Digital Commons Network^™

N- And C-Terminal Domains In Human Holocarboxylase Synthetase Participate In Substrate Recognition, Yousef I. Hassan, Hideaki Moriyama, Lars J. Olsen, Xin Bi, Janos Zempleni

Hideaki Moriyama Publications

Holocarboxylase synthetase (HCS) catalyzes the binding of the vitamin biotin to carboxylases and histones. Carboxylases mediate essential steps in macronutrient metabolism. For example, propionyl- CoA carboxylase (PCC) catalyzes the carboxylation of propionyl-CoA in the metabolism of oddchain fatty acids. HCS comprises four putative domains, i.e., the N-terminus, the biotin transfer/ATP binding domain, a putative linker domain, and the C-terminus. Both N- and C-termini are essential for biotinylation of carboxylases by HCS, but the exact functions of these two domains in enzyme catalysis are unknown. Here we tested the hypothesis that N- and C-termini play roles in substrate recognition by HCS. …

Online Support And Online Assessment For Teaching And Learning Chemistry, Claire M. Mcdonnell, Natasa Brouwer

Books/Book chapters

In this chapter, examples of innovative approaches that use educational technology to support active learning in chemistry lectures, tutorials and laboratory sessions are considered. The scope of the chapter is limited to blended learning. The strengths and weaknesses of e-learning are examined and the options available for online assessment using electronic tests and e-portfolios are discussed. In addition to the literature references provided in the chapter, several examples of good practice involving the implementation of information and communication technology for chemistry teaching in higher education are incorporated. A list of online resources for lecturers is also included.

Development Of Quantitative Bioanalytical Methods For The Measurement Of Pharmaceutical Compounds Via Hplc-Uv And Hplc-Ms/Ms, Melissa A. Mcculloch

ETD Archive

Research in pharmaceutical treatments for illnesses and disease processes has rapidly grown in the past decade. The field is fueled by advances in our understanding of the molecular mechanics of the human body, coupled with the development of sophisticated scientific instruments which can efficiently generate massive amounts of important data. This has led to an ever-growing need for the development of quantitative bioanalytical methods to measure pharmaceutical compounds. In this work, the theory behind the analytical processes and instruments that make these investigations possible is discussed. Further, the development of two high performance liquid chromatographic (HPLC) methods with both ultra …

Systems Chemistry And Parrondo’S Paradox: Computational Models Of Thermal Cycling, Daniel C. Osipovitch, Carl Barratt, Pauline M. Schwartz

Chemistry and Chemical Engineering Faculty Publications

A mathematical concept known as Parrondo’s paradox motivated the development of several novel computational models of chemical systems in which thermal cycling was explored. In these kinetics systems we compared the rates of formation of product under cycling temperature and steady-sate conditions. We found that a greater concentration of product was predicted under oscillating temperature conditions. Our computational models of thermal cycling suggest new applications in chemical and chemical engineering systems.

Liposomes Recruit Ipac To The Shigella Flexneri Type Iii Secretion Apparatus Needle As A Final Step In Secretion Induction, C. R. Epler, Nicholas E. Dickenson, A. J. Olive, W. L. Picking, W. D. Picking

Chemistry and Biochemistry Faculty Publications

Shigella flexneri contact with enterocytes induces a burst of protein secretion via its type III secretion apparatus (TTSA) as an initial step in cellular invasion. We have previously reported that IpaD is positioned at the TTSA needle tip (M. Espina et al., Infect. Immuno. 74:4391-4400, 2006). From this position, IpaD senses small molecules in the environment to control the presentation of IpaB to the needle tip. This step occurs without type III secretion induction or IpaC recruitment to the S. flexneri surface. IpaC is then transported to the S. flexneri surface when target cell lipids are added, and this event …

A Comparison Of Cationic Surfactant Immobilized Ion Exchange Membranes In Their Application For Use In Extraction Of 4-Nitophenol, Robert Derrek Brown

Mahurin Honors College Capstone Experience/Thesis Projects

Solid Phase Extraction has replaced distillation and liquid-liquid extraction as the most widely used method for extraction from solution. Though traditional SPE has seen great success, its downfalls are that it requires meticulous preparation procedures requiring funtionalized silanes and silica or polymerization courses. An alternative is ion exchange membranes to which long carbon chain ionic surfactants have been attached. The S1000 membrane ion exchange capacity was measured to be approximately 110 micro-equil/disc while the P81 membrane was 150 micro-equil/disc. Octadecyltri-methylammonium surfactant was immobilized on the membrane surface, qualitated through the use of ATR-FTIR, and quantified through elemental analysis. Kinetic adsorption …

Analysis And Treatment Of Emerging Polar Contaminants, Daniel E. Connors

Electronic Theses and Dissertations

Two major classes of polar compounds have recently become a major focus as sources of contamination of water systems. Pharmaceuticals and personal care products (PPCPs) enter water through wastewater streams, and many of these compounds survive current wastewater treatment processes. High production volume chemicals (HPVCs), defined as chemicals produced in excess of one million pounds per year have numerous entries into surface and drinking waters due to their ubiquity. The commonality between many of these compounds is their polarity, which makes them water-soluble.

While both PPCPs and HPVCs have been entering into the environment for decades, advances in analyte detection …

Loop Dynamics Of The Extracellular Domain Of Human Tissue Factor And Activation Of Factor Viia, Agnese S. Minazzo, Reuben C. Darlington, J. B. A. Ross

Chemistry and Biochemistry Faculty Publications

In the crystal structure of the complex between the soluble extracellular domain of tissue factor (sTF) and activesite- inhibited VIIa, residues 91 and 92 in the Pro⁷⁹-Pro⁹² loop of sTF interact with the catalytic domain of VIIa. It is not known, however, whether this loop has a role in allosteric activation of VIIa. Time-resolved fluorescence anisotropy measurements of probes covalently bound to sTF mutants E84C and T121C show that binding uninhibited Factor VIIa affects segmental motions in sTF. Glu⁸⁴ resides in the Pro⁷⁹-Pro⁹² loop, and Thr¹²¹ resides in the turn between the …

Emissions From Biomass Burning In The Yucatan, Robert J. Yokelson, J. D. Crounse, P. F. Decarlo, T. Karl, S. P. Urbanski, E. Atlas, T. Campos, Y. Shinozuka, V. Kasputin, A. D. Clarke, A. Weinheimer, D. J. Knapp, D. D. Montzka, J. Holloway, P. Weibring, F. Flocke, W. Zheng, D. Toohey, P. O. Wennberg, C. Wiedinmyer, L. Mauldin, A. Fried, D. Richter, J. Walega, J. L. Jimenez, K. Adachi, P. R. Buseck, S. R. Hall, R. Shetter

Chemistry and Biochemistry Faculty Publications

In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle species were measured from 20 deforestation and crop residue fires on the Yucatan peninsula. This included two trace gases useful as indicators of BB (HCN and acetonitrile) and several rarely, or never before, measured species: OH, peroxyacetic acid, propanoic acid, hydrogen peroxide, …

Biomass Burning And Urban Air Pollution Over The Central Mexican Plateau, J. D. Crounse, P. F. Decarlo, Donald R. Blake, L. K. Emmons, T. L. Campos, E. C. Apel, A. D. Clarke, A. J. Weinheimer, D. C. Mccabe, Robert J. Yokelson, J. L. Jimenez, P. O. Wennberg

Chemistry and Biochemistry Faculty Publications

Observations during the 2006 dry season of highly elevated concentrations of cyanides in the atmosphere above Mexico City (MC) and the surrounding plains demonstrate that biomass burning (BB) significantly impacted air quality in the region. We find that during the period of our measurements, fires contribute more than half of the organic aerosol mass and submicron aerosol scattering, and one third of the enhancement in benzene, reactive nitrogen, and carbon monoxide in the outflow from the plateau. The combination of biomass burning and anthropogenic emissions will affect ozone chemistry in the MC outflow.

New Generation Of Electrochemical Sensors For Nitric Oxide;Ruthenium/Carbon-Based Nanostructures And Colloids As Electrocatalytic Platforms, W. Pubudu M. Peiris

ETD Archive

Nitric oxide (NO) is an important intercellular messenger that acts in many tissues to regulate a diverse range of physiological and pathological processes. The physiologically implications of NO function are far from being completely understood. The multifaceted reactivity of NO prompted the need for accurate determination of the concentration of this molecule. However, it is difficult to detect nitric oxide, particularly in biological media and near live cells due to its short half-life, a result of its reactivity and the low levels of NO produced in vivo. As a result, the accurate and reliable detection of NO under varying experimental …

Ua94/6/1 Student / Alumni Personal Papers Western Kentucky University Small Collections, Wku Archives

WKU Archives Collection Inventories

Small collections of personal papers and oral histories relating to the Western Kentucky University.

Nos-Based Biopolymers: Towards Novel Thromboresistant No-Release Materials, Charbel Abou Diwan

ETD Archive

Nitric Oxide releasing biopolymers have the potential to prolong vascular graft and stent potency without adverse systemic vasodilation. It was reported in literature that eNOS-overexpressing endothelial cell seeding of synthetic small diameter vascular grafts decreased human platelet aggregation by 46 and bovine aortic smooth muscle cell proliferation by 67.2 in vitro. We hypothesized that incorporating the enzyme nitric oxide synthase (NOS) in biocompatible polymeric matrix will provide a source of NO that utilizes endogenous compounds to maintain an unlimited supply of NO. To test this hypothesis, we have incorporated the enzyme nitric oxide synthase into a polyethyleneimine film using a …

Cofactor Control Of A Vital Enzymatic Reaction;The Effect Of Factor Va On Thrombin Formation During Blood Coagulation, Jamila Hirbawi

ETD Archive

The LONG-TERM goal of our research is to study and analyze the structure and function of the factor V molecule in order to understand its regulatory effects on the natural process of hemostasis and its role in the life-threatening development of deep venous thrombosis. The SHORT-TERM goal of our research is to identify the amino acid residue(s) of factor V that interact with prothrombin during the assembly and function of the prothrombinase complex in order to fully understand its particular role in maintaining the integrity of the blood coagulation cascade. The final goal of the coagulation cascade is the formation …

Hemoprotein-Mediated Activation Of Nitroalkanes, Ling Li

ETD Archive

Chemicals and drugs are known to be metabolized mostly by Cytochrome P450 xenobiotic metabolizing enzymes. However, the detailed mechanism of nitro-compounds metabolism is still unclear. The activation of nitro-xenobiotics by heme-P450 enzymes is a potential explanation for the origin of nitro-compound carcinogenesis. Investigating the interaction of simple nitro-compounds with redox activity of heme enzymes is therefore critical to explore the mechanism and products of activation. In this study, multiple analytical methods and instrumentations are employed and graphic and simulation software such as Origin┬« and Digisim┬« are utilized to quantitatively derive parameters from experimental raw data. This study shows that myoglobin, …

Development Of A Novel Gradient Chromatofocusing Tandem Mass Spectometry Technique For The Determination Of Cationic Compounds In Biofluids;Identification Of Caspace 3 Cleavage Sites Of Nhe-1 By High Performance Liquid Chromatography- Mass Spectrometry, Jianhua Tang

ETD Archive

In Part I, work was done to develop a novel gradient chromatofocusing liquid chromatography-tandem mass spectrometry (MS/MS) technique for the determination of ionic compounds in biological matrix. The analysis of ionic compounds poses a great challenge to current LC-MS techniques, due to the fact that there is little or no retention. These ionic compounds are eluted at almost the same time as biological matrix, which is normally directed to waste prior to connecting to the mass spectrometer. A review of current LC-MS techniques for ionic compounds is given in Chapter 1. They all have advantages and disadvantages. To retain and …

Plasma Biomarkers For Age-Related Macular Degeneration, Jiaqian Ni

ETD Archive

No abstract provided.

Tuning The Electronic Properties Of The Golden Buckyball By Endohedral Doping: M@Au16− (M=Ag,Zn, In), Lei-Ming Wang, Rhitankar Pal, Wei Huang, Xiao Cheng Zeng, Lai-Sheng Wang

Xiao Cheng Zeng Publications

The golden Au₁₆^- cage is doped systematically with an external atom of different valence electrons: Ag, Zn, and In. The electronic and structural properties of the doped clusters, MAu₁₆^- (M =Ag,Zn, In), are investigated by photoelectron spectroscopy and theoretical calculations. It is observed that the characteristic spectral features of ₁₆^-, reflecting its near tetrahedral (T_d) symmetry, are retained in the photoelectron spectra of MAu₁₆^-, suggesting endohedral structures with little distortion from the parent Au₁₆^- cage for the doped clusters. Density functional calculations show that …

Magnetic Doping Of The Golden Cage Cluster M@Au16− (M=Fe,Co,Ni), Lei-Ming Wang, Jaeil Bai, Anne Lechtken, Wei Huang, Detlef Schooss, Manfred Kappes, Xiao Cheng Zeng, Lai-Sheng Wang

Xiao Cheng Zeng Publications

Structural, electronic, and magnetic properties of the golden cage doped with a transition-metal atom, MAu₁₆^- (M =Fe,Co,Ni), are investigated using trapped ion electron diffraction, photoelectron spectroscopy, and density-functional theory. The best agreement to experiment is obtained for endohedral M@Au₁₆^- structures but with considerable distortions to the parent Au₁₆^- cage. Fe@Au₁₆^- and Co@Au₁₆^- are found to have similar structures with C₂ symmetry while a C₁ structure is obtained for Ni@Au₁₆^-. The 4s electrons are observed to transfer to the Au₁₆ cage, whereas atomiclike …

Anion Binding Modes In Meso-Substituted Hexapyrrolic Calix[4]Pyrrole Isomers, Kai-Chi Chang, Tsuyoshi Minami, Petr Koutnik, Pavel Y. Savechenkov, Yuanli Liu, Pavel Anzenbacher Jr.

Chemistry Faculty Publications

We report on the synthesis of a new receptor for anions, meso-substituted hexapyrrolic calix[4]pyrrole 1. The calix[4]pyrrole's core features two additional pyrrole side-arms suspended above or below the calix[4]pyrrole core. This hexapyrrolic calix[4]pyrrole 1 is formed as cis- and trans-configurational isomers, the structures of which have been determined by single crystal X-ray diffraction. The anion binding experiments revealed interesting difference in the binding mode: The cis-1 isomer binds anions in a mixed binding mode featuring a combination of hydrogen bonding and anion-pi interactions resulting in an unexpected strong binding. On the other hand, the trans-1 isomer displays only hydrogen bonding …

Classification And Cluster Analysis Of Complex Time-Of-Flight Secondary Ion Mass Spectrometry For Biological Samples, Stephen E. Reichenbach, Xue Tian, Qingping Tao, Alex Henderson

School of Computing: Conference and Workshop Papers

Identifying and separating subtly different biological samples is one of the most critical tasks in biological analysis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is becoming a popular and important technique in the analysis of biological samples, because it can detect molecular information and characterize chemical composition. ToF-SIMS spectra of biological samples are enormously complex with large mass ranges and many peaks. As a result the classification and cluster analysis are challenging. This study presents a new classification algorithm, the most similar neighbor with a probability-based spectrum similarity measure (MSN- PSSM), which uses all the information in the entire ToF- SIMS …

Organocatalysis With Endogenous Compounds: Towards Novel Non-Enzymatic Reactions, David G. Alberg, Thomas B. Poulsen, Søren Bertelsen, Kasper L. Christensen, Rune D. Birkler, Mogens Johannsen, Karl Anker Jørgensen

Chemistry Faculty Work

The aldol reaction of the endogeneous compounds acetone and methylglyoxal has been studied using organocatalysis in relation to biologically relevant non-enzymatic reactions. Under preparative conditions, 3-hydroxy-2,5-hexadione, known as Henze’s ketol, is formed in high yield and with enantioselectivities up to 88% ee. Furthermore, Henze’s ketol is also formed under simulated physiological conditions at micromolar scale, indicating that this reaction might take place in living organisms.

Polyelectrolyte-Linked, Multi-Layer Film Assemblies Of Aqueous Nanoparticles And Nanoshells, Anne Galyean

Honors Theses

Multi-layer films of nanoparticles and nanoshells featuring various polymeric linkage molecules have been assembled and their optical properties characterized. The growth dynamics, including molecular weight effects, and stability of the various nanoparticle film constructions, using both single polymer as well as combinations of alternating charge polyelectrolytes as linking mechanisms, are presented. The polymeric linkers studied include poly-L-lysine, poly-L-arginine, poly(allylamine hydrochloride), and polyamidoamine dendrimers. Significantly air stable films were achieved with the use of multi-layered polymeric bridges between the nanoparticles and nanoshells. Optical sensitivity normally observed with these nanomaterials in solution was observed for their corresponding film geometries, with the nanoshell …

Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao

Turkish Journal of Chemistry

Six novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles were synthesized by introducing 1,3,4-oxadiazole moiety into the stilbene skeleton. The synthesis route included the cyclization of p-toluic acid and hydrazine hydrate catalyzed by polyphosphoric acid (PPA), bromination of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), esterification, and the Wittig-Horner reaction. All the title compounds were characterized by ^1H-NMR, MS, and elemental analysis. UV-Vis absorption and fluorescence emission spectra in THF solution were investigated; the compounds may have potential for use in organic optical materials.

Air-Sea Gas Exchange Of Co2 And Dms In The North Atlantic By Eddy Covariance, Scott Miller, Christa Marandino, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report the first simultaneous eddy covariance flux measurements of CO2 and dimethylsulfide (DMS) over the open ocean for two North Atlantic cruises. After normalization for Schmidt number, the two gases give essentially identical gas transfer coefficients and wind speed dependences for the wind speed range 2-10 ms(-1). The data indicate a linear relationship between the gas transfer coefficient and mean wind speed, with measured gas transfer coefficients slightly above the Wanninkhof (1992) parameterization, particularly at low wind speeds. Citation: Miller, S., C. Marandino, W. de Bruyn, and E. S. Saltzman (2009), Air-sea gas exchange of CO2 and DMS in …

Co Chemisorption On The Surfaces Of The Golden Cages, Wei Huang, Satya S. Bulusu, Rhitankar Pal, Xiao Cheng Zeng, Lai-Sheng Wang

Xiao Cheng Zeng Publications

We report a joint experimental and theoretical study of CO chemisorption on the golden cages. We find that the Au_{17 ⁻} cage is highly robust and retains its cage structure in Au_{17 ⁻} (CO)⁻. On the other hand, the Au_{16 ⁻} cage is transformed to a structure similar to Au_{17 ⁻} upon the adsorption of CO. Au_{18 ⁻} is known to consist of two nearly degenerate structures, i.e., a cage and a pyramidal isomer, which coexist in the cluster beam. However, upon CO chemisorption only the cage isomer is observed while the pyramidal …

Investigations Of S-Glutathionylation Of Brain Proteins In The Progression Of Alzheimer's Disease And Of A Potential Glutatione Mimetic As A Treatment Of Alzheimer's Disease, Shelley Faye Newman

University of Kentucky Doctoral Dissertations

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by neurofibrillary tangles, senile plaques and loss of synapses. Many studies support the notion that oxidative stress plays an important role in AD pathogenesis. Previous studies from our laboratory employed redox proteomics to identify oxidatively modified proteins in the AD inferior parietal lobule (IPL). The proteins were consistent with AD pathology and have been central to further investigations of the disease. The present study was focused on the identification of specific targets of protein S-glutathionylation in AD, early AD (EAD), and mild cognative impairment (MCI) using a redox proteomics approach. In AD …

The Effects Of Buckminster Fullerenes On Mitochondrial Function, Sara Rosario

Undergraduate Honors Theses

Since the discovery of Buckminster Fullerenes (C60), this carbon nanoparticle has been the subject of intense study. C60 has been investigated in such applications as photodynamic therapy of cancer, photovoltaic cells, semiconductors, and enzyme inhibition. Despite two decades of research, the biological effects of C60 remain a mystery. The intention of this study was to examine the effects of Buckminster Fullerenes on mitochondrial function in an effort to determine the concentration of C60 as well as the time frame of exposure that causes maximum dysfunction. Thus, bovine heart mitochondria were exposed to different doses of C60 (2 -35 ppm). To …

Synthesis Of The Bicyclic Core Of Pyrrolizidine Alkaloids, Fatmagul Tuluoglu

Master's Theses and Doctoral Dissertations

Pyrrolizidine alkaloids are a large class of natural products whose members exhibit a variety of biological properties including potential applications toward the treatment of cancer, diabetes, and viral infections such as HIV. In addition, some of these compounds exhibit insect antifeedant activity, and so have potential applications in the agricultural industry for the protection of crops.

For these reasons, we were interested in developing a method to form the bicyclic alkaloid core that could be functionalized to generate many pyrrolizidine alkaloids. Specifically, our goal was to synthesize the pyrrolizidine B-ring by a novel McMurry cyclization strategy (Scheme 1). The synthesis …

Development Of Methodology For The Use Of Multi-Bed Sorbent Traps With Gas Chromatography Time Of Flight Mass Spectrometry, Siva Maheswara Reddy Anna Pareddy

Master's Theses and Doctoral Dissertations

The lipid peroxidation of unsaturated fatty acids in cellular membranes leads to the formation of alkanes, aldehydes, alkanals, alk-2-enals, and hydroxyl alkenals. The free radicals formed during the process of lipid peroxidation can react with and damage cellular components. Lipid peroxidation is known to cause a number of diseases such as cancer, diabetes, and heart disease. Various analytical methods that include spectrometric assays and chromatographic analyses of derivatized products are available for the detection of the lipid peroxidation products.

The development of rapid, non-invasive monitoring of reactions occurring in biological systems, such as cell cultures, is highly desirable, as such …