Chemistry Commons^™

Fidelity Of Implementation: An Overlooked Yet Critical Construct To Establish Effectiveness Of Evidence-Based Instructional Practices, Marilyne Stains, Trisha Vickrey

Department of Chemistry: Faculty Publications

The discipline-based education research (DBER) community has been invested in the research and development of evidence-based instructional practices (EBIPs) for decades. Unfortunately, investigations of the impact of EBIPs on student outcomes typically do not characterize instructors’ adherence to an EBIP, often assuming that implementation was as intended by developers. The validity of such findings is compromised, since positive or negative outcomes can be incorrectly attributed to an EBIP when other factors impacting implementation are often present. This methodological flaw can be overcome by developing measures to determine the fidelity of implementation (FOI) of an intervention, a construct extensively studied in …

Fluorogenic Protein Labeling Using A Genetically Encoded Unstrained Alkene, X. Shang, X. Song, C. Faller, R. Lai, H. Li, Ronald Cerny, Wei Niu, Jiantao Guo

Department of Chemistry: Faculty Publications

We developed a new fluorogenic bioorthogonal reaction that is based on the inverse electron-demand Diels–Alder reaction between styrene (an unstrained alkene) and a simple tetrazine. The reaction forms a new fluorophore with no literature precedent. We have identified an aminoacyl-tRNA synthetase/tRNA pair for the efficient and site-specific incorporation of a styrene-containing amino acid into proteins in response to amber nonsense codon. Fluorogenic labeling of purified proteins and intact proteins in live cells were demonstrated. The fluorogenicity of the styrene–tetrazine reaction can be potentially applied to the study of protein folding and function under physiological conditions with low background fluorescence interference.

Closing The Science And Achievement Gap: Overlap Of The Next Generation Science Standards And Culturally Relevant Pedagogy, Brenna G. Bloome

Departmental Honors Projects

The United States is experiencing both a science gap and an achievement gap within science education. To shrink the science gap and prepare American students for the innovative and rigorous STEM career fields ahead, the Next Generation Science Standards (NGSS) were implemented in science education. Additionally, culturally relevant pedagogy was implemented in general education to alleviate the achievement gap. To ensure that all students are prepared to succeed in the competitive global world they are going to be a part of, science education needs to incorporate both NGSS and culturally relevant pedagogy. To examine the overlap of both pedagogies working …

Synthesis, Characterization, And Activity Of Co/Fe Alumina/Silica Supported Ft Catalysts And The Study Of Promoter Effect Of Ruthenium, Sunday Azubike Esumike

Doctoral Dissertations

The alumina and hybrid alumina-silica FT catalyst were prepared by one-step solgel/oil-drop methods using metal-nitrate-solutions (method-I), and nanoparticle-metaloxides (method-2). The nanoparticle-metal-oxides did not participate in solubility equilibria in contrast to metal nitrate in method-1 causing no metal ion seepage; therefore, method-2 yields higher XRF metal loading efficiency than method-1. The thermal analysis confirmed that the metal loading by method-1 and method-2 involved two different pathways. Method-1 involves solubility equilibria in the conversion of metal-nitrate to metal- hydroxide and finally to metal-oxide, while in method-2 nanoparticle-metal-oxide remained intact during sol-gel-oil-drop and calcination steps.

The alumina supported catalysts were dominated by γ-alumina …

Tying The Knot: Applications Of Topology To Chemistry, Tarini S. Hardikar

Honors Theses

Chirality (or handedness) is the property that a structure is “different” from its mirror image. Topology can be used to provide a rigorous framework for the notion of chirality. This project examines various types of chirality and discusses tools to detect chirality in graphs and knots. Notable theorems that are discussed in this work include ones that identify chirality using properties of link polynomials (HOMFLY polynomials), rigid vertex graphs, and knot linking numbers. Various other issues of chirality are explored, and some specially unique structures are discussed. This paper is borne out of reading Dr. Erica Flapan’s book, When Topology …

A Test Of The Principle Of Critical Point Universality In Chemistry, Khamees Abuqutesh

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

In Silico Identification Of Oropouche Virus Protease Inhibitors, Cashmaron Crutcher

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Computational Optimization And Characterization Of Molecularly Imprinted Polymers, Jacob Jordan Terracina

Legacy Theses & Dissertations (2009 - 2024)

Molecularly imprinted polymers (MIPs) are a class of materials containing sites capable of selectively binding to the imprinted target molecule. Computational chemistry techniques were used to study the effect of different fabrication parameters (the monomer-to-target ratios, pre-polymerization solvent, temperature, and pH) on the formation of the MIP binding sites. Imprinted binding sites were built in silico for the purposes of better characterizing the receptor – ligand interactions. Chiefly, the sites were characterized with respect to their selectivities and the heterogeneity between sites.

Structure And Characterization Of A Class 3b Proline Utilization A: Ligand-Induced Dimerization And Importance Of The C-Terminal Domain For Catalysis, David A. Korasick, Thameesha T. Gamage, Shelbi Christgen, Kyle M. Stiers, Lesa J. Beamer, Michael T. Henzl, Donald F. Becker, John J. Tanner

Department of Chemistry: Faculty Publications

The bifunctional flavoenzyme proline utilization A (PutA) catalyzes the two-step oxidation of proline to glutamate using separate proline dehydrogenase (PRODH) and L-glutamate-y-semialdehyde dehydrogenase active sites. Because PutAs catalyze sequential reactions, they are good systems for studying how metabolic enzymes communicate via substrate channeling. Although mechanistically similar, PutAs vary widely in domain architecture, oligomeric state, and quaternary structure, and these variations represent different structural solutions to the problem of sequestering a reactive metabolite. Here, we studied PutA from Corynebacterium freiburgense (CfPutA), which belongs to the uncharacterized 3B class of PutAs.A2.7A˚ resolution crystal structure showed the canonical arrangement of PRODH, L-glutamate-y-semialdehyde dehydrogenase, …

Preventing Gene Expression Through The Interruption Of Dna Binding, Olivia Perdue

Honors College Theses

The interruption of DNA binding is a gateway to the inhibition of unregulated expression of genes which can possibly lead to illnesses such as cancer and epilepsy. The goal of this research is to produce high affinity DNA binding molecules which could act to displace the binding of natural transcription factor thus reducing the over- or under-expression of various proteins. Literature shows that the interruption of DNA binding can be completed using both organic and inorganic means, such as by means of natural transcription factors like the NF-κB protein or with metal-ligand complexes in order to bind DNA. NF-κB, a …

Approaches Toward Novel 1,2,3-Triazole Sensors For The Detection Of Anions And Heavy Metal Cations, Richard D. Govan

College of Graduate Studies: Theses & Dissertations

Cations and anions play pivotal roles in biological and physiological processes, however an imbalance in concentration of any ion can be detrimental. Therefore, research into the selective recognition of anions and heavy metal cations has acquired much attention. One approach involves the use of chemosensors. Upon interaction with targeted analytes, chemosensors produce a distinct response, in some cases a fluorescent or colorimetric signal. The 1,2,3-triazole unit has much potential as a chemical sensor due to its unique photophysical properties. The specificity, selectivity, and signaling mechanism of triazole sensors can be tuned with conjugation in the motif and choice and placement …

Investigation Of Host-Sensitized Luminescence Of Trivalent Lanthanide Doped Yttrium Phosphate Using Vuv Spectroscopy, Zachary Way

All Master's Theses

Host-sensitized luminescence of yttrium phosphate doped with trivalent lanthanide elements prepared via two synthetic approaches was studied using VUV spectroscopy. A correlation between an unusually intense 150 nm excitation intensity and the ground state energy level of select trivalent lanthanide elements was proposed. Using spectroscopy, the host-to-activator transfer efficiencies of YPO₄:Ln³⁺ (Ln³⁺ = Sm³⁺, Eu³⁺ and Tb³⁺) were evaluated for two synthetic approaches. Electron-hole pair trapping efficiencies and S_loss values were calculated using published kinetic models.

Detecting Haloacetic Acids Using Chromatography, Nathan Perinovic

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey

Department of Chemistry: Faculty Publications

Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting that S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids, including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in the gudB gene, coding for glutamate dehydrogenase, which generates 2-oxoglutarate from glutamate, significantly reduced …

Laterally Extended Atomically Precise Graphene Nanoribbons With Improved Electrical Conductivity For Efficient Gas Sensing, Mohammad Mehdi Pour, Andrey Lashkov, Adrian Radocea, Ximeng Liu, Tao Sun, Alexey Lipatov, Rafal A. Korlacki, Mikhail Shekhirev, Narayana R. Aluru, Joseph W. Lyding, Victor Sysoev, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Narrow atomically precise graphene nanoribbons hold great promise for electronic and optoelectronic applications, but the previously demonstrated nanoribbon-based devices typically suffer from low currents and mobilities. In this study, we explored the idea of lateral extension of graphene nanoribbons for improving their electrical conductivity. We started with a conventional chevron graphene nanoribbon, and designed its laterally extended variant. We synthesized these new graphene nanoribbons in solution and found that the lateral extension results in decrease of their electronic bandgap and improvement in the electrical conductivity of nanoribbon-based thin films. These films were employed in gas sensors and an electronic nose …

Nanomaterials As Stationary Phases And Supports In Liquid Chromatography: A Review, Sandya Beeram, Elliott Rodriguez, Suresh Doddavenkatanna, Zhao Li, Allegra Pekarek, Darin Peev, Kathryn Goerl, Gianfranco Trovato, Tino Hofmann, David S. Hage

Department of Chemistry: Faculty Publications

The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent …

A Surface-Stabilized Ozonide Triggers Bromide Oxidation At The Aqueous Solution-Vapour Interface, Luca Artiglia, Jacinta Edebeli, Fabrizio Orlando, Shuzhen Chen, Ming-Tao Lee, Pablo Corral Arroyo, Anina Gilgen, Thorsten Bartels-Rausch, Armin Kleibert, Mario Vazdar, Marcelo Andrea Carignano, Joseph S. Francisco, Paul B. Shepson, Ivan Gladich, Markus Ammann

Department of Chemistry: Faculty Publications

Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br•OOO⁻] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapor interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor …

Cytotoxic Polyketides With An Oxygen-Bridged Cyclooctadiene Core Skeleton From The Mangrove Endophytic Fungus Phomosis Sp. A818, Wei Zhang, Baobing Zhao, Liangcheng Du, Yuemao Shen

Department of Chemistry: Faculty Publications

Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5'-adenosine monophosphate-activated protein kinase).

Chemoselective Alteration Of Fluorophore Scaffolds As A Strategy For The Development Of Ratiometric Chemodosimeters, Xinqi Zhou, Lauren Lesiak, Rui Lai, Jon R. Beck, Jia Zhao, Christian Elowsky, Hui Li, Cliff I. Stains

Department of Chemistry: Faculty Publications

Ratiometric sensors generally couple binding events or chemical reactions at a distal site to changes in the fluorescence of a core fluorophore scaffold. However, such approaches are often hindered by spectral overlap of the product and reactant species. We provide a strategy to design ratiometric sensors that display dramatic spectral shifts by leveraging the chemoselective reactivity of novel functional groups inserted within fluorophore scaffolds. As a proof-of-principle, fluorophores containing a borinate (RF₆₂₀) or silanediol (SiOH2R) functionality at the bridging position of the xanthene ring system are developed as endogenous H₂O₂ sensors. Both …

The Future Of Nmr-Based Metabolomics, John L. Markley, Rafael Bruschweiler, Arthur S. Edison, Hamid R. Eghbalnia, Robert Powers, Daniel Raftery, David S. Wishart

Department of Chemistry: Faculty Publications

The two leading analytical approaches to metabolomics are mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Although currently overshadowed by MS in terms of numbers of compounds resolved, NMR spectroscopy offers advantages both on its own and coupled with MS. NMR data are highly reproducible and quantitative over a wide dynamic range and are unmatched for determining structures of unknowns. NMR is adept at tracing metabolic pathways and fluxes using isotope labels. Moreover, NMR is non-destructive and can be utilized in vivo. NMR results have a proven track record of translating in vitro findings to in vivo clinical …

Resolving The Cofactor-Binding Site In The Proline Biosynthetic Enzyme Human Pyrroline-5-Carboxylate Reductase 1, Emily M. Christensen, Sagar M. Patel, David A. Korasick, Ashley C. Campbell, Kurt L. Krause, Donald F. Becker, John J. Tanner

Department of Chemistry: Faculty Publications

Pyrroline-5-carboxylate reductase (PYCR) is the final enzyme in proline biosynthesis, catalyzing the NAD(P)H-dependent reduction of [?]1-pyrroline-5-carboxylate (P5C) to proline. Mutations in the PYCR1 gene alter mitochondrial function and cause the connective tissue disorder cutis laxa. Furthermore, PYCR1 is overexpressed in multiple cancers, and the PYCR1 knock-out suppresses tumorigenic growth, suggesting that PYCR1 is a potential cancer target. However, inhibitor development has been stymied by limited mechanistic details for the enzyme, particularly in light of a previous crystallographic study that placed the cofactor-binding site in the C-terminal domain rather than the anticipated Rossmann fold of the N-terminal domain. To fill this …

Indole-Induced Reversion Of Intrinsic Multiantibiotic Resistance In Lysobacter Enzymogenes, Yong Han, Yan Wang, Yameng Yu, Haotong Chen, Yuemao Shen, Liangcheng Du

Department of Chemistry: Faculty Publications

Lysobacter species are a group of environmental bacteria that are emerging as a new source of antibiotics. One characteristic of Lysobacter is intrinsic resistance to multiple antibiotics, which had not been studied. To understand the resistance mechanism, we tested the effect of blocking two-component regulatory systems (TCSs) on the antibiotic resistance of Lysobacter enzymogenes, a prolific producer of antibiotics. Upon treatment with LED209, an inhibitor of the widespread TCS QseC/QseB, L. enzymogenes produced a large amount of an unknown metabolite that was barely detectable in the untreated culture. Subsequent structural elucidation by nuclear magnetic resonance (NMR) unexpectedly revealed that …

Synthesis Of Cerium Oxide Nanorods, Chin Li Cheung, Zane Charles Gernhart

Department of Chemistry: Faculty Publications

Cerium oxide nanorods having a variety of aspect ratios can be produced by providing a first mixture that includes a cerium precursor material, and using microwave to heat the first mixture to a first temperature for a period of time to produce first plurality of cerium oxide nanorods having a first range of aspect ratios. A second mixture that includes a cerium precursor material heated using microwave to a second temperature for a period of time to produce second plurality of cerium oxide nanorods having a second range of aspect ratios. The first plurality of cerium oxide nanorods and the …

Human Serine Racemase Structure/Activity Relationship Studies Provide Mechanistic Insight And Point To Position 84 As A Hot Spot For Β-Elimination Function, David L. Nelson, Greg A. Applegate, Matthew L. Beio, Danielle L. Graham, David B. Berkowitz

Department of Chemistry: Faculty Publications

There is currently great interest in human serine racemase, the enzyme responsible for producing the NMDA co-agonist D-serine. Reported correlation of D-serine levels with disorders including Alzheimer’s disease, ALS, and ischemic brain damage (elevated D-serine) and schizophrenia (reduced D-serine) has further piqued this interest. Reported here is a structure/activity relationship study of position Ser⁸⁴, the putative re-face base. In the most extreme case of functional reprogramming, the S84D mutant displays a dramatic reversal of β-elimination substrate specificity in favor of L-serine over the normally preferred L-serine-O-sulfate (~1200-fold change in k_cat/K_{m …}

Assessment Of Metabolic Changes In Mycobacterium Smegmatis Wild Type And Alr Mutant Strains: Evidence For A New Pathway Of D-Alanine Biosynthesis., Darrell D. Marshall, Steven Halouska, Denise K. Zinniel, Robert J. Fenton, Katie Kenealy, Harpreet K. Chahal, Govardhan Rathnaiah, Raul G. Barletta, Robert Powers

Department of Chemistry: Faculty Publications

In mycobacteria, D-alanine is an essential precursor for peptidoglycan biosynthesis. The only confirmed enzymatic pathway to form D-alanine is through the racemization of L-alanine by alanine racemase (Alr, EC 5.1.1.1). Nevertheless, the essentiality of Alr in Mycobacterium tuberculosis and Mycobacterium smegmatis for cell survivability in the absence of D-alanine has been a point of controversy with contradictory results reported in the literature. To address this issue, we examined the effects of alr inactivation on the cellular metabolism of M. smegmatis. The M. smegmatis alr insertion mutant TAM23 exhibited essentially identical growth to wild type mc²155 in the …

Transcriptional And Antagonistic Responses Of Biocontrol Strain Lysobacter Enzymogenes Oh11 To The Plant Pathogenic Oomycete Pythium Aphanidermatum, Yangyang Zhao, Guoliang Qian, Yuan Chen, Liangcheng Du, Fengquan Liu

Department of Chemistry: Faculty Publications

Lysobacter enzymogenes is a ubiquitous, beneficial, plant-associated bacterium emerging as a novel biological control agent. It has the potential to become a new source of antimicrobial secondary metabolites such as the Heat-Stable Antifungal Factor (HSAF), which is a broad-spectrum antimycotic with a novel mode of action. However, very little information about how L. enzymogenes detects and responds to fungi or oomycetes has been reported. An in vitro confrontation bioassay between the pathogenic oomycete Pythium aphanidermatum and the biocontrol bacterial strain L. enzymogenes OH11 was used to analyze the transcriptional changes in the bacteria that were induced by the oomycetes. Analysis …

Ion Mobility-Resolved Collision-Induced Dissociation And Electron Transfer Dissociation Of N-Glycopeptides: Gathering Orthogonal Connectivity Information From A Single Mass- Selected Precursor Ion Population, Venkata Kolli, Katherine N. Schumacher, Eric Dodds

Department of Chemistry: Faculty Publications

Glycopeptide-level mass spectrometry (MS) and tandem mass spectrometry (MS/MS) analyses are commonly performed to establish site-specific protein glycosylation profiles that are of central importance to gaining structure-function insights on glycoproteins. Confoundingly, the complete characterization of glycopeptide connectivity usually requires the acquisition of multiple MS/MS fragmentation spectra. Complementary ion fragmentation techniques such as collision-induced dissociation (CID) and electron transfer dissociation (ETD) are often applied in concert to address this need. While structurally informative, the requirement for acquisition of two MS/MS spectra per analyte places considerable limitations upon the breadth and depth of large-scale glycoproteomic inquiry. Here, a previously developed method of …

Phage Display To Identify Functional Resistance Mutations To Rigosertib, Nedim Filipovic

CMC Senior Theses

In vitro protein selection has had major impacts in the field of protein engineering. Traditional screens assay individual proteins for specific function. Selection, however, analyzes a pool of mutants and yields the best variants. Phage display, a successful selection technique, also provides a reliable link between variant phenotype and genotype. It can also be coupled with high throughput sequencing to map protein mutations; potentially highlighting vital mutations in variants. We propose to apply this technique to cancer therapy. RAF, a serine/threonine kinase, is critical for cell regulation in mammals. RAF can be activated by oncogenic RAS, found in over 30% …

Assessment Of Short-Term Toxicity Of Titanium Dioxide Nano Fiber (Tdnf) In Sprague Dawley Rats, Daniel A. Hunter

College of Graduate Studies: Theses & Dissertations

Nanotechnology is easily becoming one of the fastest growing markets around the globe. Synthetic nanomaterials have many unique chemical and physical properties, mainly due to their huge specific surface area and chemical makeup. Specifically, titanium dioxide (TiO₂) nanomaterials have high stability, anticorrosive and photocatalytic properties. These nanomaterials have applications for semiconductor photocatalysis, treatment of water, as a photoactive material in nanocrystalline solar cells, and medicine. However, not much is known about the toxicity of TiO₂ in the nanofiber form. The objective of the present study is to investigate the adverse effects associated with acute ingestion of TiO …

Infusion Of Essentail Oils In Agarose Gels To Create Antimicrobial Surfaces, Simran Guron

Honors College Theses

The current use of antibiotics is very excessive in multiple settings, from treating patients to being present in cleaning products. This overuse of antibiotics is resulting in multiple consequences, ranging from having a negative impact on human health to breeding antibiotic-resistant strains of microorganisms. Antimicrobial surfaces are useful today to aid in sterilization, especially in the medical setting. This would help prevent the spread of infection of microorganisms in these settings. In our research, agarose acts as the antimicrobial surface and essential oils would act as the solution incorporated into the surface that has the antimicrobial properties. Agarose is a …