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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Association Of G-Quadruplex Forming Sequences With Human Mtdna Deletion Breakpoints, D. W. Dong, F. Pereira, Steven Paul Barrett , '13, J. E. Kolesar, K. Cao, J. Damas, Liliya A. Yatsunyk, F. B. Johnson, B. A. Kaufman
Association Of G-Quadruplex Forming Sequences With Human Mtdna Deletion Breakpoints, D. W. Dong, F. Pereira, Steven Paul Barrett , '13, J. E. Kolesar, K. Cao, J. Damas, Liliya A. Yatsunyk, F. B. Johnson, B. A. Kaufman
Chemistry & Biochemistry Faculty Works
Background: Mitochondrial DNA (mtDNA) deletions cause disease and accumulate during aging, yet our understanding of the molecular mechanisms underlying their formation remains rudimentary. Guanine-quadruplex (GQ) DNA structures are associated with nuclear DNA instability in cancer; recent evidence indicates they can also form in mitochondrial nucleic acids, suggesting that these non-B DNA structures could be associated with mtDNA deletions. Currently, the multiple types of GQ sequences and their association with human mtDNA stability are unknown. Results: Here, we show an association between human mtDNA deletion breakpoint locations (sites where DNA ends rejoin after deletion of a section) and sequences with G-quadruplex …
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott Harpstrite, Julie Prior, Hannah Gu, David Piwnica-Worms
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott Harpstrite, Julie Prior, Hannah Gu, David Piwnica-Worms
Chemistry & Biochemistry Faculty Works
Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI.
High Resolution Electronic Spectroscopy Of The A 2 Σ − − X 2 Π 1/2 Transition Of Ptn, Kaitlin Womack, Sean Whittemore, James O'Brien, An Le, Timothy Steimle
High Resolution Electronic Spectroscopy Of The A 2 Σ − − X 2 Π 1/2 Transition Of Ptn, Kaitlin Womack, Sean Whittemore, James O'Brien, An Le, Timothy Steimle
Chemistry & Biochemistry Faculty Works
The (2,0) vibrational band of the A {sup 2}Σ{sup −} − X {sup 2}Π{sub 1/2} transition of platinum nitride, PtN, was recorded at Doppler-limited resolution using intracavity laser absorption spectroscopy (ILS) and at sub-Doppler resolution using molecular beam laser induced fluorescence (LIF) spectroscopy. Isotopologue structure for {sup 194}PtN, {sup 195}PtN, and {sup 196}PtN, magnetic hyperfine splitting due to {sup 195}Pt (I = ½), and nuclear quadrupole splitting due to {sup 14}N (I = 1) were observed in the spectrum. Molecular constants for the ground and excited states are derived. The hyperfine interactions are used to illuminate the nature of the …
Relay Cross Metathesis Reactions Of Vinylphosphonates, Raj Malla, Jeremy Ridenour, Christopher Spilling
Relay Cross Metathesis Reactions Of Vinylphosphonates, Raj Malla, Jeremy Ridenour, Christopher Spilling
Chemistry & Biochemistry Faculty Works
Dimethyl (β-substituted) vinylphosphonates do not readily undergo cross metathesis reactions with Grubbs catalyst and terminal alkenes. However, the corresponding mono- or diallyl vinylphosphonate esters undergo facile cross metathesis reactions. The improved reactivity is attributed to a relay step in the cross metathesis reaction mechanism.
N-Methylimidazole Promotes The Reaction Of Homophthalic Anhydride With Imines, J. Liu, Z. Wang, A. Levin, T. J. Emge, Paul R. Rablen, D. M. Floyd, S. Knapp
N-Methylimidazole Promotes The Reaction Of Homophthalic Anhydride With Imines, J. Liu, Z. Wang, A. Levin, T. J. Emge, Paul R. Rablen, D. M. Floyd, S. Knapp
Chemistry & Biochemistry Faculty Works
The addition of N-methylimidazole (NMI) to the reaction of homophthalic anhydride with imines such as pyridine-3-carboxaldehyde-N-trifluoroethylimine (9) reduces the amount of elimination byproduct and improves the yield of the formal cycloadduct, tetrahydroisoquinolonic carboxylate 10. Carboxanilides of such compounds are of interest as potential antimalarial agents. A mechanism that rationalizes the role of NMI is proposed, and a gram-scale procedure for the synthesis and resolution of 10 is also described.
2-Acylamido Analogues Of N-Acetylglucosamine Prime Formation Of Chitin Oligosaccharides By Yeast Chitin Synthase 2, Jacob Gyore, Archana Parameswar, Carleigh Hebbard, Younghoon Oh, Erfei Bi, Alexei Demchenko, Neil Price, Peter Orlean
2-Acylamido Analogues Of N-Acetylglucosamine Prime Formation Of Chitin Oligosaccharides By Yeast Chitin Synthase 2, Jacob Gyore, Archana Parameswar, Carleigh Hebbard, Younghoon Oh, Erfei Bi, Alexei Demchenko, Neil Price, Peter Orlean
Chemistry & Biochemistry Faculty Works
Chitin, a homopolymer of β1,4-linked N-acetylglucosamine (GlcNAc) residues, is a key component of the cell walls of fungi and the exoskeletons of arthropods. Chitin synthases transfer GlcNAc from UDP-GlcNAc to preexisting chitin chains in reactions that are typically stimulated by free GlcNAc. The effect of GlcNAc was probed by using a yeast strain expressing a single chitin synthase, Chs2, by examining formation of chitin oligosaccharides (COs) and insoluble chitin, and by replacing GlcNAc with 2-acylamido analogues of GlcNAc. Synthesis of COs was strongly dependent on inclusion of GlcNAc in chitin synthase incubations, and N,N′-diacetylchitobiose (GlcNAc2) was the major reaction product. …
Spontaneous Transfer Of Chirality In An Atropisomerically Enriched Two-Axis System, K. T. Barrett, A. J. Metrano, Paul R. Rablen, S. J. Miller
Spontaneous Transfer Of Chirality In An Atropisomerically Enriched Two-Axis System, K. T. Barrett, A. J. Metrano, Paul R. Rablen, S. J. Miller
Chemistry & Biochemistry Faculty Works
One of the most well-recognized stereogenic elements in a chiral molecule is an sp(3)-hybridized carbon atom that is connected to four different substituents. Axes of chirality can also exist about bonds with hindered barriers of rotation; molecules containing such axes are known as atropisomers(1). Understanding the dynamics of these systems can be useful, for example, in the design of single-atropisomer drugs(2) or molecular switches and motors(3). For molecules that exhibit a single axis of chirality, rotation about that axis leads to racemization as the system reaches equilibrium. Here we report a two-axis system for which an enantioselective reaction produces four …
N-Methylmesoporphyrin Ix Fluorescence As A Reporter Of Strand Orientation In Guanine Quadruplexes, Navin C. Sabharwal , '14, V. Savikhin, Joshua R. Turek-Herman , '16, John Michael Nicoludis , '12, V. A. Szalai, Liliya A. Yatsunyk
N-Methylmesoporphyrin Ix Fluorescence As A Reporter Of Strand Orientation In Guanine Quadruplexes, Navin C. Sabharwal , '14, V. Savikhin, Joshua R. Turek-Herman , '16, John Michael Nicoludis , '12, V. A. Szalai, Liliya A. Yatsunyk
Chemistry & Biochemistry Faculty Works
Guanine quadruplexes (GQ) are four-stranded DNA structures formed by guanine-rich DNA sequences. The formation of GQs inhibits cancer cell growth, although the detection of GQs invivo has proven difficult, in part because of their structural diversity. The development of GQ-selective fluorescent reporters would enhance our ability to quantify the number and location of GQs, ultimately advancing biological studies of quadruplex relevance and function. N-methylmesoporphyrin IX (NMM) interacts selectively with parallel-stranded GQs; in addition, its fluorescence is sensitive to the presence of DNA, making this ligand a possible candidate for a quadruplex probe. In the present study, we investigated the effect …
Thioflavin T As A Fluorescence Light-Up Probe For G4 Formation, A. R. De La Faverie, A. Guédin, A. Bedrat, Liliya A. Yatsunyk, J.-L. Mergny
Thioflavin T As A Fluorescence Light-Up Probe For G4 Formation, A. R. De La Faverie, A. Guédin, A. Bedrat, Liliya A. Yatsunyk, J.-L. Mergny
Chemistry & Biochemistry Faculty Works
Thioflavin T (ThT) becomes fluorescent in the presence of the G-quadruplex structure such as that formed by the human telomeric motif. In this report, we extend and generalize these observations and show that this dye may be used as a convenient and specific quadruplex probe. In the presence of most, but not all, G4-forming sequences, we observed a large increase in ThT fluorescence emission, whereas the presence of control duplexes and single strands had a more limited effect on emission. This differential behavior allowed us to design a high-throughput assay to detect G4 formation. Hundreds of different oligonucleotides may be …
Structural Insights Into The Interaction Between A Potent Anti-Inflammatory Protein, Viral Cc Chemokine Inhibitor (Vcci), And The Human Cc Chemokine, Eotaxin-1, Nai-Wei Kuo, Yong-Guang Gao, Megan Schill, Nancy Isern, Cynthia Dupureur, Patricia Liwang
Structural Insights Into The Interaction Between A Potent Anti-Inflammatory Protein, Viral Cc Chemokine Inhibitor (Vcci), And The Human Cc Chemokine, Eotaxin-1, Nai-Wei Kuo, Yong-Guang Gao, Megan Schill, Nancy Isern, Cynthia Dupureur, Patricia Liwang
Chemistry & Biochemistry Faculty Works
Chemokines play important roles in the immune system, not only recruiting leukocytes to the site of infection and inflammation but also guiding cell homing and cell development. The soluble poxvirus-encoded protein viral CC chemokine inhibitor (vCCI), a CC chemokine inhibitor, can bind to human CC chemokines tightly to impair the host immune defense. This protein has no known homologs in eukaryotes and may represent a potent method to stop inflammation. Previously, our structure of the vCCI·MIP-1β (macrophage inflammatory protein-1β) complex indicated that vCCI uses negatively charged residues in β-sheet II to interact with positively charged residues in the MIP-1β N …
Intrinsic Delocalization During The Decay Of Excitons In Polymeric Solar Cells, Thomas George, W. Chen, D. Jiang, R. Chen, S. Li
Intrinsic Delocalization During The Decay Of Excitons In Polymeric Solar Cells, Thomas George, W. Chen, D. Jiang, R. Chen, S. Li
Chemistry & Biochemistry Faculty Works
In bulk heterojunction polymer solar cells, external photoexcitation results in localized excitons in the polymer chain. After hot exciton formation and subsequent relaxation, the dipole moment drives the electron to partially transfer to extended orbitals from the original localized ones, leading to self-delocalization. Based on the dynamic fluorescence spectra, the delocalization of excitons is revealed to be an intrinsic property dominated by exciton decay, acting as a bridge for the exciton to diffuse in the polymeric solar cell. The modification of the dipole moment enhances the efficiency of polymer solar cells.