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- 3D structure (1)
- 5S ribosomal RNA (1)
- Artificial beta-strands (1)
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- Chemical probing (1)
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- DNA replication/DNA polymerase/accessory proteins/DNA primase (1)
- Electron transfer (1)
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- Iron; Acyl complexes; Trialkyltin hydride; Electron transfer catalysis; Cyclic voltammetry (1)
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- LPA production; ovarian cancer cells; PMA; PKC; PLA2 (1)
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Articles 1 - 14 of 14
Full-Text Articles in Chemistry
Phorbol 12-Myristate 13-Acetate Stimulates Lysophosphatidic Acid Secretion From Ovarian And Cervical Cancer Cells But Not From Breast Or Leukemia Cells, Zhongzhou Shen, Jerome Belinson, Richard E. Morton, Yan Xu
Phorbol 12-Myristate 13-Acetate Stimulates Lysophosphatidic Acid Secretion From Ovarian And Cervical Cancer Cells But Not From Breast Or Leukemia Cells, Zhongzhou Shen, Jerome Belinson, Richard E. Morton, Yan Xu
Chemistry Faculty Publications
Lysophosphatidic acid (LPA) is present in ascites from patients with ovarian cancer. It stimulates calcium release and growth of ovarian cancer cells bothin vitroandin vivo.Recently, we found that LPA levels were significantly elevated in plasma from patients with ovarian cancer and other gynecological cancers. In contrast, LPA levels were not elevated in patients with breast cancer and leukemias. In view of this, we investigated whether gynecological cancer cells could produce LPA. LPA was extracted from the supernatant of cells culturedin vitroand purified by thin layer chromatography. After hydrolysis and transmethylation, the fatty acid derivatives were analyzed by gas chromatography. We …
Fluorescence Analysis For Multi-Site Aluminum Binding To Natural Organic Matter, D. Scott Smith, James R. Kramer
Fluorescence Analysis For Multi-Site Aluminum Binding To Natural Organic Matter, D. Scott Smith, James R. Kramer
Chemistry Faculty Publications
Natural organic matter (NOM) samples isolated from different water sources in Norway were compared using their fluorescence properties. Fluorescence surfaces were observed at pH 4.36 and deconvoluted using SIMPLISMA (Windig and Guilment 1991). There were a total of seven different fluorophores observed for these samples and each sampling site had between four and six ofthe fluorescent components. These components were observed to bind Al during titrations at the same pH. Multiresponse titration curves were fit using the method of Smith and Kramer (1998) and most of the binding strengths are similar to values for Suwannee River fulvic acid (1ogK’ between …
Multi-Site Proton Interactions With Natural Organic Matter, D. Scott Smith, James R. Kramer
Multi-Site Proton Interactions With Natural Organic Matter, D. Scott Smith, James R. Kramer
Chemistry Faculty Publications
Water samples from various locations in Norway were used to isolate natural organic matter (NOM). The NOM was isolated using both reverse osmosis and low-pressure low-temperature evaporation for each sample site. These samples were titrated from -log[H+] 3 to 11 at 0.1 unit intervals. The data were analyzed using the Discrete Site Analysis (DISI) technique for pKa intervals of 0.2. The acidity constants are grouped into four classes: strong (pKa < 5), intermediate strong (5.1< pKa < 7.5), intermediate weak (7.6 < pKa < 9.2), and weak (pKa > 9.3). All samples, regardless of isolation method, were found to contain strong and weak ligands, along with some intermediate ligands. For the same …
Conserved Geometrical Base-Pairing Patterns In Rna, Neocles B. Leontis, Eric Westhof
Conserved Geometrical Base-Pairing Patterns In Rna, Neocles B. Leontis, Eric Westhof
Chemistry Faculty Publications
RNA molecules fold into a bewildering variety of complex 3D structures. Almost every new RNA structure obtained at high resolution reveals new, unanticipated structural motifs, which we are rarely able to predict at the current stage of our theoretical understanding. Even at the most basic level of specific RNA interactions – base-to-base pairing – new interactions continue to be uncovered as new structures appear. Compilations of possible non-canonical base-pairing geometries have been presented in previous reviews and monographs (Saenger, 1984; Tinoco, 1993). In these compilations, the guiding principle applied was the optimization of hydrogen-bonding. All possible pairs with two standard …
Comparison Between Dc-8 And Er-2 Species Measurements In The Tropical Middle Troposphere: No, NoY, O3, Co2, Ch4, And N2O, A. J. Weinheimer, D. D. Montzka, T. L. Campos, J. G. Walega, B. A. Ridley, Stephen G. Donnelly Ph.D., E. R. Keim, L. A. Del Negro, M. H. Proffitt, J. J. Margitan, K. A. Boering, A. E. Andrews, B. C. Daube, S. C. Wofsy, B. E. Anderson, J. E. Collins, G. W. Sachse, S. A. Vay, J. W. Elkins, P. R. Wamsley, E. L. Atlas, F. Flocke, S. Schauffler, C. R. Webster, R. D. May, M. Loewenstein, J. R. Podolske, T. P. Bui, K. R. Chan, S. W. Bowen, M. R. Schoeberl, L. R. Lait
Comparison Between Dc-8 And Er-2 Species Measurements In The Tropical Middle Troposphere: No, NoY, O3, Co2, Ch4, And N2O, A. J. Weinheimer, D. D. Montzka, T. L. Campos, J. G. Walega, B. A. Ridley, Stephen G. Donnelly Ph.D., E. R. Keim, L. A. Del Negro, M. H. Proffitt, J. J. Margitan, K. A. Boering, A. E. Andrews, B. C. Daube, S. C. Wofsy, B. E. Anderson, J. E. Collins, G. W. Sachse, S. A. Vay, J. W. Elkins, P. R. Wamsley, E. L. Atlas, F. Flocke, S. Schauffler, C. R. Webster, R. D. May, M. Loewenstein, J. R. Podolske, T. P. Bui, K. R. Chan, S. W. Bowen, M. R. Schoeberl, L. R. Lait
Chemistry Faculty Publications
We compare measurements of six species taken aboard NASA DC-8 and ER-2 aircraft during two flight legs in the tropical middle troposphere near Hawaii. NO, NOy, O3, CH4, and N2O measurements agree to within the limits set by the known systematic errors. For CO2, which can be measured with better relative precision than the other five species, differences in measured values from the two platforms are slightly larger than expected if the air masses sampled by the two aircraft were indeed similar in CO2 composition to better than 0.08%. Copyright 1998 by the American Geophysical Union.
Electron Transfer Catalysis Of The Hydrogenolysis Of Acyl Dicarbonyl Cyclopentadienyliron Complexes By Tributyltin Hydride, Christian Amatore, Mekki Bayachou, Olivier Buriez, Jean Noel Verpeaux
Electron Transfer Catalysis Of The Hydrogenolysis Of Acyl Dicarbonyl Cyclopentadienyliron Complexes By Tributyltin Hydride, Christian Amatore, Mekki Bayachou, Olivier Buriez, Jean Noel Verpeaux
Chemistry Faculty Publications
The conversion of acyl dicarbonyl cyclopentadienyliron compounds Cp(CO)2Fe(COR) into aldehydes is not straightforward. It is shown here, mainly from electrochemical results, that the hydrogenolysis of the metal acyl bond can be efficiently achieved by trialkytin hydrides under very mild conditions, according to a chain reaction process initiated by an electron transfer to the acyl complex. The expected aldehyde is formed together with the heterobinuclear iron-tin complex.
Simultaneous Formation Of Functional Leading And Lagging Strand Holoenzyme Complexes On A Small, Defined Dna Substrate, Anthony J. Berdis, Stephen J. Benkovic
Simultaneous Formation Of Functional Leading And Lagging Strand Holoenzyme Complexes On A Small, Defined Dna Substrate, Anthony J. Berdis, Stephen J. Benkovic
Chemistry Faculty Publications
The biochemical characterization of leading and lagging strand DNA synthesis by bacteriophage T4 replication proteins has been addressed utilizing a small, defined primer/template. The ATP hydrolysis activity of 44/62, the clamp loading complex responsible for holoenzyme assembly, was monitored during assembly of both the leading and lagging strand holoenzyme complex. The ATPase activity of 44/62 diminishes once a functional holoenzyme is assembled on both the leading and lagging strand. The assembly of the lagging strand holoenzyme is facilitated by several factors including biotinylated streptavidin blocks at the end of the fork strands, preassembly of the leading strand holoenzyme, and by …
Sequence-Specific Photomodification Of Dna By An Oligonucleotide-Phenanthrodihydrodioxin Conjugate, Kestutis G. Bendinskas, Andreas Harsch, R. Marshall Wilson, W. Robert Midden
Sequence-Specific Photomodification Of Dna By An Oligonucleotide-Phenanthrodihydrodioxin Conjugate, Kestutis G. Bendinskas, Andreas Harsch, R. Marshall Wilson, W. Robert Midden
Chemistry Faculty Publications
We introduce a new member of a family of photochemically active oligonucleotide conjugates. A Phenanthrodihydrodioxin (PDHD)-based agent was synthesized and covalently linked to a 5'-end of the 9-mer oligonucleotide via a hexamethylene linker. The conjugate hybridized to a complementary 30-nucleotide-long target and efficiently cleaved it in a sequence specific manner. Up to 67% of target was specifically damaged (51% cross-links and 16% direct cleavage). While the photosensitizer alone nonspecifically damaged only Gs in a single-stranded target, its conjugate cross-linked to and damaged also A, T, and C sites in a target in agreement with duplex and tripler formation.
The 5s Rrna Loop E: Chemical Probing And Phylogenetic Data Versus Crystal Structure, Neocles B. Leontis, Eric Westhof
The 5s Rrna Loop E: Chemical Probing And Phylogenetic Data Versus Crystal Structure, Neocles B. Leontis, Eric Westhof
Chemistry Faculty Publications
A significant fraction of the bases in a folded, structured RNA molecule participate in noncanonical base pairing interactions, often in the context of internal loops or multi-helix junction loops. The appearance of each new high-resolution RNA structure provides welcome data to guide efforts to understand and predict RNA 3D structure, especially when the RNA in question is a functionally conserved molecule. The recent publication of the crystal structure of the "Loop E" region of bacterial 5S ribosomal RNA is such an event [Correll CC, Freeborn B, Moore PB, Steitz TA, 1997, Cell 91:705-712]. In addition to providing more examples of …
Distance Dependence Of Electron Transfer Along Artificial Beta-Strands At 298 And 77 K, S. R. L. Fernando, Gennady V. Kozlov, Michael Y. Ogawa
Distance Dependence Of Electron Transfer Along Artificial Beta-Strands At 298 And 77 K, S. R. L. Fernando, Gennady V. Kozlov, Michael Y. Ogawa
Chemistry Faculty Publications
Photoinduced electron-transfer rate constants were measured for a series of binuclear metallopeptides consisting of a [Ru(bpy)(2)(cmbpy)](2+) electron donor tethered to a Co-III(NH3)(5) electron acceptor by an oligovaline peptide chain (bpy = 2,2'-bipyridine, cmbpy = 4-carboxy-4'-methyl-2,2'-bipyridine). These compounds were shown by H-1 NMR to adopt the conformational properties found within the individual strands of a beta-pleated sheet in both aqueous and methanol solutions. Emission lifetime measurements and HPLC product analysis show that the binuclear donor/acceptor compounds undergo photoinduced electron transfer (ET). The values of k(et) decrease with increasing donor/acceptor distance according to the expression k(et) = k' exp[-beta(r(-)r(0))]. A distance attenuation …
A Cell Cycle-Regulated Adenine Dna Methyltransferase From Caulobacter Crescentus Processively Methylates Gantc Sites On Hemimethylated Dna, Anthony J. Berdis, Irene Lee, James K. Coward, Craig Stephens, Rachel Wright, Lucy Shapiro, Stephen J. Benkovic
A Cell Cycle-Regulated Adenine Dna Methyltransferase From Caulobacter Crescentus Processively Methylates Gantc Sites On Hemimethylated Dna, Anthony J. Berdis, Irene Lee, James K. Coward, Craig Stephens, Rachel Wright, Lucy Shapiro, Stephen J. Benkovic
Chemistry Faculty Publications
The kinetic properties of an adenine DNA methyltransferase involved in cell cycle regulation of Caulobacter crescentus have been elucidated by using defined unmethylated or hemimethylated DNA (DNAHM) substrates. Catalytic efficiency is significantly enhanced with a DNAHM substrate. Biphasic kinetic behavior during methyl incorporation is observed when unmethylated or DNAHM substrates are used, indicating that a step after chemistry limits enzyme turnover and is most likely the release of enzyme from methylated DNA product. The enzyme is thermally inactivated at 30°C within 20 min; this process is substantially decreased in the presence of saturating concentrations of DNAHM, suggesting that the enzyme …
Dissociation Energies Of The Ga2, In2, And Gain Molecules, G Balducci, G Gigli, Giovanni Meloni
Dissociation Energies Of The Ga2, In2, And Gain Molecules, G Balducci, G Gigli, Giovanni Meloni
Chemistry Faculty Publications
The group III metal dimers Ga2 and In2 and the newly identified intermetallic molecule GaIn were investigated in a Knudsen cell-mass spectrometric study of the vapors over gallium–indium alloys. From the all-gas equilibria analyzed by the second-law and third-law methods the following dissociation energies were derived; D00 (Ga2)=110.8±4.9 kJ mol−1, D00 (In2)=74.4±5.7 kJ mol−1, D00 (GaIn)=90.7±3.7 kJ mol−1. The value here measured for the dissociation energy of In2 is discussed and compared with a previous experimental determination and with the results of more recent theoretical investigations.
Mea Culpa: Formal Education And The Dis-Integrated World., Brian P. Coppola, Douglas S. Daniels
Mea Culpa: Formal Education And The Dis-Integrated World., Brian P. Coppola, Douglas S. Daniels
Chemistry Faculty Publications
Formal education has removed itself so far from any truly integrated view of the Natural World that fragmentation and certainty are prevailing ethics. Technological progress has resulted in increased specialization within academic disciplines and their concurrent separation from each other. Knowledge is extracted from a fully integrated world, but is examined and defined by the 'dis-integrated' objectives.
Nano-Engineering Of Molecular Films By Self-Assembly And Langmuir-Blodgett Techniques, Erwin P. Enriquez
Nano-Engineering Of Molecular Films By Self-Assembly And Langmuir-Blodgett Techniques, Erwin P. Enriquez
Chemistry Faculty Publications
The availability of sophisticated and ultra-sensitive analytical tools and the maturity of organic synthesis have opened new possibilities for fabrication of molecular materials designed at the nanometer scale. Presently, the most promising and widely investigated methodologies are the self-assembly and Langmuir-Blodgett procedures. The former relies on the strong, preferential affinity of specific functional groups to solid surfaces, whereas the latter involves transfer of pre-formed mono layers at the air-water interface onto solid substrates. These techniques and their recent applications are reviewed.