Chemistry Commons^™

Laser-Induced Photon-Branched Chain Reaction In A Chemically-Active Gas-Dispersed Medium, Thomas George, Renat Letfullin, Galen Duree

Chemistry & Biochemistry Faculty Works

A promising avenue in the development of high-energy pulsed chemical HF/DF lasers and amplifiers is the utilization of a photon-branched chain reaction initiated in a two-phase active medium, that is, a medium containing a laser working gas and ultradispersed passivated metal particles. These particles are evaporated under the action of IR laser radiation which results in the appearance of free atoms, their diffusion into the gas, and the development of a photon-branching chain process, which involves photons as both reactants and products. The key obstacle here is the formation of a relatively large volume (in excess of 10^3 cm^3) of …

Structure And Dynamics Of Metalloproteins In Live Cells, Jeremy D. Cook, James E. Penner-Hahn, Timothy L. Stemmler

Biochemistry and Molecular Biology Faculty Publications

X-ray absorption spectroscopy (XAS) has emerged as one of the premier tools for investigating the structure and dynamic properties of metals in cells and in metal containing biomolecules. Utilizing the high flux and broad energy range of X-rays supplied by synchrotron light sources, one can selectively excite core electronic transitions in each metal. Spectroscopic signals from these electronic transitions can be used to dissect the chemical architecture of metals in cells, in cellular components and in biomolecules at varying degrees of structural resolution. With the development of ever-brighter X-ray sources, X-ray methods have grown into applications that can be utilized …

Three-Dimensional Microfluidic Devices Fabricated In Layered Paper And Tape, Andres W. Martinez, Scott T. Phillips, George M. Whitesides

Chemistry and Biochemistry

This article describes a method for fabricating 3D microfluidic devices by stacking layers of patterned paper and double-sided adhesive tape. Paper-based 3D microfluidic devices have capabilities in microfluidics that are difficult to achieve using conventional open-channel microsystems made from glass or polymers. In particular, 3D paper-based devices wick fluids and distribute microliter volumes of samples from single inlet points into arrays of detection zones (with numbers up to thousands). This capability makes it possible to carry out a range of new analytical protocols simply and inexpensively (all on a piece of paper) without external pumps. We demonstrate a prototype 3D …

Cariporide Prodrugs: Targeting Brain Cancer Cells Through Sodium-Proton Exchange Inhibition, Jacob Vervynckt, Johnathan Brantley, Jessica Moore, Mark Graves Ii, William Harley, Fredric A. Gorin, Hasan Palandoken

Chemistry and Biochemistry

More than 200,000 people in the United States are diagnosed with a primary or metastatic brain tumor annually. The life expectancy for these individuals is approximately 9-12 months from the time of diagnosis. This poor prognosis is due to the ineffectiveness of existing therapies (i.e., chemotherapy and radiotherapy) against brain cancer, where the primary problem is the inability to differentiate cancer cells from healthy brain cells.

Relative to healthy brain tissue, the heightened metabolism of cancer cells increases their reliance on the ion transport proteins NHE (sodium-proton exchanger) and NCX (sodium-calcium exchanger). Inhibition of these proteins disrupts the intricate pH …

Alkoxyamine Polymers: Versatile Materials For Surface Ligation Applications, Lindsey Hines, Jessica Moore, David Dahl, Belinda Lady, Johnathan Brantley, Hasan Palandoken

Chemistry and Biochemistry

Immobilization of biomolecules (i.e., proteins, carbohydrates), on polymeric surfaces has been an area of intense research. The resultant bioconjugates often display increased stability, bioavailability and activity. Our research program seeks to explore the utility of the alkoxyamine (RONH2) functional group in new materials as versatile ligating sites for the immobilization of various compounds.

The ease with which alkoxyamines (RONH2) condense with aldehydes or ketones has prompted their widespread use in labelling liposome, bacterial and mammalian cell surfaces as well as chemoselectively ligating small molecule ‘recognition elements' onto polyfunctional substrates. These condensation reactions proceed in aqueous media to afford the robust …

Removal Of Benzaldehyde From Methanol Using Alkoxyamine Functionalized Silica Gel, Dino Sulejmanovic, Carrie Jo Pruitt, Eric Conte, Hasan Palandoken, Shing-Yi Suen

Chemistry and Biochemistry

Alkoxyamines (RONH₂) react readily with aldehydes and ketones to form stable oxime ethers, and, thus are expected to be excellent scavengers of these compounds. We installed alkoxyamines on silica gel surface to remove benzaldehyde from methanol. Silica gel was immersed in H₂O₂/H₂SO₄ solution to activate the surface. Activated silica gel was then reacted with 3-chloropropyltrichlorosilane. Displacement of the chloride with N-hydroxyphthalimide and subsequent treatment with hydrazine provided alkoxyamines on the surface of silica gel. The resulting silica gel surface with alkoxyamine functional groups was immersed in a 100 ppm benzaldehyde solution …

The Effects Of A Networked Data Acquisition System On Student Learning In General Chemistry Laboratories, Stuart C. Burris, Les L. Pesterfield, Darwin Dahl, Hasan Palandoken, Jacqueline Pope-Tarrence

Chemistry and Biochemistry

We have recently incorporated a networked data acquisition and analysis system into in our second semester general chemistry laboratories. Our investigation team has conducted a study to evaluate the effects of the networked data acquisition system on student performance on a Beer's Law laboratory. We focused on two specific phenomena: the effect of the networked data acquisition system on 1) student learning of specific content material and 2) student comfort level with laboratory work and data analysis. The study involved a networked data acquisition group (employing a UV-Vis spectrometer and colorimeters) and a control group (employing traditional, single wavelength spectrometers). …

Dynamics Of Apomyoglobin In The Α-To-Β Transition And Of Partially Unfolded Aggregated Protein, E. Fabiani, A. M. Stadler, D. Madern, M. M. Koza, M. Tehei, M. Hirai, G. Zaccai

Faculty of Science - Papers (Archive)

Changes of molecular dynamics in the α-to-β transition associated with amyloid fibril formation were explored on apo-myoglobin (ApoMb) as a model system. Circular dichroism, neutron and X-ray scattering experiments were performed as a function of temperature on the protein, at different solvent conditions. A significant change in molecular dynamics was observed at the α-to-β transition at about 55 ˚C, indicating a more resilient high temperature β structure phase. A similar effect at approximately the same temperature was observed in holo-myoglobin, associated with partial unfolding and protein aggregation. A study in a wide temperature range between 20 K and 360 K …

Simple Inhibitors Of Histone Deacetylase Activity That Combine Features Of Short-Chain Fatty Acid And Hydroxamic Acid Inhibitors, Jessica L. Tischler, Basel Abuaita, Sierra C. Cuthpert, Christopher Fage, Kristi Murphy, Andrew Saxe, Edward B. Furr, Jamie Hedrick, Jennifer Meyers, David Snare, Ali R. Zand

Chemistry & Biochemistry Publications

Butyric acid and trichostatin A (TSA) are anti-cancer compounds that cause the upregulation of genes involved in differentiation and cell cycle regulation by inhibiting histone deacetylase (HDAC) activity. In this study we have synthesized and evaluated compounds that combine the bioavailability of short-chain fatty acids, like butyric acid, with the bidentate binding ability of TSA. A series of analogs were made to examine the effects of chain length, simple aromatic cap groups, and substituted hydroxamates on the compounds' ability to inhibit rat-liver HDAC using a fluorometric assay. In keeping with previous structure-activity relationships, the most effective inhibitors consisted of longer …

Molecular-Orientation-Dependent Ac Stark Effect And Its Impact On Multiphoton Processes, Xi Chu

Chemistry and Biochemistry Faculty Publications

We study the dependence of the ac Stark shifts of electronic energies on the molecular orientation relative to the polarization direction of an incident intense laser field, using a three-dimensional non-Hermitian Floquet method and H(2)+ as a model system. Simultaneously, we also study the orientation-dependent high-order harmonic generation (HHG) and multiphoton ionization (MPI). We find that with the presence of near-one-photon resonance, the Stark effect strongly mixes electronic states of different symmetries to create quasienergy states (QESs). The orientation dependence of multiphoton processes, in which these QESs play an important role, becomes complex. Population transfer is better achieved with aligned …

Phosphorylation Of P27kip1 Regulates Assembly And Activation Of Cyclin D1-Cdk4, Michelle D. Larrea, Jiyong Liang, Thiago G. Da Silva, Feng Hong, Shan H. Shao, Kathy Han, D. Dumont, Joyce M. Slingerland

Chemistry and Physics Faculty Articles

p27 mediates Cdk2 inhibition and is also found in cyclin D1-Cdk4 complexes. The present data support a role for p27 in the assembly of D-type cyclin-Cdk complexes and indicate that both cyclin D1-Cdk4-p27 assembly and kinase activation are regulated by p27 phosphorylation. Prior work showed that p27 can be phosphorylated by protein kinase B/Akt (PKB/Akt) at T157 and T198. Here we show that PKB activation and the appearance of p27pT157 and p27pT198 precede p27-cyclin D1-Cdk4 assembly in early G₁. PI3K/PKB inhibition rapidly reduced p27pT157 and p27pT198 and dissociated cellular p27-cyclin D1-Cdk4. Mutant p27 allele products lacking phosphorylation at …

Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang

Faculty Publications

Fibrillar M13 bacteriophages were used as basic building blocks to generate thin films with aligned nanogrooves, which, upon chemical grafting with RGD peptides, guide cell alignment and orient the cell outgrowth along defined directions.

Non-Canonical Binding Of Calmodulin To Aquaporin-0: Implications For Channel Regulation, Steve Reichow, Tamir Gonen

Chemistry Faculty Publications and Presentations

Aquaporins (AQPs) are a family of ubiquitous membrane channels that conduct water across cell membranes. AQPs form homo-tetramers containing four functional and independent water pores. Aquaporin-0 (AQP0) is expressed in the eye lens where its water permeability is regulated by calmodulin (CaM). Here we use a combination of biochemical methods and NMR spectroscopy to probe the interaction between AQP0 and CaM. We show CaM binds the AQP0 C-terminal domain in a calcium dependent manner. We demonstrate that only two CaM molecules bind a single AQP0 tetramer in a non-canonical fashion, suggesting a form of co-operativity between AQP0 monomers. Based on …

Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina

Faculty of Science - Papers (Archive)

The alpha-crystallins are members of the small heat shock protein (sHSP) family of molecular chaperones which have evolved to minimize intracellular protein aggregation, however they are also implicated in a number of protein deposition diseases. In this study we have employed novel mass spectrometry techniques to investigate the changes in quaternary structure associated with this switch from chaperone to adjuvant of aggregation. We have replicated the oligomeric rearrangements observed for in vivo disease-related modifications, without altering the protein sequence, by refolding the alpha-crystallins in vitro. This refolding results in a loss of dimeric substructure concomitant with an augmentation of substrate …

Electron Crystallography Of Aquaporins, Simeon Andrews, Steve Reichow, Tamir Gonen

Chemistry Faculty Publications and Presentations

Aquaporins are a family of ubiquitous membrane proteins that form a pore for the permeation of water. Both electron and X-ray crystallography played major roles in determining the atomic structures of a number of aquaporins. This review focuses on electron crystallography, and its contribution to the field of aquaporin biology. We briefly discuss electron crystallography and the two-dimensional crystallization process. We describe features of aquaporins common to both electron and X-ray crystallographic structures; as well as some structural insights unique to electron crystallography, including aquaporin junction formation and lipid-protein interactions.

The Role Of Upstream Sequences In Selecting The Reading Frame On Tmrna, Allen R. Buskirk, Mickey R. Miller, David W. Healey, Jonathan D. Dewey, Stephen G. Robison

Faculty Publications

tmRNA acts first as a tRNA and then as an mRNA to rescue stalled ribosomes in eubacteria. Two unanswered questions about tmRNA function remain: how does tmRNA, lacking an anticodon, bypass the decoding machinery and enter the ribosome? Secondly, how does the ribosome choose the proper codon to resume translation on tmRNA? According to the -1 triplet hypothesis, the answer to both questions lies in the unique properties of the three nucleotides upstream of the first tmRNA codon. These nucleotides assume an A-form conformation that mimics the codon-anticodon interaction, leading to recognition by the decoding center and choice of the …

Cyanobacterial Toxins As Allelochemicals With Potential Applications As Algaecides, Herbicides And Insecticides, John P. Berry, Miroslav Gantar, Mario H. Perez, Gerald Berry, Fernando G. Noriega

Department of Chemistry and Biochemistry

Cyanobacteria (“blue-green algae”) from marine and freshwater habitats are known to produce a diverse array of toxic or otherwise bioactive metabolites. However, the functional role of the vast majority of these compounds, particularly in terms of the physiology and ecology of the cyanobacteria that produce them, remains largely unknown. A limited number of studies have suggested that some of the compounds may have ecological roles as allelochemicals, specifically including compounds that may inhibit competing sympatric macrophytes, algae and microbes. These allelochemicals may also play a role in defense against potential predators and grazers, particularly aquatic invertebrates and their larvae. This …

Identification Of Guanylate Cyclases And Related Signaling Proteins In Sperm Tail From Sea Stars By Mass Spectrometry, Mia Nakachi, Midori Matsumoto, Philip M. Terry, Ronald L. Cerny, Hideaki Moriyama

Hideaki Moriyama Publications

Marine invertebrates employ external fertilization to take the advantages of sexual reproduction as one of excellent survival strategies. To prevent mismatching, successful fertilization can be made only after going though strictly defined steps in the fertilization. In sea stars, the fertilization process starts with the chemotaxis of sperm followed by hyperactivation of sperm upon arriving onto the egg coat, and then sperm penetrate to the egg coat before achieving the fusion. To investigate whether the initiation of chemotaxis and the following signaling has species specificity, we conducted comparative studies in the protein level among sea stars, Asterias amurensis, A. forbesi …

Iron(Iii)-Salophene: An Organometallic Compound With Selective Cytotoxic And Anti-Proliferative Properties In Platinum-Resistant Ovarian Cancer Cells, Thilo S. Lange, Kyu Kwang Kim, Rakesh K. Singh, Robert M. Strongin, Carolyn Mccourt, Laurent Brard

Chemistry Faculty Publications and Presentations

Background: In this pioneer study to the biological activity of organometallic compound Iron(III)-salophene (Fe-SP) the specific effects of Fe-SP on viability, morphology, proliferation, and cell-cycle progression on platinum-resistant ovariancancer cell lines were investigated.

Methodology/Principal Findings: Fe-SP displayed selective cytotoxicity against SKOV-3 and OVCAR-3 (ovarian epithelial adenocarcinoma) cell lines at concentrations between 100 nM and 1 μM, while the viability of HeLa cells (epithelial cervix adenocarcinoma) or primary lung or skin fibroblasts was not affected. SKOV-3 cells in contrast to fibroblasts after treatment with Fe-SP revealed apparent hallmarks of apoptosis including densely stained nuclear granular bodies within fragmented nuclei, highly condensed …

Diethyl 2-[(4-Nitro­Phen­Yl)(4-Phenyl-1,2,3-Selenadiazol-5-Yl)Meth­Yl]Malonate, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, C22H21N3O6Se, the heterocyclic ring makes dihedral angles of 50.03 (11) and 67.75 (11)°, respectively, with the benzene and phenyl rings. The terminal C atoms of the ester groups are disordered over two positions: the site occupancies for the C atoms are 0.62 (3)/0.38 (3) and 0.48 (3)/0.52 (3). In the crystal structure, weak intra- and inter­molecular C-H...O inter­actions are observed.

Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)­Molybdenum(Vi), Manoj Trivedi, Daya Pandey, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, [Mo(C5H4NO2)2O2], the MoVI atom exhibits a distorted octa­hedral coordination geometry formed by two terminal oxo ligands and two monoanionic O,O-bidentate pyridinone ligands. The two terminal oxo ligands lie in a cis arrangement, the ketonic O atoms of the pyridinone ligands are coordinated trans to the oxo ligands and the deprotonated hydroxyl O atoms are located trans to each other. The crystal structure contains inter­molecular N-H...O hydrogen bonds, C-H...O contacts and face-to-face [pi]-[pi] stacking inter­actions with an inter­planar separation of 3.25 (1) Å.

Progress Toward Cariporide Analogs For Sodium-Proton Exchange Inhibition, Jessica Moore, Mark Graves Ii, Jacob A. Vervynckt, William Harley, Fredric Gorin, Hasan Palandoken

Chemistry and Biochemistry

The sodium proton exchanger (NHE) is particularly important in maintaining the intracellular pH in human heart and brain. Under anaerobic conditions (i.e., ischemia), a shift from oxidative to nonoxidative glycolysis occurs. The resultant decrease in the intracellular pH activates NHE, which increases the intracellular sodium, initiating the sequence of physiological events that lead to cell death. Thus, there has been great interest in the development of compounds that inhibit NHE. Indeed, potent NHE inhibitors are available. However, a fundamental impediment to the field is the delivery of these compounds to poorly vascularized tissues during the early phases of ischemia when …

The Effects Of Pc-Based Laboratories On Student Learning, Lester L. Pesterfield, Stuart Burris, Darwin B. Dahl, Hasan Palandoken, Jacqueline Pope-Tarrence

Chemistry and Biochemistry

The Department of Chemistry at Western Kentucky University recently incorporated a net-worked MeasureNet data acquisition and analysis system into in the second semester General Chemistry laboratories. Our investigation team has conducted a study to evaluate the effects of the MeasureNet system on student learning and performance on a Beer's Law laboratory. We focused on two phenomena: the effect of the MeasureNet system on 1) student learning of specific content material and 2) student interest in chemistry and science in general. The study involved a MeasureNet system group (employing a UV-Vis spectrometer and colorimeters) and a control group (employing traditional Spectronic …

Volume 01, Jessica Fields, Stephanie Neeley, Derek W. Hambright, Mary E. Lehman, Andrew R. Grzankowski, Zachary Johnson, Boone M. Prentice, Ashley M. Swandby, Victoria Morgan, Katie Williamson, Kristine G. Bender, Katelyn N. Romaine, D. Nicole Swann, Jessica Fox, Mike Mcateer, Alex Grabiec, Laura Nodtvedt, Nick Costa, Rachel Wolfe, Zack Dalton

Incite: The Journal of Undergraduate Scholarship

Introduction from Dean Dr. Charles Ross

Three Decades of Digging: Undergraduate Archeology at Longwood by Jessica Fields and Stephanie Neeley

Interactions of Allelopathy and Heat Stress in Plants by Derek W. Hambright and Mary E. Lehman

Inertial Electrostatic Confinement D-D Fusion Device: Construction and Simulation by Andrew R. Grzankowski

Shackled Nim by Zachary Johnson

Development of GC-MS and Chemometric Methods for the Analysis of Accelerants in Arson Cases by Boone M. Prentice

A Comparison of Image Analysis Methods in cDNA Microarrays by Ashley M. Swandby

Perceived Sexual Activity of Short and Long-Term Relationships by Victoria Morgan and Katie Williamson

Elderly …

Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan

Faculty Publications

Exact results in any field, including statistical mechanics, are both aesthetically pleasing and very valuable in assessing theoretical approximations.

4-Hydroxyphenylretinamide (4hpr) Derivatives Regulate Aromatase Activity And Expression In Breast Cancer Cells, Bin Su, Serena M. Mershon, Laura A. Stonerock, Robert W. Curley Jr., Robert W. Brueggemeier

Chemistry Faculty Publications

Recent studies exhibit that 4-hydroxyphenylretinamide (4HPR) decreases aromatase activity in breast and placental cells. The effect of synthetic 4HPR analogs on aromatase and expression was examined in three breast cancer cell lines. Most derivatives did not decrease cellular aromatase activity. Two of the analogs even stimulated aromatase activity at the transcriptional level. Only one derivative significantly decreased aromatase in all three breast cancer cell lines and also suppressed CYP19 gene expression in one of the cell line. Placental microsomal aromatase assay rule out the possibility that this compound directly inhibits the aromatase enzyme. A non-genomic mechanism in suppression of cellular …

4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, C18H15Cl2N3O2Se, the selenadiazole ring makes dihedral angles of 49.87 (3) and 55.70 (3)° with the two benzene rings. The dihedral angle between the two benzene rings is 11.90 (5)°. In the crystal structure, intra­molecular C-H...O and C-H...Se inter­actions and inter­molecular C-H...O, C-H...Cl and C-H...N inter­actions are observed.

Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Relaxation of highly vibrationally excited pyrimidine (C4N2H4) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyrimidine (E'=40,635 cm^-1) was prepared by 248-nm excimer laser excitation, followed by rapid radiationless relaxation to the ground electronic state. The nascent rotational population distribution (J=58–80) of the 0000 ground state of CO2 resulting from collisions with hot pyrimidine was probed at short times following the excimer laser pulse. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J=58–80 of the 0000 state. Rate constants and probabilities for collisions populating these CO2 rotational states …

Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …

Flash: A Rapid Method For Prototyping Paper-Based Microfluidic Devices, Andres W. Martinez, Scott T. Phillips, Benjamin J. Wiley, Malancha Gupta, George M. Whitesides

Chemistry and Biochemistry

This article describes FLASH (Fast Lithographic Activation of Sheets), a rapid method for laboratory prototyping of microfluidic devices in paper. Paper-based microfluidic devices are emerging as a new technology for applications in diagnostics for the developing world, where low cost and simplicity are essential. FLASH is based on photolithography, but requires only a UV lamp and a hotplate; no clean-room or special facilities are required (FLASH patterning can even be performed in sunlight if a UV lamp and hotplate are unavailable). The method provides channels in paper with dimensions as small as 200 μm in width and 70 μm in …