ... | | 2006 |
14 |
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Armentrout, Peter B. | Activation of methane by size-elected iron cluster cations, Fen+ (n=2-15): cluster-CHx (x=0-3) bond energies and reaction mechanisms | The kinetic energy dependences of the reactions of Fen + (n=2 - 15) with CD4 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. All reactions exhibit thresholds and two main products, FenD+ and FenCD2+, are formed. | Metal clusters; Iron ions; Bond energies; Dehydrogenation; Endothermic reactions; Transition metal ions | 2001 |
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Miller, Joel Steven; Epstein, Arthur J. | Anomalous charge transport phenomena in the molecular-based magnet V(TCNE)x.y(solvent) | We present charge transport studies on recently developed molecular-based magnets V(TCNE)x. y(solvent) (TCNE= tetracyanoethylene) which show local magnetic ordering at temperatures, T, as high as 400 K. V(TCNE), .y(solvent) prepared from the solvent CH2Cl2 has o(300 K) - 10-3 S/cm, and that prepar... | Frequency; Conductivity; Spin | 1993 |
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Miller, Joel Steven; Epstein, Arthur J. | Anomalous magnetoresistance in high-temperature organic-based magnetic seminconducting V(TCNE)x films | Anomalous positive magnetoresistance (MR) in high temperature organic-based magnet V(TCNE)x (TCNE=tetracynoethylene) thin films is reported. MR increases linearly with applied magnetic field and shows a maximum at the ferrimagnetic ordering temperature. The suggested roles of oppositely spin pola... | Spin; Ferrimagnetic; Resistance | 2003 |
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Miller, Joel Steven; Epstein, Arthur J. | Anomalous relaxation in a quasi-one-dimensional fractal cluster glass | The low-temperature spin glass state of the quasi-1D organic-based magnet [MnTPP]+[TCNE]- .x(1,3-C6H4Cl2) has unusually long relaxation times due to frustration induced by dipole-dipole interactions between fractal spin clusters. This long relaxation is investigated with in-field relaxation measurem... | Sweep rate; Bifurcation; Magnetization | 2004 |
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Morse, Michael David | The bond energy of Rh? | In a spectroscopic investigation of jet-cooled Rh2 by the resonant two-photon ionization method, an abrupt predissociation threshold is observed in a dense set of vibronic levels at 19 405?4 cm-1. Based on the high density of states expected in the rhodium dimer, the sharp definition of the prediss... | | 1997 |
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Truong, Thanh | Branching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics study | The dynamics of the initial thermal decomposition step of gas-phase ?-HMX is investigated using the master equation method. Both the NO2 fission and HONO elimination channels were considered. The structures, energies, and Hessian information along the minimum energy paths (MEP) of these two channels... | Thermal decomposition; HMX | 2001 |
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Poulter, Charles Dale; Jiang, Yunfeng | BTS1 encodes a geranylgeranyl diphosphate synthase in Saccharomyces cerevisiae | Protein prenylation utilizes different types of isoprenoids groups, namely farnesyl and geranylgeranyl, to modify proteins. These lipophilic moieties attach to carboxyl-terminal cysteine residues to promote the association of soluble proteins to membranes. Most prenylated proteins are geranylgeranyl... | Amino Acid Sequence; Cloning, Molecular; Gene Expression | 1995-09-15 |
21 |
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Armentrout, Peter B. | C+(2P) + H2(D2,HD)→CH+(CD+) + H(D). I. Reaction cross sections and kinetic isotope effects from threshold to 15 eV c.m. | Total cross sections for the reactions of carbon (1 + ) ions with isotopic molecular hydrogen (H2, D2 , and HD) to form methyliumylidene (CH+ and C D + ) have been measured using guided ion beam techniques. Cross sections are reported as a function of the translational energy of the reactants fro... | Ion-molecule reactions; Isotope effects; Translational energy; Threshold behavior; Endothermic reactions | 1986 |
22 |
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Armentrout, Peter B. | C+(2P)+H2(D2,HD)→CH+(CD+)+H(D). I. Reaction cross sections and kinetic isotope effects from threshold to 15eV c.m. | Total cross sections for the reactions of carbon (1 + ) ions with isotopic molecular hydrogen (H2, D2, and HD) to form methyliumylidene (CH+ and CD+) have been measured using guided ion beam techniques. Cross sections are reported as a function of the translational energy of the reactants from th... | Methyliumylidene; Endothermic reactions; Isotope effect; Threshold energy | 1986 |
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Poulter, Charles Dale | CaaX proteases, Afc1p and Rce1p, have overlapping but distinct substrate specificities | Many proteins that contain a carboxyl-terminal CaaX sequence motif, including Ras and yeast a-factor, undergo a series of sequential posttranslational processing steps. Following the initial prenylation of the cysteine, the three C-terminal amino acids are proteolytically removed, and the newly fo... | Proteins; Enzymes; Hydrophobic | 2000 |
24 |
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Orendt, Anita; Pugmire, Ronald J. | Carbon-13 chemical shift tensors in polycyclic aromiatic compounds. 9. Biphenylene | The principal values of the 13C chemical-shift tensors of natural abundance biphenylene were measured at room temperature with the FIREMAT experiment. Of 18 crystallographically distinct positions (three sets of six congruent carbons each), the three primary bands have been resolved into seven singl... | Carbon-13; Chemical-shift tensors; Biphenylene; Polycyclic aromiatic compounds; FIREMAT | 2000 |
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Poulter, Charles Dale | Catalytic mechanism of Escherichia coli isopentenyl diphosphate isomerase involves Cys-67, Glu-116, and Tyr-104 as suggested by crystal structures of complexes with transition state analogues and irreversible inhibitors | Isopentenyl diphosphate (IPP):dimethylallyl diphosphate (DMAPP) isomerase is a key enzyme in the biosynthesis of isoprenoids. The reaction involves protonation and deprotonation of the isoprenoid unit and proceeds through a carbocationic transition state. Analysis of the crystal structures (2 A) of ... | Catalytic Domain; Crystallography; Organophosphorus Compounds | 2003-04-04 |